Other Kinds of Workshops -- Making a Clock with a Lathe

Somehow, this video fits well with the SolderSmoke theme.  It may be that Uri cheerfully acknowledges that the lathe can kill you (the same is true of much of our gear).  Or it may be his repeated use of the term "Bob's your uncle" (has he been listening to SolderSmoke?).  Whatever the reason, this beautiful video fits here.  This is from Uri Tuchman's channel:  https://www.youtube.com/@urituchmanpigeon.  Uri is in Germany.  Thanks Uri! 

Derek N9TD's Magnificent Build of the TJ Direct Conversion Receiver

 

I think it is magnificent.  Derek N9TD fought his EE tendencies and recognized that the perfect can be the enemy of the good.  So he went ahead and built this receiver pretty much as we intended it to be built:  Four stages:  BP filter, PTO, Diode Ring Mixer, Super-simple AF amp. 

He went several steps further and added a fixed coil to slow down the tuning and keep it in the 40 meter band.  He added an RF gain control.  And he went with a steel (vs. brass) screw.  But these are all things that I myself have done.  (We still advise people to build it the simple way first.) FB Derek. 

The challenge is still out there.  The gauntlet has been thrown down.  Derek's completed project shows us that this project is entirely do-able.  Do it!   

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! 

As a thanks for reading through this long email, I'll leave you with some photos of my build as a reward. 

73s,

 Derek N9TD

So Many Great Pictures, So Much Radio History

 

I make it a point to go back to Wes W7ZOI's web site every once in a while.  That is always a good idea. This time I found myself looking at the page that described Farhan's 2017 visit.  Wow, just look at the guys at that table. 

-- Wes W7ZOI.  The man who launched the solid state direct-conversion receiver revolution.  Author of SSDRA and EMRFD.  And so much more. 

-- Roger KA7EXM.  Son of Wes.  The guy who developed the receiver for the Ugly Weekender transmitter.  

-- Rick KK7B.   The guru of phasing type direct-conversion single signal receivers.  

-- Roy W7EL.  Father of EZNEC antenna modeling software. And the optimized QRP transceiver, with the diplexer that we are using (perhaps improperly) in our high school direct conversion receiver project. 

-- Jeff WA7MLH.  Builder of so many of the great projects in SSDRA.  Made me feel good about gear that looked a bit rough.  

-- Farhan VU2ESE.  Creator of the BITX20, the BITX 40 Module, the uBITX, the sBITX and so much more. 

Just scroll through the site.  You will see Rick there with his Classic 40 phasing receiver.  Roy with his  Optimized transceiver.  Roger with the Ugly Weekender transceiver. 

Finally, the morse key that Farhan gave to each of the participants.  Farhan gave me one of these too.  I will try to use it from the Dominican Republic on Straight Key Night. 

Check out the site: 

https://w7zoi.net/Farhan-visit.html

More Shortwave Listener Cards

Around this time every year I get an envelope from the W2 QSL bureau in New Jersey.  This year, the envelope contained two QSL cards from shortwave listeners. 

The Dutch listener heard my 12 meter SSB contact with Iceland.  The Russian SWL heard my 17 meter SSB contact with Japan.  

I think it is wonderful that we still have shortwave listeners who monitor the ham bands and send out QSL cards.  I will, of course, send cards back to them. 

Here are some cards from earlier (in some cases MUCH earlier): 

https://soldersmoke.blogspot.com/2023/11/some-short-wave-listener-qsl-cards.html

SolderSmoke Shack South -- with Mythbuster II and AN762 .1 kW Linear

This is the current operating table at HI7/N2CQR.   

The box up on top is my Mythbuster II -- like the original Mythbuster, but without the circuitry for 75 meters. Below it is the 15-10 I rig with dial from Pericles HI8P (SK). 

The shiny box with the heatsink is my new AN762 .1 kW linear from CCI. Most of this amp was assembled in Virginia, but I did the relay work and "socketry" here in the DR.  It seems to work fine.  I use it with the little box to its right which houses the Low pass filter board from a Ten-Tec Delta (Pete advised me to buy this back in October 2023). 

Out on the terrace in the upper right you can see the bottom of the 16 foot fishing pole that is holding up my 20-15 1/4 wave groundplane antenna.  I have already crossed the pond many times with this combination. 

KE5HPY's Altoids Direct-Conversion Receiver for 40 Meters

Click on the image for a much clearer view.

It is a thing of beauty.  You can see all four stages in there.  There is the Bandpass Filter in the upper left.  Below that is the VFO.  In the center you can see the SBL-1 mixer. Off to the right is the audio amplifier.  FB Chuck! 

Chuck KE5HPY writes: 

Allow me to add an endorsement of the joy and practicality of the DC receiver. Whether XTO, VFO or DDS, ring diode mixer, or Polykov, the DC IF concept is a real winner.  They really deliver wonderful audio and clarity that is very satisfying for homebrew builder.

Thought you might enjoy these photos of a 40 m receiver and built 10 or so years ago.  The design is straight out of EMRFD.  At that time, the Altoid tin craze was in full swing and this is one of several projects I stuffed in a tin.  This compact receiver has traveled on lots of camping and kayak trips where it delivered good DX reception using only a 30 foot piece of wire for antenna running back to the tent. It’s fun to hear intercontinental QSOs when you’re in the middle of nowhere. With my 40 m dipole attached at home, I think this little rig can hear anything my Icom hears.  

It’s great that you’re promoting this practical technology. Keep up the good work.

Happy Birthday to Pete Juliano, N6QW

 

Pete Juliano 

Excellent husband and father.

Vietnam veteran who went into harm's way for his country.

Master homebrewer. 

A great cook.

A wonderful friend. 

A great co-host of the SolderSmoke podcast. 

HAPPY BIRTHDAY PETE! 

Popcorn Electronics is BACK! Yea!

 

https://qrp-popcorn.blogspot.com/

Check it out at the URL above.  FB!  Thanks Todd!  And thanks Vasily!  

I never knew that Mike KL7R (the co-creator and first co-host of SolderSmoke) was responsible for the Popcorn nickname.  FB!

SolderSmoke Podcast #255 -- Accept the HB Challenge!, DeMaw SSB, Brilliant TR-3, Tube Talk, Ground Truth, Tales of Woe, SDR RX, Pico Balloons, MAILBAG

Mythbuster II -- 20 meters only

SolderSmoke Podcast #255 is avalable: 

Audio:      http://soldersmoke.com/soldersmoke255.mp3

Video:       https://www.youtube.com/watch?v=c54qiITMxwM

--   First: Happy Holidays!   I have on a Santa Claus hat!  

-- December 18.  Pete completes another orbit.  Happy Birthday Pete.  Please send him birthday greetings. 

 --  Bill was on Ham Radio Workbench: https://soldersmoke.blogspot.com/2024/11/bill-n2cqr-appears-as-guest-on-ham.html  Our challenge to HRWB.  Gauntlet thrown down... OUR CHALLENGE HAS BEEN GRACIOUSLY ACCEPTED!     We now extend the challenge to the entire SolderSmoke community: Build one of these:  https://hackaday.io/project/190327-high-schoolers-build-a-radio-receiver

Homebrewing is not for the faint of heart!  Accept the challenge!  Build stuff! 

Our question:  Did Doug DeMaw ever build an SSB transceiver?  Starting in September 1985 he wrote a five part series on an SSB TRANSMITTER for QST.  But he prefaces it by asking, "Why would anyone build an SSB transmitter today?" He says it would be fun "for the experience and understanding it would provide." But not for use, you see... And it is not a transceiver. 

Bill's theory about DeMaw, SSB,CW and sideband inversion:  He was a CW guy so sideband inversion did not really matter. He could get it wrong and still make it work.  

Pete's Bench: 

Brilliance and the TR3. https://www.youtube.com/watch?v=2C-eYB8yFzg&t=13s

A tale of woe.  Done in by a light bulb.

Thanksgiving dinner and SSB transceivers. https://n6qw.blogspot.com/2024/11/11292024-how-to-homebrew-thanksgiving.html             https://www.pastapete.com/

Hybrid plans:  https://www.youtube.com/watch?v=zKUjHZMf3Fs&t=5s

Dean's Bench:

Travelogue – Falcon 9 Launch

Building a homebrew T Match tuner for the end-fed long wave – sourcing the parts, winding the coil – taps, testing 

VWS Makers Projects

SDR Receiver Project – starting in January

VWS Pico Balloon – Traquito - Traquito - WSPR Pico Balloon

Revisiting the 10M DSB rig

Soldersmoke listener challenge – build a DCR with KK4DAS – overview then one board a week

SHAMELESS COMMERCE DIVISION:  Mostly DIY RF.    Please subscribe to our YouTube Channel.  And use the Amazon link on our blog.  Become a Patron via Patreon (on the blog). SolderSmoke is now on Blue Sky and Threads -- follow us or at least like us there. Please turn on automatic downloads on your podcast app -- most podcast apps will only store a few episodes. This will help bump the numbers, which will improve visibility.  Please give the show five stars and, if possible, a nice review on your podcast service,  That will help with the discovery rate for people looking for new podcasts.

Bill's Bench:

Is "The Ground" a Myth?   ARRL VP says Ground is a Myth: https://www.youtube.com/watch?v=KdX-978tvkY.  Bill disagrees.  Helicopter story.  Refrigerator story.  Original single wire telegraph system. https://en.wikipedia.org/wiki/Single-wire_earth_return

Front Panel and Freq Counter for the Mythbuster II. 

Another Tale of woe:  A mysterious audio problem on the 15-10 II rig.  Done in by.... Duh!   Comparing sideband suppression with Mythbuster I.  Differences in Hfe?  Notes on Mythbuster II build. 

TinySA Ap -- A cure for Fat Finger Syndrome? : http://athome.kaashoek.com/tinySA/Windows/  How to get and load the Ap (you might want to start watching at 1:11) https://www.youtube.com/watch?v=zu4X5dyUlpo&t=2s  General info video on the TinySA Ultra: https://www.youtube.com/watch?v=6C24RnYNOWQ&t=1143s

For the DR shack -- I got a Swan SWR-1A on E-Bay. 

 MAILBAG:   

-- Scott KQ4AOP trying to track down the DeMaw SSB transceiver mystery.  On the DC Receiver: This was my first receiver build and, it was great fun. When you finish the build and prove you are able to tune through the band, you are welcomed into the secret society! The build is the initiation.I am happy to print and ship the PTO if needed. 

-- Bill WA5DSS has built a High School Direct Conversion Receiver! 

-- Grayson KJ7UM liked the 1971 video on old THERMATRON AM radios: https://soldersmoke.blogspot.com/2024/11/basic-radio-circuitry-1971-film.html

-- Chris KD4PBJ sent nice electronic care package. 

-- Walter KA4KXX is honored that Dean named his dog for him (Walter was just kidding) 

-- Thanks to Bob W8SX for FDIM 2024 interviews.

-- Tony G4WIF insomnia driving him to podcasts.  Amazed by quantity of food eaten on Thanksgiving. 

-- Nice comment from Trigger about the podcast.

-- Clint says "valves" when he means THERMATRONS.   Kindly asks about "Oooo Thats Awesome"

-- Eric 4Z1UG faced with a new challenge.  Get well soon OM.

-- Sam WN5C and his Chat GPT AI Elmer. 

-- Paul VK3HN on using AI for electronic design.  I dunno... Apocalypse Now in the DR?

-- Tommy SA2CLC FB old military gear on QRZ site. Helps with HP8640B repair. 

-- Mike WN2A nice comments on Chappy Happy's FB Tezukuri DC RX https://soldersmoke.blogspot.com/2024/11/tezukuri-and-chappy-happy-amazing.html 

-- Allison KB1GMX.  Good info on ground truth. 

-- Phil W1PJE Had to throw out 15 test leads.  Fake wire!  

--Todd K7TFC Thoughtful comments on AI and ChatGPT, Help with TinySA Ap 

-- Steve KW4H Boatanchor guy.  Likes that we often scratch our heads trying to understand. 

-- Nick M0NTV built a 40 meter DC receiver: https://soldersmoke.blogspot.com/2024/12/a-40-meter-direct-conversion-receiver.html

-- Dave AA0KU asks about CCI amp (AN762)  Also woking on Drakes. 

-- Jack (Dhaka Jack!) F4WEF/AI4SV  Good thoughts on how to bolster SolderSmoke's ratings.

--Tobias thinks the decline IS ALL HIS FAULT!   

-- Tony VE7JUL building a TJ DC RX.  Go Canada! Dean says: 3D print PTO former at 110%

-- Jim KI4THC getting his uBITX on the air. 

10S November 23, 2024 1517Z SV1AER Kostas in Athens.  Said a very sincere “Oh my goodness! Congratulations!  That is not a very common thing!” when I told him rig was homebrewed.  Nice fellow.  Great response. 

An Evening Bandscan on 40 Meters using the High-School Direct-Conversion Receiver

This video shows how useful this receiver really is.  Build one of these!

Mike WU2D's Video on the SimpleX Super Receiver -- Part II

 Another FB video from Mike WU2D.   

But you know,  I too find myself kind of opposed to front panel on-off switches.  I power my rigs with small DC supplies.  I just turn on the supply when I want to use one of the rigs.  I don't have or need a switch on the front panel of the rig.  

I especially liked Mike's use of the gate dip meter and, of course, the Q meter.  FB OM. 

I must say I have a preference for the first version, but only because I dislike the regenerative circuit in the second version.  I do like the newer-style coils -- I have one in the BFO of the Mate for the Mighty Midget receiver.   

Thanks Mike for the sideband inversion factoid in Part 1!   The Hallas Rule -- words to live by. 

One word of caution.  I used 6U8s on my Mate for the Mighty Midget receiver.  I had good results, but WA9WFA had a lot of trouble.  We eventually concluded that the 6U8s didn't age well.  And they were quite long in the tooth.  We found (from the tube guys) that 6EA8s aged better and were a good and easy sub for the venerable (perhaps TOO venerable) 6U8s.  I switched tubes in my rig and it did seem to work better.  BTW, this is the receiver that I use to listen to the Old Military Radio Net on Saturday mornings.  

Here is the story of our switch from 6U8s to 6EA8s: 

https://soldersmoke.blogspot.com/2022/02/6ea8s-in-mate-for-mighty-midget-and.html

Listening to 40 meters on the DC Receiver -- And I Heard a Distinguished Homebrewer!

I made the video above to show postential builders how useful our Direct Conversion receiver really is.  Late in the video (starting at 11:17), I heard a station calling CQ.  It was N4QR.  A check of QRZ.com shows it was Bob Null.  Here is picture from Bob's QRZ page: 

Check out the old general coverage receiver and -- wait for it -- the homebrew thermatron transmitter.  TRGHS. 

Google led me to this amazing video by Stever N4LQ that describes a book that N4QR put together on how to build thermatron transmitters from Junkbox/Hamfest parts: 

Steve N4LQ is in contact with Bob N4QR and asked him which transmitter he was using when I heard him.  Bob said he thinks it was his 30 watt 807 final transmitter. 

Thanks Bob. and thanks Steve!