Just go to http://soldersmoke.com. On that archive page, just click on the blue hyperlinks and your audio player should play that episode.
http://soldersmoke.com
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!
----------------------------
For more information on how you too can build the receiver:
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:
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:
Jason did a great job on this receiver, hanging in there as he worked to overcome techincal difficulties, some of which were related to test gear. That is a big part of the homebrew process. The receiver looks and sounds great Jason. Congratulations.
Jason wrote:
I really like the camaraderie and elmering during the process. Not to mention seeing the different builds and how people approached the design. That helped me, as I’m a visual learner. I’ve been a ham for almost 40 years and I love building rigs. This was a blast.Thanks again, Jason WV3V
------------------------------------------
For more information on how you too can build the receiver:
Herodotus once said that "learning is not child's play -- we cannot learn without pain." I think Jim KF8BOG proved that in this build. I'm sure he burned his fingers at least a few times. I remember fondly almost seeing the light buld turn on when Jim came to understand how the diode ring mixer really works. He struggled to tame a rebellious AF amplifier (we've all been there). Throughout Jim demonstrated the persistance and determination that are needed to turn a bunch of parts into a well-functioning receiver. He did it. He built it. Congratulations OM!
Jim wrote:
I am not just an appliance operator now but only half way through. Time to make a transmitter!
A little about me I became interested in Ham radio about 45 years ago in Boy Scouts I tried really hard with my Radio shack straight key and morse code chart to learn code by myself and just could never get it. Fast forward to last year and I had a friend who did CERT and he told be about it and said he used 2 meter for communications I was impressed and said “how did you learn morse code?” he replied “ I didn’t you don’t need it anymore” I promptly signed up for Ham in a day in June and got my technician license and my then my general in August. I have been studying radio ever since. This project was perfect for me. I like to make things I have been a mechanic for 40 years plus ASE master. Fixed all sorts of crazy electrical issues but DC and RF are way different lol.
Again Thanks Bill and Dean you don’t know what you have started. 73s KF8BOG
----------------------------------
For more information on how you too can build the receiver:
In many ways it was for guys like John W8UC that we launched this project. These are guys who have been hams for a long time, but -- like most hams -- never built anything. Most guys don't see this as a problem. But some guys just don't like to think of themselves as "appliance operators." For years the ARRL and others told hams that receivers were just too difficult for them to build. We found this not to be true. So we launched this project, first at a local high school, then to a larger group.
In his comments John says he has been an appliance operator for 48 years. Well, you are an appliance operator no more John -- you have built a receiver.
John wrote:
I can hear the signals on a receiver I built so I am super happy about that... I have learned more in the last month about how a receiver works than I have in the last 48 years of being an appliance operator. Thank you Dean and Bill. 3. Would like to build a transmitter next. Also a receiver for another band.
---------------------
For more information on how you too can build the receiver:
Dean and I often say that we too have learned a lot from this project, and that the receiver has gotten better as a result of all these builds. But in KE2AMP's case we really see an innovation that nobody has used before. But it is a great idea and it solves the "loose screw" problem of the PTO. Check out the spring on John's PTO. That is really smart. Thanks John.
John also sent me a crystal wrapper that will long be cherished by the CBLA (Color Burst Liberation Army):
John wrote:
Well I completed my DCR, and am receiving signals on 40 meter at 1900UTC. My audio amp will oscillate if I turn up over half way and my pto is little loose and makes it bit hard to tune. I put a light spring behind the pto bolt to give it some friction and tighten up. I’m thrilled that I’m receiving signals. I still want to add a front panel to mount the volume pot, the on/off switch and speaker if I have the room.
I am so Thankful to Bill, Dean and everyone on the discord for this project I learned so much more being able to ask questions and follow along with other builders as we worked through each stage of the build. I definitely learned some things about oscilliscopes. And testing each of the stages as we went along.
I would like to try my hand at a SSB transmitter to go along with this receiver. I have built a working MMM but was just to see if I could. I don’t know CW
Oh and I included pic’s of something Bill will like.
Pick it up at a ham fest last summer.
Will that get me into the color burst liberation army?
Thanks Again, 73
de John KE2AMP
Consider yourself inducted John. The CBLA needs innovative people like you!
-------------------------
For more information on how you too can build the receiver:
It was really great to hear those Australian voices coming from Phil's receiver. Check out the video above.
Phil writes:
Completion! So pleased, it works really well. And there were lots of lessons for me along the the way. Thank you Dean, Bill and Pete, it's been a great way to get me into homebrewing. 73s from sunny Queensland. Phil VK4PG
I also like Phil's front panel. Note how he put to use the circular piece that remained after cutting the speaker hole; that became the tuning knob. FB Phil. Thanks.
For more information on how you too can build the receiver:
Derek N9TD was another of the early builders of the Direct Conversion receiver; he has done really magnificent work. He is an Electrical Engineer, and you can see in his work (and in the email below) the tension that exists between the desire for simplicity and the urge to improve. In the above photo, for example, we see that Derek had already gone ahead with the installation of an RF gain control. We also see his use of a steel screw and an outboard coil in series with the PTO coil. All of these mods are fine -- I have used all of them. We just advise newcomers to build the basic receiver first, then put in mods from there.
Derek has gone the extra mile (many miles in fact) by building a Double Sideband transmitter to go along with his receiver. We know many will want to do this. Our advise remains: Build the basic receiver first, get it working, then do the mods, perhaps culminating in the build (as Derek did) of a Double Sideband transmitter and the creation of a DC-DSB transceiver.
Here is a video of just the receiver in action.
Note that the DSB transmitter circuitry is on the board:
And here is Derek demonstrating a phone contact with the resulting DC-DSB transceiver:
Derek wrote:
Bill,
Let me introduce myself, I am a recent electrical engineering graduate from Purdue and a long-time listener of the podcast. I want to thank you and Pete for being one of the reasons I chose to pursue my degree in the first place. I'll admit that in the more difficult stretches of getting my degree, I often pulled out the podcast to be reminded of the fun that can be had with radio and electronics.
Until recently I had to hang my head low along with the majority of the other 'appliance operators' out there having never built anything with my two hands that can be used to pull signals out of the ether.
I am no stranger to building projects, PCBs, and melting solder but I usually chose to either stick to the dreaded digital domain or focus on antennas, filters, and other ancillary equipment. The logic being that I like to have a "known good" radio for the shack and that I would focus on other equipment to supplement the radio. I still follow this logic when I want to contest and we all know that antennas are well worth the effort, I've just finally had enough of being an appliance operator and have your podcast to thank for the extra push.
I had been following the original effort of the TJ DCRX with interest from the start and earmarked this project as one I would like to build based on its inherent simplicity and good performance. However, the demands of school and a recent (at the time) abortive attempt to build an AM superhet with an SA602 the year prior made me (I got as far as feeling the joy of oscillation but regretfully petered out after that) put this one the backburner for about two years until December 2024.
By coincidence, I independently decided to start this project just before your show with the HRWB folks and the gauntlet being thrown down, which has spurred many to build this receiver. It has been great to see the extra coverage on the receiver, and the commentary has been very insightful for someone trying to build this for the first time and with as many of the "improvements" as possible.
For better or for worse, I'm the type of guy who wants to understand the "why" behind all the design choices and, from there, try to incorporate as many lessons and improvements as possible to make the "best" version possible. I'm not saying I make the best version of anything, but it's just a quirk of the way I think and justify doing a project. It always has to be "this and some additional improvement;" otherwise, I would decide against doing it.
Rambling aside, I ended up building the DCRX, adding the RF attenuator from N3FJZ's website, and incorporating the lessons you learned after experimenting with improving the tuning on the PTO. I added an external series inductor wound on a dowel rod and used a zinc-coated steel screw as opposed to brass. I found that this gave solid tuning performance across 40m and was easy enough to tune in CW or SSB signals (after 3D printing a large knob for the PTO bolt). Alan W2AEW's video on mixers was a great tutorial to use to verify that my mixer was mixing. With the radio assembled I was treated to the joy of hearing my receiver breathe in the sounds of 40m for the first time last weekend and even managed to copy some Croatian DX during last week's contest. As Farhan said to do, I have spent the last few days enjoying the receiver and figuring out its quirks before moving on to the next step.
The only "issue" I have noticed is that I still get some AM breakthrough despite tuning in the bandpass filter. The problem is very noticeable if I accidentally put my finger on the wires going to the AF gain pot. If I do that the AM station is the only thing I can hear. This makes me think the problem is after the bandpass filter and more investigation is needed. Maybe using coax on the control lines to shield it will help? Regardless I am impressed with how well the receiver sounds, the stability of the oscillator, and the effectiveness of the simple audio amp....
Again thank you and Pete for your work on the podcast and for helping inspire countless homebrew radio operators!
73s,
Derek N9TD
--------------------
Thanks Derek. And thanks for helping other hams get the 3D printed PTO coil forms that they needed.
For more information on how you too can build the receiver:
A few of the builders are so new to the hobby that they don't even have ham licenses yet. That is the case with Chris from Wales.
Chris writes:
Here’s mine up and working, antenna is now 84’ of wire from a window to a tree with 33’ counterpoise hanging to the ground. Just for the record I have absolutely no experience of radio and only one year of messing around with electronics. I’ve learnt more in the last 4 weeks thanks to you guys. It has been a great experience. Thanks
I replied that if there were any justice in the world, Chris would be given a ham license just on the basis of having built this great looking and great sounding receiver. You can hear it handling some 40 meter SSB signals in the clip above.
Thanks a lot Chris!
For more information on how you too can build the receiver:
Scott KQ4AOP's build of this receiver is especially noteworthy, becasue he used the receiver to hear the very first ham radio signals he ever received. I don't think any of us can make a similar claim.
Scott wrote: "Those first sounds were my first time ever hearing any Amateur Radio first hand!" You can see Scott's deep commitment to homebrew: "I want to build my own gear for 40m. I want to learn morse code. I want my first contact to be on my own gear." Wow Scott, the building of the receiver is the hard part, and you have already done that. I think you are well on your way. In the video above you can watch Scott tune the entire 40 meter band and a bit beyond. You hear CW at the low end. Then FT-8. Then SSB. Up just above the top of the band I think you can hear our old nemesis Radio Marti. And this powerful broadcaster is NOT breaking through on the rest of the band. FB Scott. Congratulations.
Matt was one of the first builders of this receiver (see above). He heroically stuck with the very small speaker that we had used in the high school receiver.
Matt wrote:
I just wanted to publicly thank you for doing this. I’m sure it’s been a lot of work but I’m very grateful for the experience. I’ve always wanted to home brew and I’ve done a few little things such as filters and attenuators but this has really given me the motivation to really dive in deep.
I’m 44 and I’ve only been a ham a few years so hopefully I have lots of time ahead to get others excited about home brewing. We have a very active club here in KY and there are quite a few folks mildly interested in home brewing, I’m going to push some of them to start a builders group in the club with me. This is entirely due to the effort you have put into this project!
Thank you.
Matt also builds balloons with tiny solar-powered ham radio transmitters aboard. These balloons fly around the world. He is advising Vienna Wireless Society on their balloon project. Just last night Matt wrote:
In case anyone is interested, my balloon that has been spending a lot of time in the northern latitudes popped back up again today after being quite for nearly two weeks. Looking at the path prediction on HYSPLIT it's going to make another loop to the north but at least the earth is tilting back to give me a more favorable solar angle. It's only going to get better as spring rolls in.This balloon lost a little altitude shortly after launch for unknown reasons so it's not quite a high as I would like but as long as it can stay away from spring storms, it should still have quite a bit of life left in it. This one is still flying on my old callsign. I got my vanity callsign when I thought the balloon had gone down, then it showed back up. Whoops, oh well, I tried. Matt NE3U
Peter VK3TPM is a long-time member of the SolderSmoke community. He is a software developer and technology commentator based in Melbourne. But that digital background did not stop him from diving headfirst into this highly analog project. He fought a lot to get the stages of his receiver working properly. The AF amp was full of challenges. He overcame all of them and ended up with a very fine looking and sounding receiver. See above.
Going the extra mile, Peter took his newfound abilities into the world of phone transmitters. He whipped up a 75 meter DSB transmitter and used it to check into two Australian Technical nets:
This is really great. You can see the look of pleasure and pride in Peter's face as he uses his machine to send his voice far across Australia and into Tasmania. This is the kind of satisfaction that comes from homebrew.
I am encouraging him to combine the his DC receiver with additional stages (perhaps from the DSB transmitter) to make a DC-DSB transciever.
Thanks Peter!
---------------------------------------------
For more information on how you too can build the receiver:
"SolderSmoke -- Global Adventures in Wireless Electronics" is now available as an e-book for Amazon's Kindle.
Here's the site:
http://www.amazon.com/dp/B004V9FIVW
Bill's OTHER Book (Warning: Not About Radio)
Click on the image to learn more
Where are the readers of SolderSmoke Daily News?
Pete Juliano N6QW
Master Homebrewer
Dean Souleles KK4DAS
With beret and with a Michigan Mighty Mite in hand
Proposed Australian FreeDV RADE1 net
-
I've had two good contacts VK3-VK5 using FreeDV RADE1 today. Quite a lot of
stations on air.It would be good to have a regular net for Australian
stations ...
Nostalgia Time
-
A Trip Back in Time. My middle son, Tim and his lovely Amy visited
yesterday as we celebrated the 4th of July. Several visits ago, Tim
mentioned some items...
Radio Marti Logs & Recordings: July 4, 2025
-
Many thanks to SWLing Post contributor, Dan Greenall, who shared the
following message and recordings yesterday, July 4, 2025. Dan writes: Hi
Thomas Happy ...
Is There Such a Thing as a Homebrew System?
-
There's been a lot of talk about what is and isn't homebrew lately. I
started hearing the all-in-good-fun contention around the Soldersmoke DC
Receiver...
HRWB 240 - Test Leads with Carlos from Parts Candy
-
In this episode we meet Carlos from Parts Candy. Carlos is an experienced
electronics technician and he shares his life-long love of electronics and
his...
The Communicator July - August 2025
-
*A Big One to Last the Summer*
We're coming up to our club's 50th Anniversary and this is another big
issue, with a look back at our history, great article...
A Real ZN414!
-
Recently, I built a simple little TRF receiver for the AM broadcast band
using a TA7642, a modern equivalent for a chip that was quite popular with
electro...
W2ARP
-
Episode 526 - Bob Pantazes - W2ARP In this episode of QSO Today, Eric Guth
4Z1UG returns from a health break to interview Bob Pantages, W2ARP, whose
journe...
The "George Batterson 1935 CW QSO Party" - Summary
-
The first *George Batterson CW QSO Party* has concluded and the results are
in! The "*GB*" was introduced to honor George Batterson (W2GB), who along
wi...
KK4DAS MB 20 Transceiver Complete
-
The MB 20 transceiver is now complete. The rig is a homebrew 10-watt
20-meter SSB transceiver. The VFO module was an ebay purchase of a
salvaged Yeasu...
A Curious 9 MHz Crystal from Mouser Electronics
-
Just a quick post to share info about a good 9 MHz crystal sold by Mouser
Electronics.
I last purchased batches of crystals for xtal IF filters back in 2...
40m Pelican Case SSB Transceiver
-
See YouTube channels for details:
http://www.youtube.com/c/CharlieMorrisZL2CTM
*Test code for the LCD and Si5351*
#include
...
Hollow-State Design, 3rd Edition
-
Hollow-State Design, 3rd Edition is available from: Lulu Press:
tinyurl.com/hollowstatedesign3 eBay: search for “hollow-state design”
Electric Radio bookst...
I Finally Bought My Dream Airplane
-
Aviation has been a love of mine since I was a very little person. Living
in Nevada, seeing posters and ads for the Reno Air Races, specifically the
Texa...
Daylight Again – An all Analog Radio
-
What’s all this? In 10 seconds, A high performance, 7MHz, 5 watt SSB rig
Draws just 24 mA of current 90 dB dynamic range, 80 dB close-in dynamic
range 3D ...
Digi-chirp! Digital synthesis of ‘nostalgic’ CW
-
The bottom ends of 80, 40 and 20m are not what they used to be. For
starters, the busiest part is the digital segment where computers talk to
computers – l...
Modifications to the Dayton/FDIM-2019 Antuino
-
The Dayton Antuino has sub-optimal performance. This is a short note on
improving it to an 80 db range of measurements. The trouble with Antuino
2.0 (the o...
Raduino as NBFM TX
-
Here is a neat, 30 minute hack for your Raduino to turn the Si5351 into a
pretty stable, solid NBFM transmitter. The hack is to add a varactor diode
in ...
QRP Labs shop!
-
[image: Shop]
All QRP Labs kits may be ordered online securely at the shop, with PayPal
payment.
*Click here to visit the shop!*
*Click!*
*Shop! Order...
Posts
