Roy WN3F's FB SolderSmoke Direct Conversion Receiver

First, very cool sticker Roy.  Thanks for designing this.  We look forward to defacing cities, bars,  and coffee shops across the globe with these stickers.  

At the very end Roy ran into an unusual problem:  His receiver did a good job with CW, but not so good with SSB.  Hmmm.  I remembered that we had a similar problem with Chris G7LQX.  That problem turned out to be in the diplexer.   With Roy's I took a close look at a picture he sent.  He had C-16 as an electrolytic.  Uh oh.  What value did he have there?  Roy told me that he had overlooked the decimal point and had put a 47 uF cap there instead of a .47  cap.   Snip snip, a few minutes later all was well with Roy's receiver.   

Great job Roy.  Don't worry about the cap, that is exactly the kind of mistake that all homebrewers make.  

Roy wrote:  

It's finally done! Many thanks to Dean and especially Bill for all the help getting my receiver completed. I had a lot of challenges so it was hard to pinpoint anything in particular. Overall it was a tremendous learning experience in basic radio electronics and in the uses and limitations of my test gear.

Next up I need to finish the Norcal 40A I got about halfway done with before putting aside a year ago when I moved house. I also need to complete my PSSST-20 (Pete's Simple Seven SSB Transceiver) which I had barely started - I feel much better equipped to get that done now. 

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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:

https://www.youtube.com/@soldersmoke 

Adam AA1N's SolderSmoke Direct Conversion Receiver

Adam built a fine receiver. 

Abam wrote:  

Thanks Bill! And @Soldersmoke and lots of others on the Discord here as well. I did tune some SSB, need to add a larger plastic knob/cover to the tuning screw to make it a bit more easily tweakable. Learning process to hit it right on the double-sideband but when you get it dialed it sounds pretty good. Will try this evening and other times of day as well...

 Congratulations Adam! 

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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:

https://www.youtube.com/@soldersmoke 

Nate KA1MUQ's Frying Pan SolderSmoke Direct Conversion Receiver

This one is kind of "out there," on the fringes of radio respectability.  But on the other hand Nate KA1MUQ has just took to a new limit the old ham radio tradition of raiding the kitchen for items that will serve the bases of support for new rigs.  Usually, these items are wooden breadboards (hence the term).  Nate has taken this quite a bit further, appropriating an entire frying pan because of its copper bottom.  Nate reports that there is good news and bad news:  The good news is that the receiver is working.  The bad news is that his wife has banned him from the kitchen.  It takes a brave and dedicated homebrewer to do something like this.  Kudos Nate.  But you probably should stay out of the kitchen.  

Nate's receiver sounds great, and had provoked some much-needed humor on Discord:   There were comments about too much bacon frying noise.  And about the frequency readout being eggzactly right.  Dead pan humor, and the possibility of a pan-adapter.  FB!  

Thanks a lot Nate 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:

https://www.youtube.com/@soldersmoke 

Piotr KD9NHZ's SolderSmoke Direct Conversion Receiver

 Nice job Piotr!   Congratulations!  In his comments he captures well the excitement that comes from listening to receiver as it first comes to life:    

Piotr writes: 

It's alive! Thank you Solder Smoke team. My winding on PTO bit loose, I think I'll just hot glue gun it. Tuning is delicate, but front panel added some friction. Need to swap audio pot (used linear I had handy), and speaker is 12R (from junk box). Audio stage has a lot of gain - that stage alone did pick up loud AM station with my finger as antenna :). Thanks again de Piotr KD9NHZ

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:

https://www.youtube.com/@soldersmoke 

Steve N9SZ's FB SolderSmoke Direct Conversion Receiver

FB Steve! Your receiver looks and sounds great!  Congratulations!   

Steve writes:  

Thanks to Bill and Dean for all their work and promotion of this project. I learned alot and had fun. The receiver works well now after much tweaking. I need to finalize how the boards will be mounted. I am thinking of mounting the BPF and audio amp boards vertically on the edge of my small piece of wood and create a front panel using a PCB to mount a on-off switch, volume control. on/off LED, and the speaker/headphone jack. I also want to add a rear PCB to hold an antenna jack and power jack.

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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:

https://www.youtube.com/@soldersmoke 

Martin GM5JDG's SolderSmoke Direct Conversion Receiver Inhales on SSB Contest Weekend

When I first saw Martin's boards, I thought I was looking at something that was not really Manhattan style.  But I was wrong -- Martin had simply drawn grid squares on his boards.  He used MeSquares for his non-ground connections.  The SSB his receiver was picking up sounded great.  

Martin is a relatively new ham -- he started in 2020.  It is really nice to have Scotland represented in the group.  

Martin writes:  One of the main things I learned was how to really start to use my oscilloscope. The band pass filter proved to be challenging as I initially placed my trimmers incorrectly and it took quite a while to find the problem. I'm looking at this as a potential high school project, so all my soldering was with lead free solder, as I run a community interest company providing tech workshops for disadvantaged kids. I would like next to look at building a complimentary transmitter. Will also have a look at the mods and upgrades.

Martin has noted the touchiness of the main tuning knob.  One of the mods he should look at is the one that allows for easier tuning across the 40 meter band.  It is described in detail in a post on mods-and-modifications. 

Thanks Martin, 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:

https://www.youtube.com/@soldersmoke 

Mark KI5SRY's SolderSmoke DC Receiver with a Cool Gear-Driven Tuning Dial

Mark KI5SRY came up with a very innovative solution for the tuning dial problem.  See above.  My solution was much less sophisticated:  At the suggestion of VK3YE, I just put a calibrated card underneath the screw.  By looking at the screw edge from above, I could get a rough estimate of where I was in the band: 

Looking back on his successful build of the receiver, Mark wrote: 

You made this pretty straightforward. My biggest challenge was trying to understand what was really happening in the circuit.

I learned how to use my oscilloscope, seeing the oscillator come to life was great.

I would like to build a transmitter or a complete transceiver.

Bill, thanks to all of the effort you and Dean are putting into this project. There was definitely a magical feeling dialing in and getting legible sound out something built on my bench.

Very cool Mark.  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:

https://www.youtube.com/@soldersmoke 

Jeff N0NQD's Direct Conversion Receiver has led to a problem like Jean Shepherd's Heising Modulator Obsession

Wow, Jeff N0NQD built a beautiful receiver, and has been bitten bad by the homebrew bug.  Jeff admitted that he recently went to a gala with his wife.  He was preoccupied with the problems he was having with his DC receiver. Suddenly DURING THE GALA he remembered having mis-identified two capacitors in the mixer.  So he and his wife HAD TO GO HOME FROM THE GALA so that he could fix the problem.  And apparently he is still alive, and married!   Amazing! 

Jeff wrote:  

I have been a ham for just about 40 year and typically build kits lots of them most recent the QMX. I found a new passion and seemingly addiction now because of this build. My next Home-brew project is probably going to be a transceiver or a complex receiver not sure what type just yet. It has been so much fun and highly distractive to be apart of this Soldersmoke DCR family. And hope this continues!! Thank you and 73 Jeff N0NQD

Jeff N0NQD's Bench

Thanks Jeff. 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:

https://www.youtube.com/@soldersmoke 

Erik N2EPE's SolderSmoke Direct Conversion Receiver

Erik built a really nice receiver.  I was glad that he took to heart our advice on the need for a large, insulating tuning dial.  He made one!  As he made this entire receiver. 

Eric wrote:  

I would like to make a homebrew QSO! I am learning CW, mainly because I find it easy to use QRP/POTA. I have a Michigan Mighty Mite, but it has not reached farther than my backyard yet, so a CW transmitter in the single Watt range would be a great next project. 

Congratulations Erik! 

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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:

https://www.youtube.com/@soldersmoke 

Ryan AC3NG's FB SolderSmoke Direct Conversion Receiver

All the way through, Ryan displayed a desire to really understand each of the four circuits included in this receiver.  He wanted, as Maxwell said,  to know not only the "go of it" but "the particular go if it." FB! 

Ryan wrote: 

Here's a short video of my receiver in action.  I'm very pleased to be receiving real radio!    I'm too inexperienced, so don't really know if this is good or bad performance for this receiver.  This is about as good as I've gotten so far.  A few people I can understand well, but many are not really intelligible.  Thanks to everyone, this is a fun project!

I think it sounds great.  Tuning in an SSB station with a DC receiver is an aquired skill -- we all get better at it over time.  

Congratulations on building a really nice receiver Ryan. 

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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:

https://www.youtube.com/@soldersmoke 

Wayde VA3NCA Receives SSB, CW, FT8, and CHU Canada on his SolderSmoke Direct Conversion Receiver

Above you can watch and listen to Wayde's receiver as he tunes across 40 meters. It sounds good, even though Wayde is thinking about some improvements. 

 It was highly appropriate that Wayde's first reception report should be of CHU Canada, the Canadian time signal on 7.850 MHz, a bit above the 40 meter band, but clearly in tuning range for an unmodified SolderSmoke direct conversion receiver.  CHU is probably unique in the world in that it is transmitting the carrier and JUST ONE SIDEBAND.  It transmits only the upper sideband.  This makes it clearly detectable by our receiver.  As Dean pointed out to Wayde, all he had to do was "zero beat" the carrier with the PTO signal (tune to the point where they are on the same frequency and the audio tone disappears).   Because there is only one sideband, the direct conversion receiver can demodulate it very well.  If there had been two sidebands, this would have been a standard AM signal, and our little receiver -- which does very well with SSB and CW -- would have been unable to demodulate the signal without distortion. (For an explanation of why this is, see: https://soldersmoke.blogspot.com/2022/12/but-why-why-cant-i-listen-to-dsb-or-am.html   Warning -- this is kind of in the "advanced course" category.)

Here is an overhead shot of Wayde's receiver: 

This is a really nice build.  The use of what appears to be a kitchen cutting board harkens back to the early days of radio when young hams took the cutting boards from their mothers' kitchens and used them as bases for rigs.  This is origin of the term "bread board."  Frank Jones continued in this tradition by building most of his rigs on wooden boards.  Wade's DC receiver continues in that tradition. 

Wade was able to decode some FT8 picked up by this receiver and recorded on his phone: 

Congratulations Wade!   

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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:

https://www.youtube.com/@soldersmoke 

Ken W4KAC's Wonderful SolderSmoke Direct Conversion Receiver -- with a Leaf Blower Tuning Dial

Ken W4KAC tells me that the tuning knob that he used to minimize hand-capacitance effects on his PTO started out as a gear in a leaf  blower.  I commented that the engineers who designed that gear surely never thought that it would someday be used in a homebrew direct conversion receiver.   

Ken lamented the polemical nature of the SSB discussion captured in the above video, but the clip does give a good demo of the SSB capabilities of Ken's receiver. And the video gives some nice close-ups of the receiver itself.  

Ken is a CW guy, and he has already homebrewed a QRP CW transmitter that he hope to pair-up with the receiver.  Here it is: 

Ken reports 160 mW output with a 377 mile reception report on the Reverse Beacon Network.  I made a contact with something similar: https://soldersmoke.blogspot.com/2023/02/first-qso-with-high-school-receiver-100.html

Ken wrote about the importance of persistence: 

Good morning. Just wanted to say, don't give up if your receiver is not quite right. Mine was working, I even posted a video here. When building the AF amp from the transformer end back, the Q4 stage was fine. I added Q3 and had a "motor-boating" oscillation when I applied a signal. I tore it all off the board and started over. I still had the problem, so being stubborn I continued on and kept adding more filter caps to quiet it down all I could. The receiver worked and sounded pretty good during the day when I copied WA4FAT and others. That evening was a different story when the band was working well and very full of signals. Very strong stations were ok, but I was getting lots of "hash" and noise other than normal band noise. FT8 was breaking through weakly all over the band along with other unidentified stuff. Yesterday morning I grabbed a new piece of copper clad and built and entirely new AF amp. It tested properly all through the build. Instead of installing that board I decided to find the problem with the original. I "thought" I had used new transistors when I rebuilt it the first time. Turns out I had probably put the original Q3 back, because replacing it cured the problem. I had an entirely different receiver last night. A pleasure to listen to. Don't give up like I did at first!!

Ken went the extra mile by building a SECOND Direct Conversion receiver.  So he may soon get TWO Hall of Fame credits.  Here is the second one that Ken built: 

 https://www.youtube.com/watch?v=HUSWKJZdc8E&t=39s

Thanks Ken!  

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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:

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