SolderSmoke Daily News

School for Danger -- the SOE, and Radio, in Nazi Occupied France

2026-05-21T06:59:43.293-04:00

Hack-a-Day had a link to this film. It is really good. There is some stuff about radio, and especially the S-Phone system. But the bigger message of the film is the danger faced by the heroic teams who parachuted into occupied France. As shown in the film, many of these people were young women who risked it all in the most dangerous of airborne operations. It is a reminder of how ridiculous the focus on masculine valor in airborne and special operations really is. Three cheers for the SOE. For all of them.

Farhan Talks LARCSet (CW & SSB) at FDIM (with a Lot of Homebrew Wisdom)

2026-05-20T09:26:56.621-04:00

Watch the presentation here: https://www.youtube.com/watch?v=MefojjQ84YY

Farhan made it to FDIM 2026 (he must hold the "distance travelled" record!). We thought he might be talking about the latest version of the digital SDR sBITX, but NO! Farhan talked about the entirely analog LARCSet, a 30 dollar SSB/CW monobander. And in the process he shared a lot of good homebrew history and wisdom. I took notes on the video of his presentation:

-- Farhan recounts his discussion with Steve Hartley, President of GQRP. Farhan said he started to talk about SDR projects, but Steve steered him away from all that. Farhan said he realized that the homes of GQRP members are often small, and projects need to fit into took boxes that are pulled out as needed. There is often not even enough room to mount a screen. Analog rigs just fit better.

-- Farhan talked about the beauty of analog. He also shared some info on the recent timeline of analog rigs, going back to 1976 with the IARU gift kits made available by W1VD. Farhan very kindly mentioned the DC receiver that Dean and I are promoting. He talked about the 2003 BITX 20 rig, and the subsequent uBITX. Farhan talked about the cleanliness of all-analog rigs. "SDR's are a mess!" he said. "With SDRs it is difficult to avoid hash."

-- Farhan said he had trouble measuring the phase noise of the VFO in the LARCSet. He consulted with Wes W7ZOI. Wes told him this was NOT a measurement problem; VFOs have almost no phase noise. The level is even lower than that of crystal oscillators. Of course, crystal oscillators are more stable, but they also have more phase noise.

-- He noted that almost no recent homebrew design does not rely on an Si5351. This, he said, is "not a healthy situation." Indeed.

-- Farhan talked a bit about how Indian regulations seemingly require a deviation from the completly open source ethos. Indian regs require companies to have assets. So the PC board layouts have to remain proprietary.

-- Farhan talked about the sharpness and shape of the BP filter in the LARCSet. I remember talking to him about the shape of my BP filters in my dual banders -- I had to rebuild the filters.

-- On the crystal filters that form the heart of SSB rigs, Farhan noted that cheap low Q crystals often introduce a lot of loss in the filters (that may explain my problem with some styles of computer crystals).

-- A member of the FDIM audience asked about the Sharpie written frequency readout on the LARCset that Farhan showed to the group. Farhan told them that this was the only frequency readout used in the rig.

-- With the LARCSet, Farhan used varactors to vary the frequency. But the varactors he used were cheap but horrible. They varied the frequency as the rig hearted up. The LM386 was the source of heat. He also noted that the cheap varactors, while cheap, did not provide linear frequency readout. Farhan said the varactor scheme was still not perfect; he offered a PTO solution that could be used instead. Three cheers for the PTO!

-- Farhan said the LARCset was really an SSB rig, but when coming to FDIM he said he felt obligated to present a rig that included CW, "or they would throw me out of the room." Farhan described a scheme to generate CW based on what was done with the Atlas rigs.

-- Farhan said the LARCset might even work on 2 Meters. Hmmm.

-- On tuning, Farhan said he used a very large tuning dial (he said it was like a steering wheel) and then recommended the use of a smaller control that could serve as an SSB "clarifier."

-- Farhan pointed out that homebrew rigs are never really done; even decades later, they can still be modified.

Watch the presentation here: https://www.youtube.com/watch?v=MefojjQ84YY

Rick N3FJZ on the Red Summit Podcast with Charlie NJ7V

2026-05-17T07:35:54.782-04:00

Check it out!

https://www.youtube.com/watch?v=sUQA2uNskEs

I liked Rick's story about his early days in radio electronics. Taking old TVs from the street -- been there, done that! FB Rick,

Rick points out that he has never used a commercial ham radio rig, so he is unfamiliar with some of the "features" of such rigs. Sometimes, I think, the lack of experience is a good thing.

I really like the display that Rick uses, showing the operating frequency, the VFO frequency and the BFO frequency. This might help with our struggle with those who complain that we are 40 Hz off. Rick then notes that he used 15,000 lines of code for this display. Wow, that shows the benefits of being -- like Rick is -- both a real software wizard and a hardware wizard.

Rick describes how he uses tin-plated steel boards in lieu of copper clad boards.

I liked his approach to schematic drawing -- we benefited from this in the SolderSmoke Direct Conversion receiver project.

When Rick talks about taking pieces of schematics from other rigs and making them work in new rigs, Charlie notes that, "this is the ham radio way." Exactly.

There is a lot of really sentimental stuff in this podcast. SolderSmoke is mentioned frequently. They mention Pete and Dean. This starts at around 22 minutes. Rick talks about Farhan at around 26 minutes. And he talks about Wes W7ZOI.

Rick talks about some of his early projects. I have a sentimental attachment to his Lakeside DC receiver:

Then, a few years later, we had our first HB2HB contact. Homebrew rigs on both sides:

https://soldersmoke.blogspot.com/2015/10/hb2hb-n3fjz-n2cqr-si5351-and-bitx-tias.html

Finally, I agree with the last sentiment expressed by Rick in his conversation with Charlie: The Red Summit podcast -- especially with its focus on homebrew -- is exactly what this hobby needs. Anything that encourages hams to experience the fun of homebrewing is a good thing. Three cheers for Rick and for Red Summit.

SolderSmoke 264: CW TX, Repair of 17-12 Rig, AI and Repair, Back on 40m, HB for 2m, VWS WSPR Makers Project , MAILBAG

2026-05-12T13:50:25.137-04:00

QSO May 8, 2026 with Lou EA3JE. I was using my Mythbuster

May 12, 2026

SolderSmoke Podcast #264 is available for download:

Audio: http://soldersmoke.com/soldersmoke264.mp3

Video: https://www.youtube.com/watch?v=_9FcfuqjZxA

We had a small recording glitch at the beginning of this video. But we didn't lose much. We had talked about the success of the SolderSmoke Direct Conversion Receiver Project. We talked about the receivers built by Nader Omer ST2NH and Chuck Adams AA7FO. We had also gloated a bit about our April 1 post -- you know, the (bogus! ) story about how the Administration is "Supporting Homebrew Radio." (Let us know if you were taken in by this, even for just a few seconds.) At that point, we were just beginning Pete's section; that is where the recording began. Here are the notes for the rest of the podcast:

Pete:

Three CW transmitter projects featuring low parts counts. Good results from Reverse Beacon Network.

The goal in these projects is to raid the junk box and severely limit any new purchases of components. Pete had no idea of the depth of parts he bought and just stashed away. https://www.youtube.com/watch?v=5YLZ7aZpmxQ&t=30s

Bill:

Fixing the 17-12 Rig. Parasitic VHF Oscillations with the SK3050. Good advice from Gemini. Killing NE602s. Fat Finger Syndrome -- hard to work with ICs. Different freq when on transmit -- need for .1 uF cap on pin 8. Worked South Korea -- TRGHS.

Putting the DIGI-TIA back on the air. On 40! And SW listening with the Q-31.

Hard to homebrew for 2 meters. Did some beacon experiments to Puerto Rico on last day in DR.

SHAMELESS COMMERCE DIVISION:

The importance of Patreon! Thanks! patreon.com/SolderSmoke

Mostly DIY RF! https://mostlydiyrf.com/

Universe Today Podcast with Fraser Cain. No Ads. Great stuff. Listen! https://www.patreon.com/public-rss/75186?show=1744036

Dean:

The VWS WSPR project.

Mailbag:

Ed N3EML Heard me on 40 with my Digi-Tia

Grayson KJ7UM Liked WWII training video: https://soldersmoke.blogspot.com/2026/05/radio-receivers-1942-training-film.html

Mike WN2A -- Pete Juliano is our Shifu! (Lexicographer Steve Silverman KB3SII approves,)

Todd K7TFC Thoughtful comments on ARRL "Clean Signal Initiative."

Danny ON1MWS's regen with unusual variable capacitors.

Mike WU2D S-38, Nearfest, Mu Metal. https://www.youtube.com/watch?v=YUQ4xml1dSY

Charlie NJ7V Interviews Mitch NK3H who homebrewed an SSB transceiver.

Charlie also had Don KM4UDX, President of the Vienna Wireless Society on the podcast.

Bob KD4EBM -- El Cilindro. Radioactive Hospital Waste -- basis for a Ruben Blades song. It was 1987 in Brasil. Cesium 137 left in hospital waste.

Hamilton KD0FNR Big fans of "The most interesting man in the world."https://soldersmoke.blogspot.com/2026/04/background-from-maine-on-most.html

Rhett KB4HG -- TW-100! Used on the OMRN. https://soldersmoke.blogspot.com/2026/05/the-tw-100-fly-away-transceiver-cw-ssb.html

What happened to Glenn KU4NO's homebrew rig? https://soldersmoke.blogspot.com/2018/07/a-rig-with-maximum-soul-5-band.html

Ryan KJ7KVD is listening to OLD SolderSmoke podcasts. He will build a Michigan Mighty Mite.

Will N5OLA restored a Heath SB rig. We now know why they went to HW rigs. https://www.youtube.com/watch?v=Bt2d1Ia8lqQ

Paul G0OER -- Thanks us for PTOing the HB world, but sends us a video of a unique Eddystone receiver with 39 permeability tuned coils! https://www.youtube.com/shorts/L4oQHU5_kQk?feature=share

Rick N3FJZ -- A very cool video today on his homebrew HF power amplifiers: https://www.youtube.com/watch?v=-CUVAF4HyfY

Farhan VU2ESE -- I heard from him yesterday as he was landing in Chicago.

A Very Impressive Workshop from the UK

2026-05-10T05:42:58.550-04:00

This one is almost scary. There is an amazing number of machines crammed into that workshop. There is even more stuff in the drawers down below. Honestly, I sometimes thought that we radio homebrewers would be the worst offenders in this regard, but I see here that most of us are not even close. This guy wins!

At the end, at about the 24 minute mark, he demonstrates the use of a "scissor table" that can be used to bring the item he is working on to the needed height. That is pretty cool, and would be quite useful for those working on really heavy gear -- think DX-100s or R-390As. I have heard of hams installing small cranes in their shacks to move these heavy boatanchors around (they do seem to get heavier with time!). The scissor table would take care of this.

After showing the scissor table, he hits a button and an empty work table top drops from the ceiling to cover the scissor table. Very cool. Very useful.

One note of caution. I found myself worried about all those propane torches that he seemed to have stashed in odd corners of the workshop. I would be worried about the danger of fire. It might be wise to add a fire suppression sytem to the impressive inventory of gear in that shed.

Sorry for that nanny-state suggestion. That said, this workshop is magnificent. Three cheers for the owner.

WA4CHQ -- A Virginian QRPer and Homebrewer

2026-05-07T10:07:15.068-04:00

This guy had a Drake 2-B, Heathkit DX-35 with VF-1, and an FT-101EE. He builds homebrew rigs. He sailed from England to Virginia on a reproduction of a 1607 ship.

He notes that Wes W7ZOI was and is his mentor. FB OM.

Check out his QRZ page: https://www.qrz.com/db/WA4CHQ

Radio Receivers -- 1942 Training Film -- Crystal Sets to Superhets

2026-05-03T05:44:52.620-04:00

This 17 minute film provides a good but simplified description of the state of the art at the start of World War II.

-- The description of how a signal gets to the input coil of a receiver is quite good. Imagine if that coil had no good ground, and no counterpoise. We see the importance of the counterpoise in this video: https://soldersmoke.blogspot.com/2023/03/an-antenna-for-high-school-direct.html

-- I like the repeated demonstration of the reality of envelope detection. Too often people have bought into the idea that envelope detection is not real, and that some form of mixing using the carrier in lieu of the local oscillator is what is really happening. That is just not true. Envelope detection as described in this film is real.

-- The description of mixing is very simplistic. They describe the generation of the difference product, but not the sum. But hey, the film is only 17 minutes long! It takes a lot longer than that to fully describe mixing (ask me how I know!).

-- At the very end, there is a shout-out to the BC-348. FB.

The TW-100 "Fly Away Transceiver" --- A CW-SSB Rig I Never Heard of Until Today

2026-05-02T07:12:24.391-04:00

I was listening to the Old Military Radio Net this morning. Rhett KB4HG checked in on Upper Sideband. He was using a loaner TransWorld TW-100 "Fly Away" CW-SSB transceiver. I had never heard of this rig. It is very interesting. See the W7UUU YouTube video above for more details.

OM John W3JN called into the net and commented on Rhett's rig. John noted that the State Department had sold at auction a number of these rigs. John reported that the ROM had been removed from MOST of these rigs. But one of them still had the memory. This allowed all the other TW-100s to be put back on the air. FB.

BTW: W7UUU has a very FB YouTube channel. Check it out:

https://www.youtube.com/@davesradioshack

The Agony of Troubleshooting -- Shielding, Bypassing, Testing, Throwing Things at the Wall

2026-04-30T09:01:48.540-04:00

This might not seem like it has a lot to do with homebrew radio, but I had it playing as I was going through a similar level of agony with a recalcitrant NE602 frequency readout. I found it reassuring that I was not alone in my agony.

We see a lot of applicable stuff in this video. Note how he tries to suppress some toublesome noise using electrolytics, resistors, and ceramic caps. He thinks he has the problem solved, until he loads the entire thing in the case, at which point the problem returns. Sound familiar? Indeed, he found that inside the case an unshielded cable ended up too close to a noise-carrying wire.

He also comments on the need to do a full system check before flight. Good point.

It will be cool to watch the video that this device is built to capture. Stay tuned.

Homebrew Cylindrical Variable Capacitors: What the Steering Wheels are Controlling in Danny's Regen Receiver

2026-04-28T10:06:00.942-04:00

Grayson KJ7UM asked a very good question about Danny ON1MWS's regen receiver: What were those two very cool "steering wheels" actually controlling?.

Perhaps because of our recent experience with Permeability Tuned Oscillators, I kind of assumed that we were talking about some form of variable inductor. But no, I was wrong. They are for homebrew variable capacitors. That just makes it a lot cooler.

Danny explains:

Dear Grayson,

Tnx for the compliments. I used to build normal square boxes while I was a mechanic in a light advertisement factory. We had a one hour lunch break and were allowed to work for ourselves during the break. But I left that firm in 2019, as a consequence I had to find a way to build rigs without custom square boxes… the result is wood, tin cans of all sorts and a simple ground plate. After posting my CW rig on the FB group ‘the art HAM radio homebrew’ in 2023, Steve Fabricant noted ‘It could be a radiosonde that they sent down from a saucer to detect intelligent life, and failed.’ LOL, I found that very funny actually.

As for your question, all of my homebrew tuning capacitors have a shaft made off a M8 (about 8mm) threatened rod. The rod turns through a steel girder bracket. I am not sure how these things are called in English, but they are easy to find on the net and very cheap. The rod is the ‘ground’ of the capacitor. The ground plate is clearly visible in the pictures of the solid state regen and the ground plate is hidden under the wood in the tube regen. In the case of the tube regen, the left tube has an inner diameter of 10mm and the right one about 13mm. The right one is coarse and the left one fine tuning. Not sure about the capacitance. 30pF at most I think. The tube regen tunes from 7 to 7.25 Mhz so that's ok.

As you turn the rod the rod will shift in or out the metal tube. The tube is obviously the ‘hot’ side of the capacitor. The M8 rod moves 1.25mm for one turn of the rod. If memory serves me right the tube is 80mm for the tube regen, so we have a tuning gear reduction of 80/1.25= 64. The hot side is connected to the main tuning coil to create a tank circuit.

I did try different designs before but this is the best one. The tube/treaded rod capacitor is just as good as a commercial one. One thing I learned is that any friction must be avoided in a homebrew capacitor or it is useless in practice.

I am going to try to build a similar 400pF version for a homebrew crystal set as I wrote to Bill. It will be huge I guess.. I think I will need a 2”tube… But my current homebrew projects are insulating our house better as our natural gas prices are rising.

Like the way you call tubes Thermatrons. Yes, sound much cooler and more fitting for these beautiful devices. My ultimate aim is building a one band thermatron SSB exiter. No time for the moment.

Kind regards Danny.

This technique could prove very useful in homebrew projects. We found it very difficult to source suitable variable capacitors for our direct conversion receiver. That is why we went with the PTO circuit. But this technique makes it possible to actually homebrew the capacitors. FB Danny.

Thanks Danny. Thanks Grayson.

Other Workshops: Homebrew Sailboats

2026-04-27T05:36:45.138-04:00

In the Dominican Republic I sometimes find myself wanting to take sailing lessons on Juanillo Beach. Maybe next winter. I've also been following the far more sophisticated wooden boat-building effort of Leo Sampson and the Tally Ho. All of this helps explain why I watched this video. And a big part of this is simply an interest in "other kinds of homebrew workshops."

There is some practical advice for us: The importance of pilot holes. The fact that Philip head screws sometimes break (who knew?).

Check it out. Thanks to Hack-A-Day for alerting us to this. And thanks to the Cumberland Rover guy.

Don KM4UDX Talks about Homebrewing and the Vienna Wireless Society on Red Summit Video-cast with Charlie NJ7V

2026-04-26T06:35:57.869-04:00

It was a really nice surprise to see Don KM4UDX on the Red Summit Video-cast with Charlie NJ7V. Don talked about homebrewing and the Vienna Wireless Society (he is the current President of the club).

Check it out: https://www.youtube.com/watch?v=uAIcltCbF0c

Thanks Don. Thanks Charlie.

Heathkits and American Industrial Decline

2026-04-25T10:02:36.500-04:00

This is an interesting video about the rise and fall of the Heathkit company, and how that company affected the rise and fall of American manufacturing.

The Heathkit history is interesting, but I disagree about the extent to which building a Heathkit led to an increase in technical knowledge. I guess it could, but Heath was famous for making kits that could be built by people who knew nothing about electronics. Even when many of them were done assembling the kit, most still "knew nothing" about electronics. Just look at those color TV kits: Did assembling one of those kits mean that you came to understand TV? I don't think so.

I'm looking at my HW-101 manual. It is 199 pages long. It is mostly instructions on which part should be soldered where. There is a section called "Circuit Description" but it is only 19 pages long and is at the end of the book. You could assemble the whole thing without ever reading the descriptions of the circuit. I suspect that this is what usually happened.

As for the fall of Heathkit, I think the video is closer to being correct. But it puts too much blame on the advent of small surface mount parts. That is, of course, part of it. But another part of this has to do with the shift towards FPGA and CPU chips.

Anyway, in spite of being AI produced, the video is worth watching. I note that at the end, we see a prominent homebrewer in his shack. Who is this guy?

Thanks to Rogier PA1ZZ for sending this to me.

UPDATE: Mike WN2A reminded me of who that guy in the video was: It was Greg, N8ZRY. He has been on the SolderSmoke blog several times. And here is his video showing his homebrew 20 meter transceiver: https://www.youtube.com/watch?v=R-k73b6ojyQ&t=21s Ironically, Greg proves my point about the Heathkits and kits in general: You just do not see a lot of Heath stuff in Greg's shack. You do see a lot of homebrew stuff, and it is probably from this gear that he really learned a lot. Thank you Mike, and thanks Greg!

SolderSmoke Direct Conversion Receiver -- Total Receivers Built: 132 (124 plus 8 honorable mentions). Total Count: 132. Receivers built in 19 countries.

2026-04-23T04:31:34.891-04:00

The Chuck Adams Build of the SolderSmoke DC RX

Please let us know if you spot any errors, or if we have inadvertently missed anyone. Don't worry about being late to the game -- the challenge continues. All of the info is still available.

As of April 26, 2026 0855Z:

So far, total receivers built: 132 (124 plus 8 honorable mentions). Total Count: 132. Receivers built in 19 countries.

NE3U (KY4EOD) Matt

KQ4AOP First ham signals ever heard!

N9TD Derek

AC3NG Ryan

VK3TPM Peter Marks

W4KAC Ken

W4KAC Ken built a second one!

N2EPE Erik

VA3NCA Wayde (Canada)

KI5SRY Mark -- Gears on PTO screw

KA1MUQ Frying pan receiver

AA1N Adam

ZL1AUN Aaron -- Using SSB transmitter -- (New Zealand)

W8UC Never before homebrewed.

VK4PG Phil -- Nice case, "really pleased"

G7LQX Working well, video of CW and SSB. -- (England)

KE2AMP John Spring on PTO screw -- great

N9SZ Steve nice receiver

KD9NHZ Piotr Nice one

KE8ICE Calvin, Very cool receiver.

WV3V Jayson! Got it done!

GM5JDG Martin. -- (Scotland)

KF8BOG Jim: A long struggle, but success.

Chris Wales Fantastic video. -- (Wales)

YD9BAX Wayan! Homebrew transformer! (Indonesia)

N0NQD Jeff

WN3F Roy -- Made new stickers!

AB5XQ Bill
KB7ZUT Andy
AA1OF Jer

VictorKees Holland (Netherlands)
KC9OJV John -- Manhattan-style convert
WZ5M 1, 2 or maybe even 3 receivers!
K1KJW Jim in Vermont
KC5DI Dallas -- friend of WZ5M
Gary Australian -- Wooden PTO form (Australia)
LU2VJM Juan in Argentina -- (Argentina)
K1OA Scott "Most fun in 50 years"
KC9DLM Ben -- Had EFHW problems
PH2LB Lex Yellow, Glue Stick -- (Netherlands)

AI6WR David
G6GEV Dave (It was a blast!) (England)
KC1ONM Wayne MakerLabs NH
KB1OIQ Andy MakerLabs NH
KA1PQK Jay MakerLabs NH
W1TKO Mike MakerLabs NH
K5KHK Karl
SM0TPW Mikael -- (Sweden)
KI7LKB Brian (coat hanger tube)
M6CRD Chris (England)

W2DAB Dave in NYC
W4JYK Wes of VWS
KA4CDN Mike of VWS
M7EFO Adrian
VK5RC Rob (Australia)
KD8KHP Dave
VK1CHW Chris (Australia)
KA0PHJ Brian
W0IT Louis
W1PJE Phil

W2AEW Alan
KN6FVK John (Barkhausen-Be-Gone Spray)
VU2JXN Ramakrishnan -- (India)
AA0MS Doug
9V1/KM7ABZ Paul -- (Singapore)
VK2BLQ Stephen -- (Australia)
N3FJZ Rick
Daniel VE5DLD -- (Canada)
Student 1 Student of VE5DLD
Student 2 Student of VE5DLD

Student 3 Student of VE5DLD

K7WXW Bill

NK3H Mitch

KN4ZXG Ted

WA1MAC Paul

N4AVC Chuck

K3IY Kevin

N6ASD Ashish in Bangalore (India)

W1DSP Rick

WD4CFN Steve

KM5Z Mike

KF5DAN Dan

Fritz Fritz

N9OK Joe

WA5DSS Bill

K0GDB Grant

G0JNR Shane Glow-in-Dark Coil Form

KK7BCO Tobias

K2BVR Bob

Robert Sutton

K5YFO Dave (Texas)

KD4PBJ Chris

KN4GAH Chris -- EE perspective

F1GMA Philippe -- (France)

W2TEF Todd

EI9ITB Karl -- (Ireland)

VU2TUM Puneit Singh (India)

AA7EE Dave Richards

KI5VIR Jay

CT7AXD Graham -- Promoted from Honorable Mention! (Portugal)

G3MOT Josh (England)

KW4H Steve

NJ7V Charlie (RedSummit)

N2ETZ Denny

AB9LM James

W9XT Gary

G0PJT Alex

KF8FZZ Tyler

N7HPR Steve (Instructor) (N7HPR Group)

Clark (N7HPR Group)

KQ4ZHO Kurt (N7HPR Group)

KQ4OBR Brian (N7HPR Group)

KR4CUF Justin (N7HPR Group)

Amanda (N7HPR Group)

David (N7HPR Group)

KM4AED Jamey (N7HPR Group)

KN4MVH Larry (N7HPR Group)

N5GVW Dick (N7HPR Group)

W7KAL Kal

KC9LFP Joe

SP9DEL Marian (Poland)

LB8VA Ivar (Norway)

AA7FO Chuck Adams!

WE6Z Doug

-------------------------
Honorable Mentions:

*AA7U Steve No PTO

*VK7IAN Ian -- No Manhattan boards -- (Tasmania)

*KC1FSZ Bruce's build on a PC board

* DL1AJG Andreas -- (Germany)

* Matthew Student of DL1AJG

* Arash Student of DL1AJG

*KA4KXX Walter -- FB 20 Meter version

*M9KCA-ST2NH Nader - LM386 in place of AF amp

Nader M9KCA-ST2NH's Beautiful Build of the SolderSmoke Direct Conversion Receiver: NO SMOKE!

2026-04-21T13:28:00.000-04:00

Nader wrote:

Hello everyone! After more than 30 years, I've rebuilt the DCR again. I wanted to share the fun of the 40m SolderSmoke DCR Challenge with all of you. It was a fantastic project — fully documented, with many people sharing their experiences online. I'm truly delighted to show you my prototype. The best part? It ran from the very first power-up — no smoke, no tuning needed! Yes, all on one board. The audio amp isn't quite ready to challenge the role yet, but it's still a lot of fun.

Nader's Sudanese callsign rang a bell with me. I had talked about him in SolderSmoke podcast #58 on May 13, 2007. Here it is: https://www.soldersmoke.com/soldersmoke58.mp3 And I included a long quote from him in the SolderSmoke -- Global Adventures book. So Nader is an old friend indeed.

He clearly built the receiver, with excellent results. He used the innards of a glue stick to build the support for the PTO inductor. But he has not yet built the three-transistor AF amplifier. So, in the interim, I am placing him in the "Honorable Mention" category. When he completes the AF amplifier, he will be promoted to full membership in the Hall of Fame.

The REALLY BIG Dish: China's Sky Eye

2026-04-21T05:28:00.000-04:00

The technology used is really interesting, as is the struggle to maintain a radio quiet zone around the telescope. The limestone geology with lots of useful sinkholes was very helpful in selecting the site (we have similar geology in the Eastern part of the Dominican Republic). The contrasts with Arecibo are also quite telling.

Thanks to Rogier PA1ZZ for sending this.

Dean KK4DAS and I Receive the G QRP G2NJ Trophy

2026-04-19T12:58:00.001-04:00

This award means a lot to us. It is for making "the greatest contrbution to international QRP." Dean and I are both big fans of G QRP and of their journal, SPRAT. (As we say on the SolderSmoke podcast, if you are not a member of G QRP and are not getting SPRAT, you are just WRONG.)

This award is a real honor. Thanks very much to G QRP, and especially to their chairman Steve Hartley, G0FUW.

Mitch NK3H Talks Homebrewing with Charlie NJ7V of Red Summit RF

2026-04-19T07:33:00.002-04:00

This is a really cool interview. Both Mitch NK3H and Charlie NJ7V are members of the SolderSmoke Direct Conversion Receiver Hall of Fame. Mitch has built a dual-band superhet rig, which is the subject of this interview:

https://www.youtube.com/watch?v=wK_EVt5iAQ4

Here is a video Mitch did about his SolderSmoke DC receiver:

https://soldersmoke.blogspot.com/2025/05/mitch-nk3hs-fb-soldersmoke-direct.html

Mitch also built the Michigan Mighty Mite. And he did an SSB version!

Mitch is a very interesting guy. He was a professor, he worked in biotech, founded his own company which was funded by venture capital, later retired, got interested in astronomy, and came to ham radio at the start of the pandemic. Wow, great stuff.

In Charlie's video, Mitch provides a lot of good explanation of his experimentation process. I had to chuckle when Mitch pointed out that he did NOT invent the Colpitts oscillator. Good point Mitch!

Mitch credits Pete N6QW as one of the people who helped him design his superhet transceiver. He also mentions Farhan VU2ESE, Alan Wolke W2AEW and several others. FB. And he credits SSDRA, EMRFD and ChatGPT. Mitch also likes the videos of the IMSAI Guy.

Mitch has already made 50 contacts with this rig.

Mitch makes excellent use of microcontrollers and digital VFOs. He provides great info on the speed and cost of various sources of commecial PC boards.

Quote of the day from Mitch: "Electrons don't care how pretty or ugly your board is!"

Mitch concludes with a quote from Pete N6QW: "You gotta know stuff to do stuff." But Mitch adds to this an important coda: "But the process of doing it is the learning experience." Exactly right Mitch.

Thanks to Mitch and Charlie for a really great video: https://www.youtube.com/watch?v=wK_EVt5iAQ4

Pete N6QW is our Shifu

2026-04-17T06:31:00.002-04:00

In a comment to a recent post, Mike WN2A wrote: "N6QW is the Shifu.

( https://en.wikipedia.org/wiki/Shifu )"

I found this term intriguing. I think we should consider including it in the SolderSmoke Lexicon. Steve? BTW, I agree on the designation of Pete N6QW as the Shifu.

AI Overview

In the context of electronics, Shifu (师傅) generally refers to a skilled craftsman, technician, or master tradesperson, such as a master electrician, repair technician, or electronics expert. It is a Chinese term denoting respect for someone with high-level technical expertise in areas like welding, circuit design, or device repair.

Here is more info on the origin of the term and its useage:

Thanks Mike!

Another 40 meter DSB Transceiver

2026-04-17T04:30:00.003-04:00

I like the homebrew spirit in this one, how it started out as a Direct Conversion receiver and expanded into a full double sideband transceiver.

Indonesian Direct Conversion Receiver (Another one - Not Wayan's)

2026-04-15T06:13:00.000-04:00

Who can forget Wayan's heroic homebrewing of the AF transformer? While others complained about the difficulty of ordering from an on-line store, OM Wayan YD9BAX rewound his own AF transformer in Indonesia. FB Wayan!

This morning I stumbled across another 40 meter DC receiver from Indonesia. See above. I got the blurb translated. Here it is:

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1,759 views  Aug 2, 2020  #diyradio #homebrewradio #timetables

This radio is a DSB (Double Side Band) type, not a Regenerative radio like in yesterday's video, this radio circuit uses VFO as the main tuning and is set for a frequency range of around 6,950MHz - 7,150MHz (comma, not thousands), and can be set to a larger or smaller frequency range as desired. This radio circuit is the result of a friend's assembly (Channel: Dr 504k), because I don't really understand radio science so I only made the box. The box is made of plain PCB, if you are interested in making a similar box using plain PCB too, try not to use fiber PCB, because it will itch on the skin when grinding, just use pertinax material, it is cheaper, flexible and looks more vintage. Disclaimer I deliberately did not focus the sound on a radio wave for too long because it concerns someone's conversation, so I apologize if there are parties whose voices were recorded. I am not a radio person, I am only a receiver for entertainment and additional insight. Thank you.

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

I couldn't find the channel of the designer (Dr 504k) but from this video it looks like this builder used a polivaricon capacitor and a homebrew gearing mechanism. I also see a lot of electrolytic capacitors. FB. Can anyone find the schematic?

Background (from Maine!) On the "Most Interesting Man in the World"

2026-04-13T09:11:00.000-04:00

I know, I know. This doesn't really have anything to do with homebrewing. But in a way it does. This guy didn't get his start until age 68. So there is hope, right? And there is the Latino angle.

And here are some Dos Equis "greatest hits": https://www.youtube.com/watch?v=ukosls76res My favorite from this bunch is "The last time he flirted with danger, danger got clingy."

One prominient homebrewer says that Pete N6QW is the "Most Interesting HAM in the world." I agree.

Stay thirsty my friends.

DSB Homebrew from Macedonia -- Sasho Z33ST

2026-04-11T07:55:00.000-04:00

This is a really nice DSB transceiver in progress. Below you see the modules, above you see how the modules will fit onto the board.

DOUBLE sideband is a mode too often dismissed by potential builders. Sasho shows that it is indeed a practical and relatively simple way to get on phone. Sasho has been using these rigs on Parks On The Air operations.

The modular approach is admirable.

Sasho writes:

Hello Bill,
This is a DSB radio design by R0AHZ using NE612 chip as mixer on receive and transmit.
Audio amp is LM386.
Frequency generation is by arduino nano and si5351
RF power amp consists of 2n3553 or any npn eqivalent as pre drive and BD139 as final. Power is about 1 to 2 watts max. I use it together with my power amp and I measure about 40 watts on tx.
Here is a link of me making a QSO wih it.
https://youtu.be/0GKlVfAPgV0?si=KstoJ64kyWRpE-up
73 de Z33ST

Thanks Sasho!

https://www.qrz.com/db/Z33ST

Sasho on POTA

SolderSmoke Homebrew Direct Conversion Receiver Hall of Fame Update: 129 Completed, 122 + 7 Honorable Mentions: (As of April 11, 2026, 0852Z)

2026-04-11T05:14:00.000-04:00

Marian SP9DEL's Receiver