Puneit is also a CW man -- we hope he pairs this receiver up with a simple CW transmitter and makes some "fully homebrew" contacts.
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Monday, November 10, 2025
Puneit Singh VU2TUM's FB Homebrew 40 meter SolderSmoke Direct Conversion Receiver
Tuesday, October 21, 2025
"Rig Here is Homebrew" -- The Joys and Sorrows of Building your own Rigs
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Dean KK4DAS asked me to speak to our local radio club, the Vienna Wireless Society. It was a lot of fun. I talked about my evolution as a homebrewer, some of the rigs I made, the moments of joy, and the tales of woe. You can watch the presentation in the video above.
I was really glad to be able to explain in the presentation the importance of people like Pete, Dex, Farhan, Wes, Shep and even Dilbert.
I was also pleased to get into the presentation the N2CQR sign that Peter VK2EMU made for me. Thanks Peter!
Here is the URL to the YouTube video (also above):
https://www.youtube.com/watch?time_continue=3414&v=VHSr-v4QO7Q&feature=emb_logo
And here are the PowerPoint slides I used:
https://viennawireless.net/wp/wp-content/uploads/2020/06/VWS-presentation-Rig-here-is-homebrew.pdf
Thursday, August 7, 2025
SolderSmoke Podcast 261: Travel, AI-Apocalypse, ARRL Award, Amplifiers (with Claude) , Transcoms, Smoke released in DR, QRP, CW, MAILBAG
Opening: Travel notes: Pete to Denver. Dean to Alaska. Bill in the Dominican Republic.
The future of the podcast. We will embrace our NIMCEL status and fight on in spite of the AI Apocalypse. Thanks to Peter VK3TPM, Hamilton KD0FNR, Sam AI7PR, Todd K7TFC and the WayBackMachine for providing backup and transfer options for the blog. Google could end Blogspot at any time.
Dean and Bill win the 2025 ARRL Technical Service Award. Thanks to Bruce KC1FSZ for the nomination. And thanks to Bill Morine N2COP for letting us know. 91 receivers completed so far!
SolderSmoke East was pleased to host Phil W1PJE, a distinguished MIT radio astronomer AND member of the SolderSmoke Direct Conversion Receiver Hall of Fame.
Dean: Amplifier design, woes, triumphs, tribal knowledge. And help from Claude.
Pete: Project X -- The Transcom SBT-3, Crossroads and Decisions.
SHAMELESS COMMERCE DIVISION: FIGHT THE AI-APOCALYPSE -- BECOME A PATREON SPONSOR.
Mailbag:
Who is the Project 326 Guy? A British engineer resident in China for last 20 years.
Steve EI5DD Ham Radio Ireland magazine. Hey -- Why no Irish DC RX builders?
Paul K9ARF -- Thanks for the very kind e-mail about SolderSmoke.
Rogier PA1ZZ -- Many nice videos and suggestions on blog backup.
Grayson KJ7UM on the EF-50 valve (thermatron!)
Bruce KC1FSZ Four DC RX builders at the Wellesley Mass radio club.
Chris KD4PBJ -- Long trip to pick up two directional beacons possibly for 630m or 2200m bands!
Alan W2AEW did a Minimum Discernible Signal test on the DC RX. FB!
Mike WN2A -- Many great comments on MDS in its various forms.
Philippe F6GUH is a FB homebrewer.
Mike EIOCL -- Always great to talk on the air with an old friend.
Walter KA4KXX -- I checked into the Sunrise net! With my HW-101! Thanks Walter.
Farhan VU2ESE -- Watched our interview with Phil W1PJE
Wednesday, June 25, 2025
WD4CFN Makes Contact Using the SolderSmoke Direct Conversion Receiver and a Michigan Mighty Mite
Saturday, June 21, 2025
My Eleven Contacts using the SolderSmoke Direct Conversion Receiver -- It is NOT a toy!
I have made 11 contacts using the SolderSmoke Direct Conversion receiver. Ten of the 11 were after June 3, 2025. This was in very casual operation, operating with less than 1 watt with a dipole antenna.
1. The first of course was back in February 2023 with W4AMV. On this one I was using a simple "10 Minute Transmitter" that I threw together thinking that I would use it to demonstrate the receiver to our high school students. "Wait a minute," I thought. I called CQ and W4AMV answered. I was running about 100 mW. He too was using homebrew gear. https://soldersmoke.blogspot.com/2023/02/first-qso-with-high-school-receiver-100.html
2, 3, 4. On June 4, 2025 I again fired up the 10 minute transmitter. My T/R scheme was VERY simple: I have an MFJ coax switch that I use to select the rigs that will connect to my various antennas. On the antenna switch I selected my 40 meter dipole. I ran two pieces of coax from two different positions on the MFJ switch. One I marked RX, the other TX. The transmitter and the receiver were working off 9 volt batteries. I quickly worked N2WJW. Gil in New Jersey. But I noticed that the 10 Minute rig was drifting. So I pulled out my trusty old Tuna Tin 2 transmitter and used it to heartlessly replace the 10 Minute Transmitter. Now with SEVERAL HUNDRED milliwatts, I worked W2XS, John in New York on June 5, 2025. Later that same day I worked N9FGC in Indiana.
5. My most amazing contact came on June 7, 2025. Here is my log entry: 40CW K1OA First 2 way contact with station also using a SolderSmoke DC Receiver!At around 0630 EDT on June 7, 2025 I heard K1OA calling CQ on 7030 kHz CW. This was exactly where I had a crystal. I called him, but he didn't hear me. I sent him an e-mail. We tried again -- he heard me calling him and I heard him responding by calling me, but I don't think we succeeded in exchanging signal reports. It was close, but no cigar. I had to walk the dog. Scott and I agreed to meet on 7030 kHz at 0730 EDT. Arggh. There was a QSO there. I thought we might have to try to change frequency, but this would have been tough because both of us were crystal controlled on transmit. Fortunately, the contact on 7030 kHz wrapped up. Scott called me, I responded, and we were able to exchange signal reports. I was so excited that I almost forgot to hit the record button on my phone. But I caught the last minute or so.This was really something. This really goes to prove what Dean and I have been saying all along: this receiver is not a toy! It can be used for real ham radio contacts. And now we have had these receivers on both ends of a contact. For transmit, Scott was using a KA4KXX transmitter with about 3 watts output. I was on my Tuna Tin 2 at about half a watt output.
6, 7, 8. Later on June 7, 2025 I worked an old friend, Jim W1PID. Jim is a friend of Homebrew Hero Mike AA1TJ, and was involved in Mike's effort to cross the Atlantic with a voice-powered rig. Jim also was one of my contacts with the ET-2 QRPppp rig. I also worked WZ2J Vin in NJ. I also worked John W2XS again.
9. June 11, 2025 (Really evening of 10 June 2025) Famous homebrewer, Anchorologist, Heatkit authority and fellow member of the QRP Hall of Fame Mike Bryce called me! 40CW 0034 WB8VGE Mike Bryce came back to my CQ! Mike wrote: Nothing like quartz locked frequency control!You know it sounded pretty damn good at 500mW. You were holding your own until QSB would take you out in a deep fade. But all in all, one hell of great QRP QSO.I was running my Ten Tec Scout that I had just put back together a couple of days ago. Got around to putting the case back on it tonight, and had it cooking in the back ground just listening to the stations come and go. I had worked a few POTA stations near by and found a quite spot. I was working on a project when I heard your CQ through the din of the 40M band. Glad I took a break and worked your QRPp signalbest 73 QRP # 4816 You get a QSL for that QSO!
Here's my post about Mike, WB8VGE: https://soldersmoke.blogspot.com/2018/09/wb8vge-on-qso-today-qrp-hb-boatanchors.html
10. Around June 11, 2025 I worked W4MY in a contest.
11. On June 12, 2925 I worked some DX with the rig. It was VA3ICC, Ian in Ontario.
Friday, June 13, 2025
Britain's Secret Listeners
Today Hack-A-Day has an unsually good report on Britain's Voluntary Interceptors. I was especially touched by the story of the guy who provided reports while still bedridden from devastating wounds received in World War I.
https://hackaday.com/2025/06/12/crowdsourcing-sigint-ham-radio-at-war/#more-786810
I've had the video on the SolderSmoke blog several times. It is so good that it warrants inclusion yet again:
https://www.youtube.com/watch?v=RwbzV2Jx5Qo&t=228s
That regen looks a lot like the one I bought at the Kempton Park rally (London) so long ago. I still have it. And those headphones found in the old "radar" station look a lot like some that I have in my shack today. And of course there is that HRO dial. I build a whole receiver around that gem from Armand WA1UQO.
I thought the comments on the ability to detect the nationality of the enemy operator from his Morse Code "fist" (sending style) was very interesting.
Three cheers for the Voluntary Interceptors!
Saturday, June 7, 2025
A FIRST! K1OA Contact with N2CQR -- All Homebrew with SolderSmoke Direct Conversion Receivers on Both Ends
At around 0630 EDT on June 7, 2025 I heard K1OA calling CQ on 7030 kHz CW. This was exactly where I had a crystal. I called him, but he didn't hear me. I sent him an e-mail. We tried again -- he heard me calling him and I heard him responding by calling me, but I don't think we succeeded in exchanging signal reports. It was close, but no cigar.
I had to walk the dog. Scott and I agreed to meet on 7030 kHz at 0730 EDT. Arggh. There was a QSO there. I thought we might have to try to change frequency, but this would have been tough because both of us were crystal controlled on transmit. Fortunately, the contact on 7030 kHz wrapped up. Scott called me, I responded, and we were able to exchange signal reports. I was so excited that I almost forgot to hit the record button on my phone. But I caught the last minute or so. See above.
This was really something. This really goes to prove what Dean and I have been saying all along: this receiver is not a toy! It can be used for real ham radio contacts. And now we have had these receivers on both ends of a contact. For transmit, Scott was using a KA4KXX transmitter with about 3 watts output. I was on my Tuna Tin 2 at about half a watt output.
Thanks Scott! And thank you Walter!
Friday, June 6, 2025
A Tale of "Ten Minute Transmitters" and "Tuna Tin Twos": N2CQR Goes Back to CW QRP!
Inspired by K1OA and KA4KXX, I put the SolderSmoke DC receiver to work on the CW portion of 40 meters. At first I used a very (perhaps overly) simple "Ten Minute" transmitter. On June 4, 2025 I worked N2WJW in New Jersey. But the transmitter drifted as it got hot. So I switched to the more robust Tuna Tin 2 (TWO transistors!) and worked W2XS in NY and N9FGC in Indiana on June 5. With both transmitters I was "rock bound" -- crystal controlled. Power out was always less than 200 milliwatts. Antenna was a low to the ground dipole. The receiver was powered by our beloved 9V battery. The transmitter had a second 9V battery. Some observations: First, even if you CAN hear other signals, the different tones allow your brain to seperate them out (this has long been known to CW operators, but might not be readily apparent to newcomers). So even if the DC receiver is broad in frequency response and even though it IS also receiving the other side of zero beat, you can make CW contacts (unless, of course, another station is on a frequency that produces exactly the same tone as the one you are trying to work), even at very low power . Second, you don't always really have to be right on the other station's frequency. Here's why: If he is looking he can see you in his waterfall! So that SDR waterfall is now a friend to crystal-controlled HDR operators. Who would have thought? Above is a picture of the my station with the Ten Minute transmitter. See the notes I wrote on the QSO with N2WJW.
Saturday, May 31, 2025
Not a Toy! K1OA Making Contacts with the SolderSmoke Direct Conversion Receiver and a KA4KXX Transmitter
This goes to prove what we have been saying all along: this receiver is not a toy! It is capable of operating as part of a real 2-way ham radio station. Hall of Fame member Scott K1OA has paired his receiver up with a Merry Christmas transmitter designed by Walter KA4KXX and has been making CW contacts with it (see above). Walter supplied the crystal and many of the needed parts. Scott has already worked WA9RNE, N4HAY and W3RJ, and has tried making contact with Walter but no luck yet. He has gotten RBN reports from Germany and New Zealand. All that with just 3 watts.
This is not the first time this receiver has been out to use. I made one contact with it using a "Ten Minute" QRPp transmitter that I had intended only to use for test purposes:
https://soldersmoke.blogspot.com/2023/02/first-qso-with-high-school-receiver-100.html
HoF member Aaron ZL1AUN used his receiver with an SSB transmitter to make contact using his receiver:
https://soldersmoke.blogspot.com/2025/02/soldersmoke-direct-conversion-receiver_23.html We understand Aaron's article about the receiver has been published in "Break-In" magazine -- we hope to get a copy (electronic would be fine!)
And who can forget HoF member Nate KA1MUQ who turned his "frying pan" direct conversion receiver into a double sideband transceiver and used it to make phone contact with Idaho from California:
https://soldersmoke.blogspot.com/2025/03/nate-ka1muq-turns-his-frying-pan-dc.html
If anyone is aware of other contacts made using this receiver, please let me know.
Thursday, April 24, 2025
The Copasteic Flow Blog -- German UHF Mobile CW Through a Geostationary Satellite, Agent Sonya's Homebrewing, More
It is always good to be reminded that someone out there is listening and reading, especially when it is nice folks like Hamilton and his family. These are the people who built the TouCans rig that was (is?) suspended above San Francisco at the center of a dipole antenna.
Following posts on the SolderSmoke blog, Hamilton has been monitoring the CW activites of a German ham who sends UHF CW signals through the sunroof of his car to the QO-100 satellite in geostationary orbit. See above. Very cool. Listen live to the satellite here:
https://eshail.batc.org.uk/nb/
Also cool is Hamilton's analysis of Agent Sonya's ability to homebrew a 1930s era CW station that could be used to communiate with Moscow Center. Hamilton believes she could do it. I have my doubts. But the discussion is a lot of fun.
Check our their blog:
https://copaseticflow.blogspot.com/
Thanks to Hamilton and his kids!
Thursday, March 6, 2025
Honorable Mention: Bruce KC1FSZ's SolderSmoke Direct Conversion Receiver ON A PRINTED CIRCUIT BOARD
Hi Bill:
I had refrained from any postings of my work because the "purity" of my build may be called into question and I didn't want to create further distractions from your efforts. HIHI. If you scroll down this page you'll get an idea of what I've been up to: https://github.com/brucemack/
kc1fsz-tjdcr. I also see that you've switched away from the Schottky diodes which I have not done, so I'll make that change to see how it impacts performance.
Moving fully into the realm of unauthorized deviations, I've been experimenting with the simple "frequency offset" feature shown in SSDRA on page 218. Hanging that simple circuit from the high side of C2 seems to provide the hook needed for a simple companion CW transmitter module. Joking aside, I'd never built an analog VFO before the TJDRC project, nor did I ever learn CW, so it's been quite interesting to try to create a sister board that stays true to the TJDCR ethos but can still make legit contacts.
Thanks for all the work you guys are doing to educate the rest of us,
Bruce KC1FSZ
Dean and Bill:What you guys have done with this project is truly amazing. I didn't build the rig in the "original wave," but I recently made one just for fun. I finally got around to looking at your Discord this weekend and was completely amazed... And Dean's tutorial videos are surely headed for YouTube platinum status!
Congrats and 73s,
Bruce MacKinnon KC1FSZ, Wellesley, MA
Bruce: There are several builders on Discord who would be very interested in your CW transmitter module.
Thanks Bruce! Congratulations! 73 Bill Hi7/N2CQR
Saturday, March 1, 2025
Ken W4KAC's Wonderful SolderSmoke Direct Conversion Receiver -- with a Leaf Blower Tuning Dial
Join the discussion - SolderSmoke Discord Server:
Documentation on Hackaday:
https://hackaday.io/project/
SolderSmoke YouTube channel:
Wednesday, January 1, 2025
Happy New Year from the Dominican Republic! SKN from HI7/N2CQR
Tuesday, December 24, 2024
So Many Great Pictures, So Much Radio History
Monday, December 9, 2024
Listening to 40 meters on the DC Receiver -- And I Heard a Distinguished Homebrewer!
Thursday, September 19, 2024
AG5VG's Homebrew 20 meter Superhet (with a CW rig Coming) (Video)
Michael AG5VG finished this receiver last weekend. He hopes to build a CW transmitter using an output of the Si5351. Obviously I defer to Pete on that one. Good going Michael. I think it sounds great and looks even better.
Monday, September 16, 2024
"QRP Classics" The Book that Got Me Started in Homebrew
A question this morning from Scott KQ4AOP caused me to Google this old book On page 59 I found the article about my first transmitter. Someone has put a copy of the entire book on the interenet. Here it is:
Friday, September 6, 2024
Ham Radio in the 1970s (and earlier, with some cool Jazz). What favorite rigs do you see?
Thursday, May 16, 2024
A Light-beam QSO in Hollandia, Christmas 1944
Christmas, 1944
In a wartime world the singular and exclusive camaraderie that exists in the hobby of amateur radio results in so many unexpected and coincidental meetings between good friends, who have previously never seen each other, as to make such happenstance fairly commonplace. But I boast a tale in which time, place and circumstance combined to cause a similar occurrence to be most extraordinary.
The Liberty ship El Segundo Ruiz Belvis lay at anchor in the murky waters of Humbolt Bay, New Guinea, on a tepid tropical night in '44. In the absence of the moon, the Dipper and the Southern Cross scintillated bewitchingly. On the shore, the lights of the army base of Hollandia burned steadily in contrast to the varipowered signal blinkers which intermittently pieced the opaque darkness throughout the harbor. The latter were visual communication between ships and shore plus an admixture of ship-to-ship chatter, official and otherwise. There was an underlying tense tinge to the atmosphere and the stillness was broken only by the sharp staccato of the Belvis' blinker shutters as the signalman transacted port business with the powerful land station.
This was rendezvous. Our Liberty, with scores of army personnel aboard, had here become a unit in the formation of a huge convoy. Crammed into holds, on hatches and into every available nook and cranny of the steel deck, we were Leyte-bound. Stifled, sweaty and hungry on our two meals per day, we wore out deck after deck of pinochle cards and read every available piece of literature over and over again. It was almost a month since we had left Sansapor, scene of our last operation. We were exuberant in the knowledge that we were soon to leave New Guinea.
Christmas was but a few days away and we had had no mail for weeks. Men leaned languidly on the rail and thought of home while others dreamed of the same in their cramped quarters. The circumstances certainly made this Yuletide one to be long remembered. Nevertheless, all that would feature this day for us would be a possible piece of priceless turkey added to the usual dehydrated viands. Just another dragging equatorial day to be piled atop hundreds of others like it.
It was ten o'clock. I was wide awake; only my eyes were tired. Presently, I found myself detachedly reading the blinkers which poked their focused fingers indiscriminately about the bay. My quarters, in the cab of a 399, were on the port rail amidships and afforded a good view across the water. I became absorbed in various bits of chatter between nearby vessels. It struck me that QRM was quite heavy tonight—a sort of an optical 80 meters. I saw one of the lights sign off with a "73." This was interesting as among the host of merchant marine signalmen, hams are spread pretty thinly. I seized my M-1 torch and focused an insipid beam in the direction of that ship. I sent CQ CQ CQ K. A ham call sign is a cumbersome thing to handle with a blinker. Furthermore, I had no faith in the DX powers of my 3-volt flashlight bulb. I was therefore elated when a bright interrogatory sign beamed forth, aimed obviously in my direction. Contact! True, it was outside the hambands, but band divisions in the microwave region are indefinite anyway.
I was still dubious as to whether my man was an amateur. Rather than complicate matters immediately, at this speed of 8 words per minute, I began in the language of the layman: HELLO PAL WHERE YOU FROM? K. Back in an agreeably rhythmic style came: R TULSA OKLA NAME IS HAL K. The given name and place struck a subconscious inner chord vaguely. Next, I blinked: GE HAL IM ROD FROM CHGO K. There was a pause. He reoriented his beam to compensate for tidal drift and then startled me with: W9BRD DE W5EGA K.
The night quickly took on an exhilarant aspect as we lapsed into ham vernacular, spiced with many Morse slaps on the back. Hal Frank was no other than an old c.w. crony of mine. We had heckled each other on 80, 40 and 20 a countless number of times in the prewar days. In memory I was hearing again that beautiful swing and T9X sledge-hammer signal off his three-element rotary. We discovered mutual ham friends and we exchanged much welcome information and recounted bygone days. He was quite amazed to learn that I was behind a mere GI flashlight (with low batteries at that). The QSO continued far into the night—the next and the next.
We seemed destined to rot in our anchorage. The convoy movement was postponed from day to day. However, this Christmas season took on a much different aspect for me as arrangements were made and, at 0900 Christmas Day, my friend, Wilbur Kuure, W9YNY, and I debarked unsteadily down the ladder and made our way across an undulating swell to the Liberty ship Chittenden. There, we met Lt. Hal Frank, W5EGA, personally, for the first time. We all agreed that it was quite a small and bizarre world that December 25th.
Verbal reminiscences cluttered the air within W5EGA's exceedingly neat cabin for several hours. Shelves in his quarters were lined with excellent reading material including many late QSTs. Compared to our situation aboard the Belvis, Kuure and I thought this a bit of heaven.
We were thoroughly acquainted by the time we appeared in the officers' mess. As the cuisine took shape before us and disappeared into our eager gullets, my army pal and I felt somewhat sorry for our less fortunate buddies on the home ship. But such is life. We had, in nautical terms, a "Little Roundhouse," consisting of a generous helping of everything on the menu. We swept our plates clean to Hal's amusement. I remember, most distinctly, the dessert of apple pie and ice cream.
Nightfall found Kuure and me "back to earth" on the Belvis after a most delightful Christmas Day. According to plan, we blinked a "goodnight and thank you" to W5EGA through the twilight. That was our last QSO of that series. Not long after that we weighed anchor and headed for our next stop on the long road back home. Our holiday was over, a new year had begun and there was still a war to be won.
| From S/Sgt. R. H. Newkirk, W9BRD, "Christmas, 1944" QST, January 1946, pages 25 and 102. |










