SST Information from QRP-L

AL7FS Jim Larsen

http://www.AL7FS.us/

April 97 through Sep 2004

 

1. Subject: SST parts list/schematic error: output low-pass filter

2. Subject: SST article typo: 40m novice-band version VXO range...

3. Subject: SST: First production unit completed!

4. Subject: SST transceiver theory note: receiver front-end response

5. Subject: SST: First QSO on 30m version (WL7VO), plus misc. factoids

6. Subject: KC1 FREQ. COUNTER NOTE (w/SST): Simple way to improve VFO signal

7. Subject: SST #1

8. Subject: re: SST #1; how to increase power

9. Subject: Re: Extending the SST Frequency Range

10. Subject: SST on the Air! <plus construction notes>

11. Subject: SST-40M On the Air <plus output power comments>

12. Subject: 20 Meter SST done <plus construction comments/toroids, etc.

13. Subject: SST Field-Test notes From the Wilderness Engineering Lab

14. Subject: SST Mods Text files Available from Ken Brown, N4SO

15. Subject: Spectrum analyzer test of an SST

16. Subject: HELP, my SST howls

17. Subject: SST-Lucky #13! <next time sockets>

18. Subject: Re: HELP, my SST howls

19. Subject: SST-13 < problem with the audio level of the "sidetone" being

very hot>

20. Subject: Re: SST-13 < problem with the audio level of the "sidetone" being

very hot>

21. Subject: Re: SST-13 < RIT board for the NE4040 for use in SST>

22. Subject: SST Howls < optional DC filter can be installed to prevent the oscillation>

23. Subject: SST howells < Another thing you can try>

24. Subject: SST Howls (Update) < Terry (W0OFR) mod worked!>

25. Subject: SST & KC-1

26. Subject: Re: SST &KC-1 < Is your ground lead short?>

27. Subject: SST 20 - de N3XRV < sounded a bit muddy (400Hz?) so I changed>

28. Subject: In praise of the SST-20 <alludes to: Dave-W6EMD's

mods -- and one of my own>

29. Subject: Re: Noise reduction w/ LM386

30. Subject: BuzzNot noise blanker < installed it in my SST on 20M>

31. Subject: Re: SST ABX Mod

32. Subject: Using TiCK with the SST

33. Subject: More TiCK/SST Mods

34. Subject: Another SST is Born

35. Subject: Re: Fw: SST Tuning Range

36. Subject: Re: SST Tuning Range

37. Subject: SST not a toy!/SST mods summarized...

38. Subject: W6EMD mods summary

39. Subject: LM386

40. Subject: Re: LM386

41. Subject: Re: SST-20 mods query from AL7FS <VXO Mod>

42. Subject: SST 2 diodes mod.

43. Re: SSTs Changing Headphones

44. Subject: SST Varactor Switching

45. Subject: SST VXO Problem

46. Subject: Re: SST & TiCK

47. Subject: "Choking" the SST

48. Subject: Re: SST Tuning Mod revisited

49. Subject: The HB Sprint and the SST

50. Subject: SST-Internal Batteries

51. Subject: "Potential" Super SST

52. Subject: Re: "Potential" Super SST

53. Subject: Re: SST - working (replace the PA with an MRF 237)

54. Subject: SST for WWV 10.000 Mhz

55. Subject: Re: SST/40 Question (SST seems to drift a bit)

56. Subject: Simple Superhet Transceiver SST

57. Subject: SST/20 Question (very (*VERY*) loud blast of noise.)

58. Subject: SST-40 (change C10 to 22pf to increase side tone )

59. Subject: sst (Lots of notes from N6KR, Wayne)

60. Subject: SST 20 mods, thoughts...

61. Subject: Re: SST 20 VXO range

62. Subject: sst 40M audio problems-howl

63. Subject: Re: SST Mods URL (Fall issue of NorCal QRPp has my SST mods)

64. Subject: Re: SST: Greatly improved VXO Range (thanks, N6GA!)

65. Subject: SST: Greatly improved VXO Range (thanks, N6GA!)

66. Subject: SST VXO Range (Thanks W6RCL!)

67. Subject: SST XCVR SURVEY: your input needed for next release

68. Subject: SST Coyote Killer -- One Easy Step

69. Subject: Expanded SST Freq Coverage

70. Subject: SST problem (most common parts for failure when hooked up backwards)

71. Subject: Re: SST problem

72. Subject: XMAS SST and winding Toroids.

73. Subject: Re: SST Frequency Range Modification

74. Subject: SST (Discrepancy on rfc-2 (1mh)

75. Subject: Just-built SST and Frequency Range

76. Subject: just-built sst and Frequency Range answer

77. Subject: SST Mods - xtal filter

78. Subject: Another SST on 20 meters -- and a few questions...

79. Subject: Re: Another SST on 20 meters (answers)

80. Subject: SST AF Gain and Monitor Tone Problem identified

81. Subject: Frequency Range Adjustment Parts change

82. Subject: SST not quite there, help (freq. Range and AF levels)

83. Subject: Moving SST to 15mtrs

84. Subject: Move 20mtr SST to 15mtr: component values (also 87)

85. Subject: sst vxo (to extend vxo range)

86. Subject: SST sidetone (info from N6KR, Wayne) via AB7CE

87. Subject: moving SST to 15mtrs (another component change) (see 84)

88. Subject: TiCK Audio in SST? (Question but no answer: Ask Steve?)

89. Subject: Mounting a Tick/K8+

90. Subject: Another SST lives (Frequency Range issues)

91. Subject: NC 40A versus SST - per N6KR Wayne

92. Subject: AW: alternate crystals for SST/40

93. Subject: Re: SST/40 bandwidth issues

94. Subject: Tick keyer into SST (will have to ask for the solution)

95. Subject: Re: sst question... 8V to NE612's and LM386.

96. Subject: Tick keyer into SST (Perhaps Allan now knows how.)

97. Subject: SST fine tuning mod?? (Perhaps Allan now knows how.)

98. Subject: SST Labeling (Perhaps Rick now knows how)

99. Subject: 40m SST Crystal

100. Subject: SST-40 VXO expanded range - component values

101. Subject: RE: LM386 question answered

102. Subject: New rigs (SST versus OHR type rigs) de AL7FS

103. Subject: NC 40A versus SST - per N6KR Wayne

104. Subject: SST Question - higher SWR with SST than with other rigs

105. Subject: Wilderness SST Troubles! touch the cap output jumps

106. Subject: N4BP request for info SST Sidetone-answer?

107. Subject: Varicaps for use in SST wide coverage VXO & 15 mtr conversion

108. Subject: SST Mods from W9AC, Paul

109. Subject: SST es KC1

110. Subject: SST VS SW30

111. Subject: SST warble - Too big capacitor?"

112. Subject: SST 20 Tuning Range - More!

113. Subject: Re: SST 20 Tunning Range - More! De N6KR

114. Subject: Re: SST 20 Tuning Range - More! R5 Tuning Range

115. Subject: SST-20 R5 tuning range mod R5 change results

116. Subject: Brief SST Description - KB9LGJ

117. Subject: 10M SST-ALIVE!

118. Subject: KI0AF's 15 Meter SST Newsletter Article

119. Subject: 10m SST comments from N6KR

120. Subject: 10 M SST - More details

121. Subject: Re: SST-40 R5 tuning range mod - good details.

122. Subject: 10M SST OPERATES-Comments from KI0F the builder

123. Subject: Norcal SST Keying - Wave Shape Info.

124. Subject: 2Re: QRP SST-20 info - Lots of info from San >> WB9ELB

125. Subject: re: audio-out freq. counter for the SST de N6KR

126. Subject: SST RIT - RIT SST - A source for Info?

127. Subject: RIT for SST by Bob Callahan KC5T

128. Subject: SST howling problem and solution

129. Subject: SST: shifting the VXO up; narrow filtering de N6KR

130. Subject: SST -Need cure- Rec Freq. Vs Tx Freq.

131. Subject: SST - rig appeared to change in freq when touched

132. Subject: SST sidetone Questions.

133. Subject: 10 M SST - Adding and IF Amp

134. Subject: Re: 15M SST - and 17M

135. Subject: 15 Meter SST - Text file from N4SO

136. Subject: SST 20 mods for 15M @ KJ5TF website

137. Subject: SST-20 Query - RFC5 Mod Information

138. Subject: SST RFC5 34-36 uh 10 turns de AL7FS

139. Subject: XCVR: SST-20m alive; VXO range question; summary of mods used

140. Subject: Replacement for MV1404, MRF-237 (SST)

141. Subject: re: SST on 9 volts

142. Subject: SST RIT-Dave Benson's RIT Kit works

143. Subject: XCVR: Definitive Tick - SST installation.

144. SST Modifications compiled by AE5X

145. Subject: Moving the SST20 Frequency range - RFC3

146. Subject: Moving the SST VXO frequency range - more info

147. Subject: Re: RIT for SST?

148. Subject: Scratch built sst-40

149. Subject: Re: SST Sidetone too LOUD!

150. Subject: Scratch SST & L/C Pill Bottle

151. Subject: Scratch SST's case.

152. Subject: Re: Scratch SST's Layout

153. Subject: Re: Scratch SST's Layout

154. Subject: RE: SST Enclosure Question

155. Subject: SST layout

156. Subject: TiCK in SST--here's what I did

157. Subject: SST success. changed out RFC3 to move range

158. Subject: AL7FS SST output is low - Need help

159. Subject: Re: AL7FS SST output is low - Need help

160. Subject: Re: AL7FS SST output is low - Need help

161. Subject: Re: AL7FS SST output is low - Need help

162. Subject: SST Low Output Power

163. Subject: WCH 20 meter SST transceiver+Builder's notes,howl,Tick-1

164. Subject: SST question

165. Subject: motorboating is sst 20

166. Subject: motorboating is sst 20 - Answer

167. Subject: AE5X SST Mods and Comments

168. Subject: SST and Tick-1 Keyer (duplicate info but good info)

(SST info through 7 Sep 04)

 


 

1. Subject: SST parts list/schematic error: output low-pass filter

Date: Wed, 30 Apr 1997 08:54:11 -0800

From: svecbrdk@well.com (L.Svec,W.Burdick)

 

There's an error in the SST schematic and parts list. For the 40 meter

SST, L2 and L3 should have 18 turns, or approx. 1.3 microhenries. These

are the same values used in the 40A and Sierra. (Thanks to Bob Parks,

K6AEC, for catching this.)

 

Also, the crystal filter circuit has been improved since I wrote the

article, and now has L-C impedance transformation at either end. I'll

post the new values for this circuit soon.

Wayne

N6KR

 

2. Subject: SST article typo: 40m novice-band version VXO range...

Date: Wed, 30 Apr 1997 20:37:41 -0800

From: svecbrdk@well.com (L.Svec,W.Burdick)

...is about 7.105 to 7.115, not 7.110.

 

Wayne

N6KR

 

3. Subject: SST: First production unit completed!

Date: Wed, 14 May 1997 01:49:50 -0800

From: svecbrdk@well.com (L.Svec,W.Burdick)

 

Hi all,

 

I just built the first SST using the revised schematic, production PC board

and cabinet. Looks and works great. Made three test QSOs late this

evening (AZ, TX, WA), all coming back on the first call. I'll try to hook

up with a local tomorrow to get a detailed signal report.

 

I built the 40-meter version first, but I'll build 30 and 20-meter versions

ASAP. Some preliminary observations on the 40m unit:

 

 

* 2.3W out max at 14VDC (this can be increased with one resistor change)

 

* QSK is fast enough to hear between the dots at >35WPM, with no thumps

 

* filter bandwidth is about 300Hz at -6dB; peak is near 600Hz

 

* opposite sideband suppression is >50dB (better measurement later)

 

* noise floor is extremely low; "sounds like" -140dBm, but I'll

post an actual measurement later (let's put it this way: with the

antenna disconnected, I hear nada!)

 

* quick test with the KC1 showed no audible receiver interference w/KC1

running

 

* turns out that the "S-meter"/AGC LED was supposed to be a high-efficiency

red type, not a regular red type. I have to call Bob Dyer first thing

tomorrow to have him change the Mouser order :) Could have been worse....

 

<material deleted>

 

I'd like to once again thank those of you who ordered early for being

patient. Doing things right takes time!

 

73,

Wayne

N6KR

 

4. Subject: SST transceiver theory note: receiver front-end response

Date: Wed, 21 May 1997 08:01:14 -0800

From: svecbrdk@well.com (L.Svec,W.Burdick)

In the SST article in QRPp, my explanation of how the SST's receiver

front-end filter works left too much to the imagination. Funny how when

you take away some parts, the thing gets more complicated ;) Here's how

it works:

 

C1 and RFC1 actually form a *series-tuned* circuit, with RFC1 effectively

connected to AC ground by C3 (.01uF). Since the signal is shunted to

ground by C3, the load for the tuned circuit is U1 (NE602), via C2 (5pF).

At the junction of C1/RFC1, the impedance is very high, and C2 provides a

good match to the 1500-ohm input impedance of U1. On transmit, D1 shunts

C1/RFC1 to ground so the series-tuned circuit has no effect.

 

When the series-tuned circuit is considered together with the low-pass

filter (C34/35/36 and L2/3), you find that the overall response on receive

is much more complex than with the series-tuned circuit alone. It is a

double-humped band-pass response, with the second hump's location dependent

on where the knee in the low-pass filter curve is located. The 5-pole LPF

greatly attenuates the image response, which on 40m is around 15.04 MHz.

 

Ideally, you want the low-pass filter's knee to be at the same location as

the peak of C1/RFC1. While it is possible to select components for the

low-pas filter that result in an optimal band-pass peak at the operating

frequency, this compromises transmit performance. As an example, consider

C34=C36=1000pF, C35=1500pF, and L2=L3=1100nH. These values work well on

receive, but show a high SWR and excessive ripple on transmit.

 

Modelling

 

If you're interested in modelling this circuit, you'll need to also add in

the parasitic capacitance for RFC1 (about 6pF in parallel), as well as

about 4pF for pin 1 of the NE602. On 40 meters, C1's value is around 24 pF

at resonance; RFC1 is 15uH.

 

For the low-pass filter, I used C34=C36=330pF, C35=820pF, and L2=L3=1.4uH,

which provides a good match from the 2N3553 to a 50-ohm load. This places

the low-pass knee somewhat above 7MHz. You may want to plug in the

low-pass values I mentioned earlier to see the effect of moving the knee

down in frequency.

 

In order to make the model match reality on receive (with the actual LPF

values), I had to include some capacitance for the zener diode and the

2N3553's collector. I used about 400pF, which may be on the high side, and

eventually I'd like to use a more accurate figure. (If anyone else tries

to model the circuit, please let me know.) In the real SST, the second

hump is near 8.5MHz and about 10dB below the 7MHz peak of the series-tuned

circuit, and the model agrees when I add the extra 400pF at the zener side

of the LPF.

 

73,

Wayne

N6KR

 

5. Subject: SST: First QSO on 30m version (WL7VO), plus misc. factoids

Date: Thu, 22 May 1997 01:13:57 -0800

From: svecbrdk@well.com (L.Svec,W.Burdick)

More SST news (all good) from SST headquarters in Belmont, CA.

 

I finally had a chance to put the 30m version of the SST on the air.

Conditions were marginal, but I hooked Dick, WL7VO, in Chicken, AK on the

first call. 439 report--not bad for 2W and a vertical. No luck calling

the ZL4 after that....not yet, at least.

 

Here are a couple of measurements taken on the completed 30-meter version

w/13.8V supply:

 

Transmit power out, max: 2.7W

 

Transmit PA efficiency: 77% at 2.O W out

 

VXO range: 10.105-10.118 w/MV209 varactor

10.097-10.112 w/MVAM108 varactor

 

Note: High end of VXO range can be moved up to

10.123 with an inductor change

 

Receiver selectivity: approx. 300Hz at -6dB (AGC off)

 

Wayne

N6KR

 

6. Subject: KC1 FREQ. COUNTER NOTE (w/SST): Simple way to improve VFO signal

Date: Tue, 3 Jun 1997 00:22:35 -0800

From: svecbrdk@well.com (L.Svec,W.Burdick)

Hi all,

 

The frequency counter section of the KC1 is typically coupled to a strong

VFO or VXO using a small capacitor. However, in the SST, the VXO signal is

both high in frequency and low in amplitude, so I needed a different

method. The technique I'll describe may work in other KC1 installations,

too.

 

NOTE: These instructions will be included in the SST manual.

 

Here's the trick:

 

Instead of connecting the KC1 directly to the VXO, I connected it to the

output of the receive mixer's on-chip buffer (U1, NE602 or NE612, pin 7).

Using this buffer effectively isolates the VXO from the KC1. However, due

to the low VXO amplitude, a large (100pF) coupling cap is needed from U1

pin 7 to the KC1. This large cap causes the KC1 to load down the buffer,

reducing its output voltage. What to do?

 

An often-used trick with the NE602 to improve oscillator starting is to put

a resistor from pin 7 to ground. What I discovered is that this trick also

stiffens up the buffer, allowing it to tolerate the large coupling cap for

the KC1 without much reduction in signal. (The current drain of the '602

goes up slightly when you do this--less than a milliamp.) There is no

other apparent effect on the NE602's performance.

 

Besides using the trick above, there are a couple of other steps you'll

need to perform when installing a KC1 in an SST. Here's the complete list:

 

1. Change R3 on the KC1 from 3.3K to 470 ohms. This greatly improves the

gain of the KC1's on-board VFO amp at high frequencies. (It also adds 3mA

to the KC1's current drain. Can't get something for nothing....)

 

2. Use a large value for the VFO coupling cap (Cv). 100pF seems to work

fine. Connect the SST to pin 7 of the receive mixer (NE602) through Cv as

shown in the KC1 manual. This is the normal connection point, indicated by

"CTR" on the SST PC board.

 

3. On the SST, add a resistor from pin 7 of U1 to ground to lower the

impedance of the NE602's on-chip buffer. 15K will do the trick.

 

4. Other aspects of the KC1 installation in the SST are similar to the

NorCal 40/40A, except that I recommend NOT using the KC1's MUTE output.

Just leave it disconnected. As for the sidetone coupling cap, try .01uF.

 

The KC1/SST combination installed as described draws 22 to 23mA from 12V

when using headphones. You can shave a couple of mA by substituting a

"micropower" 5V voltage regulator for U2 on the KC1.

 

73,

Wayne

N6KR

 

7. Subject: SST #1

Date: Mon, 9 Jun 1997 14:29:01 +0100

From: adams@chuck.dallas.sgi.com (Chuck Adams)

Gang,

 

<material deleted>

 

Doug sent me email saying that he had good news and he had bad news.

Good news --- he was bringing SST #1 from the production of kits and I

was going to get to build it. Bad news --- the rig was his and he gets

to keep it. :-) followed by :-(

 

<material deleted>

 

After dinner Doug and I head for the house which is on the other side of

Dallas from the hotel. We get setup and here is the scenario. We have

a complete kit (many thanks to Wilderness Radio and Bob Dyer for doing this)

but the manual was not back from the printers or whatever, so all we have

is a bag of parts and a hand written parts list that Doug did from the only

copy of a list that Bob had. :-) Now, there was a schematic in the Dec

issue of QRPp from NorCal, but that is on the other side of the house,

for the time being. So Doug calls out the part number, say R1, and hands

me the X-ohm resistor and I install it using only the silk screen parts

numbers. It takes us a little of 1.5 hours or so to do this. Time may

vary..... etc. Can't do a review of the manual as I have not seen it.

But you don't need the manual if you have the parts list as witnessed

by the building that took place for this rig.

 

Parts are good quality and the board is excellent. More detailed review

to follow when I get my 30M version. Only problems encountered and they

are minor, but be warned. Board has two R12 labels. One should be R1.

You won't get this mixed up as one is 1/8W resistor and the other is

a board mounted variable for the RF gain. No biggie. The other is the

PC board mounted slide power switch has the three switch connections and

two legs that need to be soldered to the board. The two legs are slightly

closer together than the holes on the board, so you have to file/scrape

the inside area of the legs to get a neat fit, but experienced builder

and careful builder will lose just a little time in doing this.

 

There are two trimmer caps to peak receiver input and to tune a LC

bandpass on the transmitter side for the only two adjustments for tuning

up the receiver and the transmitter. I found that the leg separation on

the parts and the board are slightly off and the caps did not sit flat

on the board and the pins did not protrude all the way out the bottom

of the board, but they did solder nicely anyway.

 

After getting the board assembled and using the toothbrush to remove

the water soluable flux we are now ready for the smoke test. So get

the gel-cel and measure about 12.33V or so and attach the power

cable we are ready to fire the puppy up (it is smaller than the NC40a)

and see how it plays. Power on (the power switch is in the down

position gang) and we hear a hiss in the headphones. Good sign and

I don't hear any frying or smell any thing burning (that comes later).

Get the Tek 191 RF generator and sweep the 20M band (did I tell you this

SST was for 20M?) and hear a signal. Proceed to peak (at this point I

did have to treak down the hallway to the bookcase and get the QRPp

issue with the schematic) the receiver input. Seems to be sensitive

enough.

 

Now get OHR WM-1 and dummy load and peak output of transmitter. Getting

about 1W out. Now at this point in writing this, let me predict. We

are going to see tons of mods for this rig or add-ons 'cuz there are not

many serious milliWatters in this group. :-) Output test at this time

is at a battery voltage of 12.3V or so and I did not have rig in my

possession long enough to do the detailed K5FO experiments, so later we'll

see and remember this is at 20M where things get a little more difficult

at the RF level.

 

With Heath freq meter we get a range of 14.045 to 14.059MHz, so not bad

for VXO again on 20M.

 

During this building and testing I had turned on the Philips PM-3266

scope to look at waveforms and use for peaking. At about the time we

powered up the SST and were peaking stuff and at the time I started

RF output I heard a 'pop' and then the smell of something burning.

I probably lost a heartbeat there somewhere for fear that I had

personally fried something with the screwdriver that I was using to

key the rig (hey, you didn't expect me to go one more time across the

house to get a keyer, paddles, and cables and come back and lose all

that time, did you? I knew you didn't.). Well, it is another prime

example of what I call the 'visitor effect', known to this group as

Murphey's Law. The scope power supply decided to show off for Doug

and went belly up. Not to worry, got a Tec 475 at the HamCom fleamarket

and we'll let you know later in the week or early next week on both

the condition of the insides of the Philips and the Tek 475.

 

Doug carried the SST around and used it for show-and-tell all over the

place in Arlington and Dallas. :-) Sunday afternoon after the meet

he and I hooked it up to a real antenna and heard VE5, EA1, EA2, and

all up and down the east coast and central US. I picked a clear freq

and called CQ on and off for 30 minutes or so, but noone worked.

Band may have not been in good shape for QRPp as I was doing 900mW at

the time as measured on the WM-1.

 

Because of the time constraints, I don't have a relative comparison

on RCVR sensitivity to other rigs, so I'll leave the 20M version for

someone else to do. I'll do the 30M and we will see postings on

others experiences. That is partly what this group is all about.

Selectivity seems to be excellent from first impressions.

 

Doug wasn't about to leave the rig here in TX (you know how the CA vs.

TX thing goes) for any period of time, so at the time of this posting

Doug and JoAnne are on a flight to KS and the SST rig is on its way

to a worldwide adventure over the next year.

 

Thanks to Doug for giving me a chance to see first hand what we can

expect to see from Wilderness Radio shortly. It was fun kit to build

and the early buy of $69 looks like a good deal and our thanks to

Wayne Burdick for the design and Wilderness Radio for the production

of the kit.

<material deleted>

FYI

dit dit

Chuck Adams K5FO CP-60 adams@sgi.com http://reality.sgi.com/adams/

 

8. Subject: re: SST #1; how to increase power

Date: Tue, 10 Jun 1997 08:13:09 -0800

From: svecbrdk@well.com (L.Svec,W.Burdick)

Folks, Chuck and Doug didn't have the SST manual to look at, but you will.

The manual has a few suggestions for increasing power output, including the

following: reduce the value of R10 from 220 to 150 or even 120 ohms. At

14V, expect about 2W out or more on each band.

 

I expect Bob to begin shipping the kits in a day or two.

 

73,

Wayne

N6KR

 

9. Subject: Re: Extending the SST Frequency Range

Date: Wed, 11 Jun 1997 08:43:05 -0800

From: svecbrdk@well.com (L.Svec,W.Burdick)

Hi Paul,

 

To get 40 kHz from the SST you would have to modify the VXO, making it a

VFO instead. The 40-meter version is the only one that this would work on,

since it's the only band where the VFO freq. would be low enough to be

stable (i.e., about 3MHz). I have not attempted this, partly because the

rig is not inteded to be a be-all radio. I'm sure someone will,

eventually.

 

You'd have to use the varactor tuning, still, but add a large toroid and a

few polystyrene caps, then hand-adjust the toroid until you get to the

desired range. One problem is that the VXO tuning pot is a small one, not

really suitable for tuning a wide range because it is mechanically not as

"clean" as a larger pot. You might be able to find a small 10-turn pot

that fits in the same space, but it won't be easy.

 

73,

Wayne

 

>Wayne:

>

>Do you think it will be reasonably possible to extend the frequency range

>of the SST in a similar manner as the Norcal 40? In a previous posting,

>you indicated that limited extended coverage was possible by "bending" a

>second crystal or varactor position and adding a switch.

>

>It would sure be nice to have the 40M version cover 40 or 50 kHz! What do

>you think?

>

>-Paul, W9AC (Ex-N9AZ)

 

10. Subject: SST on the Air! <plus construction notes>

Date: Thu, 12 Jun 1997 20:48:17 -0600

From: "Bob Follett" <bfollett@ditell.com>

Gang:

 

>From Post Office delivery this afternoon to now -- 4.5 hours construction, the

SST is on the Air!

 

A Quick construction report:

 

1. I don't think we will be generating as many modification/how do I change

this? messages with this rig as the 40'9er or 38S. Of course there is always

room for the keyer/noiseblanker/frequency readout/tuner/battery and solar

charger additions :-)

 

2. I found zero errors in the manual.

 

3. I do have an accurate L/C meter now, and found I needed one T removed from

L2 & L3, the output filters, to get down to specified value.

 

4. I found the BFO too low in frequency. Wayne mentions using a trimmer

instead of a fixed cap, but I reduced the 33pF to 22pF and got it about equal

to the side tone, where I liked it.

 

5. The frequency range, using the 108 varacter, is 7.027 to 7.039kHz. I'll

try to raise/expand that tomarrow (You really shouldn't widen the tuning range

-- with the very sharp filter and small tuning knob, the signals pop in and

out as it is. Perhaps Wayne's idea of using both diodes with the s/w is a good

answer, but all I want to do is raise the freq. up to 7.043+

 

6. I matched the IF crystals and caps to optimize the IF filter design ---

Probably not a good idea. My filter is VERY narrow currently -- guessing, in

the 200-250hz range. I'll either widen with different caps, as Wayne

outlined, or add the VBX which I have on both my Sierra and 40A.

 

7. The Xmit tuned up immediately to between 2.6 to 2.8 watts (I need to

measure with the scope instead of the WM-1) Very nice! Sidetone is totally

w/o clicks/thumps, and other assorted garbage.

 

8. Needless to say, with VXO, the rig is very stable. Oh yes, and the AGC

really works well.

 

Now to add a keyer, 9V supply, swap out the voltage regulator for 9V

operation, etc. Oh yes, and the great paint-the-case debate. (Maybe we could

get a group rate on a mass-anodizing somewhere) I'll have the front and rear

panels scanned in to CorelDraw 5, if anyone needs them in that format. ( can

try .TIF, but generally don't like the conversion to bitmap)

 

In summary, a great rig! Thanks Wayne and Bob D. I am really looking forward

to taking it backpacking. I think my PL259 plus BNC adapter weighs more than

the rig!

 

73, Bob

----------------------------------------------------------------

Bob Follett AB7ST, QRP-L # 129, NorCal, ARCI, 10-10, ARS

2861 Estates Dr. VOICE: 801.649.6457

Park City, UT 84060 E-mail: bfollett@ditell.com

 

11. Subject: SST-40M On the Air <plus output power comments>

Date: Sat, 14 Jun 1997 03:47:30 -0400 (EDT)

From: Steve Bornstein <saborns@freenet.columbus.oh.us>

 

G'day Gang,

 

Completed and tested my SST-40M rig in the wee hours. Rig tunes 7030 to

7039.9 with D4B installed. (Am going to move it up a bit with D4A). Output

power is about 2.5 watts with R10 at 120 ohms (Operating on 13.5v). Power

adjustment pot will adjust power down to nil. Phones audio is sufficient

(using Yaesu phones). Made first contact with WB4KKL in FL at 0620 hrs Z.

A nice haul from Columbus, OH. Sigs varied from initial 459 to 589. FL station

was troubled by static crashes. Painted enclosure by first spraying with zinc

chromate primer followed by black for enclosure halves and grey for front and

rear panels. I will report on further progress, but first impressions are all

positive. Assembly is a snap and manual is excellent. Given it's very small

size and minimal current draw the SST is an ideal take along rig.

 

73 DE K8IDN STEVE QRP-L 331, ARCI 9059, NORCAL 1717, MIQRP, FISTS 2441,

GQRP 8332, CQRP 1

 

12. Subject: 20 Meter SST done <plus construction comments/toroids, etc.

Date: Mon, 16 Jun 1997 00:45:57 -0400 (EDT)

From: WD6BOR@aol.com

Just a quick report to the list about the 20 meter version of the SST that I

just finished. It works great!

 

I started the kit Wednesday or Thursday evening and stuffed the board in just

over two hours. Friday I wound the toroids during lunch after I finished my

sandwich and cookies. last night I soldered in the toroids and cleaned the

board before bedtime. This afternoon I connected it up to the power supply

and an antenna and aligned the receiver, then put it on a dummy load and

peaked the output. All together I figure it went together in just a little

over four hours. Piece of cake.

 

This comes as no surprise after having built Wayne Burdick's Norcal 40.

Wayne's method of mounting eveything on the board and the high quality of

that board and the parts supplied make this an excellent kit for a first time

builder. Very easy, well written manual and, as always, that wonderful kick

when it comes to life as soon as the switch is thrown.

 

I measured the toroids as I wound them and found RFC5 was 17.5 uH and L2 and

L3 came out at .88 uH with twelve turns. Ten turns brought them both down to

just a little over the specified .6 uH and the power out and resultant

waveform looked great.

 

Power out at 12.0 volts was 2.25 watts and at 13.5 volts was 2.9 watts. After

trimming C28 the waveform was a perfect sine wave. The AGC worked fine as I

tuned around as evidenced by the blinking LED and indeed did indicate power

output as I transmitted.

 

I found that my tuning range with the MVAM108 and 6.7 uH RFC3 was 14.032 to

50. I tried a 5.6 uH chocke and got .041 to .050. The MV209 gave me a range

of .042 to .058 with the 6.7 uH and .049 to .060 with the 5.7, so I stayed

with the original choke to maintain the greater tuning range. You'll just

have to look for me below.

 

The case went together without a hitch and will look great with that as yet

undecided paint job. Maybe Wayne will extend his contest to the August

meeting.

 

Two thumbs up, four stars and a grand prize for this one. The SST has my

endorsment.

 

Darrel, WD6BOR

 

13. Subject: SST Field-Test notes From the Wilderness Engineering Lab

Date: Tue, 17 Jun 1997 07:12:23 -0800

From: svecbrdk@well.com (L.Svec,W.Burdick)

Early results suggest that the VXO range on the 20m SST is lower on

production units than on my original prototype. I'm still looking into

this. Meanwhile, you can reduce the size of the VXO choke and move the

range up, although this will decrease total range. There may be other ways

to move the range, such as reducing the values of the feedback caps in the

VXO. If anyone beats me to it, please post your results.

 

Yup, there are some holes in the cabinet that aren't perfectly lined up,

although none are show-stoppers. I admit it, I did that drawing at 3AM.

:) Next rev. will be much closer. This is why we do field tests.

 

RFC5's value is a misprint in the P/L. Please wind using the indicated

number of turns.

 

All of the other toroids should also be wound as I indicated in the P/L;

I'll measure the actual values and modify the P/L accordingly. I may also

change the windings by one turn in some cases, but this shouldn't affect

performance significantly.

 

Finally, I have heard one report of hard keying (as heard in the

headphones). This is perhaps unavoidable due to the simplicity of the T/R

circuitry, but if it bothers anyone, try using an 8-50pF trim cap for

setting the TX offset as decribed in the troubleshooting section. Normally

this method is used for modifying the TX offset pitch, but moving the TX

pitch also changes the monitor tone attack and decay characteristics.

 

Other than that, so far so good--no DOAs that I know of! Thanks for

getting those SSTs up and running.

 

73,

Wayne

N6KR

 

14. Subject: SST Mods Text files Available

Date: Sat, 02 Aug 1997 17:52:42 EDT

From: n4so@juno.com (charles k brown)

 

A compiled text file on SST Mods is here.

Ask for SST mod file. Approx. 16,000 bytes long.

from: n4so@juno.com

 

Also about 4 files on the LM386 noise reduction.

 

Ken Brown, N4SO

QTH nr Mobile, AL/ EM50tk

qrp-l #622

n4so@juno.com


15. Subject: Spectrum analyzer test of an SST

Date: Sun, 13 Jul 1997 19:58:49 -0400 (EDT)

From: Mike Czuhajewski <wa8mcq@u1.abs.net>

Back on 18 June (Daily Digest 761, message #21579), NA5N gave a

detailed technical report on an SST. Among a whole lot of other

things, he mentioned the harmonic suppression seen on a spectrum

analyzer. A while back, WA4KAC (Walt Thomas) let me borrow his

40M SST and check the spectrum at work. I went into it in more

detail, measuring both the second and third harmonics at a variety of

power supply voltages. Here are the details in case anyone is

interested.

 

Walts rig is pretty much stock, although he did experiment with a

variety of final transistors and ended up with a 2N5262 that I gave

him once, since it provided a bit more power. He mentioned that he

simply wound the toroids as specified in the manual and did not

experiment with compressing and squeezing the turns to get maximum

power. (I wanted to keep the rig longer and remove the coils and caps

in the filter to check the actual values, but he wanted to get the rig

back on the air.)

 

Equipment setup--HP E3630A variable DC power supply, HP 8590B

spectrum analyzer, .Weinschel 30 dB attenuator (50 watt rating!)

model 24-30-34. The output of the SST was fed through the

attenuator into the spectrum analyzer. Power levels given are in dBm,

or in relation to 1 milliwatt at 50 ohms, and were later converted into

watts. Precise attenuation of the Weinschel was not checked since I

wasn't interested that much in the fundamental power, just the

harmonic suppression, and is presumed to be the nominal 30 dB. The

harmonics are given in negative dBc, or dB below the carrier level.

 

DC volts Power Power 2nd harmonic Third harmonic

dBm watts -dBc -dBc

 

13.8 34.4 2.75 37.3 61.3

12.0 33.2 2.09 37.4 61.0

11.0 32.48 1.77 37.44 60.8

10.0 31.59 1.44 37.7 60.0

9.0 30.85 1.21 37.66 59.55

8.0 29.53 0.90 37.77 58.8

7.0 28.27 0.67 37.76 58.0

6.0 27.1 0.51 37.62 57.5

 

Although the sweep on the analyzer was set wide enough to see

higher harmonics, they were lost in the noise level (which was around

70 dB below the carrier level when the voltage was set to 12.0). No

attempt was made to monitor the signal for quality or otherwise check

performance at the various voltages. The sole purpose of the test was

to observe the harmonic suppression. Interestingly, the second

harmonic remained relatively constant (and easily legal since the FCC

requirement for under 5 watts is 30 dB minimum), while the third

harmonic showed a steady deterioration as voltage went down. I'm

not going to worry about that too much, considering that it still

exceeds the FCC spec by at least 27 dB :-)

 

73 and Queue Our Pea DE WA8MCQ wa8mcq@abs.net

 

16. Subject: HELP, my SST howls

Date: Tue, 15 Jul 1997 22:18:21 -0700 (PDT)

From: Kory Hamzeh <kory@avatar.com>

I just finished build my 30M SST, it seems to work well, except for the

fact that the receiver starts to howl (go into feedback or oscillation)

when I tune to a strong signal and the volume is turned all the way up.

If I back down on the volume, the howling stops. While it is howling, the

AGC LED is pegged.

 

This is not a stock build, I've done the following mods:

 

1. The PA is a MRF237

2. C10 is a 50pf trimmer. What is the correct procedure for determining

the optimum setting for C10?

3. I've done the ABX mod as described in the SST manual.

4. I've installed a 39uh choke between X4 and C10.

5. I've removed one turn from L2.

 

Other than that, its pretty much stock! :-)

 

The audio sounds a bit muddy, as compared to my Sierra. Is this normal?

 

Any help would be greatly appreciated.

 

Thanks,

Kory

AC6RN

 

17. Subject: SST-Lucky #13! <next time sockets>

Date: Wed, 16 Jul 1997 01:35:29 -0700

From: talljazz@teleport.com (Dan Presley)

 

Lucky #13 SST 20 is now alive & well (I think!). This is the kit I recieved

as a prize for the "Bumblebee" event (to be held July 27) -I was the 13th

person to sign up for the event through the Adventure Radio Club.

Anyway, I finally finished the radio, and discovered I had intalled IC U5

backwards!I was able to unsolder (next time, sockets!), and even though I

didn't think the chip would withstand being yanked on and slightly chipped

(no pun intended), I was able to reinsert it correctly, and it seems to

work fine.Tuning range is about 14040-058 w/ a 4.7 uH & a 1uH together at

RFC 3 , so I may try to lower it a little more to move the range to above

060. Please listen for me tomorrow (Wed 7/16) at about 1700-1900 UTC around

14055 +-. This rig will be "Bumble-beeing" if all goes well! Thanks again

to Russ & crew for the nice prize, and Russ, I will be contacting you soon

for more detail on our 'secret location' for July 27!

Dan N7CQR

 

18. Subject: Re: HELP, my SST howls

Date: Wed, 16 Jul 1997 11:07:27 -0700

From: chunt@macromedia.com (Christian Hunt)

 

I have a similar problem on my 40m SST. If I have the AF gain fully

clockwise and I key, after releasing the key, I get a howl that gradually

fades away. It's loud enough to cause a buzz in my headphones.

 

Mine is pretty much stock except has a wider filter. This doesn't seem to be the

cause as the howling occurred without it as well.

 

73, KF6IHU

 


19. Subject: SST-13 < problem with the audio level of the "sidetone" being

very hot>

Date: Thu, 17 Jul 1997 00:41:10 -0700

From: talljazz@teleport.com (Dan Presley)

Well-first QSO w/ my SST-20-13 was about 10 blocks away! But,it works quite

nicely.A few comments- freq coverage is from 14052-060 with 4.7uH choke for

RFC 3, and 14044-055 with other varactor (I have them selectable with

toggle switch mounted on the front). The mod for tuning linearity (18K

resistor across R4) works very well, and I had no trouble with sharp

tuning. Audio is a bit lower than I prefer, but will leave it as is for

now. I am having a problem with the audio level of the "sidetone" being

very hot, and I have to back off the audio gain before xmit or my ears are

blown off!I realize that it's actually monitoring the output- Anyone else

experience this, or is it unique? Other than that, it recieves quite well,

and I'm anxious for condx on 20 to improve for more qsos!

Dan N7CQR

 

20. Subject: Re: SST-13 < problem with the audio level of the "sidetone" being

very hot>

 

Date: Thu, 17 Jul 1997 08:48:28 -0400 (EDT)

From: Chris Cartwright <ccart@dns.vidtel.com>

Dan,

 

I had the same thing with the 30M version. I opened the IF filter up as

noted in the manual, and it improved the audio, and seemed to reduce the

sidetone a bit. Or maybe I just don't need as much volume, or I got used

to it:) I've see a few posts about the wider filter being nicer to listen

to. I've been having a blast with the little thing, gotta get that KC-1

in there though... and ABX... and RIT... and...

 

-- Chris Cartwright, Technical Engineer | ccart@vidtel.com --

-- N3XRV QRP WAS 17/9 (w/c) | ccart@erols.com --

-- QRP-L #655 NORCAL #1891 QRP-ARCI #???? | http://dns.vidtel.com/~ccart --

-- WIMPS Q's=04 30M=04 17M=00 12M=00 STATES=03/00/00 DX=00/00/00 QSL's=00 --

 

 

21. Subject: Re: SST-13 < RIT board for the NE4040 for use in SST>

Date: Thu, 17 Jul 1997 09:57:21 -0700 (PDT)

From: Kory Hamzeh <kory@avatar.com>

On Thu, 17 Jul 1997, Chris Cartwright wrote:

 

>

> I had the same thing with the 30M version. I opened the IF filter up as

> noted in the manual, and it improved the audio, and seemed to reduce the

> sidetone a bit. Or maybe I just don't need as much volume, or I got used

> to it:) I've see a few posts about the wider filter being nicer to listen

> to. I've been having a blast with the little thing, gotta get that KC-1

> in there though... and ABX... and RIT... and...

>

 

Now that you mentioned RIT ....

 

I ordered the RIT board for the NE4040 from Dan's Small Parts. Once I get

my SST to work properly (no howling!) I will try it and let you guys know

how it works.

Kory

AC6RN

 

22. Subject: SST Howls < optional DC filter can be installed to prevent the oscillation>

Date: Sat, 19 Jul 1997 02:27:05 EDT

From: tshilhanek@juno.com (Terence J Shilhanek)

My SST 40m version also howled when the audio gain was at maximum.

Looking at the application notes on the LM386 audio chip that is in the

SST, I noticed that there is a comment that if the chip oscillates then an optional DC filter can be installed to prevent the oscillation. The filter is

only a resistor and a by-pass capacitor placed in the lead supplying

power to the chip. I have installed the modification and it seems to

work. The changes can be done on the etched side of the pc board.

 

1. cut the trace going to pin 6 of U3

2. solder a 100 ohm 1/4 watt resistor from pin 6 of U3 to the contact

next to pin 1 of U3 .

3. solder a .1mf disc cap from pin 6 of U3 to pin 4 of U3

Terry, W0PFR

 

23. Subject: SST howells < Another thing you can try>

Date: Sat, 19 Jul 1997 14:24:49

From: Steven Weber <kd1jv@moose.ncia.net>

Another thing you can try is adding a BFC say 470 ufd to 1000 ufd across

the raw DC power supply leads. Ideally, wire the cap directly across the

power pins of the LM386. A small resistor, say 1 to 10 ohms in series with

the plus supply pin might also help. (with the cap across the audio amp

power pins)

Steve, KD1jv....In the White Mountains of New Hampshire

 

"Melt Solder"

 

24. Subject: SST Howls (Update) < Terry (W0OFR) mod worked!>

Date: Mon, 21 Jul 1997 17:48:22 -0700 (PDT)

From: Kory Hamzeh <kory@avatar.com>

Thanks to Terence W0OFR, I tried the attached mod and it worked! Also,

another note, while in radio shack picking up the parts for this mod, I

picked up a Nove 43 headphone per someone's recomendation on this list.

Anyway, I tried the headphone before the applied the mod, and the howling

does not happen with the Nova 43 (actually, there is a short burst when the

rig is first turned one, then the howling stops very quickly).

 

By the way, I highly recommend the Radio Shack Nova 43 headphones. Very

nice and sensitive.

 

Thanks Terence!

 

73,

Kory

AC6RN

 

25. Subject: SST & KC-1

Date: Thu, 24 Jul 1997 09:20:02 -0700

From: talljazz@teleport.com (Dan Presley)

 

Has anyone had problems installing a KC-1 keyer in the SST? I have a 20M

SST and KC-1 that seems to be misbehaving-won't key consistently from the

paddle, and keeps spitting out the letter "D", and then freezing

up-sometimes it will send a string of dits until I shut the rig down. I

have isolated the paddle lines with ferrite beads & .01 caps in case of

RFI, but this still happens even with reduced power out on the SST. Any

ideas?

Dan N7CQR

 

26. Subject: Re: SST &KC-1 < Is your ground lead short?>

Date: Thu, 24 Jul 1997 13:14:25 -0700 (PDT)

From: "David D. Meacham" <ddm@datatamers.com>

 

Dan,

I have no problems with the KC-1 in my 20m SST. Maybe yours is picking

up some RF. Is your ground lead short?

72, Dave, W6EMD


27. Subject: SST 20 - de N3XRV < sounded a bit muddy (400Hz?) so I changed>

Date: Fri, 25 Jul 1997 22:49:32 -0400 (EDT)

From: Chris Cartwright <ccart@dns.vidtel.com>

Just got the 20M SST from K7SZ, sounded a bit muddy (400Hz?) so I changed

C10 from 33pF to 18pF and sounds much more gooder :) Set the output to

one watt, and connected it to a hamstick, stuck in the ground in my front

yard, with three radials, and came within microwatts of working AC4YW in

Florida (abt 800 mi). Even with a bunch of repeats, just couldn't quite

get there. With a straight key no less. Guess I have a chance at the bumble

bees this weekend. I just love this QRP stuff. Sorry, just wanted spout

off a little, I'm going back to sit in the front yard play radio now...

 

Oh, for the curious: 18ma RX, 185mA TX@12V, 14.035-064 w/MV209

 

-- Chris Cartwright, Technical Engineer | ccart@vidtel.com --

-- N3XRV QRP WAS 17/9 (w/c) | ccart@erols.com --

-- QRP-L #655 NORCAL #1891 QRP-ARCI #???? | http://dns.vidtel.com/~ccart --

-- WIMPS Q's=04 30M=04 17M=00 12M=00 STATES=03/00/00 DX=00/00/00 QSL's=00 --

 

28. Subject: In praise of the SST-20 <alludes to: Dave-W6EMD's

mods -- and one of my own>

Date: Wed, 30 Jul 1997 22:35:50 -0700 (PDT)

From: Alan Kaul <kaul@netcom.com>

I can't say enough nice things about my optimized SST (using Dave-W6EMD's

mods -- and one of my own to increase the VXO tuning 14.046-14.063).

 

Terrific little rig!!!! Running about 3W output, 15V AC supply.

 

I've had only 4-contacts -- BUT WITH FOUR DIFFERENT DXCC COUNTRIES!

 

K0EVZ, SM5AGI, VE4GEC and VK2KM (the SM5 lost me in Euro QRM--but the

rest of the QSO's went to completion).

 

Three times I answered CQ's, once someone answered mine.

 

All QSO's between 0420Z and 0530z on 3 different evenings.

My sigs ranged from 589 to 529.

 

My antenna is an A3 tri-band Yagi at about 40-feet.

 

Wow!

 

[<Alan Kaul, W6RCL>] kaul@netcom.com


29. Subject: Re: Noise reduction w/ LM386

Date: Fri, 01 Aug 1997 12:56:18 -0400

From: Randy Hargenrader <randyh@harksystems.com>

 

Hi Bob,

There are a couple of ways to reduce the high freq hiss

from the LM386.

One is to use a small inductor (2.2mH) in series with the output

device (spkr or headphones).

Another is to play with the feedback circuit by using a "T"

circuit as the feedback circuit.(two resistors and a cap)

You can also peak the audio response by putting an inductor and

capacitor in series to ground from pin 1.

Some circuits I've seen roll off the output with R/C networks.

I have component values for the inductor/cap to pin 1 if youre

interested.

--

73, (Sir)Randy WJ4P

Knightlites QRP-L #296 ARCI #9152 1996 40-9er High Scorer

 

30. Subject: BuzzNot noise blanker < installed it in my SST on 20M

Date: Mon, 14 Jul 1997 08:55:55 -0600 (MDT)

From: bcutter@teal.csn.net (Bob Cutter)

I cannot say enough about the BuzzNot noise blanker. I installed it in my

SST on 20M and it does an amazing job on my electrical noise.

 

Another great design from Wayne and available from Wilderness Radio.

 

72, Bob KI0G

 

31. Subject: Re: SST ABX Mod

From: "Paul Christensen" <paulc@mediaone.net>

Date: Sun, 22 Jun 1997 07:01:46 -0400

I just went through my notes....

 

In order to make the ABX mod work on the SST, you'll need to insert a 39

uH choke (molded or toroid) between C10 and X4. Additionally, it will

become necessary to add a 50 pF trimmer at in place of the fixed capacitor at

C10.

Since there's such a tight fit between U2 and X4, you'll need a really

small trimmer cap. I've done the homework for you:

 

Mouser P/N 24AA024

 

This is a high quality ceramic trimmer and fits perfectly in place of

C10.

 

-Paul, W9AC

nnnn

 

32. Subject: Using TiCK with the SST

From: "Paul Christensen" <paulc@mediaone.net>

Date: Sun, 22 Jun 1997 07:11:35 -0400

 

I went out on a limb and tried something I hadn't done before.

 

Since the TiCK is rated between three and five volts, and the SST's

regulated voltage is eight volts, some form of voltage drop is required.

While it's possible to use the TiCK's 78L05 regulator (supplied with the

DIP-style kit), I chose to use two LEDs in series between the SST's eight

volt supply and the TiCK. I'm not sure what, if any additonal current is

spared by not using the additonal regulator, but it was an interesting

experiment nevertheless. If I get a chance, I'll measure current

consumption with both configurations. Until then, I plan on leaving it

this way in mine.

 

-Paul, W9AC

 

33. Subject: More TiCK/SST Mods

From: "Paul Christensen" <paulc@mediaone.net>

Date: Sun, 22 Jun 1997 08:48:50 -0400

 

Like the Like the Wilderness KC1, the Embedded Research TiCK has he

ability to inject sidetone audio into a transceiver. While I generally like to

keep the sidetone off and let the rig provide it's own sidetown when

available, it's still necessary to couple this audio into the rig for

programming puposes. Embedded's Piezo alternative just doesn't cut it

for me.

 

The TiCK manual states a value of a 1Meg resistor for R3 for use with the

Norcal 40A. The results in a very low sidetone audio level on the SST.

Simply change R3 to 100K to form a more proportional voltage divider. To

my ears, this value provides a sidetone level that's "just right." As an

alternative, one could replace the TiCK's R2/R3 voltage divider with a

100K micro-potentiometer. then you'll have the ability to set the level

anywhere you want it.

 

-Paul, W9AC

 

34. Subject: Another SST is Born

From: Craig LaBarge <LaBarge_C@CompuServe.COM>

Date: Sun, 22 Jun 1997 10:04:07 -0400

 

Gang:

 

My 30 meter SST kit arrived last week and I finally had some time

yesterday to build it. It took somewhere in the neighborhood of 4 to 5 hours to

build and I encountered absolutely no problems whatsoever. All the parts

were there, instructions were excellent, alignment was trivial, and it

worked like a champ the first time I fired it up. The case was a perfect

fit (and even looks great with the unfinished aluminum).

 

The only mod I made was to reduce the number of turns on L2 and L3 by

one. When I originally wound them with the specified 14 turns, the inductance

measured at 10MHz seem a tad high. 13 turns brought them in a little

closer to the specified .8 uH. I think mine measured at about .9 or so.

Anyway, I get 2 watts out with a 13.6 volt power supply. Stable as a

rock and the receiver has plenty of audio. I opted to used "D4B" in the VXO

and the tuning range is as specified in the manual.

 

This morning I fired up the SST and heard a K5 station calling "CQ QRP"

and got him on the first call. He was down in MS and we had a nice chat

despite some very noisy band conditions and the fact that I was pumping 2

watts into my rainspout antenna. He gave the SST a clean signal report.

So, Southeastern PA to MS wasn't a bad first QSO for the little SST.

 

I finished the SST just in time for some real field testing on an

upcoming vacation to the Outer Banks of NC. I think I'm going to have some fun

with this little rig. After I get back, I'll have to get it painted and

pretty it up a bit.

 

73, Craig WB3GCK

 

P.S. The only problem with the rig is that I tend to get hypnotized by

that flashing LED on the front panel!

nnnn

 

35. Subject: Re: Fw: SST Tuning Range

From: "Bob Follett" <bfollett@ditell.com>

Date: Sun, 22 Jun 1997 10:44:54 -0600

 

Hi Ken:

 

Well, its sort of in the manual....

 

Wayne says you can install both Varacters to cover both their ranges. He

doesn't say how to do it.

 

Its just a matter of finding a reall small SPDT switch, drilling a hole,

then mounting both Varacters to the switch, hot side of each to the two outer

s/w poles. Then run a wire to the hot side of the PCB board to the s/w

center, and the ground side wire up to both ground sides of the varacters. Its

simple, other than planning where you want the s/w on the panel.

 

I ended up with mine up high enough to clear the electrolitic caps on the

PC board behind the led.

 

73, Bob

----------------------------------------------------------------

Bob Follett AB7ST, QRP-L # 129, NorCal, ARCI, 10-10, ARS

2861 Estates Dr. VOICE: 801.649.6457

Park City, UT 84060 E-mail: bfollett@ditell.com

nnnn

 

36. Subject: Re: SST Tuning Range

From: "Paul Christensen" <paulc@mediaone.net>

Date: Sun, 22 Jun 1997 18:07:36 -0400

 

Ken:

 

It's the mod suggested by Wayne in the SST's manual: use a SPDT switch to

switch between the two supplied varactor diodes.

 

-Paul, W9AC

 

37. Subject: SST not a toy!/SST mods summarized...

From: pmeier <pmeier@tir.com>

Date: Sun, 29 Jun 97 11:19:11 -0400

 

Although the SST is a lot of fun to build and operate, I have come to the

 

conclusion it is not a toy but a very decent rig. I used it for a few

hours yesterday during field while enjoying the beautiful weather in a

local park here in Michigan.

 

To preface the next statement let me state that I don't compete seriously

 

during the June Field Day ( I save that for the Sept. QRP to the Field

:). I go out to a local park and operate for just a few hour to enjoy the

 

outdoors and have some radio fun. But to my point here... The SST is a

wonderful radio which is very well designed and thought out. I say this

after spending Friday evening building it and then taking it out to

yesterday's FD event.

I made 7 contacts in the first hour on 20 meters with just about 2 watts

into an SLV! This may not sound outstanding but considering the low

power, the ease in which I made contacts in the crowded frey and in with

 

relatively small 10khz of tuning space I WAS IMPRESSED!

 

Tuning is smooth as is the keying with no THUMPS! The audio is plenty

loud with a very nice tone. As reported in Chuck's early review the unit

went together easily and quickly. I found only one minor mistake and that

was the value given for the choke RFC5 on the schematic. It was listed as

15uh but is closer to about 34uh. Follow the parts list and use 10 turns

for RFC5. I incorporated the mods posted here on the list and found them

all to be useful. I replaced C10 with a variable trimmer (8-60pf). I

installed the VBX mod but found I kept it about mid way through its

range. I followed Dave Meacham's mods for using a 15K resistor across the

pads of the tuning pot (for tuning linearity) and replaced the 6.8 choke

at RFC3 with a 5.6uh unit to bring the top of the range up from 14058 to

14062. This mod reduced bandwith from 20khz to 10khz however. But then

again, I mostly look for QRPers and this allows plenty of range for "us".

 

I also added a KC1 keyer which installed easily and worked flawlessly

(just follow Wayne's directions in the SST manual).

 

All in all this is a great rig that is very small and very easy to build

and for well under a hundred bucks. In my opinion it's not a toy but

another of WAYNE'S WONDERS.

 

Pete WK8S

 

38. Subject: W6EMD mods summary

From: "David D. Meacham" <ddm@datatamers.com>

Date: ??

Gang,

Since I posted the tuning mod on June 18, someone commented that 18k was

a better resistor value. I just got around to trying it. It IS better, in

fact, it is optimum, according to my measurements. Higher values don't do

any good, while lower values give poorer linearity. At 18k, with dial

full counter-clockwise I get 14.054, straight up I get 14.059, and full

clockwise I get 14.063. So the first half of the dial covers 5kHz, while the secondhalf covers 4kHz. Not too shabby!

 

In case you missed the first posting, the resistor goes across two of the

terminals of the tuning pot (from the wiper to the 8V side). I use the

MV-209 varactor, and a 5.6uH choke (Mouser # 43LS566) for RFC3.

Enjoy!

 

72, Dave, W6EMD

nnnn

 

39. Subject: LM386

From: lve1@inel.gov (Larry V East)

Date: Fri, 28 Feb 1997 16:57:36 -0700

 

Paul -- I just read "The LM386 Cookbook" by you in the latest "Low Down".

Lots of good information there, but I was a bit amazed that you failed to

mention the use of a bypass cap on pin 7. A small electrolytic or

tantalum cap of a few uF from pin 7 to ground will isolate the high gain input

stage of the LM386 from power supply noise, hum, transients, etc. Such a bypass

cap is much more effective in this regard than the "brute force" Vcc

filter that you recommend in your note #2.

 

You aren't the only one to ignore this; most commercial rigs (and kits)

using the LM386 either fail to bypass pin 7 at all or use too small a

value (0.01uF or 0.1uF) to be totally effective. For example, Index labs uses a

value of 0.1uF in their QRP PLUS and increasing the value to 4.7uF

completely eliminates the "thumps" in the audio output produced by Vcc

transients when the transmitter is keyed.

 

I don't mean to be critical, but I just don't understand why the proper

use of the LM386 "bypass pin" seems to be overlooked by almost everyone (in

"hamdom", at least) using this device! It's even label "bypass" in the

data books (and your Fig. 2 in your "cookbook" as well).

 

72, Larry W1HUE/7

 

40. Subject: Re: LM386

From: gsurrency@juno.com (Gary L Surrency)

Date: Fri, 28 Feb 1997 22:39:06 EST

 

Amen, Larry! The LM386 data sheet shows up to a 50db Power

Supply Rejection Ratio (PSRR) with a 10uf cap from pin 7 to

ground and the gain at 20 with 6V supply and 1 khz operation.

 

My Ark30 had a squirrley sounding low level noise before I put a

10uf tantalum on pin 7 to ground. It might have been coming from

some of the digital synthesis circuitry and was most noticeable

when using headphones.

 

One glance at the LM386's internal equivalent schematic shows

why this decoupling cap is so needed. Pin 7 is right on the chip's

bias network.

 

BTW, on the ARK30, I placed the 10uf tantalum cap on the foil

side of the transceiver board. It just fits between the PCB and

the shield plate.

 

I have also found on many op amp circuit designs, that the unused

input pin ALWAYS need to be decoupled if it is not grounded or you

will invariably get keying or T/R thumps in the audio chain. Several

radios I have or have looked at omit this decoupling cap on the

resistive divider on the non-inverting input (+ lead). The TAC-1 had

this problem on the op amp following the CMOS bilateral switch chip.

A 0.33 uf monolythic axial cap fixed it completely, and killed the thump.

 

Bypass that lil sucker!

 

72,

 

Gary Surrency AB7MY

S&S TAC-1(40&80m) and ARK30, AT-11 (QRO and QRP)

QRP-L #571 Chandler, AZ (near Phoenix)Grid Square DM43BH

Az ScQRPions

nnnn

 

41. Subject: Re: SST-20 mods query from AL7FS <VXO Mod>

Date: Sat, 2 Aug 1997 18:27:49 -0700 (PDT)

From: Alan Kaul <kaul@netcom.com>

CC:

"David D. Meacham" <ddm@datatamers.com>

 

 

Hi Jim ... my mods are simple ... Dave, W6EMD's are a little harder.

 

Mine involves the VXO --- add a second 18mHz xtal in parallel (solder it

on bottom of board across the first 18mHz rock), then change the VXO

inductance to around 4uH. I have not yet experimented with a high Q

coil, but I think using a toroid with parallel xtals would increase the

tuning range a bit more. My molded choke coil is low Q and from Mouser

(nominal value approx 3.8uH). VXO range is 14047-14063 using the MV 108

diode. I'm not finished yet -- I plan to experiment a little more.

 

Dave's mods are a little more complex -- his e-mail address is:

 

ddm@datatamers.com

 

and you might ask him about them....I don't want to steal his thunder,

he's told me he's writing a piece for the next issue of QRPp.

 

GL and report back on your results! 73/72 de alan

 

[<Alan Kaul, W6RCL>] kaul@netcom.com

 

42. Subject: SST 2 diodes mod.

Date: Wed, 2 Jul 1997 11:29:12 -0600 (MDT)

From: bcutter@teal.csn.net (Bob Cutter)

 

I just finished my SST(20M) with the two diodes and a SPDT switch. I really

like the bandspread this gives and would encourage anyone to give it a try.

As the bands improve it is going to get crowded around those calling

frequencies and we need to spread out a bit.

 

72, Bob KI0G

 

43. Subject: Re: SSTs

Date: Wed, 2 Jul 1997 13:54:55 -0500

From: wmcshan@REX.RE.ouhsc.edu (Mike McShan)

 

>John,

(snip)

>reciever. Maybe the problem is your headphones. Have you tried a different

>pair? 72, Dave, W6EMD

 

I have to agree with Dave. Changing headphones can make a big difference.

On my NC38s, the audio is mediocre with a pair of Sony stereo phones.

However, switching to a similar pair from Radio Shack (Nova 43) results in

a dramatic increase in volume (often to the point of uncomfortable).

 

Mike N5JKY

Edmond, OK

 

44. Subject: SST Varactor Switching

Date: Thu, 3 Jul 1997 12:32:03 -0800

From: "walter.b.thomas.1@pop300.gsfc.nasa.gov" <wthomas@pop300.gsfc.nasa.gov>

For those folks using a switch to change between

the MVAM108 and MV209 diodes in the SST VXO, consider

using a subminiature DPDT switch. Use one pole to

switch the diodes and the other pole to switch the

resistors used to make the "dial" more linear. The

linearizing resistors will be different for the two

diodes. This worked great on my SST40.

Dave W6EMD found 18K to work best for the MV209 on his

20M SST. I used a 3K0 resistor for the MVAM108 on my

SST40. Your mileage may vary, so you may have to

experiment with the resistor values.

 

73 Walt WA4KAC

 

45. Subject: SST VXO Problem

Date: Fri, 04 Jul 1997 22:27:52 EDT

From: kk5py@juno.com (dennis l foster)

 

Hello to all and hope this makes it to the list as it is my first try! I

built my SST the day it arrived and it worked as advertised except for

one problem that I have sort-of solved. I used the D4A diode and found

that at the top of the tuning range the VXO shuts down. I noticed that I

could push RFC-3 away from X6 with what little movement it had, and the

VXO would work again. I can also just touch X6 and it shuts everything

down until I tune to the lower part of the band spread and it starts up

again. I have temporarily solved the problem by moving the RFC-3 to the

bottom on the board. Touching X6 still shuts everything down but it

recovers as soon as I remove finger! Has anyone else had this problem

and what might be the cause and the correct solution? I think using a

lower value choke in place of RFC-3 would be the remedy but not sure! I

just don't like having to move parts around to get things to work right.

Any and all input would be received graciously! Also, has anyone

successfully integrated the Tick Keyer into the circuit so Tick audio is

available at the headphones?

 

Dennis Foster

KK5PY

 

46. Subject: Re: SST & TiCK

Date: Sat, 5 Jul 1997 06:51:06 -0400

From: "Paul Christensen" <paulc@mediaone.net>

 

Dennis:

 

Here are two reposts of my previous messages:

 

I went out on a limb and tried something I hadn't done before.

Since the TiCK is rated between three and five volts, and the SST's

regulated voltage is eight volts, some form of voltage drop is required.

While it's possible to use the TiCK's 78L05 regulator (supplied with the

DIP-style kit), I chose to use two LEDs in series between the SST's eight

volt supply and the TiCK. I'm not sure what, if any additonal current is

spared by not using the additonal regulator, but it was an interesting

experiment nevertheless. If I get a chance, I'll measure current

consumption with both configurations. Until then, I plan on leaving it

this way in mine.

 

-Paul, W9AC

Like the Like the Wilderness KC1, the Embedded Research TiCK has the

ability

to inject sidetone audio into a transceiver. While I generally like to

keep the sidetone off and let the rig provide it's own sidetown when

available, it's still necessary to couple this audio into the rig for

programming puposes. Embedded's Piezo alternative just doesn't cut it for

me.

 

The TiCK manual states a value of a 1Meg resistor for R3 for use with the

Norcal 40A. The results in a very low sidetone audio level on the SST.

Simply change R3 to 100K to form a more proportional voltage divider. To

my ears, this value provides a sidetone level that's "just right." As an

alternative, one could replace the TiCK's R2/R3 voltage divider with a

100K

micro-potentiometer. then you'll have the ability to set the level

anywhere you want it.

 

-Paul, W9AC

 

47. Subject: "Choking" the SST

Date: Tue, 8 Jul 1997 20:49:11 -0700

From: talljazz@teleport.com (Dan Presley)

 

I couldn't locate (locally) a 5.6uH choke for my 20M SST, to replace the

6.5 choke in the VXO circuit. I did find a 4.7, so was wondering if I can

wind a few turns on it to get it up around 5.6. Anyone have a 'formula', or

suggestions? Also, this is a smaller molded choke than supplied w/ kit-any

problems? Thanks!

Dan N7CQR

 

48. Subject: Re: SST Tuning Mod revisited

Date: Fri, 11 Jul 1997 02:14:32 -0700 (PDT)

From: Alan Kaul <kaul@netcom.com>

 

Hi Gang .... got home from my trip to Northern California to find

my 20M SST waiting (Bob shipped it priority mail -- it beat me back from the

Norcal Meeting!!!!). I know Dave Meacham has made a pretty good linear

tuning mod by soldering an 18k resistor from the tuning pot to the 8V

regulator. I've still got his post. And I read where someone else changed

C10 to 15pf AND R10 to 120 Ohms -- but I don't know if that was on the 20M

version. If anyone has any mods for the 20 Meter SST, I'd love to hear

about them before I plug in the solder iron!!

 

Pls and tnx and best 73/72 de alan

 

[<Alan Kaul, W6RCL>] kaul@netcom.com

49. Subject: The HB Sprint and the SST

Date: Fri, 11 Jul 1997 03:44:57 utc

From: k7sz@juno.com (Richard H. Arland)

 

Gang:

 

Had the 20 meter SST on the bands this evening for the HB sprint. What

follows are a few observations.

 

1. The tuning on my SST is 30 kc with the MV-201 and 50 kc with the

MVAV-108. Unfortunately the latter does not offer coverage in the QRP

section of the band, as it stops at 14052.5 khz. Therefore I opted to use

the narrower tuning range offered by the MV-201 varactor.

 

2. The stock IF BW is way too narrow. I performed the mod as outlined in

the manual and it is still too narrow for my liking. I;ll have to do some

cap substitutions and see what I can come up with.

 

3. Even with the wider IF BW (after the mod) tuning was still much too

critical. There is no room for a vernier drive so out came the box of

knobs and a spare NC-40A main tuning knob was stuck on the front of my

SST. It looks a little wierd, but it does a much better job of tuning in

stations.

 

4. This is a Minimalist's radio. Therefore, it is designed to be used

when camping, hiking, ect, NOT in a normal hamshack. The controls are

somewhat crowded and I find that this is not a pleasurable rig to operate

like the Sierra of the NC-40A.

 

5. Performance is fantastic considering that it has about 1/2 the parts

of a NC-40A and is about 1/3 the size. Wayne Burdick did one hell of a

job designing this rig. Power output with a 13.8 volt DC supply was 2.25

watts. On a 12 volt Gel-Cell power drops off to just under 2 watts.

Receive sensitivity is very good and selectivity (of the stock radio) is

so good, you often tune right past stations unless you tune R-E-A-L

S-L-O-W.

 

I have not tried this radio into a less-than-optimal antenna, and I

suspect, upon reading the manual, that performance will suffer

drastically if the antenna is not exactly 50 ohms at the operating

frequency. End of the month, I'll be testing this theory on the Flight of

the Bumblebees from Lake Wallenpaupak.

 

73 rich K7SZ

 

50. Subject: SST-Internal Batteries

Date: Sun, 13 Jul 97 18:49:47 +0000

From: tgordish@concentric.net

 

QRP Folk,

 

Well after starting a never ending thread on Renewal Batterys, I was

discouraged from using them do to the problem with charging them while in

the rig. I opted for little cordless phone batterys available from Radio

Shack. I bought 2 packs of 3 cells and one pack of 4 cells and soldered

them all together. They fit nicely into the SST and give 12v. Total rig

weight with batteries is only 11.5 oz. Then I hooked up to the switch

and made a solder bridge accross the power switch contacts so that I

could charge the batteries while hooked up to external power and the

switch set in the BATT position. Checked it out and seems to be working

fine. Tried a couple of CQ's but no one was out there. Now a couple of

questions:

 

1. These batteries are rated at 250mah, will this amount of power get me

through a 2 hour Spartan Sprint or do I need to crank the power down a

bit?

 

2. What would make a good charging voltage for these 10 little ni-cads?

Is it 13.8v like I use with my gel-cell?

 

Look out you Spartan Sprinters! (I hope I don't regret divulging the

secrets of my set up!) I won't be able to run the August Sprint, but will

be bringing the rig with me while I serve my annual 35 Navy reserve days

at Great Lakes Naval Station.

72 de

Tim & Aretta Gordish

KB9LGJ & N0YDG

Yuma, AZ

 

51. Subject: "Potential" Super SST

Date: Fri, 22 Aug 1997 16:53:54 -0400 (EDT)

From: Chris Cartwright <ccart@dns.vidtel.com>

Gang,

 

I now have an SST for every band (except/N), no I don't want to part with

any:) However, I got a 20M unit from Rich, K7SZ and it tunes ~14.002-052

or 14.036-065 depending on the varactor. This seems *abnormally* wide

and I'd like to find out why, and pass it on to other SST owners. (and

expand coverage on my other two) And yes it's very non-linear, the

"bottom" of the dial is *very* crowded.

 

I have a fair compliment of test equipment but ne

 

52. Subject: Re: "Potential" Super SST

Date: Fri, 22 Aug 1997 15:17:18 -0700 (PDT)

From: "David D. Meacham" <ddm@datatamers.com>

Chris,

Why not find out what K7SZ did to it? BTW, my 20m SST xtal says:

 

ECS H

18.00-20

CHINA K5

 

It gives a range of 14.054-14.063 with the MV209 Varactor and 5.6uH for

RFC3.

72, Dave, W6EMD

 

53. Subject: Re: SST - working (replace the PA with an MRF 237)

Date: Wed, 27 Aug 1997 16:29:31 -0700 (PDT)

From: Kory Hamzeh <kory@avatar.com>

 

I was able to get 3 watts easily with a 12 volt supply. The replace the PA

with an MRF 237 (e & c are backwards), took one turn of off L2, and used

110 ohms for r10. I haven't checked to see how much about I can put out at

13.8v yet.

 

Kory

AC6RN

 

54. Subject: SST for WWV 10.000 Mhz

Date: Sat, 06 Sep 1997 20:39:37 EDT

From: n4so@juno.com (charles k brown)

The SST for 30 meters can be modified to receive WWV

on 10.000 Mhz.

I have a mod file that has some suggestions for

doing this which are by the designer.

The text file is on this computer-- ask for WWV.txt.

 

from: n4so@juno.com

Ken Brown, N4SO

QTH nr Mobile, AL/ EM50tk

qrp-l #622

n4so@juno.com

 

 

55. Subject: Subject: [27051] Re: SST/40 question

Date: Mon, 22 Sep 97 09:12:03 -0400

From: cjl@mail09.mitre.org (Charles J. Ludinsky)

Frank, G3YCC, writes:

 

> In message <199709172335.TAA47088@nss2.CC.Lehigh.EDU>, Joel Malman

> <malman@BBN.COM> writes

>

>> 2. The SST seems to drift a bit more than I expected. Did anyone else

>> notice this?

>>

> I am surprised at that. Unless you have extended the tuning range

> greatly, there should be no problem.

> Have fun!

 

If the power supply is not quite "solid", some frequency drift will occur. For

example, alkaline batteries (e.g., AAs) will drop sufficiently in voltage

during use to cause the output from the internal voltage regulator to change by

some 10s, or even 100s, of millivolts. This is more than enough to cause

annoying drift and chirps.

 

72 de Chuck, K1CL

 

56. Subject: Simple Superhet Transceiver SST

Date: Fri, 26 Sep 1997 12:01:02 -0800

 

http://www.fix.net/~jparker/wilderness/sst.htm

 

Wilderness Radio

P.O. Box 734

Los Altos, CA 94023-0734

(415) 494-3806

 

CREDIT CARDS NOT ACCEPTED

 

The Simple Superhet Transceiver

SST

 

 

The SST is an optimized, superhet rig with an extremely low parts count

(only 80 parts, vs. 100 for a

38-special and 120 for a NorCal 40A).

 

This may be the easiest to build superhet ever, and it comes with a

miniature custom enclosure, less than

half the size of a NorCal 40A.

 

 

SST Features:

 

- 2 watts out (varies w/band and supply voltage), adjustable down to

zero

 

- fast, clean QSK with transmit monitoring

 

- 3-pole crystal filter at a low I.F. (about 4 MHz)

 

- built-in, no-adjustments AGC with received signal indicator LED

 

- stable VXO coverage of 10 to 20 kHz using varactor tuning (range

varies w/band)

 

- very low current drain--about 15mA

 

- stable operation from 10 to 16VDC, or internal 9V lithium battery

 

- works with the Wilderness KC1 keyer/ counter and BuzzNot noise

blanker.

 

- both the KC1 and BuzzNot can be installed inside the SST

 

- all controls, connectors, and parts mount on a single 3.0" x 3.4"

PC board

 

- 1.5"H x 3.2"W x 3.5"D custom enclosure (supplied unfinished)

 

RECEIVER:

 

A superhet with a sharp, three-crystal filter, operating at a low I.F.

(around 4MHz). The receiver uses a

novel AGC circuit employing a single LED as both the detector and signal

indicator. The AF gain control

and headphone jack are on the front panel. The RF gain is rarely used in

the SST, so I put it on the back.

 

TRANSMITTER:

 

The Transmitter has *really* fast, exceptionally clean (totally

thump-free) QSK with TX monitoring, as

in the '40A. Power output is around 2 watts on all three bands with a

13.8V supply, and proportionally less

at 12V or 9V. Power out is adjustable down to zero.

 

Varactor-controlled VXO rather than a VFO with excellent stability.

Frequency coverage (approximate):

 

40m 7.032 - 7.042

40m/novice 7.105 - 7.115

30m 10.105 - 10.120

20m 14.046 - 14.064

 

 

 

VXO range can be increased by switching in a second varactor. All VXO

and I.F. crystals used are

*standard* frequencies available from Digikey.

 

The custom enclosure is about 3W x 3.5D x 1.5H", and is supplied

unfinished. Since the box is so small,

we use .050 aluminum to reduce weight. (With a KC1 on the top and an

internal 9V lithium battery, the

SST makes a great TFR.

 

PRICE AND KIT INFO:

 

The SST is supplied only as a complete kit -- no partials.

 

The kit includes a high-quality double-sided and silkscreened PC board;

a custom, unfinished .050

aluminum enclosure with hardware; all controls, connectors, knobs,

rubber feet, etc.; detailed manual;

and all parts for your choice of bands.

 

The price for each complete SST is $85.

 

ORDERING INSTRUCTIONS

 

1. Please enclose $85 per kit ordered.

 

2. For each kit ordered, you must specify the band: 40m, 40m/novice,

30m, or 20m. (Remember, this is a

VXO-based transceiver, so the rig does not cover the entire CW band.

Approximate coverage is: 40m,

7.032-7.042; 40m/novice: 7.105 - 7.115; 30m, 10.105-10.120; 20m,

14.046-14.064. Other ranges are

possible with small modifications.)

 

3. California residents must add 7.75% sales tax.

 

4. Shipping charges are extra: $3 U.S., $5 Canada/Mexico, $15 DX

(other). This is a per-kit shipping

charge.

 

5. Please make out checks to Wilderness Radio. We'll also need your

name, call, address, phone number,

e-mail address.

 

6. Send U.S. funds only (checks drawn on US banks, or an international

money order) to:

 

Wilderness Radio

P.O. Box 734

Los Altos, California 94023-0734, USA

 

For more information, call Bob at:

 

(415) 494-3806

 

CREDIT CARDS NOT ACCEPTED

 

57. Subject: SST/20 Question

Date: Sun, 5 Oct 97 19:21:53 EDT

From: Joel Malman <malman@BBN.COM>

 

Group,

 

I finished building an SST for 20 meters today. It seems to work fine..

(first QSO: PA0IJM). Problem: every time I power the SST on, and the AF

gain and RF gain happen to be ALL the way up I get this very (*VERY*) loud

blast of noise.

 

If I power the SST on, at any other AF or RF gain setting, the rig is

fine .. no loud blast.

 

Anyone have a clue??

 

thanks,

 

/joel wa1qvm

 

58. Subject: SST-40

Date: Mon, 06 Oct 1997 23:21:26 EDT

From: kc4mhm@juno.com (ed miller)

 

Gang:

Got the new SST-40 on the air this P.M.

 

Heard AR station calling CQ and he answered me on my first response. He

was QRO so I had good copy on him, he gave me a 599 for my 2 watts. Who

could ask for any more?

Had to change C10 to 22pf to increase side tone to where I like it.

Tunning range is 7.030 to 7.039. Would rather have 7.035 to 7.043, will

work on that later. Hope the fox is below 7.040 tomorrow nite.

See ya'll tomorrow; Tally Ho.

73 de Ed

KC4MHM@juno.com

 

59. Subject: sst (Oct 1996 Info from Wayne Burdick)

Date: Sun, 20 Oct 1996 21:27:45 -0800

 

SST Progress Report #2: built-in keyer option (the

"KC0")

 

L.Svec,W.Burdick (svecbrdk@well.com)

Thu, 17 Oct 1996 23:42:51 -0800

 

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For those interested in upcoming SST kit:

 

I thought I'd give you a little more detail on the promised SST keyer

option, as well as a couple of other SST notes. The SST is so compact

that

I had to plan ahead for where the keyer, speed control and paddle jack

will

go.

 

By the way: I'm doing the KC0 on my own at this point--it isn't clear

whether I or NorCal will supply it. Also, it is intended just for the

SSTs--it is not a new "product." The KC0 name is just a reminder of its

ancestry. More on that in a minute.

 

Someone mentioned the pending availability of a keyer based on the new

PIC

12XXX series 8-pin SOIC microprocessor. For those who don't know, SOIC

=

small-outline IC = SURFACE MOUNT. Thank you, in advance, for providing

the

world's smallest keyer, and congratulations for being first to announce

a

ham product based on the new PIC 12XXX series.

 

The SST keyer uses the same chip, except it's the through-hole version

(i.e., it has 8 leads--same form factor as an NE602AN or LM386N). In my

experience SOIC parts are hard to see, much less solder, so I'm glad

someone else is doing the dirty work. In fact, I'll bet Jeff Anderson

(of

40-9er-in-a-9V-battery-can fame) can't wait to get his hands on one! On

the other hand, if consumer electronics conspires to make through-hole

parts go away, noone over 25 will be able to build kits anymore. ;(

 

KC0 Features

 

Back to the KC0: I'm porting the KC1 code to it, less the frequency

counter, which isn't needed on the SST since the dial only covers 20 or

30kHz and it will be calibrated by the user. There's also no message

memory, since the PIC 12XXX parts don't have any EEPROM (yet). When

they

do, probably in 1997, the KC0 will get retrofitted with message memory.

 

The KC0 includes an input pin that lets you choose between two Iambic

keying emulations, just like the KC1: Curtis mode "A" and Super CMOS

mode

"B". The latter is similar to Curtis mode B except the timing is easier

to

use (thanks again to Bob Finch for pointing this out!). Ya know, I

still

think mode B started off as firmware accident, perhaps on a night when

the

lighting was bad and there was a pet Iguana on the keyboard. :) But

then,

I learned on an old 8044 with mode "A", so I may be a distant relative

of

the Iguana. But there it is--mode B if you want it.

 

The KC0 will come with a VERY small PC board (< 1" square) that has the

micro, 1/8" paddle jack, and the speed control (a small pot, not a

button). This board will plug right into the SST board using only 3

wires,

and it will mount to the rear panel with holes provided. The keyer jack

holds it to the panel and the speed pot's shaft acts like a stop to the

board from spinning around :)

 

Other SST News

 

I'm getting closer to nailing down the custom enclosure size, for those

who

want one. It will be 2.5" wide and 4.5" deep, and just about 1.3" tall.

The 9V lithium battery fits inside, and uses 9V battery clips on the PC

board itself--no more floppy 9V battery connector with wires! In fact,

except for the pots and some happy electrons, the SST is a no-moving

parts

radio :)

 

Note on the SST's audio output: it WILL drive a speaker, unlike the

40-9er, although I'll still recommend headphones for minimum distortion.

 

 

73,

Wayne

N6KR

 

60. Subject: SST 20 mods, thoughts...

Date: Thu, 9 Oct 1997 16:37:22 +0100

From: Frank G3YCC <g3ycc@gqrpclub.demon.co.uk>

 

I must say I am delighted with the SST (20m) rig, but just pondering

some ideas for mods:

1 It could do with a bit more on the Rx side. Wondering whether to

add a dual gate MOSFET preamp or perhaps a balanced 741 audio preamp.

2 VFO thoughts - I obtained a 16mhz xtl and thought that instead

of the VXO, a NE601 (or 612) mixer/osc using the 16mhz and mixing with

that a 2mhz VFO, which should be pretty stable at that low freq. A

simple tuned cct would clean the o/p up and perhaps a small rf amp to

boost the o/p. This could be built in or external. The VXO could be

either left in and switched off if the VFO is used, but would be there

for compactness if required. If the VXO is not needed, it could be

modded as the VFO on 2mhz +/-.

3 The RF gain on the back is never used here, so, I could use that

as a speed control for a built in keyer...

4 The pwr switch on the back also is redundant in my case, so it

could be used to either switch the VXO on/off and activate the VFO

(above).

 

With the standard varicap mine tunes 14.046 - 14.056 about. Funny thing

is though, with the tuning pot at either end of it's travel, the VXO

stops working, any ideas?

The output is exactly one watt on the d/load-pwr meter.

--

Frank G3YCC GQRP 042

QRP Web Page: http://www.gqrpclub.demon.co.uk

Packet: G3YCC@GB7HUL.#15.GBR.EU

 

61. Subject: Re: SST 20 VXO range

Date: Fri, 10 Oct 1997 14:30:35 -0400 (EDT)

From: G3TUX@aol.com

 

Hallo Frank!

 

I still have not got around to building my SST/20 - but my pal, Hanns DK9NL,

has completed his. He replaced D4 with a BB205B and now tunes from 14041 to

14063. Hope this info is helpful.

 

I have downloaded the SST mod. file from your web site - many thanks.

 

Hope to see you at Rochdale. 73 Chris G3TUX

 

 

62. Subject: sst 40M audio problems-howl (See Number 68)

Date: Sun, 12 Oct 1997 10:45:22 -0400 (EDT)

From: PULLJIM@aol.com

HELP ! My 40M SST has a howl or some kind of tone on receive. It draws

17.5M.

Parts are placed correctly, and there are no solder bridges.

I have tried several different head phones, all have the same results. The

howl is clearly heard even with the volume turned down. As volume is

increased the howl is louder, and it draws 22M. Anyone have any ideas ?

 

63. Subject: Re: SST Mods URL

Date: Sun, 19 Oct 1997 17:09:00 -0700 (PDT)

From: "David D. Meacham" <ddm@datatamers.com>

Frank,

The Fall issue of NorCal QRPp has my SST mods article on page 10. (W6EMT

is listed on the cover as the author, by mistake. It should be W6EMD.)

It's not a web site, but it has several mods!

 

I understand that the mags will be shipped within the next two weeks.

72, Dave, W6EMD

 

64. Subject: Re: SST: Greatly improved VXO Range (thanks, N6GA!)

Date: Thu, 23 Oct 1997 23:37:35 -0700 (PDT)

From: Alan Kaul <kaul@netcom.com>

Hi Wayne ... I did the same thing as CAM and have about 18kHz tuning.

Article describing ''super VXO'' written by a JA and posted to this list

about a year ago, but the Japanese version uses a higher Q coil (slug

tuned from about 4uH to 7uH) according tov the post. I still have a copy

of the original if anyone is interested.

 

There's another version on one of the 7L-amateur websites (also have it

bookmarked somewhere) and he also uses a shunt resistor of about 10K

across the coil.... let me know if anyone wants to see either.

 

73/72 de alan, w6rcl

 

65. Subject: SST: Greatly improved VXO Range (thanks, N6GA!)

Date: Thu, 23 Oct 1997 23:01:47 -0800

From: svecbrdk@well.com (L.Svec,W.Burdick)

 

Hi all,

 

Hope this hasn't already been posted--if it has, I missed it.

 

At Pacificon, Cam Hartford (N6GA) showed me his 20 meter SST with a neat

twist: over twice the usual VXO range! How did he do it? By simply

paralleling a *second* VXO crystal of the same frequency across the first.

Cam said he got the idea from an article, but I didn't catch where or when

it was published. The basic idea is that the second crystal lowers the

circuit Q. Perhaps Cam will fill us in on more details.

 

In addition to adding the crystal, he had to reduce the size of the series

RF choke to keep the range from being too large (!). At some point that

tiny pot is too small to tune signals in.

 

I'm hoping to convince some of you SST owners to try this on your own SST.

Since all of the VXO crystals used are standard microprocessor frequencies

available from Digikey, you shouldn't have trouble getting a "sample"

(wink, wink) of one or two crystals from them.

 

If you try this experiment, please let me know, whether you do it on the

SST or any other rig. Since I'm revising the SST manual for the next run,

I'd like to include as much information as possible about modifications

that increase the rig's performance.

 

Have fun!

 

73,

Wayne

 

66. Subject: SST VXO Range (Thanks W6RCL!)

Date: Sun, 26 Oct 1997 07:30:15 -0800 (PST)

From: camqrp@cyberg8t.com (Cam Hartford)

Gang -

 

Sorry for being slow on the draw here, but sometimes the digests just pile

up. It was Alan Kaul, W6RCL, who gave me the idea for using the Japanese

wide-Range VXO in the SST.

 

In stock form, my 20 meter SST tuned about 16 KHz. Alan sent me one of the

postings from QRP-L that he had collected on the subject of the wide range

VXO, so I thought I'd give it a try.

 

I sent off to Mouser for a couple 18 MHz crystals and several small molded

chokes like the ones used in the SST. I got a variety of small values so I

could use them singly and in series to get small steps from 1 to 10 uH.

 

At this point I'll leave out lots of gory details about hundreds of

different crystal/inductor combinations except to say that with the two

Mouser crystals in parallel and the original 6.8 uH inductor in the circuit,

the tuning range was about 70 KHz! This was way too much range for a

one-turn pot, and the thing was drifty.

 

Wilderness was kind enough to send along two different varactors with the

kit, an MVAM108 and an MV209, so we could choose different frequency ranges.

I ended up using both. My rig is now configured like this - 1) A toggle

switch on the front panel to chose between the two varactors; 2) two of the

Mouser crystals in parallel (one in the original X6 board location, the

second one tacked soldered on the bottom of the board parallel to the

first); and 3) the final value of RFC 3 is 4.8 uH.

 

This configuration gives the following frequency coverage range - Lo

position, 14.026 to 14.058, and Hi position, 14.056 to 14.070. I could have

gone with a little more inductance and covered 14.000 to 14.070, but this is

a bit much for only two turns of the tuning pot. As an example, a 5.6 uH

inductor gave tuning ranges of 13.982 to 14.047 and 14.039 to 14.065,

respectively.

 

The downside is that it does drift more than a normally configured VXO. I

haven't done extensive drift tests, but a quick check reveals the following:

in the Lo position, which pulls the crystals farther from their design

frequency, it drifts about 200 Hz in the first twenty minutes, but is fairly

stable from then on. The High position, which covers frequencies much nearer

the crystal frequency, shows only about 60 Hz drift from startup.

 

All of which suggests that the range can be extended quite a bit by using

two parallel crystals. The tradeoffs are increased drift, along with a

greater range to be handled by a one-turn pot. Miniature ten-turn pots, anyone?

 

72/73,

 

Cam N6Ga

 

67. Subject: SST XCVR SURVEY: your input needed for next release

Date: Wed, 19 Nov 1997 09:14:15 -0800

From: "L.Svec,W.Burdick" <svecbrdk@well.com>

Hi gang,

 

The SST has passed its field-test, and will now become a permanent part of

the Wilderness Radio product line. I'll be making a number of minor

adjustments to the PC board, enclosure, and circuitry, based largely on

comments sent to me by INET and NorCal QRP club members. Thanks again for

your help!

 

While I think I've got everything nailed, I wanted to get one more round of

input from those of you who modified the SST circuit in some way, either to

fix a problem or to add new features. Even if you have only duplicated

someone else's modification, I'd like to hear from you. Please send your

answers to the questions below directly to me at svecbrdk@well.com. No

need to copy them to QRP-L unless they are relevant to the entire group

(which I imagine has by now heard plenty of SST stories :)

 

The revised SST will be available after Jan 1, 1998, and the price is $85.

As before, it will be offered for 40, 40/novice, 30, and 20 meters. If

you'd like more SST information or a Wilderness Radio catalog, please call

Bob Dyer, KD6VIO at 650-494-3806, or send him e-mail at:

qrpbob@datatamers.com.

 

72,

Wayne, N6KR

 

* * *

 

1. Did you build any accessories into your SST, such as a

KC1, Buzznot, etc.? If so, please describe any modifications

that were needed, how well it worked, etc.

 

2. Describe any modifications that you made to the SST's VXO:

 

3. Which varactor diode did you use?

 

___MV209 ___MVAM108 ___BOTH

 

4. What is your VXO frequency range?

(List two ranges if you used both varactor diodes)

 

5. Describe any modifications that you made to the receiver:

 

6. Describe any modifications that you made to the transmitter:

 

7. Please list any other changes that you'd like to see made

to the SST in the future:

 

 

68. Subject: SST Coyote Killer -- One Easy Step

Date: Mon, 24 Nov 1997 20:59:36 -0800

From: "L.Svec,W.Burdick" <svecbrdk@well.com>

 

A long, long time ago (well, about five months) someone on the list

suggested that the cure for the SST's "howl" problem was to put an

electrolytic cap between pin 7 of the LM386 and ground. He was right!

Normally you don't need a cap here if you run the '386 from a regulated

supply, which is why I left it out. But it turns out that the LED-based

AGC circuit I'm using creates enough of a feedback loop that in some cases

it causes trouble. The pin 7 bypass cleans it up.

 

Other suggested solutions took two or more parts, so this single cap method

was the one I preferred. After all, I'm genetically programmed to try to

keep parts count low :) and there ain't much room left on the SST's PC

board.

 

I never could duplicate the problem at my QTH, so I enlisted the help of

several SST owners to try this, and the results are in: we're

three-for-three. Even 1uF will do it, but I already use a 2.2uF cap

elsewhere in the rig, so 2.2 it is. Safety margin doesn't hurt.

 

So, if you still have a coyote in SST's clothing, kill that critter now

with a "2.2" gauge. You can use any cap with a 10V or higher rating. The

smaller ones will actually fit on the bottom of the PCB.

 

Once again the INET troops have come through--thanks!

 

72,

 

waYne

 

69. Subject: Expanded SST Freq Coverage

Date: Fri, 28 Nov 1997 18:14:05 -0700

From: Steve Galchutt <n0tu@webaccess.net>

 

I just tried strapping another 18 MHz rock accoss the other one in my

20m SST and I couldn't believe my eyes the the counter said 14,004 to

14,057! WOW...that almost 50KHz hmmmm... now if I can just move it up to

above 14,060! Tunning is a little rapid. Maybe a 10 turn pot would

solve this? But my counter just died @#$*&! ....well time for something

else...like XC skiing. We just got about 15" of new white stuff last

night here in Colorado. sush....sush....sush

--

CUL Steve/n0tu . .

Solar powered QRP/CW

Monument, CO..........email:N0TU@webaccess.net

 

70. Subject: SST problem

Date: Sun, 14 Dec 1997 19:52:20 -0500 (EST)

From: Chris Cartwright <ccart@dns.vidtel.com>

 

Just wondering what the most common parts for failure are on an SST that

had been hooked up to a 7AH gel cell backwards. I'm asking for a friend,

really, yeah that's it... I... err... He knows the RFC in the final is

burnt open, the zener and final don't look to healthy, but there is also

no RX. The KC1 seem to function, but is confused, and audio from the SST

(from the KC1) is very weak.

 

I've told him he should put a fuse and diode in the power jack. I'll make

sure he does when *I* "help" him fix it. 72 es tnx

 

All kidding aside, I did smoke it, and have and unbuilt 40M SST so I have

"spares" of almost everthing. If no one have been through this before

I'll post the casualty list when I get it back together, and it will have

a fuse and diode this time :) I would like to get the list down to

individual parts instead of "shotgunning" it to get it going. I have the

schematic out now... making a list and checking it twice.

 

-- Chris Cartwright, Technical Engineer | ccart@vidtel.com --

-- N3XRV ARRL-VE QRP WAS 27/10(w/c) | http://dns.vidtel.com/~ccart --

-- QRP-L #655 NORCAL #1891 QRP-ARCI #???? NJ-QRP #105 LIQRP #???? --

 

 

71. Subject: Re: SST problem

Date: Mon, 15 Dec 1997 00:18:41 -0500 (EST)

From: Chris Cartwright <ccart@dns.vidtel.com

 

Muuuhaaaahhhaaa! IT LIVES! <big 'ol giant grin> I got a nice note from

NA5N recanting how he killed Dougs SST :) He was right on all counts,

Zener, choke and trace fried.

 

It took five parts, and all of them were "in stock". The 15uH choke in

the final had been vaporized so I rewound the toroid, and measured it

(six turns instead of ten just like last time). The zener in the output

circut seemed to take the brunt of things. It looked OK from the outside,

but it had turned into a 0 ohm resistor. I replaced the final just on

general principle, it ohmed out a little different than the new one and I

had a bunch of 3553's around anyway. The 78L08 "fused" most of the 602's

and the VFO, it shorted its input to ground and was only putting out 1V,

saving all the "expensive" parts.

 

I had pulled out all the bad parts, put the new 78L08 in, and fired it up

to see if the RX worked, Jackpot! W7 calling CQ, now where the paddles?

Oh yeah, this thing ain't got no finals in it, pooh. Could have been

worse, could have been a JA at 5NN calling :) Put the final, zener, and

coil in, cranked it up 2W out just like before. Now for the KC-1...

 

The regulator had gone QRT, put the new one in and turned the radio on,

hmm... no frequency readout, bummer, must have killed it really dead.

Then I accidentally leaned on the key, the familiar .---- .---- -. came

out. Cool, I didn't kill it but it still didn't work. Found the trace

that I was using to ground the keyer was toast, patched the trace and all

is well. (Holding the key closed also grounded the KC-1 so that's what

made it run)

 

Of course by the time I got it back together the band had folded up, guess

I'll have to fire it up tomorrow night, right after I put that fuse in...

Thanks Wayne for a sturdy little rig, I figure even it I had to go out and

get the parts I'd be out less the ten bucks. 72 es cu on 30 at 100mw!

 

-- Chris Cartwright, Technical Engineer | ccart@vidtel.com --

-- N3XRV ARRL-VE QRP WAS 27/10(w/c) | http://dns.vidtel.com/~ccart --

-- QRP-L #655 NORCAL #1891 QRP-ARCI #???? NJ-QRP #105 LIQRP #???? --

 

72. Subject: XMAS SST and winding Toroids.

Date: Mon, 5 Jan 1998 10:48:26 -0500

From: Peter_Simpson@3com.com

 

Well, not really. I bought it last summer, but

last week, I dug out the box and decided I had

enough uninterrupted time to build it.

 

Wayne has done a super job with this rig! It went

right together in about three hours. 4 toroids,

but they are easy to wind if you know the toroid

magic and have the secret toroid tool I learned

about by reading QRPp :-)

 

It came right up! Alignment took about 10 minutes.

All you need is a voltmeter and a power meter or CB

type SWR meter. I still can't believe the rig was

so easy to build and align.

 

I haven't even painted the case yet, because I was

so eager to get it on the air. Heard the WO3B fox

with it, but was unable to work him.

 

No, I don't get anything for this "celebrity"

endorsement, but I think I got a super rig for the

price, and I would recommend the SST for a first time

QRP rig builder because it's so easy to get on the air.

 

Cheers,

Peter, KA1AXY

 

P.S.: Toroids are easy...if the wire goes through

the center of the toroid, it counts as a turn. Make

the secret toroid tool by bending a paperclip into a

hook and using it to pull a loop of wire through the

center of the toroid, until the free end slips through.

Count one turn each time the tool goes through the toroid.

 

[now I'll probably get in trouble for spilling the beans :-]

 

73. Subject: Re: SST Frequency Range Modification

Date: Wed, 21 Jan 1998 23:36:53 -0800 (PST)

From: "David D. Meacham" <ddm@datatamers.com>

 

Paul,

I tried it and had unsatisfactory results. Others have had good results.

I think it has to do with how well the two xtals are matched. I had only

one to try, and did not compare the two.

72, Dave, W6EMD

 

 

74. Subject: SST (Discrepancy on rfc-2 (1mh)

Date: Sat, 31 Jan 1998 20:21:19 -0800

From: dave_epps@juno.com

 

Is anyone else building a SST?

A little discrepancy. On rfc-2 (1mh) the parts list reads color code of

blk-brn-red. The rfc furnished reads brn-blk-red.

I am assuming that brn-blk-red really is 1mh and the parts list is

wrong.

Am I right?

This is my first project with my new Edsyn 951sx soldering station that

Tech Amer had on sale and my soldering looks better than ever.

dave ab5pc fresno, ca.

 

 

75. Subject: Just-built SST and Frequency Range

Date: Tue, 3 Feb 1998 10:47:48 -0800

From: dave_epps@juno.com

 

Sure like the operation of the rcvr, although it seems to only tune 3 khz

and should tune 10. Has anyone else solved this?

I don't have a counter yet (anyone recommend one?), so I listen to the

vfo in another rcvr and it tunes 11.043 khz to 11.046 khz.

tks dave ab5pc fresno, ca.

 

 

 

76. Subject: just-built sst and Frequency Range answer

Date: Tue, 3 Feb 1998 14:23:29 -0800

From: dave_epps@juno.com

 

Re my earlier post of 3 khz tuning.

I just changed the varactors. Wayne was kind enough to supply another one

with the kit.

I mounted it on the bottom of the board "easier" and it worked better

than

I expected. It lowered the vfo 10 khz on the bottom and 5 khz on the top

increasing

the tuning range greatly from before.

Am really happy with the little rig. The rcvr is far better than I

expected.

dave ab5pc fresno, ca

 

77. Subject: SST Mods - xtal filter

Date: Wed, 04 Mar 1998 20:12:08 EST

From: k7sz@juno.com

 

 

I was just wondering if there is a source of mods for the SST by

Wilderness Radio? I have a 40 meter version and would really like to

expand the tuning range without resorting to swtiching between two

varactors or adding a 2nd xtal. Has anyone tried ordering an AT cut

xtal from Jan or Bomar and using this in place of the xtal supplied by

Wilderness? If memory serves, the AT cut xtal will provide the maximum

amount of tuning range.

 

The xtal filter in the receiver is much too narrow for my liking and I

tried replacing C6 & C9 with 68 pf caps and C7 & C8 with 180 pf

caps...this helped but I needed a wider passband. So, I tried a 56 pf for

C6 & 9 and 150 pf for C7 & 8. This is much better. These ratios are all

basically 1:3 so I don't see why 47 pf and 120 pf could not be employed

for those who desired a wider bandwidth.

 

rich K7SZ

 

 

78. Subject: Another SST on 20 meters -- and a few questions...

Date: Sat, 11 Apr 1998 20:07:27 -0500

From: "Fred Ringwald" <fred@innocent.com>

 

After letting it sit on the shelf for way too long, I finally built my

20 m SST this morning. After stuffing the board and mounting the case

front, back, and bottom, I fired it up, tuned for minimum smoke, and

found the initial signs encouraging. When I peaked C1, I heard code,

and wondered if this was going to be one of those rare conditions when

my kit worked correctly the first time, with no need for

troubleshooting!

 

Well, when I proceeded to the transmitter alignment, all was not so

well, as I had zero watts out.

 

After the visual inspection, and voltage checks, I found that all DC

voltages for U4 were correct, but that on U5, Pins 1, 5, and 8 read

several volts rather than 0 as specified on the table. U4 had all the

right voltages. The initial indication was to suspect U5. However, a

scope look at Pin 3 of U5 showed no signal at key-down. Tracing back

to U4, Pin 4, I also had virtually no signal at key-down. Checking

the U4 oscillator circuit, U4 Pins 7 & 8 showed a garbled, minor

signal, not a nice sine wave.

 

I decided to try replacing U4 with an NE602 that I had on hand. Yes,

the plated through holes made it a little difficult, but I used the

old technique of snipping all the IC leads and removing them one by

one, rather than applying so much heat so as to destroy the board.

After power up, I still had no power out as indicated on my OHR QRP

Wattmeter, but the scope showed encouraging signs. I had a sine wave

on U4, Pins 7 & 8, and also on Pin 4. I followed the xmtr alignment

procedure and got about one watt out. Since my bench supply was a

little over 12 volts, and not 13.8, I figured that I was doing okay.

A few minutes later, I responded to K4QIL's CQ from near Myrtle Beach,

SC, and we had a short QSO despite the efforts of QRO QRM.

 

The lingering question is: Why does U5, Pins 1, 5, and 8, show

appreciable voltage, and not 0 as the assembly manual table suggests

they should??

 

Also I found that with the MV209 at D4, I got a tuning range of

14.043 - 14.058 MHz, rather than the spec range of 14.046 - 14.064

MHz.

 

Trying the MVAM108, I got 14.032 - 14.051 MHz, which was a little

wider band coverage, but further away from the 20 Meter QRP calling

frequency.

 

Does anyone have any advice on how I can use the wider band coverage

of the MVAM108, but get 14.060 near the center of the tuning range??

(Or at least within the range by at least 5 KHz??

 

Finally, since I likely missed this discussion when I was

significantly distracted and couldn't monitor QRP-L shortly after the

SSTs came out, does anyone have any noteworthy experience regarding

mods to this rig to improve it? I am particularly interested in the

9V battery option, band coverage ideas, and I do plan to install a

KC-1, as it has been awhile (apart from today) since I have operated a

straight key. I guess I need to participate in straight key night

sometime!!

 

Thanks for the bandwidth, and thanks in advance for any help you might

be able to offer.

 

73s,

 

Fred Ringwald, AB0AE

fred@innocent.com

 

 

79. Subject: Re: Another SST on 20 meters

Date: Thu, 16 Apr 1998 09:27:13 -0700

From: "L.Svec,W.Burdick" <svecbrdk@well.com>

 

Hi Fred,

 

Thanks for the input on the SST. I'm looking at the voltages you mentioned

to see if there's a mistake in the table, and I'll get back to you on this

later.

 

As for the frequency coverage:

 

There is more variation than I thought there would be in the VXO crystals I

selected for the SST. I was constrained to use off-the-shelf frequencies

to keep the cost of the kit low, and some people have ended up being just

shy of the 14.060 mark with the 20-meter unit. (It still amazes me that

there are standard microprocessor crystal frequencies available that get us

close to the QRP frequencies on all three bands...)

 

There are several possible solutions, and I'll leave it to you to choose

which way to go. We may change the kit in the future to make this easier.

 

1. The simplest (but not the least expensive) thing you can do is order a

custom crystal from ICM, JAN, etc. Specify an HC49-can crystal with a

frequency about 5 kHz above the highest intended frequency of operation.

Custom crystals are on the order of $10, although this varies widely

depending on what lead time you request and how many you order. If the SST

remains a popular kit, we could conceivably use a custom crystal for 20

meters in the future, but only if the volume is high enough to keep the

crystal cost low. (In large quantities, such a crystal might go for $2,

but only with a 3-month lead time!)

 

2. The basic issue with a VXO is minimizing capacitance across the crystal

to extend the high-frequency end of the range. The MV209 has a fairly high

minimum capacitance--something like 10pF at 8V--so you could try a

different, lower-capacitance varactor here. The MV2104 comes to mind, but

check out the Motorola RF devices catalog (on the web), as well as Zetex

(also on the web). You can also reduce the size of the choke in series

with the crystal: the smaller the choke, the higher the high end of the

range (in general), with a corresponding reduction in tuning range.

 

3. You can try to put two identical VXO crystals in parallel, one on the

bottom of the board soldered directly to the leads of the one on the top.

If you do this, you can greatly extend the tuning range; in fact it will

tune farther than you want in some cases, necessitating a reduction in the

size of the choke. I haven't tried this on the 20m unit, but it would be

worth expermimenting to see what you get. What you don't want to do is

tune more than about 30kHz. The small pot on the SST is easiest to use

with a 10 to 20kHz range.

 

4. As I mentioned, reducing capacitance at the high end is everything.

You may want to experiment with a small air-variable capacitor as a

substitute for the varactor tuning, in which case the pot will be replaced

with a panel-mount variable capacitor. Make sure you use one with a really

low minimum capacitance, perhaps 2 to 3 pF.

 

I hope one of these techniques does the trick! Let us know your results--

 

73,

Wayne

N6KR

 

 

80. Subject: SST AF Gain and Monitor Tone Problem identified

Date: Tue, 12 May 1998 23:05:19 -0600

From: "mike newbold" <newbold@cmn.net>

 

i just assembled a wilderness SST rev. B. The kit went together great and

is working, but in the digital portion of twenty mtr. i.e. 14.065 to

14.070. should be 14.050 to 14.060. Also I have to crank the AF almost all

the way to hear anything. And by then the monitor tone is way to loud. any

one have any suggestions..... please. Catch a

wave 72 73, Mike K YO newbold@cmn.net

 

 

 

81. Subject: Frequency Range Adjustment Parts change

Date: Sun, 17 May 1998 19:20:36 -0600

From: "mike newbold" <newbold@cmn.net>

Thanks everybody for you help, my SST is now up and running. pulled the MV

209 and replaced with the MVAM108 varactor. now works from 14.052 to

14.063. my son added heat with a soldering iron and i pulled. the

toothpick won out over the dental tool clearing the hole. The monitor

volume is still too loud but i was happy to make my first qso with WD0GXI,

Wayne in Carthage Mo. 519 booth ways. tough copy but pulled off the

inaugural qso. second qso was with KE4DDI, Rick in Aiken, Sc. I got a 569.

The best part was when he sent "rig hr also SST great rig". after a 40

min. qso i tended to agree with Rick ... great rig. this is a great group

and thanks again to all who helped.

Catch a wave 72 73, Mike K YO

 

 

 

82. Subject: SST not quite there, help

Date: Tue, 12 May 1998 23:05:19 -0600

From: "mike newbold" <newbold@cmn.net>

 

i just assembled a wilderness SST rev. B. The kit went together great

and is working, but in the digital portion of twenty mtr. i.e. 14.065 to

14.070. should be 14.050 to 14.060. Also I have to crank the AF almost

all the way to hear anything. And by then the monitor tone is way to loud.

Any one have any suggestions..... please.

Catch a

wave 72 73, Mike K YO newbold@cmn.net

 

Subject: SST BLUES NO MORE

Date: Sun, 17 May 1998 19:20:36 -0600

From: "mike newbold" <newbold@cmn.net>

 

Thanks everybody for you help, my SST is now up and running. pulled the

MV209 and replaced with the MVAM108 varactor. now works from 14.052 to

14.063. my son added heat with a soldering iron and i pulled. the

toothpick won out over the dental tool clearing the hole. The monitor

volume is still too loud but i was happy to make my first qso with

WD0GXI, Wayne in Carthage Mo. 519 booth ways. tough copy but pulled off the

inaugural qso. second qso was with KE4DDI, Rick in Aiken, Sc. I got a

569.The best part was when he sent "rig hr also SST great rig". after a

40 min. qso i tended to agree with Rick ... great rig. this is a great

group and thanks again to all who helped.

Catch a wave 72 73, Mike K YO

 

 

83. Subject: Moving SST to 15mtrs

Date: Wed, 1 Jul 1998 13:01:40 -0600 (MDT)

From: marion@montana.com

 

I was easily able to move a 20mtr SST to 15 mtrs and it is

Working great. Changes to the VXO and output filter and XMIT mixer where all

Thats required. Covers 21.050 to 21.070 with single varactor. Thought I would

Let those who had been thinking about it know it works great.

72 Roy AB7CE

 

Date: Wed, 1 Jul 1998 17:36:38 -0600 (MDT)

From: marion@montana.com

At 01:48 PM 7/1/98 -0600, you wrote:

>marion@montana.com wrote:

>>

>> I was easily able to move a 20mtr SST to 15 mtrs and it is

working

>> great. Changes to the VXO and output filter and XMIT mixer where all

thats

>> required. Covers 21.050 to 21.070 with single varactor. Thought I

would let

>> those who had been thinking about it know it works great.

>> 72 Roy AB7CE

 

Sounds good Roy! Do you think it could be made to work on 10 meters?

72, Tom WB5QYT

 

--

I have not explored this to a success. The component values at twenty

Were close enough to work at fifteen for most of the circuits, except those

Three cicuits. So far moving to ten has involved major circuit changes.

However, moving to 17mtrs is as easier than moving to 15mtrs. Roy AB7CE

 

84. Subject: Move 20mtr SST to 15mtr: component values

Date: Thu, 2 Jul 1998 11:26:25 -0600 (MDT)

From: marion@montana.com

DOZENS of requests on moving 20mtr SST to 15mtrs, so here is

how I did it. If you make changes or improvements other than these, please

let me know so I can use them as well.

 

LOWPASS FILTER

These are standard values from any handbook

L2, L3 = 11turns #26 on T37-6(yellow)

C34, C36 = 150pf, I used silver mica

C35 = 270pf " " "

 

XMIT MIXER

L1 = 18t #26 on T37-6(yellow)

C27 = 30pf, I used ceramic NPO

VXO

X6 = 25mhz crystals. I used two, one on top, one under

board.

RFC3 = 23t #26 on T37-2(red). This was a critical value

for proper oscillation and range. You may have to adjust

a turn plus or minus, or compress or spread turns to

adjust to desired tuning range.

 

PA

2.2uh molded choke from base of Q2 to ground.

 

As above changes were all that was neccessary to put it on 21.050 to

21.070 with the MVAM108. Output was 1 watt, so I put in MRF237(ECG341) for two

watts out. Its also very easy to move to 17mtrs by using same approach.

Good luck and 72. Roy AB7CE

 

85. Subject: sst vxo

Date: Thu, 2 Jul 1998 18:20:44 -0600 (MDT)

From: marion@montana.com

 

I put two crystals in both of my SST's to extend vxo range. One

Is 20mtrs and the other is one I moved to 15mtrs. With the MVAM108

varactors I was able to get about 20khz range. I was experimenting with different

varactors I had on hand. Was not getting much difference. Then I tried

a MV1404. WOW! The 20mtr version is covering from 14.013 to 14.064. The

15mtr version is covering from 21.039 to 21.073. Scope shows solid waveforms

across oscillator ranges. I don't know where to get them. They don't

show up in my cross reference, so I don't even know what they are rated as.

Mine were in a envelope of a dozen, that was in one of Dans Small Parts

20lbs of parts for $10.00. They are not listed on his current page. If any one

knows what they are rated or where to get them, they might inform the rest of

the list. 72 Roy AB7CE

 

86. Subject: SST sidetone

Date: Thu, 9 Jul 1998 12:53:57 -0600 (MDT)

From: marion@montana.com

 

After unsuccessfully trying various methods to reduce the

Sidetone on my SST, I decided to ask someone who knows the best way to go about

it. That someone was Wayne, N6KR, The rigs designer. The following info

works with mine with some values adjusted for best performance.

--------------

Hi Roy,

 

Usually there is a good balance between the incoming signals and the

sidetone in the SST. But you're right--if you have to turn it way up,

the sidetone gets loud.

 

The only sure-fire way to mute the sidetone to a lower level is to

insert a low pinch-off JFET like a J201 into each leg of the audio connection

from the product detector to the audio amp. This is how I do it in the

'40A. Actually you can probably find other JFETs that will work; J310s are

mostly low pinch-off, too. MPF102s will work if you hand-select them for low

pinch-off.

 

The source leads go to the '602 and the drains to the original capacitors

that go to the '386. Tie the gates together and add a 1 to 10M pull-up

resistor from the gates to one of the source leads. Next, connect a

diode from the gates to the key input. Test the circuit thus far by keying

the rig: you should hear ZERO sidetone at this point, because pulling the

gates low cuts off the JFETS, making them look like an extremely high

resistance. If you hear a click on keydown, put a resistor (start with 1K) in

series with the gate diode. If you hear a click on key-up, add a capacitor

from gates to ground; start with about 0.1uF and see if you can go smaller.

(It will depend on the pull-up resistor; 10M and .047 work well in most

cases.)

 

Once this much is working, you can add a resistor *across* one of the

JFETs (source to drain) to allow some sidetone to sneak through--as much or

As little as you want. It will take a large resistor, something like 1 to

15M in my experience.

 

Let me know if this does it! You might also post this message to QRP-L

If you have good results.

 

Thanks & 73,

Wayne

N6KR

-----------------------------

 

I was able to use some bargain J305s, no matching effort was

done. They completely muted the sidetone. I did not use the resistor to

bypass some of the tone, as I have the KC1 installed, so I use its sidetone.

In my case the pull up resistor is 2megohms, the capacitor to ground is

.1mfd. Keyline is a 1k resistor in series with 1N4148 switching diode. No

clicks or pops, smooth QSK. Did loose some of the ability to hear other stations

at the same time as in transmit, but don't have to juggle the volume all

the time now either. A big thanks to Wayne. 72 Roy AB7CE

 

 

87. Subject: moving SST to 15mtrs

Date: Fri, 10 Jul 1998 10:17:24 -0600 (MDT)

From: marion@montana.com

 

I recently posted info on moving 20mtr SST to 15mtrs. Heres

Another component change, RFC1 to 2.7uh(or close to it). Improves match to

Filter and recieve. 72 Roy AB7CE

 

 

88. Subject: TiCK Audio in SST?

Date: Tue, 14 Jul 1998 22:00:23 -0600

From: "Steve Galchutt" <n0tu@webaccess.net>

 

Where did those of you who put a TiCK keyer in your SST hook up to the

Audio chain. I'm afraid of unbalancing my LM386 by dumping it in on pin 2 or

3?

Where is best? 72...Steve

______________________________________________

n0tu - solar powered QRP & wire antennas @ 7,200' ASL

Monument,Colorado - Grid Sq DM79nb

 

89. Subject: Mounting a Tick/K8+

Date: Sun, 19 Jul 1998 21:27:05 -0600

From: "Steve Galchutt" <n0tu@webaccess.net>

 

Discovered a neat trick tonite.

 

While trying to install a Tick/K8+ style keyer in my SST, I saw I was

cramped for space and no room for my keyer which was made up on a

little piece of 1"x 1 1/2" perf board and needed a place to reside. Plus, I'm

thinking of adding some other goodies to the SST and want to leave

rooom for them. So I decided build another keyer and mount it on the back end of

the keyer jack(inside the case of course). I just epoxied the a 8 pin IC

socket to opposite end of the mounting hardware on the jack. And now I'm

wiring it up and hope to have it working for the BB event. Never dreamed I would

have a keyer almost smaller than it's paddle jack! How times change.

72...Steve

______________________________________________

n0tu - solar powered QRP & wire antennas @ 7,200' ASL

Monument,Colorado - Grid Sq DM79nb

 

 

90. Subject: Another SST lives

Date: Sat, 01 Aug 1998 18:00:12 -0400

From: Scott Bauer <ke3nv@erols.com>

 

Hi Group,

 

Finally, after moving to a new home, I have found

some time to finish building my 20 meter SST kit.

I did have some trouble getting the SST to operate

in the frequency range specified in the manual. After

swapping the 18 mhz crystal out a few times and

changing D4A to D4B, I managed to get a perfect

14.048- 14.061 range. With D4A installed, mv209,

the range was way too high.

The tinkering was well worth it as the SST is a

very nice little XCVR and Im very happy with the

performance.

I managed to work K5OT in the NA Contest. Grabbed

him on the first call. He must have a great station

to hear my 1.5 watts in all of that racket going on ;-))

Now back NA contest with the Teeny Tiny SST !!

What fun it is!!!

72, Scott

 

 

91. Subject: NC 40A versus SST - per N6KR Wayne

From: <svecbrdk@well.com (L.Svec W.Burdick) <mailto:svecbrdk@well.com

(L.Svec W.Burdick)> >

Sent: Wednesday, May 21, 1997 11:36 PM

 

Hi Jim,

 

The SST is a VERY small radio, something of a novelty. My primary

reason for designing it was to try a number of circuit simplification

ideas, but also to provide a radio that would fit in a small day-pack

as part of an ultra-lightweight station. With only 60% as many parts as a

40A it has some unavoidable compromises. But it also is availble on 30

and 20 meters, which the 40A is not.

Here's what you get for the extra $$ for a 40A:

* the 40A covers from 40 to 150kHz of the 40-meter band, while

the SST covers only 8 to 12kHz using its VXO. The 40A is still quite

stable since its VFO runs at 2MHz or so. The SST's design is more amendable

to use on the high bands.

* the 40A has RIT with on/off switch; no RIT on the SST

* the 40A has room on the front panel for the KC1, it's easy to

install; the SST has room in the top cover but the KC1 installation

will not be as easy or as clean

* the 40A has a bit higher power output, typically 3W (SST

typically 2W)

* the 40A has room for a 10-turn pot for the VFO-nice if you add

a turns counter or freq counter such as the KC1

* the 40A has a more sensitive receiver with more audio output

* the 40A has much better AGC than the SST (the SST's LED-based

AGC is cute but not high-performance)

* finally, the 40A comes with a painted and silk-screened case;

the SST has a plain aluminum case that you have to finish yourself

 

 

The SST is still fun to use and easy to build, as well as being the

smallest member of the Wilderness transceiver family and covering 20

and 30 meters. But if you don't need the ultra-small size and low

price-tag, or the higher bands, the 40A is a much better radio.

Hope this helps!

 

73,

Wayne

N6KR

 

92. Subject: AW: alternate crystals for SST/40

Date: Tue, 18 Aug 1998 20:39:29 +0200

From: "Peter_dl2fi" <Peter_DL2FI@CSI.com>

 

I paralleled a second xtal (also from Wilderness, same frequency.

Tuning range is now 7023 to 7038. With an other L I had 7018 to 7034

Its somthing to experiment with.

72 de Peter

 

-----Urspr ngliche Nachricht-----

Von: owner-qrp-l@Lehigh.EDU [mailto:owner-qrp-l@Lehigh.EDU]Im Auftrag

von Allan Taylor K7GT

Gesendet am: Dienstag, 18. August 1998 19:45

An: Low Power Amateur Radio Discussion

Betreff: alternate crystals for SST/40

 

I have just purchased a SST/40m rig (from WA2HOQ). It is, of course,

centered around 7040. Has anyone successfully arranged a crystal

switching arrangement or socket to allow other center frequencies.

I am interested in occasionally trying 7020-7030 when out in the

sticks. (That's where the JAs are in the morning). Also, what is the

best sourc eof such custom crystals.

 

--

73 de K7GT

Allan Taylor (a.k.a. Grant) Pleasanton CA

email: k7gt@qsl.net

web page: http://www.qsl.net.k7gt/index.html

 

 

93. Subject: Re: SST/40 bandwidth issues

Date: Wed, 19 Aug 1998 08:16:44 -0700

From: Allan Taylor K7GT <k7gt@qsl.net>

 

I hadn't thought the responses to my SST bandwidth query merited

posting ... but I was wrong! The three suggestions I have received

were:

 

1) put in a bigger reactor (I assume that means a bigger inductance,

but not completely sure). This approach tends to unstable freq, tho.

 

2) Put both varacter diodes in (apparently two were supplied with the

SST) with a switch allowing selecting which one to use.

 

3) Parallel two xtals (yes, identical freq) and a slightly wider

range is attainable. See Super-VXO on the web, 7L4? and G3YCC.

 

3A) Put in two different crystals, switch between them.

 

I intend to implement 2 in a test jig and if it isn't sufficient, try

3A.

 

--

73 de K7GT

Allan Taylor (a.k.a. Grant) Pleasanton CA

email: k7gt@qsl.net

web page: http://www.qsl.net/k7gt/index.html

 

 

94. Subject: Tick keyer into SST

Date: Tue, 25 Aug 1998 15:53:51 -0700

From: Allan Taylor K7GT <k7gt@qsl.net>

 

For compatibility reasons, I have decided to put a Tick keyer (likely

the SuperTick Tick-3) in the SST. While it looks fairly

straightforward, I would like to hear from anyone who has done that. Exactly how did the keyer audio interface with the SST audio. Planning on 3V battery inside

to power the keyer, so no need for a 5V regulator from rig power.

 

Having not heard from anyone re a power mod for the SST, I will presume

to try one of my MRF237s in it instead of the 2N3553 and see if I can

get it up to 4W under full throttle.

 

--

73 de K7GT

Allan Taylor (a.k.a. Grant) Pleasanton CA

email: k7gt@qsl.net

web page: http://www.qsl.net/k7gt/index.html

 

Subject: Tick inside an SST

Date: Fri, 25 Sep 1998 16:00:28 -0700

From: "Jim Knopf" <knopf@halcyon.com>

 

Has anyone here put a Tick keyer inside an SST?

 

If so, what values did you use for R2 and R3, which Embedded Research

Says are "rig dependent."

Any problems with using the default resistors supplied, which are for

The Norcal-40A.

 

.....

-Jim, KI7Q

mailto:knopf@halcyon.com

Visit the "Father of Shareware" at

http://www.halcyon.com/knopf/jim

 

 

95. Subject: Re: sst question... 8V to NE612's and LM386.

Date: Thu, 6 Aug 1998 23:34:01 -0600 (MDT)

From: Paul Harden <pharden@aoc.nrao.edu>

On Thu, 6 Aug 1998, Bernie Doehner wrote:

> Can't the NE602 (or in my case NE612) and LM386 handle a full 12-14

VDC?

>

> Doesn't driving the NE612's, and LM386's with full 12V produce larger

> swing, and thus louder audio??

 

Bernie,

The VCC range for the NE602/NE612 is 4.5v to 9v. 9v is the maximum

voltage that should be applied. However, running a 602 in the 8-9v

range, near it's maximum rating, draws more current and has a higher

noise figure. As a result, most designers limit it to 8v, or in some

cases, will insert a diode between the 602 and +8v to cause a 0.6v

drop to run it around 7v to be extra safe and lower the noise.

Applying 12v WILL fry it.

 

The LM386's are suitable for +12v operation.

The LM386 is rated for +4 to +12v

The LM386A is rated for +5 to +18v

 

On the LM386, you will often see a 100 ohm resistor between the Vcc

pin (pin 6) and +12v, bypassed with a .1 cap to ground. This is to

keep the current fluctations of the LM386 out of the dc power bus,

AND causes a slight voltage drop so it runs a bit less than +12v for

a slight measure of safety. The LM386A's are a bit more robust with

their 18v rating.

 

Sometimes running an LM386 from +12v can cause "motorboating." If

this should occur, then bypass the 100 ohm resistor to the Vcc pin

with a large value electrolytic (instead of the .1uF), or lower the

Vcc below 12v.

 

Your concerns are justified. Always operate passive and active

components well within their maximum ratings. As Gary Surrency noted

on a previous post, tantalums are known to leak, or outright "blow"

by exceeding their maximum rating by only a bit. Another common

error I see is the coupling cap between the PA transistor and the

output filter. At 5W, you have 47Vpp, and a capacitor with less than

a 50V rating will experience excessive heating. The same holds true

for the caps in the output filter. 16V dipped mica's will get hot,

increase the power dissipation, leaving far less power to actually

reach the antenna.

 

GL, Paul NA5N

Who's blown a few tantalums myself!

 

Subject: Re: sst question... 8V to NE612's and LM386.

Date: Thu, 6 Aug 1998 22:38:47 -0700 (PDT)

From: Bernie Doehner <bad@uhf.wireless.net>

 

> Bernie,

> The VCC range for the NE602/NE612 is 4.5v to 9v. 9v is the maximum

> voltage that should be applied. However, running a 602 in the 8-9v

> range, near it's maximum rating, draws more current and has a higher

> noise figure. As a result, most designers limit it to 8v, or in some

> cases, will insert a diode between the 602 and +8v to cause a 0.6v

> drop to run it around 7v to be extra safe and lower the noise.

> Applying 12v WILL fry it.

 

AH... The voice of reason. Thanks. 8V it is in the unmodified SST.

Shall leave it that - thanks..

> The LM386's are suitable for +12v operation.

> The LM386 is rated for +4 to +12v

> The LM386A is rated for +5 to +18v

>

> On the LM386, you will often see a 100 ohm resistor between the Vcc

> pin (pin 6) and +12v, bypassed with a .1 cap to ground. This is to

> keep the current fluctations of the LM386 out of the dc power bus,

> AND causes a slight voltage drop so it runs a bit less than +12v for

> a slight measure of safety. The LM386A's are a bit more robust with

> their 18v rating.

 

Not in the SST design, it goes to the 7808 instead..

 

> Sometimes running an LM386 from +12v can cause "motorboating." If

> this should occur, then bypass the 100 ohm resistor to the Vcc pin

> with a large value electrolytic (instead of the .1uF), or lower the

> Vcc below 12v.

 

I may try this to see if I can get a bit more audio out of it, thanks

For the warning though.

 

> Your concerns are justified. Always operate passive and active

> components well within their maximum ratings. As Gary Surrency noted

> on a previous post, tantalums are known to leak, or outright "blow"

> by exceeding their maximum rating by only a bit. Another common

> error I see is the coupling cap between the PA transistor and the

> output filter. At 5W, you have 47Vpp, and a capacitor with less than

> a 50V rating will experience excessive heating. The same holds true

> for the caps in the output filter. 16V dipped mica's will get hot,

> increase the power dissipation, leaving far less power to actually

> reach the antenna.

 

:)

 

Oh yes... Thanks!

 

Bernie

 

 

 

 

 

96. Subject: Tick keyer into SST (Perhaps Allan now knows how.)

Date: Tue, 25 Aug 1998 15:53:51 -0700

From: Allan Taylor K7GT <k7gt@qsl.net>

 

For compatibility reasons, I have decided to put a Tick keyer (likely

the SuperTick Tick-3) in the SST. While it looks fairly straightforward,

I would like to hear from anyone who has done that. Exactly how did the

keyer audio interface with the SST audio. Planning on 3V battery inside

to power the keyer, so no need for a 5V regulator from rig power.

 

Having not heard from anyone re a power mod for the SST, I will presume

to try one of my MRF237s in it instead of the 2N3553 and see if I can

get it up to 4W under full throttle.

 

Have a 2nd op (N6RY, Terry) for the Sept 18,19 Yosemite QRPxpedition to

Grid squ DM07, Hayden Lake (elev ~7700') overlooking the Tuolumne River

canyon. Should give us a great shot at EU on 20m. Can't wait!

 

--

73 de K7GT

Allan Taylor (a.k.a. Grant) Pleasanton CA

 

97. Subject: SST fine tuning mod?? (Perhaps Allan now knows how.)

Date: Mon, 31 Aug 1998 10:30:15 -0700

From: Allan Taylor K7GT <k7gt@qsl.net>

 

Is there a 3-turn or 10-turn pot that will fit in the space of the

existing tuning pot in the SST? It looks cozy to me and would like to

know if someone has done this potential mod.

--

73 de K7GT

Allan Taylor (a.k.a. Grant) Pleasanton CA

 

98. Subject: SST Labeling (Perhaps Rick now knows how)

Date: Fri, 04 Sep 1998 22:00:07 EDT

From: wa8rxi@juno.com (Rick Arzadon)

 

Fellow QRP fans;

Built an SST and would like to paint and label the case.

In the manual is artwork for 1:1 copy to a transparency.

The question is...... How do I glue this clear plastic to the case?

 

TNX ES 72, Rick Arzadon - WA8RXI Taylor, MI.

 

Date: Tue, 29 Sep 1998 18:01:31 -0500

From: "Karl Heimbach" <heimbach@concentric.net>

To:

 

Gang,

 

I'd like to try a parallel HC-49 11.046 MHz microprocessor crystal in a 40m

SST in an attempt to increase the tuning range. My Mouser catalog does not

show it to be a stock item.

 

Anyone have an idea of where I might get one?

 

Thanks,

 

Karl - W5QJ

 

 

Subject: Re: 40m SST Crystal

Date: Tue, 29 Sep 1998 16:18:53 -0700

From: "Allan (Grant) Taylor" <k7gt@qsl.net>

 

The crystal in question is a Digikey X025-ND.

 

I have already checked with International Crystal Mfg Co. with the intent

of obtaining a few additional crystals to allow coverage down-band.

Those crystals will cost $13.68 each, plus UPS charges. I can get you

Further info if you would like regarding that option. I am contemplating

instead getting a 2nd NC40A, then repackage the new NC40A for field

use (pots on top, etc.)

 

K7GT

--

73 de K7GT

Allan Taylor (a.k.a. Grant) Pleasanton CA

 

100. Subject: SST-40 VXO expanded range - component values

Date: Mon, 5 Oct 1998 22:51:23 -0500

From: "Karl Heimbach" <heimbach@concentric.net>

To:

 

Gang,

 

I've read with interest the "Wilderness SST Notes" on G3YYC's webpage. Of

particular interest has been the commentary on expansion of the VXO tuning

range. Perhaps the following may be of interest to others wanting to expand

the range of their SST-40.

 

Tabulated below are results of a couple of combinations of crystals and

inductors and the tuning range observed with each combination.

In all cases, the X6's were 11.046 MHz HC-49's (DigiKey X025-ND) and RFC3's

were molded epoxy chokes.

 

Case: Design 1

RFC3 value: 15 uh 15 uh

# of X6's: 1 2

Tuning: 7.034-7.041 6.9814-7.0319

Range: 7 KHz 50.5 KHz

 

Case: 2 3

RFC3 value: 13.2 uh 13.2 uh

# of X6's: 2 3

Tuning: 7.019-7.040 6.949-7.035

Range: 21 kHz 86 KHz

 

Case: 4

RFC3 value: 11 uh

# of X6's: 3

Tuning: 7.007-7.042

Range: 35 KHz

 

I stopped with Case 4. RF output is approximately 3 watts throughout the

tuning range with a clean sine wave also observed throughout the range. On

air reports have been good.

 

Karl - W5QJ

 

101. Subject: RE: LM386 question answered

From: Ed Loranger [SMTP:we6w@qsl.net]

Sent: Tuesday, October 13, 1998 2:08 PM

Subject: RE: LM386 question answered

Howdy Alan et. al: You got this a bit wrong :)

I mentioned that the 220 to 470 uF Electrolytic

go from the +V input to the LM386 and Ground.

Not the 1/8 pin feedback network.....

I hope this opens up some ideas for you.

GL OM.

-Ed

K7GT mentioned:

A higher Vcc does allow wider swings in the case of high input

signals.

So, on that basis rerouting Vcc rather than regulated (+8V in my case

with the SST) to the chip may help a little on strong signals. Another

suggestion (WE6W) was to put in a HUGE capacitor across pins 1-8. It

would seem the effect of that would be to make sure the internal

biasing network is REALLY out of the picture.

--

72, Ed WE6W (CW only/VP-0); http://www.qsl.net/we6w Santa Rosa, CA

QRP-Z#106 QRP-L#1068 AR#112 NC#2227 ARCI#9397 QAA#006

 

102. Subject: New rigs (SST versus OHR type rigs) de AL7FS

Date: Sat, 07 Nov 1998 10:44:51 -0900

From: Jim Larsen AL7FS <larsennc@alaska.net>

 

Rod Cerkoney wrote:

 

> I'm going to build a single bander, and it will probably be the

> Wilderness SST for 20 MTRS. IT'S CUTE!!! 73, Rod Cerkoney, K0RWC, Ft

Collins,

> CO.

 

Hi Rod,

 

Let me throw one more thought at you. I do think you will miss the RIT

on the SST. The SST is probably a good rig but may I suggest the OHR100A for

a first kit monobander? OHR makes great kits with great manual and great help

if you need it and the rig gives great functionality. In the long run, I

think you will like it better than the SST.

 

Let me try to find some additional info for you on the SST. Also, I

have posted a large set in info on the SST on the G3YCC home page.

http://www.homeusers.prestel.co.uk/g3ycc/

http://www.homeusers.prestel.co.uk/g3ycc/sst1.html

================

Subject: AL7FS - 1998 Flight of the Bumblebees

Date: Sun, 26 Jul 1998 21:03:48 -0400

From: "Wilford D. Lindsey" <70511.3041@compuserve.com>

 

Jim:

 

I believe I heard you one time....and even called you 2X. But no joy.

Nuts. Sure always hope to QSO with you :-). Well maybe another time.

 

Rig(s) at my /BB QTH were Sierra and SST-20. Would have used the SST

more, but without RIT it became next to impossible unless the guys

called me just right for the offset frequency. So when it goo too

rowdy,I quickly switched to the Sierra.

 

Man if only RIT could be added to the SST! Bob N4BP wondered in a

recent post about putting one where the RF control is on the back.

Hmmm...

 

Anyway, glad you had a good time. CUL.

 

72/73,

--Doc Lindsey/K0EVZ Rochester, MN--Home of the Mayo Clinic.

=======================================

From: <svecbrdk@well.com (L.Svec W.Burdick) <mailto:svecbrdk@well.com

(L.Svec W.Burdick)> >

Sent: Wednesday, May 21, 1997 11:36 PM

Subject: Re: A Question

 

Hi Jim,

 

The SST is a VERY small radio, something of a novelty. My primary

reason for designing it was to try a number of circuit simplification

ideas, but also to provide a radio that would fit in a small day-pack

as part of an ultra-lightweight station. With only 60% as many parts

as a

40A it has some unavoidable compromises. But it also is availble on 30

and 20 meters, which the 40A is not.

Here's what you get for the extra $$ for a 40A:

* the 40A covers from 40 to 150kHz of the 40-meter band, while

the SST covers only 8 to 12kHz using its VXO. The 40A is still quite

stable since its VFO runs at 2MHz or so. The SST's design is more

amendable to use on the high bands.

* the 40A has RIT with on/off switch; no RIT on the SST

* the 40A has room on the front panel for the KC1, it's easy to

install; the SST has room in the top cover but the KC1 installation

will not be as easy or as clean

* the 40A has a bit higher power output, typically 3W (SST

typically 2W)

* the 40A has room for a 10-turn pot for the VFO-nice if you add

a turns counter or freq counter such as the KC1

* the 40A has a more sensitive receiver with more audio output

* the 40A has much better AGC than the SST (the SST's LED-based

AGC is cute but not high-performance)

* finally, the 40A comes with a painted and silk-screened case;

the SST has a plain aluminum case that you have to finish yourself

 

The SST is still fun to use and easy to build, as well as being the

smallest member of the Wilderness transceiver family and covering 20

and 30 meters. But if you don't need the ultra-small size and low

price-tag, or the higher bands, the 40A is a much better radio.

Hope this helps!

 

73,

Wayne

N6KR

 

=============================================

Well, there is more but this should help continue to fill your mind

with more

stuff than you probably wanted. Good luck

 

73, Jim, AL7FS -- Anchorage, Alaska

(BP51cc)@61.1009636 North 149.8237915 West(approximately)

mailto:al7fs@qsl.net ICQ 11022915

 

103. Subject: NC 40A versus SST - per N6KR Wayne

Date: Fri, 7 Aug 1998 15:28:32 -0800

-----Original Message-----

From: <svecbrdk@well.com (L.Svec W.Burdick) <mailto:svecbrdk@well.com

(L.Svec W.Burdick)> >

Sent: Wednesday, May 21, 1997 11:36 PM

Subject: Re: A Question

 

Hi Jim,

 

The SST is a VERY small radio, something of a novelty. My primary

reason for designing it was to try a number of circuit simplification

ideas, but also to provide a radio that would fit in a small day-pack

as part of an ultra-lightweight station. With only 60% as many parts as a

40A it has some unavoidable compromises. But it also is availble on 30

and 20 meters, which the 40A is not.

Here's what you get for the extra $$ for a 40A:

* the 40A covers from 40 to 150kHz of the 40-meter band, while

the SST covers only 8 to 12kHz using its VXO. The 40A is still quite

Stable since its VFO runs at 2MHz or so. The SST's design is more amendable

to use on the high bands.

* the 40A has RIT with on/off switch; no RIT on the SST

* the 40A has room on the front panel for the KC1, it's easy to

install; the SST has room in the top cover but the KC1 installation

will not be as easy or as clean

* the 40A has a bit higher power output, typically 3W (SST

typically 2W)

* the 40A has room for a 10-turn pot for the VFO-nice if you add

a turns counter or freq counter such as the KC1

* the 40A has a more sensitive receiver with more audio output

* the 40A has much better AGC than the SST (the SST's LED-based

AGC is cute but not high-performance)

* finally, the 40A comes with a painted and silk-screened case;

the SST has a plain aluminum case that you have to finish yourself

 

 

The SST is still fun to use and easy to build, as well as being the

smallest member of the Wilderness transceiver family and covering 20

and 30 meters. But if you don't need the ultra-small size and low

price-tag, or the higher bands, the 40A is a much better radio.

Hope this helps!

 

73,

Wayne

N6KR

 

104. Subject: SST Question - higher SWR with SST than with other rigs

Date: Wed, 20 Jan 1999 09:24:17 -0600

From: "Robert Radtke" <rradtke@hutman.net>

 

Hi All -

 

I just finished building a Wilderness SST Kit (my first kit - yeah!!!!)

And everything worked great straight out of the box. I have 2 questions

though.......

 

1. I had a very hard time running it through my MFJ tuner. I got a much

higher SWR when running the SST than with my other rigs (Kenwood 520

and Heath HW-7). When I adjusted the tuner to lower the SWR, I couldn't

hear nearly as much as when I bypassed the tuner. What's happening?????

 

Is the antenna impedance from the SST something very different that

50ohms? Is the tuner just sucking up that much RF in it's circuitry?

 

Any ideas would be great.

 

Thanks in advance,

 

Robert Radtke - KC0EJW

====

Date: Wed, 20 Jan 1999 07:46:52 -0800

From: "Roger A. McCarty" <rmccarty@earthlink.net>

 

Hi Robert,

 

You have one or two problems. Either your output frequency is much

Different than the band for which it was built and/or you are transmitting a

number of harmonics and spurs. If you have a scope, it would be simple to

determine if or which. You want to see a very clean sine wave on the output and of course at the freq for which the rig was built. A tell tale sign of

spurs/harmonics is your watt meter will indicate significantly more power than the unit is designed to deliver.

 

I don't know if the SST has a drive control, but if so try backing way

Down on it and see if that helps with the output waveform. If the SST

Sidetone monitors actual RF (Others experienced with this rig can comment here)

Back down on the drive control until the sidetone sounds clean. Also, if you

Have another radio at your disposal, listen for the signal to be clean and

crisp. If it is raspy and/or you hear the signal up and down the band, you

have spurs/harmonics.

 

If any of these effects are present, the most common problem is in the

output filter of the rig. Check all of your connections and coils in

the filter. Drive stage problems are also suspect. These are generalized

troubleshooting techniques, others may have specific pointers for the

SST.

 

Good Luck

 

Roger KD6CC

==

 

Date: Wed, 20 Jan 1999 22:56:48 -0600

From: Robert Radtke <rradtke@hutman.net>

 

 

Hi again -

 

I just wanted to say thanks for all of the help. After several hints

about harmonics, I tuned my Kenwood up to 20M and heard the 40MSST loud

and clear.

 

I checked on the toriod windings and realized that I had switched the

number of turns with the inches of wire number -- duuuhhhh :{ - sooo

after desoldering and rewinding everything it worked great.

 

I fired it up and got PA and OH right away from Minnesota - both QRP -

QRP.

 

Thanks again for the help --

 

Robert - KC0EJW

 

 

105. Subject: Wilderness SST Troubles! touch the cap output jumps

Date: Tue, 2 Feb 1999 01:08:44 -0600

From: "Nathan Odle" <nodle01@mail.coin.missouri.edu>

 

Hey gang,

 

Wondering if any of you could help me troubleshoot my newly-built 30M

SST. My problem is that output seems to be very low until I go to peak C28 -

At that point, the minute I touch the cap output jumps (at least as far as

I can tell on the monitoring receiver). I also notice really low

Background noise from the SST receiver. Is this characteristic? Any help will be greatly appreciated...TNX es 73

 

Nathan

KB0NNV

==

Subject: Sick SST. I'm about to go crazy...

Date: Wed, 3 Feb 1999 22:20:46 -0600

From: "Nathan Odle" <nodle01@mail.coin.missouri.edu>

To all of you technically adept QRP-L members:

 

OK, STILL have major SST probs. It's the 30m version. This is really

getting frustrating, folks. Here's the situation:

 

1. No real output to speak of from the antenna jack. I listen to the

SST on a Yaesu FT-990 and hear a small signal that doesn't even deflect the

S-Meter. It seems to be covering the correct frequency range though.

Adjusting C28 has no effect, except when you touch it with a metal tool

The S-meter on the 990 jumps to about a 5. The only meter I have around

That even gets close to what I need for this is an old Palomar 500 (hey, I'm

broke) that I think was used for CB once upon a time (before my day).

Even on the 0-10W range, the needle doesn't budge.

 

2. Not hearing anything but my own signal (and yes, I was plugged into

an antenna - a Mosley beam). When the volume is cranked, I hear a little

hiss, nothing else. I can't peak C1 because I don't hear anything - even on

a band FULL of nice signals. The FT-990 was hearing all kinds of good

sigs without an antenna even plugged in. I can, however, hear the 990 when

it's RIGHT NEXT TO ME and transmitting into a dummy load (on the same Freq I

hear the SST on - the TX/RX is not shifted). The AGC light sometimes

flickers when this is happening...and also rarely flickers when I transmit.

 

3. A thorough check of the DC voltages on the ICs as given by the

chart shows everything is pretty much within parameters, except for the

following places (checked with my Fluke DMM):

 

Rcv:

Spec Measured

---- --------

Q1-S: 0.9 1.9 !

 

Xmit:

Spec Measured

---- --------

U1-1 -0.5 1.1 !

U1-2 -0.9 0.8 !

U2-5* 7.6 8.0 ?

U4-4 6.8 6.4

U4-5 6.8 6.3

U5-2 7.2 6.9

U5-7 13.7 13.8

Q1-S: 0.9 1.9 !

Q2 **

 

! = Big discrepancy

 

? = Not a big discrepancy, but it was identical on transmit and

receive.

The numbers say it's supposed to drop on TX.

 

* When the probe is touched to this point, the little bit of noise that

IS coming out of the headphones goes mute.

 

** Even though the manual says voltages on Q2 can't be measured because

of loading by DMM probe, not even the slightest output is seen anyway

(shouldn't one see at least SOMETHING?)

 

4. Other notes: VXO is covering 10.105 - 10.118. Also, the power

supply is a good Astron that shows exactly 13.8v on my DMM.

 

I am using stereo headphones, I've checked the toroids for continuity

(poorly stripped leads) and correct winding, X6 is NOT confused with

the others and the filter XTAL cans are properly grounded, The ICs are in

correctly, none of the electrolytics are in backwards, the molded

inductors are in the right places, as are the trimmer pots, and ALL of the other

parts for that matter (I double-checked the ENTIRE parts list to verify parts

placement just now). D4 is the MV209, but it was exhibiting the

problem with the other varactor as well. There are no broken traces that I can

see.

I have also checked the solder joints thoroughly - nothing wrong there

either - no bridges, cold joints, etc...

 

I hope someone can help me with this...I'm at my wit's end. I admit

I'm don't know as much about this stuff as I'd like to, and hope it's not

something really stupid. I've told you everything I know about the

situation, hope it's enough for a solution. I was planning to show it

at our meeting on the 9th, hopefully it'll be running before then...

Thanks in advance for any of your assistance...I really don't want to wind up

Paying the "flat fee" price of $50 + shipping that I don't have, just to get

This rig going.

 

 

TNX es 73,

Nathan

KB0NNV

==

Date:

Thu, 4 Feb 1999 00:03:46 +0000

From:

"Steven Weber" <kd1jv@moose.ncia.net>

To:

"Low Power Amateur Radio Discussion" <qrp-l@Lehigh.EDU>

 

 

 

 

> 1. No real output to speak of from the antenna jack. I listen to

the SST

>

> 2. Not hearing anything but my own signal (and yes, I was plugged

into an

 

Sounds to me there isn't any continuity through the low pass filter.

Make sure the enamel is scraped clean off the magnet wire and the

solder stuck to it well. A real common problem..

 

If that's not it, good luck, but a real good look over for solder

shorts, those pesty little metal shavings caused by insterting parts

in the holes, or open pcb tracks would be a good start.

 

BTW, If you get too fustrated, I'll fix if for shipping costs (and

parts if needed), just to get a good look at one...

 

72,

Steve, KD1JV in the white Mountains of New Hampshire

"melt solder"

 

==

Date: Thu, 4 Feb 1999 16:37:07 EST

From: RangerSF5@aol.com

 

Hi Nathan,

I read you'r post on the SST that you have problems with.

I'l skip all the mumbo jumbo since it looks like you double checked

everything.

I just want to say that I built 5 for myself and 2 more for others.

The SST is a fine rig but when it comes to tuning,(peaking) you have to

go

REAL SLOW.

Ok you made all the checks and this is what i'm looking at.

1 You discovered a chip that does not pull down the voltage on one of

the pins

of *U2*

2 The tone you hear is your transmitted RF (Just about nil).

3 The red *LED* you say is flickering Sometimes)

4 You have RX noise (good sign)

5 You said that when you touch the pin,your big rig will pick up the

transmitted signal but you did not say if the red *LED* came on with

it.

At this time,i'd say that the *U2* is the problem.

BTW the way,

Most of the SST rigs I built,I used sockets for the chips.

If you bake one,it's an easy change.

I noticed no difference when using the sockets.

It's a good way for a Newbie to build the kit/s and when all seems to

Be working well,clip the pins on the sockets and remove them 1X1 then

solder in the chip.

I also found the extra diode for the extended VXO range to be the most

stable.

Put you'r findings on the reflector.

GL

72/73

Bob

WA2HOQrp <tm>

==

Subject: SST *might* be fixed...we'll see for sure tomorrow!

Date: Fri, 5 Feb 1999 00:07:07 -0600

From: "Nathan Odle" <nodle01@mail.coin.missouri.edu>

 

OK folks, thanks for all of your helpful messages. I started going

backwards from the non-antenna jack side of the low-pass filter with a

metal tool while the 990 transmitted into a dummy load, and noted where the

signal dropped off. I found one of the solder pads of L3 to not give a loud

response when I touched it like the other ones had. When I hit the

wire end dead-on with the tool (like I did when testing for continuity), I got a

signal, but when I touched the solder around it as well as components

more toward the antenna jack I got hardly anything. So, probably bad solder

joint. I reheated the joint and this appears to give some improvement

(RX audio is definitely up a bit), but I'm going to pull out that toroid

and redo the whole thing tomorrow just to be sure. Then, I can finally

test!

I'm going to St. Louis in the evening, so it looks like I might just

have 5 minutes or so to test it while there are sigs down there in the bottom

of 30m before I leave after work. I'll keep you guys posted. Man, if

that's all it winds up being I'm gonna be pretty disappointed with

myself...shame shame on me for overlooking that. But who knows, it could be that

that's not the problem and then we'll have more to talk about ;) Thanks again

guys...by the time I'm done with this I'll sure have learned a thing or

two!

 

TNX! es 73,

Nathan

KB0NNV

==

Subject: More on SST...

Date: Fri, 5 Feb 1999 00:12:51 -0600

From: "Nathan Odle" <nodle01@mail.coin.missouri.edu>

 

Oh, and I'm pulling about 400mA on TX...is this enough to assume the

final's getting into the picture? I was running the PS at about 13v (makes

5.85W), so assuming 55-60% efficiency this puts me into the ballpark, doesn't

it (assuming some of that is being used for receive audio)?

 

73,

Nathan

KB0NNV

==

Date:

Thu, 25 Feb 1999 22:34:41 -0600

From:

"Nathan Odle" <nodle01@mail.coin.missouri.edu>

To:

"Low Power Amateur Radio Discussion" <qrp-l@Lehigh.EDU>

 

 

 

 

Some of you may remember my Sick SST posting some time ago. Well,

there's

good news and there's bad news. The good news is, the RX is great.

Seems

like it's performing wonderfully. The bad news is, the TX isn't doing

well

at all. I hear my own signal when I transmit, so the oscillator chain

seems

to be working, but my newly-built (and tested!) OHR WM-2 shows no

output.

Nil, zip, nada. I started probing around. There's no major

discrepancies

on U5 (the LT1252 driver) when I checked the DC voltages on the

troubleshooting table. Pin 6, which to me looks like the output, shows

about 9v of DC voltage, which drops somewhat on TX, just as it's

supposed

to. This pin 6 is connected to C31. I get the same voltages at the

Pin 6

side of C31, then NO DC voltage on the side of C31 that connects to R12

the

drive potentiometer. I'm not familiar enough with this to know if this

is

correct, but it doesn't seem to be right to me. I checked the solder

joints

on both legs of C31 and they're fine. Can anyone help out with this?

Thanks in advance for any help...

 

73,

Nathan

KB0NNV

 

==

30m SST Update

Date: Mon, 1 Mar 1999 10:27:07 -0600

From: "Nathan Odle" <nodle01@mail.coin.missouri.edu>

Gang,

 

I posted some problems with my SST awhile back, and have been trying to

troubleshoot it when I get a chance. I was asked to let the group know

what the situation was, so here goes:

 

The inital problem with a lack of TX AND RX. On the RX side, with the

volume cranked full CW I could hear a slight hiss, so I knew the audio

amp was working. On the TX side, I knew the oscillator chain was good,

because I could hear myself on the monitor receiver, but no output from the

antenna jack. This pretty much narrowed the problem down to the output filter

-

it's involved in RX and TX, and it's after the oscillator chain.

 

A thorough check revealed something I missed in the first couple of

looks at the problem - one of the toroids was open. I missed it earlier because

I had inadvertantly been touching the DMM probe to the end of the wire

(and found continuity), but later discovered there wasn't any continuity

between solder pads. Checked ALL the solder pads again just to be sure, but

the one was all that had a problem. Out came the toroid - I rewound it for

good measure, stripped the ends VERY carefully, and reinstalled. Flipped

the power on, and was greeted by the beautiful sound of atmospheric noise.

All was well, or so I thought. Tried keying the rig, STILL no TX output.

 

Rechecked solder pads, the zener diode, drive pot, and C31. All A-OK.

Finally pulled Q2, the final transistor. Made a check (according to

directions from Mike Heitmann - N0SO), and discovered it was open.

Mike seemed to think it was probably a result of the mismatch created by the

Open toroid in the output filter. I have a replacement 2SC799 on the way,

Along with one of the ECG parts mentioned in the manual. Going to try the

hopped-up ECG-series and see how it does. If it doesn't work out, I'll

install my replacement 2SC799.

 

So there you have it. Hopefully this info will help someone out. I'll

Let you all know if the SST comes to life as soon as the transistors get

here! Hopefully not long thereafter you'll hear me on 30m QRP...

 

73,

Nathan

KB0NNV

==

Subject: SST Lives!

Date: Mon, 1 Mar 1999 23:49:14 -0600

From: "Nathan Odle" <nodle01@mail.coin.missouri.edu>

 

Well, as I noted before I had narrowed my SST's TX problem to a bad

Final transistor. I ordered up a replacement last night, as well as a

Compatible "hop-up" part with more gain. Tonight, I was sitting around getting

impatient so I started searching for a suitable replacement in the

shack.

After looking and looking I finally came across an old Regency VHF

Business band radio. I decided that might be a likely prospect for the power I

Was looking for (it put out about 5w), so I popped open the case and traced

Back from the RF jack to find the final. I find the final, it's marked with

Motorola's logo - and is numbered "696-3", and below that "536". Now I

don't know a LOT about transistor markings, but I assumed this to be an

MRF536. I search for this online, and discover a listing that shows

This transistor to be close to what I'm after (at least somewhat similar to

The 2SC799 that comes with the SST). I pop this thing in, make my solder

joints, turn on the SST, key down, and WOW! I'm greeted with the

swinging needle of my OHR WM-2. Showing about 1.5w out. Not stellar, to be

sure, but more than adequate until my ECG-341 gets here. Yippee! Woohoo! My

first kit radio is on the air! Now I just need to get the Gap vertical

up for 30m...until then I'll just drag the rig into the club station ;)

Now, I could have been wrong about the transistor markings and just got lucky

-

would any of you guys that know more about this than myself (and might

also have a transistor data manual) care to comment??? Also, some

verification that this part is at least temporarily happy with it's new living

arrangements would be nice... From a newbie's perspective, coming up

with something like this is the highlight of the week...

 

73,

Nathan

KB0NNV

 

 

106. Subject: N4BP request for info SST Sidetone-answer?

Date: Mon, 08 Feb 1999 07:25:55 -0900

From: Jim Larsen AL7FS <al7fs@pobox.alaska.net>

Date: Mon, 8 Feb 1999 03:55:51 -0500 (EST)

From: Bob Patten <n4bp@bc.seflin.org>

Any SST experimenters out there? The sidetone pounded my ears

mercilessly. How do I reduce the signal level hitting the RX stage?

Anyone play with RIT for this rig? This nearly cost me some contacts

on the edge of my bandpass. I'm reluctant to tune them to the center of

the passband since they might not be able to hear me come back. Jim, FS -

that's why I had such a tough time with you. Your signal was quite

good, but outside my passband.

 

 

73,

,'' '',

Bob Patten, N4BP ( 0 0 ) Plantation, FL

________________________________oOOo-(_)-oOO___________________________________

 

E-Mail: n4bp@bc.seflin.org

Web Page: http://wg104a.wh.uni-stuttgart.de/~n4bp

Brass Pounder BBS: (954) 472-7715

 

107. Subject: Varicaps for use in SST wide coverage VXO & 15 mtr conversion

Date: Sat, 13 Feb 1999 08:38:51 -0900

Jim Larsen AL7FS <al7fs@pobox.alaska.net>

Subject: Varicaps

Date: Fri, 12 Feb 1999 21:58:11 -0700

From: Roy <marion@montana.com>

A few folks on the list have asked me about the MV1404

varactors I used in my SSTs to create wide coverage VXOs. I had some on hand to try, but didnt know where to get more. I just saw that RF Parts has them for

$6.95 apiece. Expensive(in my opinion, since I got a dozen in a Dans Small

parts 10lbs of parts for 10 dollars, shipped) but available. They work in

SSTs really well, I haven't tried them in any thing else. My 20mtr SST

Covers from 14.003 to 14.065. My 15mtr SST covers 21.015 to 21.068. I had to

Put ten turn pots in them. Anyway, just passing along along the info. Back

To working DX on my K2. 72 Roy AB7CE, Montana.

 

 

108. Subject: SST Mods from W9AC, Paul

Date: Wed, 03 Mar 1999 18:43:17 -0900

From: Jim Larsen AL7FS <al7fs@pobox.alaska.net>

Date: Wed, 03 Mar 1999 16:11:40 -0800

From: "Arthur G. Silvers" <ags@ieee.org>

Thanks Paul,

 

I have an SST for 20 mtrs and I am also using the switched varactor

diodes for increased range. Have all I need for the parallel xtal mod

but have putted that one off for the time being.

 

I hope you don't mind but I am posting your response as it may be of

interest to others.

 

72/73 es CUL Arth W6AGS

 

"Long Live Continuous Wave (LLCW)"

 

Paul Christensen wrote:

>

> Thanks for the compliments Art. I had a plating company in Tampa

anodize the aluminum in two colors: cobalt blue and black. The anodizing

looks better than any paint job I've seen, but it's an expensive process.

>

> My SST has several mods:

>

> 1) I added the TiCK keyer chip but used a novel method of dropping

+12 VDC to the TiCK's required input voltage by using two LED's in series to

create a constant voltage drop. As a side benefit, the LED's light in

sequence with keying (i.e., as current is drawn from the TiCK).

>

> 2) Added ABX I.F. filtering using the Sierra method.

>

> 3) Extended VXO range on 40-meters by paralleling two VXO crystals.

My range is now 7010 kHz to 7060 kHz using two switched, varactor

diodes.

>

> A description of my mods are available on the G3YCC QRP web page.

>

> -Paul, W9AC

>

> ----- Original Message -----

> From: Arthur G. Silvers <ags@ieee.org>

> To: <paulc@mediaone.net>

> Cc: qrp-l <qrp-l@Lehigh.EDU>

> Sent: Wednesday, March 03, 1999 11:27 AM

> Subject: RE: Paddles

>

> >Paul,

> >

> >Looks as though you have done some interesting mods to your SST.

Care to

> >give us a few details? Nice paint job too.

> >

> >Tnx es 72/73 Arth W6AGS

> >

 

109. Subject: SST es KC1

Date: Mon, 15 Mar 1999 14:40:27 -0600

From: "Nathan Odle" <nodle01@mail.coin.missouri.edu>

OK, had a quickie building session last nite and put together my new

KC1 that's going to go into the 30m SST. In the manual, Bob says that the

Best place to mount the KC1 is in the top half of the case, along the left

Side of the rig (over the xtal filter), with the speed adjustment closest to

The front. That's all fine and dandy, but I don't really like that idea

Because I'll have knobs sticking out of the top of my rig, and not only that,

But they'll be along just one side. That being said, does anyone have

experience with or thoughts on the following two options:

 

1) Mount the KC1 in the top of the rig, but mount it parallel to the

front panel, with the speed control lined up with the volume control. This

would put the keyer over the VXO though - is this a problem??? There would

be about 3/16" clearance.

 

2) This to me is the more desirable option. Replace the 10k pot with

a remote mounted one - mounted over the top of the keyer jack. Mount the

two momentaries over the RF and Power jacks. Then, if possible, run these

connections and the board connections to a header. Wire up the mating

plug to this header to the KC1, and 3M double-stick tape the KC1 to the top

panel, plugging in the header before I put it together.

 

Any ideas/comments/suggesions?

 

73,

Nathan

KB0NNV

==

Subject: Re: SST es KC1

Date: Wed, 17 Mar 1999 01:41:05 +0100

From: hw.merz@t-online.de (Hanns W. Merz)

Hi Nathan,

 

I have built a 20m SST with the KC1 in the front panel of the rig (NOT

in the top half). This is possible if you prepare the KC1 board for horizontal

mounting. The pots and switches have to be soldered horizontal, too.

Some leads must be changed therefore. It's a little bit a puzzle work but the

result is nice and it works fine. No problems with processor noise or something

else. But I wouldn't recommend this method if you have too big fingers ;-) as the

handling of the knobs could be a little bit difficult when operating allthough I

have arranged the knobs primarily for easy use rather than for best looking.

 

If you are interested I can try to take some digital pictures of my SST

and send them to you as JPG files.

 

72,

Hanns, DK9NL,

AGCW #1966, DL-QRP-AG #Foundation Member, G-QRP #6365, RIA #894

e-mail: hw.merz@t-online.de

---------------------------

The Wilderness Radio Sierra is my favourite QRP rig!

===============================================

 

110. Subject: SST VS SW30

Date: Sat, 3 Apr 1999 08:22:20 +0500

From: Tim and Aretta Gordish <kb9lgj@leogate.kf9ug.ampr.org>

 

 

>Does anyone prefer the SST over the SW30 as a 30 m rig?

>

>======================================

>Todd M. Carpenter, N9YSQ

>President ISUARC

>Member: WVARA, THRC, GQRP, INQRP, ARCI

>

I have built the SST-20 and the SW40, and the differences in the two rigs I

built are:

 

SW+ Loud, seemingly 3D audio, low sidetone, big tuning range.

SST Low volume audio, loud and clear sidetone. Nice tiny size. Easier

construction.

 

Both put out about 2.5 watts of clean signal, and work great. Which do I

prefer....Both!

 

 

73 de Tim

KB9LGJ

 

QRP-L #457 MN-QRP NORCAL FISTS AR-QRP

==============================================================

111. Subject: SST warble - Too big capacitor?"

Date: Sat, 10 Apr 1999 13:40:35 -0800

From: Mighty Mik <mitymik@hooked.net>

 

I managed to pick off the Spring Boquet station today, who gave me a

'557'...and said later that i have a 'warble'...I was on the NC20, which

is all stock EXCEPT i put a bigger cap in the VFO, so i could use it

with a 6M transverter (47pF...gives me a range of 14.000-194). I only

have 2 QSOs on it at this point...so i'll be looking to get this ironed

out before QRPTTF. anyone have ideas, comments?

 

i'm waiting on my new case before i do the AGC mod.

 

=====================================

 

112. Subject: SST 20 Tuning Range - More!

Date: Mon, 12 Apr 1999 09:54:31 -0700

From: "Arthur G. Silvers" <ags@ieee.org>

 

Fellow QRPers,

 

I know we are all into NC20s and other projects, but I just wanted to

relate my latest improvements on the tuning range of my SST 20 with

appropriate credit to those who have posted there results to QRP-L.

 

In order to improve the tuning range of the rig, the first thing I did

was to install both varactor diodes. This resulted in rather narrow

ranges for both diodes;

 

MVAM108 about 9 kHz

MV209 about 6 kHz.

 

 

I could have stopped there because I had the QRP calling frequencies

nicely covered. Spurred on by the success of other SST builders, I

installed the second parellel crystal and lowered RFC3 to 4.7 uH (a

standard value). This resulted as follows;

 

MVAM108 14.024 - 14.046

MV209 14.049 - 14.060

 

Hmm! Interesting improvement, but now the QRP calling freq is only

marginally covered and there was still an annoying gap in coverage

between the two diodes. Then Wayne Burdick suggested that I reduce the

value of R5, thus providing a wider voltage swing accross the varactors,

to 9K from 100K. I though that a bit radical so I first tried reducing

the resistance to half (50K) with the following results;

 

MVAM108 14.022 - 14.048

MV209 14.048 - 14.061

 

Now that is promising results and motivated me to reduce R5 as Wayne

recommended. So with a shunt 10K accross the original 100K, the net

resistance is of R5 is 9K which resulted as follows;

 

MVAM108 14.022 - 14.050

MV209 14.041 - 14.0625.

 

Bingo! As far as transmit stability is concerned, I received a 559 from

Utah during the QSO party with a vertical dipole in the rafters of my

garage before the XYL reminded me that we had tickets to the Berkely Rep

and needed to get ready.

 

Many thanks Wayne! And many thanks to those QRP-Lers who posted so many

helpful notes. Now about this AGC section of the NC20......

 

72 Arth W6AGS

=======================================

113. Subject: Re: SST 20 Tunning Range - More!

Date: Sat, 17 Apr 1999 23:14:16 -0700

From: Wayne Burdick <n6kr@elecraft.com>

 

Hi Arth,

 

Thanks for the note on your success with the SST change I recommended. I'll

be including this information in the next revision of the SST manual, and

will also see if Bob Dyer obtains the same results. We might even change

the resistor value sent with the kit, although having *too* wide of a

tuning range can also be a problem with a small front-panel tuning pot such

as on the SST.

 

By the way, it was design work I was doing on the K2 that led me to the SST

mod -- there's a similar VCXO circuit in the K2 that serves as the

reference for the PLL.

 

73,

Wayne

N6KR

 

 

>.....Then Wayne Burdick suggested that I reduce the

>value of R5, thus providing a wider voltage swing accross the varactors,

>to 9K from 100K. I though that a bit radical so I first tried reducing

>the resistance to half (50K) with the following results;

>

> MVAM108 14.022 - 14.048

> MV209 14.048 - 14.061

>

>Now that is promising results and motivated me to reduce R5 as Wayne

>recommended. So with a shunt 10K accross the original 100K, the net

>resistance is of R5 is 9K which resulted as follows;

>

> MVAM108 14.022 - 14.050

> MV209 14.041 - 14.0625.

>

>Bingo! As far as transmit stability is concerned, I received a 559 from

>Utah during the QSO party with a vertical dipole in the rafters of my

>garage before the XYL reminded me that we had tickets to the Berkely Rep

>and needed to get ready.

>

>Many thanks Wayne! And many thanks to those QRP-Lers who posted so many

>helpful notes. Now about this AGC section of the NC20......

>

>72 Arth W6AGS

 

=======================

114. Subject: Re: SST 20 Tuning Range - More!

Date: Mon, 19 Apr 1999 17:42:14 -0700 (MST)

From: Joe Gervais <vole@primenet.com>

 

Howdy Wayne and Folks,

 

Wayne (N6KR), Designer of my faithful Sierra beast, wrote:

>

> Thanks for the note on your success with the SST change I recommended.

> I'll be including this information in the next revision of the SST

> manual, and will also see if Bob Dyer obtains the same results.

>

> Arth (W6AGS) wrote:

> >

> > .....Then Wayne Burdick suggested that I reduce the value

> > of R5, thus providing a wider voltage swing accross the

> > varactors, to 9K from 100K.

> > [ ... ]

> > MV209 14.041 - 14.0625.

 

Wayne and Arth, are there any other changes associated

with this mod, or can I simply put that 10K resistor in

parallel with R5 as Arth did and (*possibly*) see a similar

increase in SST tuning range?

 

Oh heck, may not wait for the answer, since most of you are

even busier than me. *8-) But if/when time allows, please

drop a note here on QRP-L, and I'll follow up with my own

experiment. Just in time for QRPTTF - Wahoo!

 

Thanks in advance!

 

Cheers de AB7TT,

 

-Joe, vole@primenet.com, AZ ScQRPions (Phoenix)

 

"And that, my Liege, is how we know the Earth

to be banana-shaped." -- Monty Python and the Holy Grail

 

===================================

115. Subject: SST-20 R5 tuning range mod

Date: Tue, 20 Apr 1999 11:28:18 -0700 (MST)

From: Joe Gervais <vole@primenet.com>

 

Yep, me again.

 

Per Wayne's idea and Arth's experiments, I added

a parallel 10K resistor to my SST-20's R5 last night,

bringing R5 down to around 9K.

 

I'd only been getting about 6 KHz of coverage before

(stock kit, no mods - yep, I plan to do extensive

tweaking after QRPTTF :-) ). After dropping down R5

I now have 11 KHz of useable tuning range (14.057-

14.068). Too bad I can't copy RTTY in me head yet. *8-)

 

Wayne warned me that, after the mod, power may drop

off at the ends of the tuning range, and sure enough

I lose output in the last 1/4-turn of the pot's range.

I'll monkey with that later. But I'm still getting

about double the coverage even with that side-effect.

 

I'll stick the SST on a power meter tonight and track

the actual output.

 

Wayne's exact words to me:

 

"Watch for low power output, though. If this happens (at

either end of the tuning range) you'll want to use a

larger resistor or put a 10uH RF choke in series with it."

 

Thanks to Wayne and Arth for their help!

 

Cheers de AB7TT,

 

-Joe, vole@primenet.com, AZ ScQRPions (Phoenix)

 

"If it ain't fun, you ain't doin' it right!" -The AZ ScQRPions

 

======================================

 

116. Subject: Brief SST Description - KB9LGJ

Date: Mon, 3 May 1999 08:04:14 -0600

From: Tim and Aretta Gordish <kb9lgj@leogate.kf9ug.ampr.org>

 

 

I much enjoy my little 20 meter model of the SST. It is a very usable rig,

and a great performer. The 3 watts it puts out is all you will need for

making consistant contacts. The cw filter is narrow so it is easy to use

this rig for contests and pick out signals in a pile up. It is excellent

size- tiny, and the 20 meter version covers both the QRP call frequency and

the FISTS call frequency. Current drain is very low and I built up an

internal batterypack from cordless phone battery packs that will keep the

rig on air for a good two hours- the perfect Spartan Sprint rig! The only

draw back with my rig is the audio volume is low and I use and external

audio amp to fill the shack with sound when no using headphones.

 

 

73 de Tim

KB9LGJ

==================================

 

117. Subject: 10M SST-ALIVE!

Date: Mon, 03 May 1999 17:56:05 -0500

From: mjfitz@uswest.net

 

Kids-

Just finished building a 10 M SST this weekend. It seems to work,

that is, it puts out about 1.5 W on 12.5 V with a good lookin' wave on

the scope, and the few signals I can hear on 10 M on the TT Delta II are

"hearable" on the SST. I must confess however, I have not made a single

contact with it yet--the band has not been up enough yet for me to

try...

 

A few of the gory details:

 

Standard circuit, but used a 16 MHz xtal(Digi-Key X143-ND) and a

frequency doubler (Solid State Design, pg. 44, fig. 24) right out of a

cookbook. Matched the diodes with an ordinary DVM. The doubler output

looks real clean on the scope also--that's why I proceeded with building

the radio...there are about ten parts to this doubler and the text

claims the fundamental is 60 dB down with matched diodes...

 

Used a bit more of a half-wave output filter (W1FB's Design

Notebook, pg. 103, fig. 4-9, 10 M. componenets).

 

Did the usual power mods. Build the rig by pad and glue method.

See the IOWA QRP newsletter, spring 99 issue for my 15 M. Pad and Glue

SST "how-to" article available on-line from the club site (below).

 

Anyone else want to try this and feel they need more details--'mail

me directly.

 

IA QRP club site:

http://www1.iastate.edu/~drcase/iowaqrp.html#NEWSLETTER

 

The newsletter IS 5 MB (Word 97) and I understand efforts are

currently underway to format it a bit differently, but it is still an

excellent job by John Burney, NU0V, and contains several interesting

articles besides my stuff...

 

Just waitin' for ten to open...

 

Mike KI0AF (of Mad Mike's Basement RF Labs...)

Mo. Valley IA

==================================

 

118. Subject: KI0AF's 15 Meter SST Newsletter Article

Date: Tue, 4 May 1999 18:54:28 -0500

From: "John Burnley" <burnley-ia@worldnet.att.net>

 

Some of you have written me about having trouble getting

the IAQRP Spring Newsletter which has Mike's article

about the 15 Meter SST. It is in Word format and huge

because of my inexperience with PC formats (hey I'm

a mainframe systems programmer and avoid PC's like

the plague hi). Fred Spinner W0FMS has converted the

newsletter to a PDF format and placed it on his website.

My apologies to you all who had trouble in getting the

info. Fred has placed the newsletter at:

 

http://zeus.ia.net/~spinner/W0FMS/IowaQRP

 

The Spring 1999 issue contains his article. We will also

have available (soon) more pictures of his SST (which BTW

won the IAQRP building contest) as well as his REGEN

receiver. Both are works of art and I hope Mike considers

entering it into the NorCal REGEN building contest to

be held at Hamcom (for those of you lucky ones who get

to go I am extremely jealous).

 

72/73, John NU0V

 

======================

 

119. Subject: 10m SST comments from N6KR

Date: Wed, 5 May 1999 09:17:04 -0700

From: Wayne Burdick <n6kr@elecraft.com>

 

Hi Mike,

 

Congratulations on your 10M SST. I haven't designed Wilderness versions of

the SST on 12m and up because the overall RF gain is a bit low on these

bands.

 

Your doubler approach is interesting. Note, though, that you can also use a

23 or 24MHz range fundamental crystal. They're available from ICM and other

suppliers. You might even consider using a higher I.F. so that a somewhat

lower frequency VXO could be used.

 

I'm curious what frequency range you chose for your 10m SST. It seems that

CW and QRP operation can be found from 28.0-28.1, with no narrow QRP range

as on the lower bands. This is a bit of a problem for a rig with a small

VXO range.

 

In any case, I hope to work you K2-to-SST on 10m someday. It's one of my

favorite bands.

 

73,

Wayne Burdick

N6KR

 

==============================

 

120. Subject: 10 M SST - More details

Date: Wed, 05 May 1999 13:38:59 -0500

From: mjfitz@uswest.net

 

Wayne,

Nice (and surprised!) to hear from you. I have been an admirer of

your work and think you are some kind of electronic genius (the right

kind, that is...).

Yea, I figured the gain would be down thru the mixers at 28 MHz and

had been eyeing the single-transistor RF amp circuits in the

cookbooks...and realizing it might need a switching transistor as a

sidekick to prevent destruction.

I was amazed, however, to hear a couple of quite weak signals on the

Ten Tec that I could also hear on the SST almost as well. I would

"guesstimate" that the signal thru the SST was only 3-5 dB down (just

noticable difference), and I swear it made my jaw literally drop when I

heard it...At this point I proceeded with building a transmiter board

and wiring the thing up.

The freq. doubler circuit I used is a half-wave 1N4148 followed by a

single NPN (metal 2N2222A) -- about ten parts. I used both varactors

(108 & 209) soldered to the backside of a DPDT toggle. The inductor is

27 T on a T50-2, and the thing tunes .043-.063 right now...haven't

really tweaked on it much yet, just got it in the ballpark. I used the

standard 3.93 Digi-Key IF xtals. The gain thru the doubler is unity,

what went in seems to come out, only twice the freq. The text in "Solid

State Design" stated that if you didn't use matched diodes you would

find the fundamental down about 40 dB at the output, and if you matched

them it would be near 60 dB down. I matched them...and cannot see

anything on the scope (Tek TDS 210) but a nice 32 MHz sine...

OK Wayne, thanks for the encouragement. And yes, I hope to work you

SST to K2 on the bands someday, too. I also expect to be able to work

you K2 to K2 one of these days soon because I know that Christmas in May

(or maybe June) is coming when the UPS guy comes strolling up the

sidewalk with a nice box and wants me to sign for it...I dropped my

order in the mail for a K2 on the Friday BEFORE the Monday when you

first started taking regular orders. Hey, tweak that baby all you can

before you sent it to me...I can wait!

 

Later, 'O Great One

Mike KI0AF

===========================

 

121. Subject: Re: SST-40 R5 tuning range mod - good details.

Date: Sat, 15 May 1999 21:02:41 +0100

From: Larry Cahoon <wd3p@juno.com>

 

After hearing of the R5 mod for the SST-20, I had to try it for the

SST-20. The range on my SST-20 was just fine in my book. But for the

SST-40 with both diodes in the rig I was did not cover 7.038.6 to

7.040.4. Not at all satisfactory. I never got around to doing any of the

other mods to open up the range. Mostly because I did not really want to

change it that much.

 

The original mod put in a 10K resister in parallel with R5 to bring R5

down to about 9K. I didn't want to open up the range as far as that did

for the SST-20. Also I did not want to get into any problems. So I first

tried replacing R5 with a 47K resister. That did not succeed in covering

the hole. So then I went down to a 33K resister. That solved the problem.

Checked the power out and it is rock solid stable across the entire

range with either diode in the circuit. I think I'm good to go.

 

The Numbers

 

100K 7.030.7 - 7.038.6 and 7.040.4 - 7.043.3

47K 7.030.6 - 7.038.8 and 7.039.1 - 7.043.6

33 K 7.030.3 - 7.039.1 and 7.038.5 - 7.043.6

 

Back to fun on the air, 73/72 de Larry.............WD3P in MD.

====================

 

122. Subject: 10M SST OPERATES-Comments from KI0F the builder

Date: Sat, 29 May 1999 19:26:54 -0500

From: mjfitz@uswest.net

 

Brewers--

Have posted a couple of times about the HB 10 M SST under

development...

Worked a few stations with it today in the contest, including CW9A

(Uruguay).

Have added a tuned input/output FET RF amp to front end, one of W1FB's

designs (grounded-gate 2N4416A). Now you must turn DOWN the gain on

strong signals... Didn't have much of an antenna, just a sloper dipole

at 30 ft or so, pointed NW.

Puts out about 1.5 W. on a gelcell and sounds good on the big rig.

Used LDG QRP autotuner and twinlead for feed. Tunes 28.043-.063 at the

moment, with a single VXO xtal (16 MHz + freq. doubler).

Think I'll try and find a few minutes to run it tomorrow--mid-late

afternoon here in IA (CDT). Be around .060 calling CQ QRP...

Mike KI0AF Mo. Valley, IA

===============================

 

123. Subject: Norcal SST Keying - Wave Shape Info.

Date: Sun, 13 Jun 1999 14:18:57 -0400

From: "Paul Christensen" <paulc@mediaone.net>

 

For the first time in nearly two years of use, I decided to look at the

keyed wave-shaping on my Norcal SST with an oscilloscope and compare it

against the Norcal 40A and Sierra. A Bird Model 43 together with a Bird

4273 coupler was used as my R.F. sample point. Supply voltage was

maintained at +13.8 VDC. The 40A and Sierra show exceptionally good keying.

However, the SST shows excellent keying on the leading edge, but a hard,

unshaped trailing edge which generates a key click.

 

In reviewing the SST's schematic, I see little, if any wave-shaping

components between J3, U4, and U5. I realize that the SST was designed as

an exercise to extract the most performance with the fewest components

possible. Has anyone else noted the same keying characteristics? Has

anyone tried inserting a simple wave-shaping circuit to increase the

trailing edge decay time? Thanks!

 

-Paul, W9AC

===================================

 

124. Subject: 2Re: QRP SST-20 info - Lots of info from San >> WB9ELB

Date: Mon, 21 Jun 1999 12:49:46 -0700

From: San Rotter <rotter@ieee.org>

 

>> San

>> WB9ELB

C:\QRP\Pictures\SST-20X2.bmp;

C:\QRP\Pictures\SST-20-dial-calib.bmp;

 

C:\QRP\SST-20-VXO-control-adjust.bmp;

C:\QRP\sst-20-10K-pot-tuning.bmp;

 

Jim -

 

I used a BNC tee connector with a dummy load on one end and a 10:1 scope

probe to a Optoelectronics Model 2210 frequency counter and made some new

measurements.

 

 

14.0 61.9 8

14.0 61.9 10

14.0 61.7 12

14.0 61.5 15

14.0 60.9 20

14.0 59.9 25

14.0 59.1 30

14.0 58.5 35

14.0 57.8 40

14.0 57 45

14.0 56.2 50

14.0 55.4 55

14.0 54.5 60

14.0 53.6 65

14.0 52.6 70

14.0 51.9 75

14.0 51.3 80

14.0 50.6 85

14.0 50.4 90

14.0 50.4 92

 

 

There is compresion on both ends. My tone deaf ears worked prety well. I is

hard to tune the transmitter fast w/o smoking the final to a even value. So

I just set the even dial values. Could turn the input voltage to the rig

down to lower the power out and measure on even MHz values sometime.

 

If you have any trouble recieving any of this email back and I can zip or try

another format.

 

72,

 

San

 

It looks like I will order some Q-dope to attempt to stop the wires from

moving on the toroids and then use a non corrosive clear low loss dielectric

RTV to strain relieve the toroids.

 

At Motorola they would put the two part RTV in a vacuum for 10 or 15 minutes

to remove all the bubbles. It was shown that migrating bubbles would pull

wire bounds. I have had trouble thermo-cycling coils of all types without

encountering some hysterics. Some coil manufactures I found where terrible

when thermo-cycled.

 

Q-dope information below:

 

72,

 

San

 

p.s. see below for a couple extra messages:

 

 

Q-dope

 

 

http://www.qsl.net/~wd8rif/qq.htm

QRP Quarterly

October 1998

"Hard as Nails" as Q-Dope Substitute, W4LJD

 

Frank Brumbaugh, W4LJD of Salinas, PR. dropped this note -- "Hard as Nails",

a clear liquid plastic intended to overcoat for colored nail polish can

replace Q-dope and is much harder than Q-dope or clear nail polish. Keep the

materials in the refrigerator along with the XYL's nail polish to extend

useful life prevent thickening.

 

/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\

 

Central Utah Electronics Supply

735 South State St., Provo, UT 84606

(801) 373-7522 or Fax (801) 373-7736

 

http://www.itsnet.com/~cues/cues.html

 

Q-Dope, a polystyrene lacquer

 

/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\

 

Mouser Electronics

Phone: (800) 346-6873

Fax: (817) 483-6899

E-mail: Sales@mouser.com

 

Mouser Stock#

Description

 

524-10-3702 G.C. THORSEN INC POLYSTYRENE Q DOPE 10-3702

 

524-10-3704 G.C. THORSEN INC Q-DOPE-4oz TUBE 10-3704

 

524-10-4102 G.C. THORSEN INC Q-DOPE THINNER 10-4102

 

524-10-5002 G.C. THORSEN INC RED-X CORONA DOPE 10-5002

 

/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\

 

http://www.action-electronics.com/gcelect.htm

 

GC ELECTRONICS 10-5002 153 8.23

 

/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\

 

http://www.allied.avnet.com

 

Q-Dope Polystyrene, fast-drying. Leaves a clear protective coating.

796-4335. 10-3702. 2 Fl. Oz. Bottle........EACH 5.11

796-4340. 10-3704. 4 Fl. Oz. Bottle........EACH 8.57

 

Electronic Grade Silicone Sealant/Adhesive One part non-corrosive, neutral

cure electronic grade silicone sealant. Will remain flexible from 60C to

+200C (70F to +390F). An excellent adhesive for many electrical and

electronic applications where corrosion to metals is a problem. Good

dielectric properties, high surface resistivity and resists electrical

tracking. Meets the requirements of Mil-A-46146a-Type 1; meets the

requirements of FDA status, FDA Regulation #177.260.

796-9845. 19-155. 3 Fl. Oz. (90 ml). Tube

........................................EACH 5.50

 

 

Date: Wed, 05 May 1999 16:21:12 -0700

>To: Roger Deutsch 0

>From: San Rotter <rotter@ieee.org>

>Subject: SST-20 VXO linearization circuit

>X-Attachments: C:\QRP\SST-20-VXO-control-adjust.bmp;

>

>Roger -

>

>I attached a linearization circuit for the SST-20 VXO. There are still

curves in it but it is a lot more linear than without additional parts. I

need to take more points on the curve by making a face plate that has degrees

calibrated on it.

>72,

>San

 

Don -

 

You can see the non-linerity close to zero in:

C:\QRP\sst-20-10K-pot-tuning.bmp; Easier to send pictures than describe on

the air. I will have to calibrate the pot more to take more points on the

curve. Here is another message I sent Roger KA9UDA:

72,

San

 

Roger -

 

 

I added a resistor and pot to slightly widen and linearize the tuning range.

 

new pot series resistor 100K//10K new 10K

/\/\/ |

| ^---- |

tuning pot /\/\/\/\/\/\/\/\/

+ wiper -

 

clock degrees

Pot Pot Freq

0 6150

9:00 45 5980

12:00 135 5525

3:00 225 5010

270 4900

 

 

You can see the old one is not very linear at all. So now that I go to

14.061.5MHz it is not that bad. Real nice radio. You can see that it gets

flat around 270 degrees. But the rest of it looks OK.

 

Tell how my ascii schematic came out. If it gets messed up I can make a BMP

schematic.

72,

San

=============================

 

125. Subject: re: audio-out freq. counter for the SST de N6KR

Date: Sat, 17 Jul 1999 10:18:35 -0700

From: Wayne Burdick <n6kr@elecraft.com>

 

Tom, I don't know about the Freq-Mite, but I designed the SST specifically

so that you could put a Wilderness KC-1 memory keyer/audio-out freq.

counter inside the box. The KC1's two buttons and keyer speed control face

up on the top cover. This still leaves room for a 9V battery inside the

case.

 

Note that the KC1, which I originally designed for the NorCal 40 in 1995,

includes a "search" mode that allows you to use the keyer paddle to specify

a target frequency. You can then turn the VFO knob and you'll be alerted by

the KC1 when you get to the target.

 

73,

Wayne

N6KR

* * * *

Gang!

 

Has anyone put a Freq Mite in a SST? If so, let me know how easy it is.

Thinking about ordering one.

72, Tom WB5QYT..."Have spud will travel!"

====================================

 

126. Subject: SST RIT - RIT SST

 

While this is a for sale message, Bob says he put an RIT in his SST. Perhaps he can answer questions for interested SST builders. JL

 

Subject: SST's for sell

Date: Sun, 18 Jul 1999 15:51:31 -0500

From: rbcallahan@juno.com

 

I have a 40 meter and 20 meter SST for sell. First, on the 40 meter SST

I have installed a switch to switch between two crystals which gives me

about 7.030 to 7.045 or so coverage. Also I installed a air cap on the

front panel for a little RIT control...Also on the 20 meter SST I have

installed a CAP for RIT control that is accessible through a hole I

drilled in the top cover and I installed a switch to switch between both

voltage variable caps supplied with the kit. Both work very well. I am

asking only $65 each. I will sell one or both. First come first served.

I will ship anywhere in US. I assure your satisfaction. I used the 20

meter SST with a homebrew external amp for over a year and love it. I

now have a Sierra and don't use the SST's anymore.

 

If interested please E-mail me at: rbcallahan@juno.com

Thanks,

Bob Callahan KC5T #1792

 

==============================

 

127. Subject: RIT for SST by Bob Callahan KC5T

Date: Wed, 21 Jul 1999 21:32:53 -0500

From: rbcallahan@juno.com

 

Hello Jim,

 

I am sending this response to you directly concerning the RIT system in

the SST.

All I did to give me a measure of RIT was to reduce the 270pf cap on the

RX mixer (NE612)by about 15 or so PF and then placed in parallel a fairly

large value air cap in with it (about 40 or so pf). I found in my junk

box one that was also small enough to be mounted on the front. Also,

this cap must be insulated from ground as the 270 pf unit is not

connected to ground directly but through another cap. I don't recall the

cap number but it was the one at a value of 270pf on the RX mixer. By

this I had some measure of RIT through the original setting of the RX

mixer.

That really about it.. If you have any questions just give me a E-mail.

rbcallahan@juno.com

 

Thanks,

 

Bob Callahan KC5T

 

================================

 

128. Subject: SST howling problem and solution

Date: Fri, 06 Aug 1999 10:04:58 -0400

From: "Ed Lawson" <elawson@lr.net>

 

I have a SST 40 and 20. Both work very well except for one

issue. With the volume up they will often develop an audio

oscillation or howl. I've looked at the list of mods and found

references to fixes, but these seem to be incorporated in the

kits I built. This is not a constant problem, but there is a tendency

to oscillate upon keying with the volume up.

 

Anyone else encounter this issue and managed to resolve it?

Any construction issues that may be causing it?

 

Like the rigs, after all I worked a RA3 with the SST20 the first night

it was completed and tested. It was QRP to QRP with Alex running

5 watts.

 

Ed Lawson

K1VP

 

Subject: SST Howl Solved

Date: Wed, 11 Aug 1999 15:41:04 -0400

From: elawson@lr.net (Ed Lawson)

 

Thanks for all the responses to my question on the SST.

Looking at the schematic made me think all the filter caps

that were suggested are now on the board.

 

Anyway,

being the type who always tries the simplest solutions,

I tried using different headphones as someone suggested

and no longer a problem.

 

Ed Lawson

 

===========================

 

129. Subject: SST: shifting the VXO up; narrow filtering de N6KR

Date: Fri, 20 Aug 1999 12:28:27 -0700

From: Wayne Burdick <n6kr@elecraft.com>

 

Mark wrote:

 

My SST runs from 7.0245 - 7.0405. How can I get that lil bugger to go up to

7.042 so I can do the AR-QRP net? I can't find any info in the manual about

moving the freq.

 

Hi Mark,

 

You can shift the VXO frequency of the SST up in two ways. The easiest way

is to use the supplied MV209 varactor diode at D4 rather than the MVAM108.

However, if you're already using the MV209, try replacing RFC3 with a

slightly smaller choke.

 

If you end up with a higher end point but a narrower range as a result of

the above, you can regain some range by changing R5 to a smaller value,

perhaps 22 K. (This is experimental, however.)

 

As for received signal sound: The 38-special has a very wide filter due to

its high I.F. (12 MHz as I recall, and probably something like 1.5 kHz wide

at -3dB). This does sound good -- until you have adjacent-channel QRM. The

SST has a *very* narrow crystal filter (200-400 Hz at -3dB) that is great

for eliminating QRM but is harder on the ears because of the constrained

audio range. This is true of any receiver with a narrow filter; a narrow

band of audio frequencies is more fatiguing to the human ear.

 

But this is a good tradeoff since the narrower filter also increases

signal-to-noise ratio, making weak signals easier to copy, especially in

the presence of noise. (This is vital on 40m if you're trying to copy

stations in a QRP net about the time that your local power lines start

humming.) To quantify this, the signal-to-noise ratio of a 300 Hz filter

will be about 14 dB better than that of a 1.5 kHz filter, assuming the

information bandwidth is well below 300 Hz (true for most CW signals!). The

math: SN_improvement = 20 log(1500/300) = 13.98 dB.

 

On the other hand you may have a problem with your SST receiver: it should

never sound "rough" even with the narrower filter.

 

73,

Wayne

========================

 

130. Subject: SST -Need cure- Rec Freq. Vs Tx Freq.

Date: Wed, 25 Aug 1999 12:46:54 -0600

From: tom whalen <wb5qyt@eFortress.com>

 

(Maybe Tom found and answer and will share is you contact him)

 

Gents!

Need a simple cure for getting the rec freq on the SST to be in more

line with the xmit freq. They have talked about c-10 making it a

variable.Is that the mod for changing the rec freq? Anyone know of a

simple RIT mod for the SST?

Great little rig, but most of the stations I talk too are too low in

freq and it's driving me crazy!!

Worked a couple of stations on 30 meters the other night....One at 100

mw and the other at 300mw...FUN FUN!!

72, and thanks....WB5QYT...."Have spud will travel!"

PS: Just finished my SW-40+.....NEAT RIG! Going to use it RR mobile this

fall and get some pelts!

 

===================================

 

131. Subject: SST - rig appeared to change in freq when touched

Date: Tue, 31 Aug 1999 08:40:37 -0500

From:"Mark Hogan" <mhogan@email.msn.com>

To:

 

Thanks to those that gave my input on my SST last week. When I looked

inside there were some extra chokes in line with the original RFC3 which

increased the bandwidth and dropped the split. They were however almost

touching the case. When I had my finger on that side of the case while

tuning, the rig appeared to change in freq. a little as I took my hand away

from the case. I moved these away from the case and this stopped. I then

reduced the value of RFC3 and now have a rig that will go up to 7043.5 this

will let me get on the AR-QRP net with a real QRP rig. Yesterdays fox hunt

announcement did not hurt either, now the rig has the right split for that

also.

I set the power to less then a watt `750 - 900mw, (the MFJ is not too

precise, WM2 is still a dream away). So I'm at least starting to milliwatt.

I need to do some antenna work and put new feedline up in the next few weeks

then I'll cut the power some more.

So there you have it, I'll be on 40 from time to time with my Speed-X bug

(ouch) or for a real challenge the Schurr mini straight key (what a dream)

trying to send at the same slow speed I copy, if ya hear me and feel up to

the challenge of my fist (I'm sure I make anyone else look like a PRO CW Op)

I'll welcome the reply (and those guys on 30 are probably glad to get a

break from me and my 38s).

 

 

Mark Hogan / N5OBC

 

===================

 

132. Subject: SST sidetone Questions.

Date: Wed, 15 Sep 1999 19:33:49 -0400

From: aa5yx@juno.com

 

They say that if you only have one clock, you always know the correct

time but if you have two, you are never quite certain which clock is

correct. I now have 2 SSTs - one for 30m and one for 40m (which I just

completed today) and they both have quite different sidetone pitches.

 

The sidetone in the 40m version is a lot higher than that in the 30m rig,

but according to the troubleshooting guide, I can adjust this tone by

changing C10. My first question is, whether or not I make this

adjustment, do I tune to a station by matching his tone to that of my own

sidetone, even though the sidetone in my 40m SST seems higher than I

think it should be?

 

And part 2 of the question is, to lower the tone, should C10 be a higher

or lower value? I'm betting it should higher but if anyone knows for

sure, it might save me a step in unsoldering/resoldering!

 

FWIW, the new rig works great. I just had my 1st QSO with it with W8IMP

in Detroit and then was called by N3AT in PA who gave it a thumbs up.

 

Thanks and 72,

 

John Harper AA5YX/2

HW-9, OHR-100A/20m, NC40A, SST/40, SST/30, NC20

YashicaMat 124G Info Page: http://home.att.net/~j..harper

 

------------------

Subject: Re: SST sidetone

Date: Wed, 15 Sep 1999 20:27:03 -0400

From: "John L. \"Jake\" Carter" <jakecart@ix.netcom.com>

 

I'm just finishing up a Small Wonder Labs GM-15 -- different rig, different

company. But the rig's manual says that increasing the value of C38 raises

the sidetone pitch (and Tx offset) and decreasing C38 lowers it. Maybe

that's because increasing capacitance increases the frequency, ie the amount

of the offset and the further you get from the zero beat the higher the pitch

-- just guessing on that one.

 

With regard to tuning the received station, I'd tune so that the received

signal matches my sidetone pitch.

 

Hope this info helps (I also hope its correct :-) )

 

72,

 

Jake -- N4UY

 

=====================

 

133. Subject: 10 M SST - Adding and IF Amp

Date: Sun, 26 Sep 1999 00:46:45 -0500

From: mjfitz@uswest.net

 

Alright!

A ten meter get-together on Sundays sounds good. A few

days ago I put an IF amp in the 10 M SST I have 'brewed.

Stole the design out of the NC20 (thanks Dave!) and put it

just behind the xtal filter. It really pepped it up a

bunch. It also has a grounded-gate 2N4416 RF preamp ahead

of the regular SST receiver, and a MRF-237 final. Puts out

about 1.5 W at 13.8 V.

Now, when you connect an antenna, the band noise is

extremely loud with the volume at max using a sensitive set

of phones.

I told John, NU0V, the editor of the Iowa QRP Journal,

that I would write up a how-to on this radio for the fall

issue. No big secret...just use a 16 MHz xtal followed by a

freq. doubler to get the VXO signal...regular 3.94 MHz 20 M

SST IF xtals and tx mixer xtal. Tunes 28.043-.063 with two

switched varactors.

Yes, I have posted about the rig before, just wanted to

BRAG about the IF amp...

Catch you on ten soon.

Mike N0MF

======================

 

134. Subject: Re: 15M SST - and 17M

Date: Tue, 28 Sep 1999 21:17:05 -0500

From: mjfitz@uswest.net

 

Folks,

 

An SST for 15 M is very easy to homebrew using

pad-and-glue method. Have posted on this topic before...see

link below for article (by KI0AF, a real cool ham) on this

topic.

 

This guy has homebrew SSTs on 40,30,20,15, and 10

meters. Watch for an upcoming article in the fall issue of

the on-line Iowa QRP Club Journal on building a 10 M SST,

coming soon to a modem near you...

 

It is also possible to put one on 17 M.

 

ftp://divis17.ped-gen.uiowa.edu/pub/iaqrp-l/journal/spring1999.pdf

 

Ah... how's that guy out east put it...melt solder?

 

Mike N0MF

Mo. Valley IA

(ex-KI0AF)

===========================

 

135. Subject: 15 Meter SST - Text file from N4SO available.

Date: Tue, 19 Oct 1999 11:10:12 EDT

From: charles k brown <n4so@juno.com>

 

<The file from n4so is below this message>

 

Two versions are in the saved text files.

One changes the parts values from the kit and

another version is a 15 Meter Pad and Glue SST.