Bob K2BVR's FB SolderSmoke Direct Conversion Receiver

Bob K2BVR homebrewed a really nice SolderSmoke Direct Conversion receiver.  On his "Proof of Life" video we hear some nice SSB signals, some great CW signals (including N7DZ/6 POTA) and even the well-known tones of FT8.  FB Bob.  Congratulations OM!  Welcome to the Hall of Fame. 

Bob writes: 

Hi Bill,

I wanted to send you a quick note of thanks. I’m very grateful to the SolderSmoke Discord users for their help, and to you and KK4DAS for all of the work you’ve both done in developing this project and sharing it through your videos.

I’ve been making progress on my build and thought I’d share a little update. I ran into some challenges with the bandpass filter – it turns out that reducing the trifilar winds per inch helped improve the performance. I also fought with a shorted test fixture along the way, which made things more confusing than they should have been.

On the audio side, my first amplifier module is still giving me trouble. I hated not getting it fixed right away, but I’ll be coming back to it. I did have to add a 470uF cap to the power rail to control oscillation but I haven't added the 220 ohm resistor. I’m thinking about putting the different modules into their own boxes so that I can experiment with them more easily in the future.

Thanks again for all of the inspiration and guidance — I really appreciate it.

73s

K2BVR

 

Tobias KK7BCO's FB SolderSmoke Direct Conversion Receiver

Sounds great Tobias!   Congratulations -- Welcome to the Hall of Fame! 

Tobias writes: 

Bill, I have joined the few. 

You guys created a project that even I could build. Thank you for the journey!

Now I plan to make duplicates of some elements, and create some kind of a terrifying musical instrument. 

Perhaps a Theremin Tobias?  AKA Etherphone!  This was reportedly one of Neil Armstrong's favorites! 

https://en.wikipedia.org/wiki/Theremin

Shane G0JNR's FB SolderSmoke Direct Conversion Receiver -- With a Glow-In-The-Dark PTO Coil Form

I was really pleased to see Shane G0JNR finish this receiver. He has been an active member of the SolderSmoke community for many years.  For example, back in 2018 we see him commenting on KU4NO's FB rig: 

https://soldersmoke.blogspot.com/2018/07/a-rig-with-maximum-soul-5-band.html

Shane writes: 

Shane G0JNR here. I've just got my Soldersmoke DC rx up and running! The thing that put me off earlier in the year was the 3d printed coil former. But my son has now got one and printer and printed one for me - as an added bonus, it glows in the dark! It didn't work straight away but perseverance has paid off. 73

Thanks Shane! Congratulations and Welcome to the Hall of Fame.

Glow-In-The-Dark PTO Coil Form

One (of several) SolderSmoke Blog Backups: This one in .pdf form

The SolderSmoke Daily News blog now has more than 4,000 posts, and some 10,000 comments.  This is both good news and bad news.  The good news is that there is on this blog site a vast repository of useful information.  The bad news is that I sometimes fear that all this info might be lost if Google someday decides that its blog service should disappear.  It could happen, and that is kind of scary, so I have been looking for backups, for ways to safeguard this information. 

Several members of the SolderSmoke community have been helping me create WordPress sites that backup the blog. More info will be coming soon.  The Internet Archive and the WayBack machine have also been of great help. 

While here in the Dominican Republic, I have been working on a kind-of compilation of blog articles, with a bit of an intro.  I think readers of the blog and listeners of the podcast might find this entertaining. 

So here it is.  Please download it to your computer.  That will increase the survivability of the blog.  I will probably do a few updates to the .pdf file: 

http://soldersmoke.com/SolderSmoke Blog Book Compilation.pdf

The World's Largest Radio Telescope -- It is in the Netherlands

This video is in Dutch, but you can easily turn on the English subtitles.   I put this on the blog for a couple of reasons:  Radio astronomy is very interesting; I am a former member of SARA, the Society of Amateur Radio Astronomers. SolderSmoke celebrates the INTERNATIONAL Brotherhood of Electronic Wizards; this blog serves the WORLDWIDE community of radio electronic homebrewers. 

Thanks to Rogier PA1ZZ for sending this.  

Brian KI7LKB's FB Modifications to the SolderSmoke Direct Conversion Receiver

 

Although we had strongly suggested that builders FIRST build the receiver in accorandance with Dean KK4DAS's excellent videos, we also told builders that once they got those receivers working, there was, of course, no limit on the modifications and circuit changes they could make. We are very pleased that Brian KI7KLB has followed this advice.

Brian writes:

The KI7LKB DCR has been modified to include the KK4DAS 3rd stage of the audio amp, a QRP guys frequency counter, and an enclosure made from scrap aircraft aluminum and hardware. My favorite mod, however, is the WB6AMT (SK and former Elmer) voltage regulator circuit. It allows me to power the DCR from the shack 13.8 volt power supply while simultaneously providing 9.5 volts for the radio and 12 volts for the frequency counter. While I ordered components from Digi-Key, it was fun to include a coat hangar, spare aircraft hardware, scrap wood, and repurpose the frequency counter from another project.

Grant K0GDB's FB SolderSmoke Direct Conversion Receiver

Congratulations to Grant K0GDB on his FB SolderSmoke Direct Conversion receiver.  Welcome to the Hall of Fame Grant! That PTO former is especially FB!  Grant is a relatively new ham, making his smooth construction of this receiver even more admirable. 

Grant writes: 

Proof of life video! Many thanks for the helpful YouTube tutorials, everything went together pretty smoothly.

The windings are actually as close to the specification as I could get them on the nanoVNA. It's been a bit since I built that part, but if memory serves I had one fewer turn and had to do some bunching to get it to read correctly. The main difference in the PTO is that I made the former on a laser cutter from slices of quarter-inch plywood since I don't have a 3d printer. The center cyllinder is actually just rolled up paper.

A Second Aeronautical Mobile Contact with Mike KX4WC/Aeronautical Mobile

August 19, 2025 20 meter SSB in the afternoon. Mike KX4WC/Aeronautical Mobile was enroute to San Juan from Miami, flying through the edges of Hurricane Erin. Also in the QSO was John VY2WW and Mike WA3O. WA3O is a long-time listener to SolderSmoke. He has a water-cooled amplifier and he sent me his Heathkit HW-7 (which I still have).

Mike and I could hear each other through most of his flight.  We were both especially strong when he reached his closest point to my location.  At this point he was about 50 miles over my north-east horizon: 

Amazingly, this was NOT my first contact from the DR with KX4WC/AM.  In January 2020 (just beore the pandemic) I was in Samana, and, early one morning Mike flew over the Dominican Republic.  Here is an e-mail that I sent yesterday to all three guys who were in this very memorable QSO: 

I really liked today's QSO.  Mike called me from around 50 miles out.  We were both very strong. 

The first link describes in detail my 2020 QSO with Mike from Samana, DR.   The second describes my Samana station.  

https://soldersmoke.blogspot.com/2020/01/aeronautical-mobile-contact-from.html

and

https://soldersmoke.blogspot.com/2020/01/contacts-from-dominican-republic.html

Here is my current station:

https://www.qrz.com/db/HI7/N2CQR

And wow!  WA3O  Who could forget that water-cooled amplifier!?  And I still have his HW-7   Thanks Mike. 

Coil-Making in Japan -- Manual and Automatic

 I found this video sort of soothing.  I liked the manual process, but the automatic process is amazing too. 

Thanks to Rogier PA1ZZ for sending this.  

SolderSmoke Podcast 261: Travel, AI-Apocalypse, ARRL Award, Amplifiers (with Claude) , Transcoms, Smoke released in DR, QRP, CW, MAILBAG

SolderSmoke Podcast #261 is available for download: 

Audio:  http://soldersmoke.com/soldersmoke261.mp3

Video:  https://www.youtube.com/watch?v=1rzw8lxBzRo

Alaska, Colorado, Dominican Republic

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. 

KK4DAS 100W MOSFET AMP

Pete:  Project X  -- The Transcom SBT-3,  Crossroads and Decisions. 

Transcom SBT-3

SHAMELESS COMMERCE DIVISION:   FIGHT THE AI-APOCALYPSE -- BECOME A PATREON SPONSOR.

GET BEZOS TO SEND US BEZOS BUCKS!  Use the Amazon link on the upper right.   

BUY PARTS AND STUFF FROM MOSTLY DIY RF. 

Bill: 

-- Smoke released in TWO RD06 finals.  Scrounged IRF-510s to the rescue.   

-- Working VK6 on 20 SSB.  

-- My old HW-101 -- inspired by Pete and by Will N5OLA.   

-- High frequency hearing loss and direct conversion receivers. 

-- Eleven contacts on 40 with the DC RX and a Tuna Tin 2. Mike Bryce WB8VGE came back to my CQ! First ever QSO with SolderSmoke DC receivers on both sides:  K1OA-N2CQR.  

-- Do real hams use ALC? Do we really NEED ALC? 

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

Phil W1PJE was an SWL with an old Halli receiver.  VOA?  Boo!  But Radio Marti is BACK! Also, the hydrogen line from the cosmic dark ages has red shifted to... 7.1 MEGA hertz!  So LISTEN UP! 

Phil W1PJE with a Halli and the Haystack Observatory Dome

Antenna Options and Views from the Terrace of SolderSmoke Shack South

Above is the view to the east.  North-east to Europe will be up to the left.  Straight out to the east gets me across the Atlantic to Central Africa.  

Here is the view looking south.   All of South America is down there, followed by Antarctica. Then up an around the pole to Sumatra and Borneo.  I can hear the Indonesians quite well on 15 SSB.   

Looking west.  Central America, then lots of Pacific Ocean all the way to Western Australia.  I have worked VK6JMS who is in the northern part of Western Australia, in "The Kimberly."

Here is the view to the north-west.  You can see how the top floor of our building blocks most of the signals from the U.S. and Canada when the antenna is at the terrace level (where it is now).    

I think I will stick with simple 1/4 wave verticals.  There is a lot of wind up here and we are not in the apartment about half the year.  I wouldn't want a Hex Beam to get blow over, especially when we are not here.  Simplicity is a virtue.   I think I can get the antenna above the top floor of our building by mounting it (base of the antenna near the top) on the support beam (for a sun shade) shown here.  This should greatly improve signals to and from North America. And I could easily take it down before we leave without having to climb up onto the roof. 

CuriousMarc Fixes the HP-182C Power Supply -- But More Fun to Come!

I really like how Marc stops and gives an account of all the parts he has changed,  and that he HONESTLY talks about parts that he mistakenly replaced, or replaced when the original turned out to be good.  Too often wizards write about their troubleshooting experiences and conveniently leave out these inconvenient changes.   But this is a big part of the troubleshooting game, and I am really grateful that Marc describes what really happens, WARTS AND ALL! 

I must say, Marc's replacement parts drawers are looking kind of empty.  He needs spare parts for videos like this.   

Wow, plastic polish!  Who knew?  I want some.   

Marc is a ham.  His callsign is AJ6JV. 

This kind of video is ALMOST enough to get me to work on my old HAMEG 'scope. 

In the next video Marc pledges to take on the 1966 trigger circuits.