SolderSmoke Homebrew Direct Conversion Receiver Hall of Fame Update: 103 Completed + 7 Honorable Mentions: Total Receivers Built: 110 (As of January 12, 2026, 1821Z)

G3MOT's Receiver

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 January 12, 2026 0821Z:

So far 103 completed receivers, and 7 honorable mentions.  Total Count:  110.       Receivers built in 17 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    

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

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

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!) 

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

W2DAB           Dave in NYC

W4JYK            Wes of VWS

KA4CDN          Mike of VWS

M7EFO             Adrian 

VK5RC             Rob

KD8KHP          Dave

VK1CHW         Chris

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

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

AA7EE             Dave Richards

KI5VIR            Jay

CT7AXD       Graham -- Promoted from Honorable Mention!

G3MOT           Josh

KW4H             Steve

NJ7V                Charlie (RedSummit)

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

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

Artificial Intelligence Not So Intelligent! AI Flunks the Parallel Resistor Test!

So this morning I asked this of AI:      

How should I make a 50 ohm dummy load capable of handling 5 watts from 330 ohm 1/4 watt resistors?'

Here was the answer: 

Oops.  Nope.  That makes a load of about 20 ohms, not 50.   

Wow,  this seemed like a fairly simple request.  AI got it wrong.  If AI (LLM) can't get a simple question like this right, you have to wonder how many other things it is getting wrong. 

More on Spark Transmission and Reception -- From Germany. Spark Transmission using a Piezo Fire Starter

More spark today.  I really liked how Robert Dalby demonstrated spark transmission and reception.  He used a simple Piezoelectric flame starter (like the one that many of us have in our shacks) as the transmitter, with a homebrew coherer connected to an LED and some batteries as the receiver.  Ingenious.  As with CuriousMarcs video of yesterday, you can see how Marconi's system really worked.  Brilliant. 

This demo also shows how many devices can generate part of the noise we hear in our receivers.  We see and hear the noise generated by a nearby electric fence, and the noise made by a simple electric motor.  Many new builders have trouble accepting the reality of noise.  Noise happens. 

The entire YouTube channel is very interesting.  Check it out here: 

https://www.youtube.com/@deutscheavionik7211

It is based on the amazing collection of Dieter Beikirch (I think he is DJ5RS) and is presented by Robert Dalby. Here is how they describe the channel: 

German avionics in the era of the vacuum tube. Join us as we investigate the most critical period in the rapid development of electronics, especially airborne electronics, from the first spark-gap radios of WW1 to the advances in radar technology in WW2.

Spark Gaps and Coherers demonstrated and Measured by CuriousMarc

CuriousMarc provides a good demonstration of how spark transmitters work with coherer detectors.  His measurements are really illuminating.  His device just needed a "tapper" to de-cohere the metallic filings.  We see the tapper in this wonderful "Secret Life" video by Tim Hunkin: 

https://soldersmoke.blogspot.com/2021/06/remastered-secret-life-of-radio-with.html

Walter KA4KXX's Innovative 20-meter SolderSmoke Direct-Conversion Honorable-Mention Receiver

 

It is a thing of beauty.  We were really pleased to see our old friend Walter KA4KXX take on the SolderSmoke challenge, and we weren't a bit surprised to see him do so using some real twists in the design.  You see, Walter is a very experienced homebrewer.   He has built many, many rigs over the years.  Just check out his QRZ page and you will see what I mean: 

 https://www.qrz.com/db/KA4KXX

Walter supported our original high school effort by offering the students a $500 prize for any student who used our receiver (and a similar transmitter) to check in to the 40 meter Sunrise Net.  Sadly, there were no takers.  But we really appreciated the attempt. 

We have listed Walter's receiver in the Honorable Mention category, only because his build is so innovative:  20 meters instead of 40.  An IC in the audio amplifier.  There were differences, but even a quick look at the above picture above shows that Walter's receiver is very much a SolderSmoke Direct Conversion Receiver.  

Here are some additional photos from Walter. 

Congratulations Walter.  Welcome to the Hall of Fame!  

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

From Walter's QRZ page

Let's Start the New Year with... THE KNACK!

Happy New Year everyone!  Our friend Rogier PA1ZZ sent this to me. I'm sure there are parts of it that people will disagree with, but the overall message (BUILD THINGS!) is, I think, right for this group. Thanks Rogier! 

 

Is the Veritasium Guy Retiring? Google says SolderSmoke is "Low Value Content."

I have been a fan for many years.  His comments on the vile influence of the algorithm and AI are right on target.  

Google recently informed me that the SolderSmoke blog has "Low Value Content."  Well, consider the source! 

Click for a better view (better than the one provided above by GOOGLE!)

I think Veritasium has made a good choice.  

Three cheers for Veritasium!  

The Coastwatchers -- Their Rigs and Their Islands

 

AWA Teleradio 3BZ used by coastwatchers during the war Source: Australian War Memorial (P01035 .006)

Here is a great site about the AWA 3BZ Wireless set: 

https://www.qsl.net/vk2dym/radio/3BZa.htm . 

AWA 3B SET

Here's a good article about the Coastwatchers: 

https://www.military.com/daily-news/investigations-and-features/2025/12/22/former-school-teacher-led-guerrilla-army-behind-japanese-lines-solomon-islands-and-helped-us-win.html

Guadalcanal 1943

I've been interested in the Solomon islands lately because my wife and I have been watching a YouTube video channel about a family living on Uepi island: 

 https://www.youtube.com/c/TheIslandLifeofUs 

Uepi is right on "the slot," near New Georgia. 

There are WWII remnants still visible (underwater) at Uepi: 

AI Overview

Uepi Island in the Solomon Islands is famous today for its World War II history, particularly its abundant, accessible WWII wreck dives (aircraft & ships) in Marovo Lagoon, a key battleground during the Solomon Islands Campaign, offering divers a tangible connection to the fierce fighting between US and Japanese forces. The area, near major WWII sites like Guadalcanal, features underwater artifacts like Japanese Zeroes and US Corsairs, with the modern Uepi Island Resort preserving these historical relics within its dive operations. 

Uepi's WWII Significance

• Location: Uepi is situated in the Marovo Lagoon, part of the Solomon Islands, which were central to the brutal Pacific Campaign of WWII.
• Wreck Dives: The waters surrounding Uepi are a "treasure trove" of sunken WWII aircraft (like P39 Air Cobra, Japanese Zeroes) and shipwrecks, making it a prime destination for historical diving.
• Preservation: The Uepi Island Resort actively manages and promotes responsible diving at these sites, emphasizing that removing artifacts is illegal. 

Key WWII Sites & Wrecks Near Uepi

• Wickham Harbour: Located near Uepi, this area contains significant WWII wrecks, accessible via boat trips from the island.
• Aircraft: Divers can find Japanese Zeroes, American Corsair fighters, and potentially B24 bombers, often in challenging conditions, with efforts to move some to cleaner areas.
• Marovo Lagoon: As one of the world's largest saltwater lagoons, it holds numerous historical remnants from the intense fighting. 

Alexanderson Alternator on 17.2 kHz Copied by YO2DXE in Romania

 On December 1st 1924, the 20kW Alexanderson Alternator with the call sign "SAQ" was put into commercial operation with telegram traffic from Sweden to the United States. 101 years later, the transmitter is the only remaining electro-mechanical transmitter from this era and is still in running condition. On Christmas Eve morning, Wednesday December 24th 2025, the transmitter is scheduled* to spread the traditional Christmas message to the whole World, on 17.2 kHz CW.

You can listen to the CW from Ciprian's setup above.  I listened to it carefully and clearly heard the "KW ALTERNATOR" words at around the 3:30 mark in Ciprian's video.  I wondered if this was in fact the SAQ Alternator (but then again, who else would be on 17.2 kHz on Christmas Eve?).  I looked at the video from Sweden (below) at around the 49.37 mark we see the operator send "200 KW ALTERNATOR." Through Ciprian's video, I copied "KW ALTERNATOR."  So Ciprian's operation was a success.  Congratulations Ciprian! 

Merry Christmas to all!  

The AN/PRC-74 -- A Covert Contact, An Analog Synthesizer, A Benefit of Channelization, and a Good Thing about Band Noise

I have a sentimental tie to this older military transceiver, for several reasons:

 

-- This was probably the transceiver that we hauled into the Uwharrie national forest when I was in the army in 1983.  I made one 40 meter CW contact with it.  It was interesting for me to see Ray tune the rig up on 40 meter CW. 

-- I like the crude, early, non-digital synthesizer. 

-- This is a good example of the use of an old military rig on 5357 kHz in the 60 meter band.  This is the only one of the chanelized frequencies on that band that is on a whole interger of kHz frequency.  It fit well with the 1 kHz tunability of the transceiver.  Thus we had the "Moose and Squirrel" net on 5357 KHz. 

-- I like how Ray uses the band noise to peak the receiver.  Band noise, you see, has its uses. 

A VERY Interesting Old "Steam Punk" Homebrew Thermatron Rig -- Can You Suggest A Home for this Rig? (Video)

Oh man.  They got me at the breadboard, but there was so much more:  

-- A mercury switch

--  A homebrew variometer

-- A reading lamp

-- A specially made (and stored!) tuning tool and a mechanical pencil 

--  A CQ paper tape and tape reader! 

-- A front panel clock

-- Space for QSL cards on the front panel   

This is a really cool homebrew radio!  Can someone find a good home for this amazing device?  The video was posted only 1 month ago.  

Pete N6QW Asks Copilot about Homebrew vs. Store Bought

Copilot is remarkably perceptive.   This AI-generated message really explains very well the differences between homebrew and store bought gear. 

Check out Pete's blog:   https://n6qw.blogspot.com/2025/12/mostly-ai-generated.html 

Homebrew vs Store Bought

There’s a moment every homebrewer knows: you shove aside the archaeological layers of past projects on the bench, uncover a few resistors stuck to a solder blob, and declare, “Yep, this is going to be a radio.” To the untrained eye, it looks like the aftermath of a nuclear explosion. But to the enlightened? It’s the beginning of greatness — or at least something that won’t catch fire too quickly.

Buying a radio is easy. Too easy. You click a button, a box arrives, and suddenly you’re the proud owner of a rig that has more menus than a chain restaurant. You spend the first week scrolling through settings trying to figure out why the audio sounds like a kazoo trapped in a tin can. But building a radio? That’s where the real fun begins. It’s where you learn that “datasheet recommended values” are merely suggestions and that toroids exist solely to test your patience and your vocabulary.

Commercial radios are sleek, polished, and packed with features you’ll never use but will brag about anyway. They’re also sealed tighter than a politician’s tax returns. You can’t poke around inside without voiding the warranty, the warranty’s warranty, and possibly a few federal regulations. Meanwhile, a homebrew rig practically begs you to poke it with a screwdriver. It’s the difference between owning a sports car you’re not allowed to open the hood on and owning a jalopy you can rebuild with duct tape and optimism.

And let’s be honest: building a radio is an act of rebellion. In a world where everything is prepackaged, preprogrammed, and pre‑approved, choosing to melt solder and wind toroids is basically saying, “I reject your consumerist convenience and substitute my own chaos.” It’s a declaration that understanding matters. That learning matters. That the journey — the mis-wired stages, the smoke tests, and the moment you realize you soldered the IC in backwards — is part of the joy.

There’s also something deeply personal about a homebrew rig. When you build it, you know every quirk. You know why the VFO drifts when the cat walks across the table. You know why the audio chain hisses like an angry snake. You know the exact moment when the rig came alive for the first time, pulling a faint signal out of the ether and making you shout, “It works!” loud enough for the neighbors to wonder if you’ve finally snapped.

And that first QSO? Pure magic. When someone hundreds or thousands of miles away responds to your signal, you feel a surge of pride no store‑bought rig can match. You didn’t just operate a radio. You created one. You made electrons dance to your tune. You built a bridge across the airwaves using nothing but determination, caffeine, and parts that probably came from a cardboard box labeled “misc — maybe useful someday.”

Homebrewing also keeps the spirit of amateur radio alive. The hobby wasn’t built on buying the latest rig because the brochure said it had “enhanced DSP algorithms.” It was built on people who asked, “What if?” and then went to the bench to find out. When you build a radio, you’re participating in that legacy. You’re keeping the flame lit — even if the flame occasionally comes from a resistor, you accidentally overheated.

And let’s not forget the best part: when something breaks, you can actually fix it. No shipping it back to the manufacturer. No waiting six weeks for a repair estimate. No customer service rep telling you to “try turning it off and on again.” You grab a meter, poke around, and mutter, “Well, that shouldn’t be glowing,” and you fix it. That’s power.