Category: DC Receiver Build

Brian KI7LKB’s SolderSmoke Direct Conversion Receiver with a FB Unique PTO Coil form Using a Coat Hanger Tube!

Brian KI7LKB has built a very FB SolderSmoke direct conversion receiver. He made the PTO coil form himself, using the cardboard from a coat hanger as the tube. (I have used these tubes for many homebrew inductors. I thought I was alone! FB Brian.) In the video above we see Brian’s receiver pulling in SSB signals.

Brian writes:

Finished the DCR! Even with S-7 noise, from here in Southern Nevada, picked up stations in Canada, Texas and Louisiana. Built to plans, except the PTO coil form was fabricated from a clothes hanger tube mounted in a fiberglass frame. Antenna is an inverted “V”. A ham since 2017, I’m always looking for something to build, and the Soldersmoke podcast provided an educational and appropriately challenging project. I particularly like the fact it is modular, and I’ve already identified other applications for the audio amplifier. Your guidance was excellent and I learned a bunch. Thank you!

Here is Brian’s receiver at work in the CW portion of 40 meters:

Thank you Brian. Congratulations! You homebrewed a receiver!

For more information on how you too can build the receiver:


Join the discussion – SolderSmoke Discord Server:

https://discord.gg/Fu6B7yGxx2

Documentation on Hackaday:

https://hackaday.io/project/190327-high-schoolers-build-a-radio-receiver

SolderSmoke YouTube channel:

Mikael SM0TPW’s FB SolderSmoke Direct Conversion Receiver from Sweden

I was very pleased to see Mikael’s video. This is our first receiver from Sweden. In his QRZ page Mikael talks of learning CW while in the military, and of making a few contacts with the equpment of his regiment. I had a similar experience — I once made a CW contact with the rig assigned to our team.

Mikael writes:

Thank you Bill.

I’ve been a Ham for 35 years with a long gap in the middle of 20+.

I am of course a Soldersmoke listener and tried to build this dcr when you built it in the highschool project, but I didn’t succeed that time and gave up.

But with all the guidance here on discord I gave it one more go, and succeeded. 😊

The hardest thing was, as for many other, the af stage and oscillation. But some bypass caps and problem solved.

I got so much help just reading all posts here so thank you all in this community!

Now I will lean back for a while and listen to my baby. I am a proud father right now.

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Indeed Mikael, that is what Farhan advises: sit back and enjoy the receiver that you have built. Congratulations! The receiver sounds great on CW and on SSB.

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For more information on how you too can build the receiver:


Join the discussion – SolderSmoke Discord Server:

https://discord.gg/Fu6B7yGxx2

Documentation on Hackaday:

https://hackaday.io/project/190327-high-schoolers-build-a-radio-receiver

SolderSmoke YouTube channel:

The MakeIt Labs of Nashua, New Hampshire — Four Successful Direct Conversion Builds

This picture came in on February 27, 2025 from Nashua, N.H.
On February 27, 2025 they wrote:

Hello from MakeIt Labs (a makerspace in Nashua, NH, USA). Andy (KB1OIQ), Jay (KA1PQK), Mike (W1TKO) and Wayne (KC1ONM) are building the DCR as a Tuesday Night Project Night activity. This week we all experienced the joy of oscillation 😂

On March 27, 2025 all four builders completed their projects, submitted “proof of life” videos, and entered the Hall of Fame.

And it looks like they had a lot of fun. That MakeIt Lab looks like a great way to pull people together for projects like this. Well done guys! Thanks and 73!

Mike W1TKO’s Beautiful SolderSmoke Direct Conversion Receiver

Mike W1TKO is a realtively new ham, getting his ticket in 2022. But he has already done something that 95% of all hams never do: He has homebrewed a receiver. The personalization of the receiver adds a nice touch of class to the project. FB Mike. Congratulations!

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For more information on how you too can build the receiver:


Join the discussion – SolderSmoke Discord Server:

https://discord.gg/Fu6B7yGxx2

Documentation on Hackaday:

https://hackaday.io/project/190327-high-schoolers-build-a-radio-receiver

SolderSmoke YouTube channel:

Jay KA1PQK’s Wonderful SolderSmoke Direct Conversion Receiver

On Jay KA1PQK’s QRZ page he says that he has long been interested in the minimalist side of ham radio. This project certainly fits in with that, but there is noting minimalist about the satisfaction that we can seeon Jay’s face as he tunes the receiver that he hombrewed himself. FB Jay. Congratulations!
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For more information on how you too can build the receiver:


Join the discussion – SolderSmoke Discord Server:

https://discord.gg/Fu6B7yGxx2

Documentation on Hackaday:

https://hackaday.io/project/190327-high-schoolers-build-a-radio-receiver

SolderSmoke YouTube channel:


Andy KB1OIQ’s FB SolderSmoke Direct Conversion Receiver

Andy has a lot of homebrew projects underway, but I think this one must have been the most rewarding. He has done something that 95% of hams never do: He has homebrewed a receiver. Congratulations Andy!

Check out Andy’s presentation on Linux to the 2025 Dayton Hamvention:
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For more information on how you too can build the receiver:


Join the discussion – SolderSmoke Discord Server:

https://discord.gg/Fu6B7yGxx2

Documentation on Hackaday:

https://hackaday.io/project/190327-high-schoolers-build-a-radio-receiver

SolderSmoke YouTube channel:

Wayne KC1ONM’s FB SolderSmoke Direct Conversion Receiver

Wayne KC1ONM built a very nice direct conversion receiver. He has done something that 95% of hams never do: He has HOMEBREWED a receiver. FB Wayne. Congratulations!

After his completion of the receiver, Wayne put it all in a beautiful homebrew case:

To mark the PC boards, Wayne says, “MakeIt Labs has a MOPA laser. They were marked after construction of the board (the focus is high enough not to interfere with the components), but before attaching them to the box.”

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For more information on how you too can build the receiver:


Join the discussion – SolderSmoke Discord Server:

https://discord.gg/Fu6B7yGxx2

Documentation on Hackaday:

https://hackaday.io/project/190327-high-schoolers-build-a-radio-receiver

SolderSmoke YouTube channel:

Dave G6GEV’s Very FB SolderSmoke Direct Conversion Receiver, with an Innovative Bic Pen PTO!

This is a really nice one. In the “proof of life” video we find a lot of proof, and a lot of life. SSB from the UK sounds really good. This is one of the beauties of the Direct Conversion architecture — you end up with a receiver that sounds very good. Doug DeMaw said these receivers have “presence” — it sounds like the other fellow is present in the room with you.

Dave’s happiness and satisfaction really shines through in his comments. Dave writes:

I’ve just completed my DCR, and it’s been an absolute blast!

I’m a retired EE, where PCBs and surface-mount components are the norm. I’ve occasionally prototyped using dead bug or Vero-board, but this is my first exposure to Manhattan construction – and I’ve thoroughly enjoyed it. Electronics and radio were my childhood passions, but inevitably, they lost some of their appeal once they became a career. Thank you, Bill and Dean, for helping me regain some of that lost joy!

My biggest challenge was trying to locate parts from a single UK source to minimize shipping costs (yes, I’m cheap). I briefly contemplated building a push-pull audio amp to avoid purchasing the transformer from Mouser, but in the end, I found most parts there, then padded the order with common junkbox parts to get free shipping. I’m so pleased that I heeded Bill and Dean’s advice to build the receiver as presented (well, almost). The results are so much better than I expected, with great-sounding, room-filling audio when connected to the passive half of an old active stereo speaker pair. Tuning is a bit fiddly but improves with practice. Luckily, I had no problems with any of the stages, and it just worked when the boards finally came together.

To save money (did I mention that I’m cheap?), I decided to use NP0 capacitors in the PTO instead of silver mica. The thermal coefficient should be similar, and if they didn’t work out, I planned to swap to mica later on. It turns out NP0 works great for me, with no noticeable drift after several minutes.

I don’t have easy access to a 3D printer, so I decided to roll my own PTO former. I wound the coil on a Bic Biro with a layer of heat-shrink tubing to bring the diameter to 10mm. This was glued to a wooden support, and the M6 threaded brass bar was a perfect fit inside the Biro. I finished it off with a tuning knob made from an old RC aircraft prop spinner. After experimenting with coil spacing, I ended up with wide spacing under the actively tuned area of the coil and tight spacing at the other end. This reduced the tuning sensitivity, and I now get around 40 kHz per revolution.
I’d really like to make a home-brew 2-way contact with this receiver, so maybe I’ll try a DSB transmitter next…
Thanks again to Bill and Dean for providing this fantastic resource. I’ve been a SolderSmoke listener since episode #1, and after 20 years of constructing radios vicariously, I’ve finally built one myself!
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FB Dave! Thanks and congratulations.
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For more information on how you too can build the receiver:


Join the discussion – SolderSmoke Discord Server:

https://discord.gg/Fu6B7yGxx2

Documentation on Hackaday:

https://hackaday.io/project/190327-high-schoolers-build-a-radio-receiver

SolderSmoke YouTube channel:

Honorable Mention: Graham CT7AXD’s Reassembled SolderSmoke Direct Conversion Receiver

Graham was another good sport. When I asked him about the receiver, he had already moved on, and — is often happens — had separated the stages and replaced some of them. He agreed to put the receiver back together and to shoot a video of it in action. Above you can see it, happily inhaling SSB from nearby Spain. He used a different AF amplifier cicruit — that is why this is in the Honorable Mention catergory.

Graham writes:

It has been an interesting exercise as I’ve tended to use active mixers before, but I think I am converted to DBMs now. The other rx I’ve been working on with a VCO is performing very well. I need to move the preamp over to the PTO one and see how it performs.

Thanks Graham and congratulations.
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For more information on how you too can build the receiver:


Join the discussion – SolderSmoke Discord Server:

https://discord.gg/Fu6B7yGxx2

Documentation on Hackaday:

https://hackaday.io/project/190327-high-schoolers-build-a-radio-receiver

SolderSmoke YouTube channel:

David AI6WR’s Beautiful SolderSmoke Direct Conversion Receiver

David AI6WR was a patient craftsman during the build of his receiver. He diagnosed and fixed defects in the AF gain controls that he was trying to use. He hung in there, found the problem, and fixed it. Even with a challenging antenna situation his receiver is pulling in SSB signals on 40 meters.

David writes:

Thank you everyone for the suggestions! I have tried a bunch of them out, those that I could try without making a ton of changes. I have made a couple of changes and it’s working much better now. It turned out that one of the major contributors to the unpredictable noise was the audio pot itself. It had poor mechanical connections between the input leads and and the internal traces that go to the resistor and wiper. They were actually wiggling around and constantly disconnecting and reconnecting randomly. I took it apart, cleaned the wiper with some rubbing alcohol, tried to get a better connection on the inputs by crimping them down and putting some solder on them, and then put it back together. Once I put that back into the circuit, it was still humming at high volume settings, but much more predictably. I also cut off the unused center tap lead on the primary side of my audio transformer. That wasn’t the source of the problem, but it wasn’t helping things. Finally, I put a 470u cap from the power rail to ground. That doesn’t totally eliminate the hum, but along with the other changes, it reduces it enough that nearly all of the volume range is reliably usable. It will still hum if I turn it all the way up, or if there is no antenna plugged in, but I think it is working in ordinary circumstances.

Congratulations David.

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For more information on how you too can build the receiver:


Join the discussion – SolderSmoke Discord Server:

https://discord.gg/Fu6B7yGxx2

Documentation on Hackaday:

https://hackaday.io/project/190327-high-schoolers-build-a-radio-receiver

SolderSmoke YouTube channel:

Lex PH2LB’s Fantastic, 3-D Yellow, Glue-Stick, SolderSmoke Direct Conversion Receiver from the Netherlands

Lex PH2LB has been a valued member of the SolderSmoke team for a long time. It was he who took our stickers into the bars and coffee shops of Holland, spearheading our efforts on Continental Europe.

He didn’t have to, but Lex took up the SolderSmoke Challenge. And he did it with panache. 3D yellow panache. Glue-stick panache!

Lex has a complete description of his build here:

Here is another video of Lex’s receiver in action

Indeed, it is working!

Bravo Lex. Thank you and congratulations.

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For more information on how you too can build the receiver:


Join the discussion – SolderSmoke Discord Server:

https://discord.gg/Fu6B7yGxx2

Documentation on Hackaday:

https://hackaday.io/project/190327-high-schoolers-build-a-radio-receiver

SolderSmoke YouTube channel:


Ben KC9DLM’s SolderSmoke Direct Conversion Receiver

Ben had to overcome some antenna problems, but as you can see here, he got it going.

He also had to overcome a capacitor shortage. He did it, using parts on hand. FB. Ben writes:

I forgot to order the 470uF caps for the audio stage, so I used some amusingly large 220uF I had in parallel.

Thanks Ben. Congratulations. 73 Bill

For more information on how you too can build the receiver:


Join the discussion – SolderSmoke Discord Server:

https://discord.gg/Fu6B7yGxx2

Documentation on Hackaday:

https://hackaday.io/project/190327-high-schoolers-build-a-radio-receiver

SolderSmoke YouTube channel:

Scott K1OA FB SolderSmoke Direct Conversion Receiver

Scott K1OA has been a licensed ham for more than 50 years, but he tells us that this was his first Manhattan-style project. He reports having built a lot of kits and even a DC receiver from EMRFD using an SA602 chip, but he says the SolderSmoke direct conversion receiver was the most fun. That comment meant a lot to us. We continue to believe there is value in homebrewing from scratch.

Scott writes:

Hi Bill,


This will be my 50th year as a licensed ham and my first

Manhattan style project. I’ve built a dozen kits in the past

15 years or so and bread-boarded a simple crystal

controlled DCR from a circuit in EMRFD

using an SA602, but the Soldersmoke DCR

challenge has been the most fun!


The most challenging aspect has been trying to get the

PTO tuning range close to 7-7.3 MHz. I’m still

experimenting with that.Audio output is loud and

sensitivity is pretty good.


I’m thinking my next project might be a simple crystal

controlled CW transmitter to pair up with the DCR, and

considering the Pebble Crusher 1/2W design from the

ARRL Handbook that uses a pair of 2N2222A

transistors. I’m interested in your thoughts on that.


Thanks for putting forth the challenge and for all the

great support you and Dean have provided!


73,

Scott K1OA


p.s. – love the podcast and your Soldersmoke Adventures

book!

Thanks Scott and congratulations.
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For more information on how you too can build the receiver:


Join the discussion – SolderSmoke Discord Server:

https://discord.gg/Fu6B7yGxx2

Documentation on Hackaday:

https://hackaday.io/project/190327-high-schoolers-build-a-radio-receiver

SolderSmoke YouTube channel:

Juan LU2VJM’s Beautiful Argentine SolderSmoke Direct Conversion Receiver

I was really pleased to see Juan LU2VJM’s rapid completion of the SolderSmoke direct conversion receiver. But I wasn’t really surprised — Juan is an experienced homebrewer who has successfully completed Farhan’s BITX transceiver. Juan and I talked about how it is worthwhile for even an experienced homebrewer to go back and build a direct conversion receiver. Farhan did this. Farhan said that we do this because we are tool makers. We have opposing thumbs that allow us to grab a soldering iron. Indeed. And you can hear the happiness in Juan’s voice when he says in the video, “Today we have reception!” Excellent.

I was also pleased to see this receiver enter the Hall of Fame becasue this marks our first receiver from Latin America. We hope there will be many more.

Here are some pictures of Juan’s receiver during construction:

Juan’s AF Amplifier

Juan’s Diplexer with homebrewed coil

Another shot of the AF amplifier

The mixer, getting ready for construction

The completed receiver. FB!

Thanks Juan! And congrastulations!


For more information on how you too can build the receiver:


Join the discussion – SolderSmoke Discord Server:

https://discord.gg/Fu6B7yGxx2

Documentation on Hackaday:

https://hackaday.io/project/190327-high-schoolers-build-a-radio-receiver

SolderSmoke YouTube channel:

Victor’s FB SolderSmoke Direct Conversion Receiver from Holland Pulls In Stations from All Over Europe… and One from Japan

Victor is a retired Electrical Engineer from the Netherlands. He doesn’t have a ham radio call sign, but as I have said about other receiver builders, he deserves one. Note the truly homebrew approach that Victor used on the PTO coil form. And he had to rebuild this part to get the receiver on 40 meters. As we can see in the above video, Victor’s homebrew receiver is pulling in stations from across Europe. Victor even reports hearing a Japanese station. FB!
Victor writes:

Hi Bill, I changed the PTO tuning unit, more stable this way. I m a retired electrical engineer, revamping on a more daily basis tube radios from the 50’s 😉 I include a Bluetooth interface too so they can be used again by “young” people with their smartphones.. I had great fun and learning experiences building the DCR !!


Thanks for the video, pictures, and messages Victor. Congratulations!

For more information on how you too can build the receiver:


Join the discussion – SolderSmoke Discord Server:

https://discord.gg/Fu6B7yGxx2

Documentation on Hackaday:

https://hackaday.io/project/190327-high-schoolers-build-a-radio-receiver

SolderSmoke YouTube channel:

Garry’s FB Australian SolderSmoke Direct Conversion Receiver with “Free Tree Printed” PTO Coil Form

Garry built a really nice receiver. I think he is in Australia. His PTO coil form is “a piece off an old rotten Australian red cedar door.” FB Garry.

Garry did a really nice blog entry on his build experience:
As with Chris, if there was any justice in the world, Garry would be issued a ham license based solely on this receiver build. He has done something that 95% of hams have never done: he built a receiver!

Congratulations Garry!

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For more information on how you too can build the receiver:


Join the discussion – SolderSmoke Discord Server:

https://discord.gg/Fu6B7yGxx2

Documentation on Hackaday:

https://hackaday.io/project/190327-high-schoolers-build-a-radio-receiver

SolderSmoke YouTube channel:

Nate KA1MUQ Turns His Frying Pan DC Receiver into a Double Sideband Transceiver and Works Idaho from California

Wow, you can see the look of homebrew satisfaction as Nate works Idaho from California with his homebrew Double Sideband Transceiver. It is a good thing that Nate got that frying pan into the shack before he was banned from the kitchen.

Nate writes:

I finally got my DCR to be a DSB transceiver. I had a lot of trouble with transmitted RF getting back in to the VFO and causing distortion. While I imagine I could have tried putting the VFO in metal box, I instead opted to move the VFO to a 4.7-5 MHz range and then mix that with a 12 MHz crystal oscillator. Now the VFO is at a frequency unaffected by transmit RF. This mixer and crystal oscillator are on the breadboard and from SSDRA. The transmit amplifier chain was taken from Fahran’s Daylight Again radio. I just got a 570 mile contact on 5 watts – conditions are good. If there is interest let me know and I’ll share my schematic.

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I looked this morning and I have 100 DSB posts on the SolderSmoke blog. There are lots of ideas there on how to homebrew for DSB, many of them from Cuba, many covering DSB rigs that I built in the Azores, and others that I used in the Dominican Republic. Check it out:

Dallas KC5DI’s SolderSmoke Direct Conversion Receiver

Dallas is a friend of Lyle WZ5M — Lyle encouraged him to build this receiver. Dallas’s son is also working on a receiver — we hope to see that one completed soon.

FB Dallas and congratulations.

For more information on how you too can build the receiver:


Join the discussion – SolderSmoke Discord Server:

https://discord.gg/Fu6B7yGxx2

Documentation on Hackaday:

https://hackaday.io/project/190327-high-schoolers-build-a-radio-receiver

SolderSmoke YouTube channel:

Lyle WZ5M’s SolderSmoke Direct Conversion Receiver

Lyle WZ5M did a great job on his receiver, and in the finest ham radio tradition encouraged two other builders to take up the SolderSmoke challenge. FB Lyle. I really like your receiver. That looks like a genuine pine board. Frank Jones would approve.

73 and congratulations!

For more information on how you too can build the receiver:


Join the discussion – SolderSmoke Discord Server:

https://discord.gg/Fu6B7yGxx2

Documentation on Hackaday:

https://hackaday.io/project/190327-high-schoolers-build-a-radio-receiver

SolderSmoke YouTube channel:

Jim K1KJW’s SolderSmoke Direct Conversion Receiver

Jim’s Vermont DC receiver is really nice. It is pulling in the 40 meter CW very well. Check out Jim’s QRZ page: https://www.qrz.com/db/K1KJW

Thanks Jim and congratulations.

For more information on how you too can build the receiver:


Join the discussion – SolderSmoke Discord Server:

https://discord.gg/Fu6B7yGxx2

Documentation on Hackaday:

https://hackaday.io/project/190327-high-schoolers-build-a-radio-receiver

SolderSmoke YouTube channel: