Farhan Describes his New 2 Meter SSB Transceiver (Video)

On May 16, 2023 Farhan gave us a look at his new BITX23 2 Meter Transceiver. Two days later he made a presentation on this rig at the Four Days in May event. Highlights: -- Use (and non-use) of the Cascade tool -- Cascade and the original BITXs -- ADE-1 -- SI570 -- Raspberry Pico -- Diplexer -- Different Grounds to get rid of digital noise -- Gimmick Capacitors (and gimmicks made from coax) -- Ugly SMD Capacitor Soldering -- Tombstoning! -- Melting RG-174 Coax -- No need to learn Arduino programming -- Dilbert! -- Bill and Pete -- Techie Tatts! Thanks Farhan!

Two days later, Farhan presenting the rig at FDIM

Surface-Mount Solder Smoke -- Is THIS Really Homebrew?

I was recently noting that the assembly of IC, CPU-based projects doesn't seem like real homebrew radio.  I realize that there is a danger here -- there is a tendency in ham radio to reject the new and to stick with the old.  "SPARK FOREVER" was the rallying cry when CW came along.  There are still a lot of AMers who refer to SSB as "Single Slop Bucket." So, with that in mind I point the blog to the above video.    He is using complicated ICs that probably have thousands if not millions of transistors.  But he is definitely making something new. And he releases some real solder smoke in the process.   FB.  

It is probably not for me, but others may like it. Like the old song says "Different strokes for different folks." YMMV.   

Repairing the Sony ICF SW1 Receiver -- Used for Numbers Station Reception? Why no replacement for C-625?

Ten years ago, my friend John gave me this tiny Sony receiver.  It wasn't working.   I tried to fix it but quickly discovered that the tiny size of the device made repair difficult.  All you needed to do was to swap out some leaking electrolytics, but they are surface mount electrolytics -- replacing them is not for the faint of heart.  Kits are available, but again, this is not easy. 

In 2020 I got one of the kits, but didn't try to use it until yesterday.   It only supplied six of the electrolytics.  In the video above, they discuss replacing seven electrolytics, including the one that seems to be placed in the round black holder. C-625.  Why didn't my kit include a replacement for that one?  Could it be that this capacitor was not one of the leaky SMD caps?  

Replacing these caps really wasn't easy. At one point I inadvertently removed not just the bad cap, but also a nearby surface mount resistor.  Luckily the schematic showed it to be 0 ohms.  That was easily replaced.  I lifted one of the pads on one of the other caps -- I just slid it back into place and hoped for the best. 

BTW, I just today discovered that this little receiver may have been used late in the Cold War by those who needed to receive messages from the infamous Numbers Stations: 

 https://www.cryptomuseum.com/spy/sony/icfsw1/index.htm

Great Video on PC Board Techniques, with a Focus on Surface Mount

Wow, lots of wisdom in this video from Leo Fernekes.  Great hints and kinks on prototyping with copper clad boards. I need a Dremel just so that I can make Leo's board cutter.  And I can see that I need some of that liquid flux and isopropyl alcohol. Surf boards and headers! Who knew?  Teflon coating for the wires -- gotta get it. Glad to see that Leo is also a fan of copper tape.

His emphasis on the importance of stage-by-stage construction and testing is right on the mark.  

My only disagreement with Leo is about his use of steel wool.  I've found that steel wool will inevitably cause little tiny "Murphy Whiskers" to float around your workbench. They will eventually settle onto the most inconvenient and damaging place on your board.  So I have banished steel wool from my workshop.  Those green, non-metallic Scotch Brite pads work just as well and don't cause shorts. 

Three cheers for Leo. He is based in Thailand.  He has an interesting background and some really amazing projects and insights:  

http://www.luminati.aero/leofernekes

http://www.fernekes.com/blog/

https://www.youtube.com/channel/UCe1bjEcBichpiAMhExh0NiQ/videos

Thanks to Tore LB4RG for alerting us to Leo's video.  

DK7IH Improves his Shirt-Pocket Transceiver

More great stuff from Peter DK7IH.   He recently made some improvements to his "Shirt-Pocket SSB Transceiver.  On his blog he explains why he made the changes.  Note the Si5351 that is in there now.  I liked the 1 cm square T/R unit that Peter wrapped in heat shrink tubing. He also provides a really nice description of how to do front panel labeling with a laser printer.

Here it is: https://radiotransmitter.wordpress.com/2020/06/28/re-engineering-my-1st-shirt-pocket-transceiver/

Thanks Peter!

Above Board: Manhattan-izing an SMT kit

A while back, Tony Parks very kindly sent me one of his wonderful Softrock RXTX V6.3 Software Defined Radio kits. I took a shot at it, but it turns out that I'm not very good with surface mount construction using small parts. I've gotten very used to the Manhattan style. Still, I did manage to build one of the Power Amplifier modules, and I put it to good use in a DSB WSPR transceiver I've been building (see above) . It worked great. For a while... Then it released some smoke.

I started trouble shooting and it was at this point that I REALLY began to miss good ole' Manhattan (you see, I was born there, and I went to Manhattan College, so I guess this helps explain the affinity). It was difficult to get to components mounted under the board. The whole thing was the size of my thumb... I know, whine, whine, whine... Luddite Geezer-ism strikes again. SPARK FOREVER!

It turns out that the problem was caused by the fact that my shack is just not well suited for this kind of construction. There is a lot of stuff floating around. Conductive stuff. Look closely at the picture below and you will see what I mean. You will see what caused the release of the smoke. Look at the leads on the PA transistor on the left. That's a little bit of stray wire that found its way to the WRONG place. Note the toasted source resistor just below!

Anyway, after a trying to fix this thing, I finally gave up and decided to use the circuit, but in Manhattan form. Everything up top. No SMT. Bigger coil cores. The temperature sensing circuitry went off to the right. The output transformer went off to the left, and the driver stage went down below the kit's board. Here is what it looks like now. Again, it works great.

I want to thank Tony and the Softrock guys for giving me this experience. Their kits are wonderful and are really making a tremendous contribution to the hobby. I strongly recommend them. The instructions are great, much like those of the old Heathkits. But for me, I'll take Manhattan.

VK6ADF: Echolink, WSPR, 6 Meter Yagi

From London I used to talk to Phil, VK6ADF, on Echolink. We have a lot of interests in common. This may be due to the fact that we were both born in the International Geophysical Year. Phil is now reading "SolderSmoke -- The Book," so we will probably discover other areas in which we have crossed paths. This week, I decided to get back onto Echolink, and in my first session I was looking for OM Phil. He wasn't on, but, IN A VERY MYSTERIOUS TWIST, that morning he sent me an e-mail. Spooky, eh? Anyway, yesterday we got on Echolink and covered our usual wide-range of tech topics. Phil alerted me to a web site called Real Flight that provides an on-line simulator for Radio Controlled airplane pilots. Obviously Billy and I could use some time in the simulator!
Phil is also into WSPR and as we spoke I fired up my 20 mW DSB WSPR rig. I was immediately heard by an Irish station, and Phil almost instantly saw the report on the WSPR database. I noticed that the EI station was reporting that I was on 40 meters, when in fact I was rock-bound on 30. Again, as Phil and I talked, I went to the WSPR chat section and asked about the freq discrepancy. Another VK6 (a friend of Phil's!) answered my question (a simple set-up problem). Small world.
Phil and I have similar curmudgeon-like thoughts on Surface Mount Soldering, and he seemed sympathetic when I said that I think I am more of a "Hardware Defined Radio" guy. Again, this may be an IGY thing. Oh yea, almost forgot: We're not crazy about LINUX either. We are only a few short steps away from the "SPARK FOREVER" mentality and full-fledged Luddite status.
One interest that Phil and I DO NOT share is Six Meters. Phil is now addicted to the Magic Band (which I still consider to be a white noise generator). Check out his video on his six meter yagi.

Stagnosald! (Italian flux)

For some reason I like the packaging for this Italian soldering flux. Sort of takes you back to the days when soldering was soldering, if you know what I mean. Now (somewhat ironically) we are using this flux for SMT soldering. On the left you can see the PA stage of my slowly-coming-together SMT SDR LINUX Compu-radio. As you can probably tell, I am struggling to keep a positive attitude towards SMT and SDR. Lately, even Linux has been giving me trouble. The problem here is clearly with the operator, not the equipment. The Softrock SDR kit is really excellent. I'm sure I will eventually get it working, but I think there will be a lot of geezer-like complaining about all this new-fangled surface mount, software stuff. Please, bear with me.

A Report from South Africa

Hi Bill

Africa "field QRP station"
Thanks for another great episode of your experiences - I'm tuning in from Africa while on my vacation Each December I make the trek from San Diego to Cape Town.
Then, my Dad (zs1xd) and I take the family out to a remote
location - and setup a field station. Around the camp-fire, under the Milky Way and no rf-pollution is a great way to hunt some dx and spend vacation time. This year
we selected a cabin located in a beautiful mountainous region about 100 miles north of Cape Town. 2 wheel vehicle will get you there and "just in case" , we
also took a capable 4x4 with.
I posted some pics and QRP HF operating notes here: http://k6wh.blogspot.com/

"SMT"
I'm following your Softrock SMT construction comments with keen interest and am glad you're finding the challenge - well - "not so much of a challenge"
I think it's so great that you're encouraging hams to jump into SMT.
I chuckled at your comment about "desoldering smt's" - Try de-soldering the Si570 SMT chip. I had the good fortune of measuring messing up the
"measure 10 x then cut once" when soldering this IC on the rxtx kit. Well - we know a mistake will happen, and when it happens, murphy's law will ensure
that it involves the most sensitive and tricky smt component on the board - hi.

It's a real trick, due to the contacts being under the chip (no pins like the other smts)
Well - try de-soldering that piece. And of course one realizes the mistake, only once the last solder joint has dried. Determined to correct the mistake there and then,
at 9pm while busy with the kit, I rushed off to the nearest radio shack to get some de-solder wick. Took me about 1 hr of patience, and careful "wicking" to suck
up all the solder underneath the chip - one contact at a time, (each desolder attempt, hoping the chip pops loose) - no easy task. I don't know of another easy way
than lots of patience, and a good magnifying glass.

I agree there is no greater reward than "homebrew" and with the advances in SDR tech, we're surely living in a wonderful age.

Once you get the SDR on-air, I'm sure you'll be blown away by the reception quality - sensitivity and especially the almost non-existent noise-floor.
(I'm not sure which model you're building, but I think all of Tony's designs are utilize the same Tayloe detector design which is very quiet)

I still can't believe the performance I get with the Softrock's kit - It's now become an antenna measuring instrument - While having fun with PSK QSO's and WSPR.
Of course, with the SDR one can adjust the output (via soundcard drive) to basically uW levels.

As we know, at these levels, each little bit of antenna optimization helps, and SDR+WSPR/PSK has become my "far field antenna measurement tool" of choice.

WSPR from Africa
Not too many stations active on WSPR on the African continent - Now that I've setup my Dad on DSL, I assisted him in activating his WSPR station in
Cape Town (ZS1XD). His antenna is a 20m homebrew 2 el yagi. I'm pointing it north during the evenings to see if n2cqr pops up in the log. Nothing yet, but I'm sure
one of these days, you may just be surprised. Keep watching for the Africa report :)

thank you again for such a great entertaining and educational program ...
73 - best wishes to you and the family from the tip of Africa.
de deon (k6wh)/zs

KD1JV's Surface Mount Video

OK SolderSmoke fans, here's a video for YOU! Steve "Melt Solder" Weber has put out his first video. It is about surface mount soldering. It is all very interesting, and some actual solder smoke is released, but I was a bit disturbed when Steve put the PC board on an electric stove and then started using this purple thing that looked and sounded like a hair dryer. Made me yearn for my Weller soldering gun. Great video Steve, thanks!