Jay KI5VIR is a new ham, but you would never know this by looking at his build of the direct conversion receiver: It looks like something built by someone with a lot more time the amateur ranks. (See above.)
Jay writes:
I have completed the direct conversion reciever and I can't thank Bill, Dean and those that commented and asked questions on discord enough. This was my first build and I can't believe how much I learned. I have a long ways to go, but this was just what I needed to get started in homebrewing. 1- (BIGGEST CHALLENGE) was probably the diode ring mixer and learning to use my scope and setting it up to test the circuit. (this was also the most rewarding stage) 2-(WHAT DID YOU LEARN AND WHAT WAS YOUR BIGGEST CHALLENGE?) I got a basic understanding of how to read a circuit and what different components do in the circuit.(I still want to revisit each stage and make sure I get a little more) 3-(WHAT WOULD YOU LIKE TO HOMEBREW NEXT?) I want to first dissasemble each board and rebuild while it is fresh in my mind and make sure I get a little better understanding. After that, I want to either build a transmitter to go with this reciever, or build a complete transciever. Not sure whether to build ssb or cw, but I definately want to build something I can make at least a few contacts with.
Congratulations Jay, and welcome to the Hall of Fame!
Dave Richards AA7EE is justifiably famous in homebrew circles for the beautiful photographs of his rigs, and for the superb documentation of his builds. You will see what I mean when you visit his blog:
We were very pleased when Dave told us he would build the direct conversion receiver that we have been discussing on Discord.
Dave writes:
Phew! Well this was a bit of a journey, and a slightly humbling experience. I looked at the schematic and thought, "Hey, I can build this. Shouldn't be too hard!" But the homebrew Gods judged that it was time to remind me of my place in the big scheme of things, by imbuing my receiver with in-band breakthrough from SSB, CW, and digi stations. Strong in-band stations within about 50KHz were breaking through and being heard in the same way that you'd hear SSB, CW, and digi signals on an AM receiver without a BFO. Their pitch wasn't changing as I tuned, because they had no pitch. Bill suggested that RF was getting into places it wasn't supposed to be, and being envelope detected by the AF amp. As it turned out, he was right. If anyone's interested, I can post a video of the issue I was experiencing. In the meantime though, I'll keep this post brief. I have quite a lot of pictures from various stages of the build, but posting them all here might be a bit TMI.
I wanted to make this receiver reasonably compact and build all the stages on one board. My near-pathological tendency to try and build things fairly small could have contributed to the breakthrough problem that I experienced. I won't go into all the details of the troubleshooting process here, unless people are really interested, though I'll detail them in a post on my blog, as I think that sharing this stuff can be helpful to other builders - just as I have benefited greatly from others sharing with me.
I made a few small changes from the original schematic, to cure the issues I was experiencing. Will detail them in another comment underneath, as the free version of Discord puts a character limit on posts.
I made the following small changes, to cure a couple of issues this little receiver was experiencing -
1) The AF amp was motorboating at anything above about medium volume, so I swapped out the 47µF capacitor in the +ve supply line to the AF amp (C10) for a 470µF part. This killed the motorboating dead in it's tracks.
2) To solve the in-band breakthrough issue, I did two things -
a) At the suggestion of Peter VK3TPM, I placed a 1K resistor in the +ve supply line to the first AF amp stage, Q5, between C15 and R8. In conjunction with C15, this forms a lowpass filter with a 3dB cutoff point at about 3Hz. With a 12V supply, ~3.5V is dropped across this resistor and at 9V, the voltage drop is ~2.3V. If this voltage drop is too much for you, you can try a lower value of resistor and perhaps increasing the value of C15. This voltage drop does decrease the gain of the stage a little. In my case, it was welcome, as the amp was tipping over into feedback at full volume. Adding the resistor eliminated this, so I can now run the AF gain pot at full tilt.
b) I added a 0.22µF capacitor from the wiper of the AF gain pot to ground, as an RF bypass. Physical placement of this cap was close to Q5. It also shapes the audio a little, cutting out some of the high-frequency hiss. You can experiment with different values here. I was initially going to use a 0.1µF part, but 0.22µF provided better protection. Greater values cut out too many of the higher frequencies for my liking. For a relatively simple receiver like this, I like the wide open sound.
I removed the spring from the tuning shaft. Tuning is smoother now, and free from backlash.
Dave
AA7EE
Here is a video of Dave's receiver inhaling CW during the CW Sweepstakes contest:
Here is one of Dave's iconic photos of the receiver:
Thanks Dave! Congratulations and welcome to the Hall of Fame!
I think this one is a bit over the top. They are way too interested in the old typewirters. The artist who destroys the old machines to make robots and sculptures... the "musical group" that plays songs on old typrwriters... all the people who decry modern digital tech, but then create internet pages that save the old typewriter shops. But hey, who am I to criticize them? Some readers really liked the New York Times article on the Bremerton Typewriters Company. And there is a lot of overlap between these typrewriter fanatics and the many shades of ham radio fanaticism (boatanchor-oligists, I'm looking at you!) So here (above) is the full movie.
One personal note: My paternal grandmother was part of that original typewriter revolution - she remained proud all of her life of hwer ability to use that machine. She kept her own typewriter in her house all of her life. And she used it.
There are a LOT of YouTube videos about old typewriters and workshops that service them. Here is one about the last typewriter shop in Melbourne, Australia:
Listen to this in its audio form. Maybe follow along with the (type?)written text. Enjoy the pictures and the videos and -- above all -- the message.
This wonderful article has a lot to say about the value of repairing -- and knowing how to repair -- old gear. Not just typewriters, although that is very cool. But this article also pertains to old boatanchor ham gear, and to the skills needed to homebrew rigs today. And it says a lot about mentorship.
Readers will remember last week's post about the homebrew rivalry between VU2RM and VU2NR. (Note the bio about VU2RM below). This morning Farhan sent me this article from a 1970s-era Indian ham radio magazine in which VU2RM describes his early efforts to get onto the satellites. I also tried during the mid 1970s, but I didn't have the kind of magic decoder ring provided (via QSL!) by OH2RK. My satellite success had to wait some 20 years, until I was in the Dominican Republic. More on this below the VU2RM article.
This morning I replied to Farhan's email:
Very cool Farhan. I see that Pete may have an Indian rival for "most SSB transceivers built."
I got into the satellites during my 1992-1996 stay in the Dominican Republic. At first, we had no way to get the up-to-date Keplerian elements to predict satellite passes. Then Compuserve opened up. I had to telephone Miami from the DR to get the Keps. I ran up a huge phone bill.
I too built an antenna for these contacts. Mine was the 2 meter portion of a 144/440 MHz project from 73 magazine called "The Ray-Gun". I built mine out of scrap lumber and refrigerator tubing. I still have these elements! I used them in the beam that I built to listen for YOUR satellite! In the DR, elevated the thing by 45 degrees and pointed it in the general direction of the satellite.
RS-11 had a very cool robot aboard. If you called it just right, it would issue you a serial number. I have the QSL.
Here are some articles about our satellite adventures.
Earlier this month I had stumbled across a 1964 QST article entitled "A Sideband Transceiver, VU2 Style." I forwarded the link to Pete N6QW, Grayson KJ7UM, and to Farhan VU2ESE. Last night Farhan sent me this insider look at early SSB in India. It is really great. The battle for preeminence among early SSB homebrewers in India reminds me a bit of Jean Shepherd's descriptions of homebrew radio in Hammond, Indiana. Farhan's description of the early rigs being "all over the place, in about 3 or 4 boxes... with a whole lot of wires running all over" really resonated with me -- yes, even today, that is true homebrew. Thank you Farhan for sharing this with us.
Farhan writes:
VU2NR, Raju was a legend! Quirky, brilliant and liked to be by himself. He lived to a very old age of 100 or so. He was the first ham to get on SSB from India. Therein hangs a story of espionage, stolen secrets, cold war, politics and kleptomania. Most of the actors are now dead, so it can be told now.
I never met VU2NR, he rarely travelled. One evening at Paddy's shack, I was shooting the breeze with VU2RM, Ram, about my own SSB efforts. Ram was probably the most knowledgeable ham on SSB in India and his RM96 was widely duplicated. Paddy and Ram were trying to empty out a bottle of the Old Monk and I casually mentioned how we had to scrounge around for SSB lattice filters until Wes showed us how to build them ourselves. At that point, Ram unloaded this story to us:
VU2NR joined the Allies and worked as a radio mechanic with the RAF. After the war, he joined the ICAO (International Civil Aviation Organization) and then finally the United Nations as a comms expert, he was in Aden for a while. He understood the radios well and he became a well known homebrewer. His most brilliant work was the NR60 (it is an SSB radio built around four CA3028 kind of mixers). It was the first SSB radio that I had built (and it worked!) but we are getting ahead of ourselves.
Back in the 50s, ham shacks of India consisted of World War II surplus receivers and a self-built 807 transmitter driven by a VFO. There was a fair amount of buzz on the bands about SSB. The hams could occasionally pick up DX that was on SSB and easily resolved by the BC-348s and the HROs but there was no way to build one. The QST was difficult to get your hands on but Raju had become a subscriber of the QST during his RAF days.
A QST sailed on a slow boat from the USA and landed up at the port on the east coast of India, Vizag and made its way to Raju's doorstep. Over weeks, he gathered parts and in the summer of 1955 he quietly came on 40 meters on SSB! This blew everyone away. Until now, one had only heard stories of SSB transmitters told by sailors of Sandra Maria Gracia after a few drinks to a bunch of hams clutching onto their 807s. It was as if Jesus had materialized!
VU2RM, Ram was not amused. He was a homebrewer with pride and honour. He could never be bested. He spent the next evening tuning on Raju's SSB up and down to note that the other sideband was missing and the carrier was gone. It sank into him that Raju had indeed beaten him to SSB. Ram worked at the Kakinada port, about 100 miles further down south on the east coast as the port radio engineer. He didn't sleep well. At 5 am, he got up, walked out and took a bus to Vizag where Raju lived. He was at Raju's door at 9 am. Raju was amused at the young guy and invited him in. They knew each other as rival homebrewers. There was tension in the air. Raju showed off his SSB transmitter in the front hall of his home. It was all over the place in about 3 or 4 boxes. There was the power supply, the PA, the ssb generator using a 2Q4 (a passive RC phasing network), a separate VFO box and a whole lot with wires running all over. In a corner was his stack of QSTs.
Raju's XYL called out for coffee and snacks (called 'Tiffin' in south Indian English) and Raju sauntered off to the kitchen to fetch his celebratory feast...
With alacrity and swiftness that only comes once in a lifetime, Ram, VU2RM, sprang to action. He darted to the QST collections, quickly found the one with the SSB transmitter on the cover, turned the pages to discover VU2NR's dog eared pages. He was staring at the circuit trying to memorize it. He realized that 2Q4's internal diagram had really odd values that he could never remember. So he did what James Bond, Bertie Wooster and Louvre thieves would have done. He rolled it up and slipped it into his pocket! (In those days, QST could be rolled and slipped into your trouser pockets, leading to wider dissemination of knowledge). He called out to Raju asking him to forget the refreshments as his bus was due back home. He legged it out and didn't stop until the bus stop. He hid around the bus yard hoping to not be caught by Raju. In the meantime, Raju, cursing the young upstart, drank both the filter coffee cups and left for work. Raju was unaware that the royal jewels were stolen.
VU2RM, Ram, started to work on his SSB radio over the next few days. He stopped going to work. At first, he figured out how to null the carrier using a twin triode modulator. Next, he fabricated the 2Q4 circuit. He sand papered lower value resistors until they read as close to the value as he could manage on his analog volt-ohm meter. He gave up on the exact capacitances and just soldered a bunch of the closest together. He had a crude 2Q4 equivalent. This, he dropped into his rat next circuit and an 'Almost' SSB signal emerged. He was probably having a sideband suppression of less than 15 dB at this point. It was suppressed and the carrier was nulled. He declared victory.
In the morning, Ram was on the band strutting off his SSB transmitter to the local gang. Graciously accepting the accolades from his fan club and extolling virtues of life on SSB to the lesser mortals. The news quickly spread over CW and AM of VU2RM as the second SSB station from India.
In the meantime, the atmosphere at VU2NR was tense. You could cut the air with a toggle switch. Raju had no idea how Ram had gotten the SSB. He carefully tuned around on his signal. He could pick up faint traces of the opposite sideband. Ram's carrier was also leaky. He decided that Ram was probably passing off his AM transmitter as a SSB. He said as much on air to his own devotees. Ram, ever watchful of his own reputation, heard this criticism and broke in, challenging Raju to prove that his was indeed not SSB. Raju's reaction was mixed. Now he wasn't sure.
It was now Raju's turn to have a sleepless night. After his breakfast, he had had enough of confusion and he hauled his old scope and himself into the 8 am bus to Kakinada and showed up at Ram's doorstep! "Show me your radio" he said crisply.
For Ram it was his moment of crowning glory. He had brought Raju down to his shack! Raju plugged his scope into Ram's transmitter. He sniffed around the transmitter which was laid all over the table. "Where is your 2Q4?" he asked. Ram pointed to bunch of resistors and capacitors and Raju realized Ram's dog headed brilliance. He sat down, traced to the balancing pots (there would be two of them as this was a phasing transmitter). At this time, he decided to show Ram his greater prowess. He reached out to the carrier nulling pots, and tweaked them to minimum carrier (Ram was watching the oscilloscope with his mouth wide open). He told Ram that he had now fixed the carrier and then showed him how to adjust the RF phasing control for minimum by tuning to the opposite sideband on Ram's Bc 348. Having proved to Ram that he was a better homebrewer, he declared that now, Ram's transmitter was indeed SSB and not semi-AM. Raju retrieved his honor by being gracious and "mentoring" Ram.
They had coffee and snacks and it was time for Raju to leave, as Ram was showing Raju to the door, Raju's eye caught a QST on the shelf... he pulled it out and stared down at the QST with his own address neatly stickered on the QST's cover. He glared at Ram for a long time and turned away and left in a huff. Ram called after him down the street but Raju was gone.
VU2NR's last radio was built when he turned 90. It was the NR90 and it was built using NE612 chips. His hamming came to an abrupt end when one day his son dropped in unannounced only to find him perched on his tower of 30 feet height, fixing a fallen element of his self-made log periodic. The son was so horrified that he took away all the radios to save him from self-harm (this part of the story is unconfirmed).
My friend Sasi, VU2XZ, was close to him and he got the family to donate his callsign to a repeater that has been established in his memory. VU2NR lives on.
- f
------------------------
Here is the link to the 1964 QST article. VU2NR's article appears on page 19:
-- We are over 100 on the Direct Conversion Receiver Builds. We talked about the receiver project at the GQRP convention. Video on the blog.
-- G4 Geomagnetic storm November 11-12. Messed up my computer. Blackout in the DR?
Pete:
-- USMC Birthday. Having served alongside them they have my deepest respect. Veterans Day.
-- Think about supporting those without a job this Thanksgiving. Cash to various organizations is best.
-- 50 Hz off frequency -- What does that mean if you tune by ear and not by mouse/waterfall?
-- The Hybrid Wireless is on the air. A unique build and not often seen.
Dean:
-- Progress on the HOMEBREW MOSFET amplifier. Claude helped.
Dean's 100 watt amplifier
SHAMELESS COMMERCE DIVISION: Mostly DIY RF. Become a SolderSmoke Patron. Buy stuff from Amazon through the link on this blog (in the right side column).
Bill:
Bill's antipode from Virginia
-- VK early in the morning. Also E51MWA and FW5K. All homebrew SSB. My antipodes. VK6ACF Charley 11,629 miles. Might be my most distant station worked.
-- Camden is a 23 year-old blind ham who is looking for some homebrew help. He lives in Pleasant City, Ohio, about an hour east of Columbus. Can you help him? camden@bopp.net
-- Dave AA7EE A completely AI SolderSmoke? "Open the pod bay doors Hal."
-- Pat W3RGA heard my 1 watt HI7 beacon. Thanks Pat.
-- Patrick Voets -- A Belgian living in the Netherlands -- supports our defiant NIMCEL position!
-- Brian "Moses" Hall K8TIY, Father of Robert of "Crank it in Robert" fame. Check out the video. Young Robert appears around the 45 minute point: https://youtu.be/Xqs2Ihucr6I?t=2730
-- Will Harris KI4POV -- an esteemed homebrewer -- asks about using 75 ohm coax. I say yes, Pete tells him how to do it right.
Please let us know if you spot any errors, or if we have inadvertently missed anyone. Don't worry about being late to the game -- the challenge continues. All of the info is still available (see below).
As of November 29, 2025 1305Z:
So far 99 completed receivers, and 7 honorable mentions. Total Count: 106. Receivers built in 17 countries.
NE3U (KY4EOD) Matt
KQ4AOP First ham signals ever heard!
N9TD Derek
AC3NG Ryan
VK3TPM Peter Marks
W4KAC Ken
W4KAC Ken built a second one!
N2EPE Erik
VA3NCA Wayde
KI5SRY Mark -- Gears on PTO screw
KA1MUQ Frying pan receiver
AA1N Adam
ZL1AUN Aaron -- Using SSB transmitter -- New Zealand
W8UC Never before homebrewed.
VK4PG Phil -- Nice case, "really pleased"
G7LQX Working well, video of CW and SSB. -- England
KE2AMP John Spring on PTO screw -- great
N9SZ Steve nice receiver
KD9NHZ Piotr Nice one
KE8ICE Calvin, Very cool receiver.
WV3V Jayson! Got it done!
GM5JDG Martin. -- Scotland
KF8BOG Jim: A long struggle, but success.
Chris WalesFantastic video. -- Wales
YD9BAX Wayan! Homebrew transformer! Indonesia
N0NQD Jeff
WN3F Roy -- Made new stickers!
AB5XQ Bill
KB7ZUT Andy
AA1OF Jer
VictorKees Holland
KC9OJV John -- Manhattan-style convert
WZ5M 1, 2 or maybe even 3 receivers!
K1KJW Jim in Vermont
KC5DI Dallas -- friend of WZ5M
Gary Australian -- Wooden PTO form
LU2VJM Juan in Argentina -- Argentina
K1OA Scott "Most fun in 50 years"
KC9DLM Ben -- Had EFHW problems
PH2LB Lex Yellow, Glue Stick -- Netherlands
AI6WR David
G6GEV Dave (It was a blast!)
KC1ONM Wayne MakerLabs NH
KB1OIQ Andy MakerLabs NH
KA1PQK Jay MakerLabs NH
W1TKO Mike MakerLabs NH
K5KHK Karl
SM0TPW Mikael -- Sweden
KI7LKB Brian (coat hanger tube)
M6CRD Chris
W2DAB Dave in NYC
W4JYK Wes of VWS
KA4CDN Mike of VWS
M7EFO Adrian
VK5RC Rob
KD8KHP Dave
VK1CHW Chris
KA0PHJ Brian
W0IT Louis
W1PJE Phil
W2AEW Alan
KN6FVK John (Barkhausen-Be-Gone Spray)
VU2JXN Ramakrishnan -- India
AA0MS Doug
9V1/KM7ABZ Paul -- Singapore
VK2BLQ Stephen -- Australia
N3FJZ Rick
Daniel VE5DLD -- Canada
Student 1 Student of VE5DLD
Student 2 Student of VE5DLD
Student 3 Student of VE5DLD
K7WXW Bill
NK3H Mitch
KN4ZXG Ted
WA1MAC Paul
N4AVC Chuck
K3IY Kevin
N6ASD Ashish in Bangalore
W1DSP Rick
WD4CFN Steve
KM5Z Mike
KF5DAN Dan
Fritz Fritz
N9OK Joe
WA5DSS Bill
K0GDB Grant
G0JNR Shane Glow-in-Dark Coil Form
KK7BCO Tobias
K2BVR Bob
Robert Sutton
K5YFO Dave (Texas)
KD4PBJ Chris
KN4GAH Chris -- EE perspective
F1GMA Philippe -- France
W2TEF Todd
EI9ITB Karl -- Ireland
VU2TUM Puneit Singh
AA7EE Dave Richards
KI5VIR Jay
-------------------------
Honorable Mentions:
*AA7U Steve No PTO
*VK7IAN Ian -- No Manhattan boards -- Tasmania
*KC1FSZ Bruce's build on a PC board
*CT7AXD Graham -- different AF amp -- Portugal
* DL1AJG Andreas -- Germany
* Matthew Student of DL1AJG
* Arash Student of DL1AJG
-----------------------------------------
Candidates for the Hall of Fame:
SA5RJS Rasmus
KA9TII James
AA7FO Chuck
VA3ZOT Tony Surface Mount -- Honorable Mention?
AB2XT John (Done, just need the video)
KO7M Jeff (Piper Cub)
For more information on how you too can build the receiver:
It was really good to see Puneit Singh finish this receiver project. He overcame many difficulties, including a lot of travel and an acute shortage of time, but he got it done. Congratulations Puneit Singh and welcome to the Hall of Fame.
Puneit is also a CW man -- we hope he pairs this receiver up with a simple CW transmitter and makes some "fully homebrew" contacts.
Because my kids went to college in the Shenandoah Valley of Virginia, I sometimes found myself asking Google Maps how long it would take to get to the radio astronomy observatory at Green Bank, West Virginia. It looked close on the map, but as these two guys found out, it really was quite far away. So we never made the trip. I am glad that these guys did. See the video above.
Look, I am a former member of the SARA, the Society of Amateur Radio Astronomers. I am a huge fan of the Parkes Radio Telescope in Australia, the focal point (!) of the movie "The Dish." I also have on my shelf the book, "Big Ear Two -- Listening for Other Worlds" by John Kraus W8JK:
