ElectroBOOM! CuriousMarc Tries (and fails) to fix an old HP182C Oscilloscope -- Words of Wisdom for all Homebrewers

"You try your best to improve something that already almost works... and then you ZAP it entirely in the process.  This is the worst feeling ever.  But don't kick yourself.   This is our lot.  We are made to suffer." CuriousMarc

Indeed.  Take heart homebrewers.  Even CuriousMarc (who is a ham!) has been there and done that. 

This particular CuriousMarc episode was, I think, especially good: 

-- It reminded me of WHY I gave up on my beloved Tek 465 and went with Rigol DSO scopes.  I found I was fixing the Tek scope too often.  Plus, my Tek 465 had PLUG-IN TRANSISTORS.  Yikes!  One false move and you would insert 2 or 3 new problems into the already broken 'scope.  The high voltage in there was really scary.  I had to borrow a high voltage probe from Alan W2AEW.  I survived, but we shouldn't have to risk our lives for hobby test gear!

-- I would advise all homebrewers to be more careful around the really high voltages you will find in old 'scopes and TVs.  Remember the lesson of Ross Hull:

https://www.wia.org.au/members/contests/rosshull/documents/Ross%20Hull%20-%20VHF%20Pioneer.pdf

Read the article that starts on page 7:

 https://www.rsp-italy.it/Electronics/Magazines/QST/_contents/QST%201938_11.pdf

-- Marc struggled with a junction FET.  This reminded me of the raging J310 debate on the Discord channel for the SolderSmoke Direct Conversion Receiver. 

-- We see the oscillator signal flat-topping when it turns on the diodes -- again DC RX memories. 

-- Marc had trouble seeing how the oscillator would start.  I too had trouble understanding how an oscillator would get going. 

-- At one point Marc replaced a transistor with a device that grounded the drain.  This will happen if you switch too quickly from say an RD06 to an IRF-510.   With the IRF-510 you need to insulate the tab from the grounded heat sink.    

It will be great to see, in subsequent episodes, how Marc makes it work.  It is really great to see someone present an unvarnished view of how troubleshooting really works.  

Thanks Marc.   73 

Here is Marc's YouTube channel:

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

More on Agent Sonya

I had completely forgotten that my blog had at least two posts on Agent Sonya way back in 2009.  I know there is a lot of interest in her alleged radio derring-do. 

Here are the two blog posts from 2009: 

https://soldersmoke.blogspot.com/2009/08/sonya-had-knack.html

https://soldersmoke.blogspot.com/2009/09/sonyas-rig.html

And here is my 2025 post on Sonya: 

https://soldersmoke.blogspot.com/2025/04/agent-sonya-did-soviet-spies-really.html

One friend recently mentioned that we have not seen any museum evidence of these kinds of homebrew spy rigs.  If this really was a widespread practice, you would expect to find at least ONE of these rigs in a museum somewhere.   Has anyone seen this kind of thing?  

Here is something more recent about Sonya from the National WWII Museum in New Orleans: 

https://www.youtube.com/watch?v=NU9-APiIUaQ

The Macintyre interview is really interesting.  A friend told me that he is a very serious writer on the topic of espionage, whose assertions have to be taken seriously.  For our purproses, here are some highllights:

22:18   Sonya goes through Soviet Spy School and is trained on how to build radios.

24:50   In China under Japanese occupation, had bamboo poles supporting antenna over her house! 

25:40  Transferred to Switzerland, "built another radio."

34:18   Transferred to UK, built a "powerful radio transmitter in her loo." 

51:41    Macintyre refers to Sonya as "the only Soviet radio operator in Switzerland." 

So, I still don't know about the claim that Sonya was homebrewing radios.  It does appear that Sonya was building them.  But it also seems like she was more of a radio operator than she was a spy...  Perhaps the Soviets didn't see the same distinction that we do.    Still, it would be nice to find in a museum somewhere at least one example of Sonya-style homebrew radio. 

Macintyre says that "all biography is burglary."  What would autobiography be? 

"Seems Like Radio is Here to Stay" -- Old Radio, Radio Magic

The first 12 minutes of this podcast are pretty good.  I think it captures well the wonder of radio -- magic carpets, signals taversing the Himalayas and all that -- but the presentation is kind of confused.  The PRX podcasters keep saying that it was recorded in the 1930s, but then we hear references to the Nuremburg trials and the possibility of sharing the atom bomb. So there is some confusion in the presentation. 

https://podcasts.apple.com/us/podcast/champions-of-old-radio/id453044527?i=1000702716017 

Can anyone find the original recording from the 1930s about the wonder of radio, without the references to things that happened in the late 1940s? 

Thanks to Rogier for sending this to me. 

Norman Corwin

Heard on the Old Military Radio Net: W4SVA

 

So there I was, early Saturday morning (earlier here -- we are one hour ahead of the East Coast) listening -- as I do -- to the Old Military Radio net.  3385 kHz  AM. I use the K3FEF Web SDR in Pennsylvania.  I heard a station that sounded familiar: Chris W4SVA.  He said he was in the Shenandoah valley and was receiving on an R-390A and transmitting with a homebrew rig.  I kind of remembered talking to a guy with a station like that.  I searched through the SolderSmoke blog.  No joy.  Then I remembered it was probably a log entry.  There he is, W4SVA.  Here is his QRZ page:  https://www.qrz.com/db/W4SVA  I was almost certainly on the K2ZA DX-100.  

Here's my log entry:  

------------------

12 August 2018

75AM W4SVA Chris in the Shenandoah, 15 miles south of Harrisonburg.  Very FB.  AM guy.  Building rack-mount rig.  Lots of HB stuff.  Sent him the Shenandoah rocket pictures.

--------------------

I also heard Buzz W3EMD from the Hudson Valley -- the dynamotor was clearly audible. FB Buzz. 

Thanks Chris. And thanks again to John Zaruba for the DX-100.

Mike WU2D Does a CCC Camp POTA with 1930's Gear

FB Mike.  CW without sidetone is not for the faint of heart.  

Walter KA4KXX saw Mike on the Reverse Beacon Network. 

Mike's QSO with KN4RRQ was especially interesting.  Tom was running a 1929 breadboard-style transmitter: https://www.qrz.com/db/KN4RRQ 

Ham Radio in the 1970s (and earlier, with some cool Jazz). What favorite rigs do you see?

Rogier PA1ZZ sent me this today.  I think I may have seen pieces of it before, but this restoration 

is really nice.  But ham radio seems to have been a lot cooler in California.  I don't remember it being so socially advantageous on the East Coast.   See Dilbert cartoon below. 

So many memories: 

-- The video opens with someone working on a QF-1 Q multipliers.  We have destroyed so many of these relics, in pursuit of the variable capacitors (which turn out to be not so good). 

-- A Drake 2-B on Field Day. 

-- An HT-37 in a shack.

--What looks like an HW-32a in a mobile rig. 

-- Maybe an HW-101. 

--  A BC-348. 

-- The ATV station with lots of homebrew gear was very cool. 

-- I also liked the single THERMATRON homebrew CW rig made from an old TV.  FB. 

-- The CW used in the video was all pretty good.  There was a lot of chirp.  This, of course, adds character to a signal.  FB.

After the video, they take a walk down memory lane, looking at ham radio magazines with some cool jazz playing in the background.  I saw a Swan 240 and a D-104.  The debauchery of the 1970s was evident on the magazine covers.  Even QST seemed to be caught up in this.  Check out the August 1975 cover of QST.  

Anyway, this video was a lot of fun.  Thanks Rogier!  

What favorite rigs do you see?   Make note of them in the comments. 

This video and the Dilbert cartoon reminded me of a discussion we had many years ago about THE KNACK: 

https://soldersmoke.blogspot.com/2008/11/cry-for-help-soldersmoke-responds.html

Ham Radio Workbench: Stuffing Digital Stuff Into Poor Old Boatanchors

Let me start by saying that I LIKE Ham Radio Workbench.  But I found a lot in the current edition that I disagreed with.  The whole panel seems to be chuckling at the older gear.  And the guest is from... Flex radio.   So what do you expect?  The title was "Radio Rejuvenation" -- I expected something different.  I thought we'd hear more about how to get old tube radios going.  Instead, the  focus seems to have been on how to take an old radio and stuff an RTL dongle, or a Raspberry Pi, or a Flex radio in there.  Yuck.  

At one point they are laughing at old magic eye tubes!  They wonder if there is a digital way of recreating this tube in digital form.  Sorry fellows, that has already been done: 

https://hackaday.com/2023/04/12/the-eyes-have-it-with-this-solid-state-magic-eye/

Even an analog guy like me spotted that one. 

Here is the show:  

https://workbench.libsyn.com/hrwb-213-radio-rejuvenation-with-dan-quigley-n7hq

But hey, like I always say:  To each his own.  I'm sure many people like this approach.  It is just not for me. 

Ragnar LA1UH's Wonderful Museums in Norway

Here are two more great museum visits by Helge LA6NCA.  In these two he visits Ragnar LA1UH.  

Ragnar has a lot of maritime experience, so we see a lot of older ships' radios.  But his interest in the radio art is much broader and we also see a lot of other kinds of gear: 

-- Wow,  a "travel radio" in a suitcase from 1927.  Was this the idea that later lead to the Parasets of WWII? 

-- Lots of "Stay Behind" gear from the Cold War. That "Africa" receiver (that never made it to Africa!) is very interesting. 

-- We see an ART-13 with autotune, ANGRC-9s, several ARC-5 command sets.  I was hoping Raganar would fire up a Dynamotor, but no. 

-- I spotted a Galaxy V transceiver.  I have the VFO reduction drive from one of these in my homebrew 15/10 rig.   

-- We see several variometers in the emergency (500kc?) maritime transmitter.  I used a variometer in my super-simple ET-2 transceiver (with an N0WVA receiver). 

-- Lots and lots of tubes. 

Ragnar says he himself is of 1944 vintage. I hope some "stay behind" provisions have been made for these amazing museums. 

Thanks to Helge LA6NCA and to Ragnar LA1UH.  

Jens OZ1GEO's AMAZING Radio Museum

Brace yourselves.  This is just too much, too much radio history, too much cool stuff.  We are into ham radio sensory overload territory here. The rigs, the radios, the radioactive stuff (including tubes!).  Lots of Whermact stuff.  A Chinese receiver.  Tesla coils and Faraday shields.  Much more. 

Thanks to Helge LA6NCA for alerting us to this and for shooting these videos.  And thanks to Jens OZ1GEO for putting this magnificent collection together.  I hope they find sometplace to keep this all together so that future generations can benefit from it. 

George WB5OYP points out there is more from Jens here: 

https://teslaman.dk/oz6zs/test/6zs/jens-exp.php

 

Some Great Reading Material -- Links to Radio Publications

 

https://www.worldradiohistory.com/Home-DX.htm

My fellow Hambassador Dave WA1LBP sent this to me today (from Taiwan, I think).  Lots of great  ham radio and SWL info in these many publications.  The one that caught my eye was "The Modulator,"  an ARRL publication done by the 2nd District in the 1920s.  Really interesting.  I will sent this to Lyle, W7QCU who has an interest in radio from this era.   

Here is the link:  https://www.worldradiohistory.com/Home-DX.htm

Thanks Dave!  73! 

The Grid Leak Detector -- Follow-up from Yesterday's Post on the Whole Earth Catalog's "Hippy" One Tube Receiver

Click on image for a better view

When I first looked at it in the Whole Earth catalog circuit, I thought it was a regen.  But a commenter correctly questioned this conclusion.  I remembered the grid leak circuit (WN2A provided more info in the comments).  This morning I found a Wikipedia page that explains it all very well.  I especially like the description of how this detector works both with small signals in the "square law" range of the tube, and with larger signals in the linear range of the tube.  The history of the discovery of the need for the large resistor is also very interesting.  I remember building FET amplifiers and finding that they would -- after time -- shut down.  This would happen as charge built up on the gate.  I had neglected to include the normal 100k ohm resistor (that would "leak" this charge to ground).  Once I put this resistor in, the amp worked fine.  

Here is the Wikipedia article:  

https://en.wikipedia.org/wiki/Grid-leak_detector

A NETFLIX Series with Boatanchors and Direction-Finding -- All the Light We Cannot See

Looks good.  November 2, 2023. 

Spy Rigs, Para Sets, Bugs, and Enigma Machines -- Dr. Tom Perera W1TP (video)

This is a really amazing presentation by Tom Perera W1TP to the Fairlawn (NJ) Amateur Radio Club. 

There is so much great info in this presentation.  Some of the highlights for me: 

-- The U.S. Civil War telegraphic (wired) spy set was just mind blowing.  I had never heard of this.  

-- The way the Nazis transmitted a signal 1 kc off the BBC frequency, so that Germans who tuned their Nazi-issued receivers to the BBC could be detected by neighbors (from the resulting 1 kc tone!) and turned in to the Gestapo.  

-- "Things don't land gently when dropped by parachute." Indeed.  This was a reminder of the courage of the young women who parachuted into Nazi-held territory during WWII.  Like Paulette.  It was great to see her with her Paratrooper wings on.  AIRBORNE!  And the picture of the operator with the bicycle generator was of Virginia Hall.  See: https://www.npr.org/2019/04/18/711356336/a-woman-of-no-importance-finally-gets-her-due  That portrait hangs in the hallway of the National War College. 

-- How they put the schematic of the PRC-5 right into the box.  Great idea.  But it had a terrible receiver.  One of the schematics showed a 455 kc IF and a BFO.  So they sent in superhets, not just regens. 

N2CQR operating the Para Set of G3ROO around 2009

This video makes me want to build a Para Set. 

Thanks a lot to Tom W1TP and the Fairlawn ARC. 

A Look at Old Radios in Australia (video)

I thought you guys would like Peter Parker's latest video.  And in it, Dean KK4DAS might see a clue or two for his Halli restoration/repair project.  

What really struck me was the dial markings on the Australian radios.  They seem to be mostly oriented toward the reception of Australian AM or LW broadcasters -- not many exotic DX locations are marked.  Australia is big! 

Looks like a lot of crystal detectors in glass tubes.  At first I thought they might have been coherers, but I think they are crystal detectors. 

Many variometers visible. 

I saw one Geloso-Milano Communications 8 receiver.  Va bene! 

I also saw one "Tasma 780" Superhet.  Cool name! 

What is up with the "Green Theme"? 

I have some of the headphones they showed. 

Please note in the Comments section anything special that you noted in watching Peter's FB video. 

More on the coil winding machine here: 

https://hackaday.com/2023/08/30/all-mechanical-coil-winder-is-a-scrap-bin-delight/#more-612604

Valveman -- The Story of Gerald Wells

Don't be deterred by the annoying test patterns at the start of this video.  Just skip past them.  The rest of the video is quite good.  Or you could just click on this link and avoid the first 83 seconds of test pattern:  https://youtu.be/Y8w6iwaAGJ4?t=83

Gerald Wells has been mentioned on this blog before, but I don't think we've ever presented the full documentary on this fellow.  Here it is.  Gerry is clearly one of us: a radio fiend, obsessed (as he admitted!) with wireless, a victim of THE KNACK.   

George WB5OYP of the Vienna Wireless Society got to meet Gerald Wells and visit his museum. George alerted me to this video.  Tony G4WIF also was able to visit Gerry and his museum. 

The documentary is full of interesting stuff, and is, in itself, a Knack Story.  Wells mentions the Crippens murder so well described by Eric Larson in "Thunderstruck."  It was this crime that brought radio to the center of public attention.  

A Very Early Radio-Controlled Device -- Using Spark and a Coherer, in Spain

Click on the picture for a better view -- check out the coherer and the tapper 

Hack-A-Day has an interesting story about Leonardo Torres Quevedo and his very early automated chess machine.  Torres Quevedo was a Spanish inventor active in the early years of the 20th century. 

The chess device was really interesting, but two things caught my eye about this fellow: 1) he lived and conducted some of his experiments in my old home of Bilbao, Spain and 2) he built a very early radio-control system that used -- in the receiver -- a coherer as the detector.  

There is a lot material on Torres Quevedo.  Here is just a sample of what is out there  

His book:  https://www.torresquevedo.org/revistas/index.php/BIB/issue/view/12/1.  Discussion of the Telekino device is on pages 109-127. 

The Branly Tube or Coherer: https://en.wikipedia.org/wiki/Coherer

https://en.wikipedia.org/wiki/Leonardo_Torres_Quevedo

https://www.researchgate.net/publication/2998424_Early_Developments_of_Wireless_Remote_Control_The_Telekino_of_Torres-Quevedo

https://cyberneticzoo.com/wp-content/uploads/2010/12/Telekine-Yuste.pdf

1903 article in Electron (Spain) about the Telekino and Coherers. https://hemerotecadigital.bne.es/hd/viewer?oid=0028654330&page=6

https://alpoma.net/tecob/?p=13766   This article contains the diagram of the device (see above).  You can see the coherer with its tapper.  

Here we see the Telekino installed in a boat in Bilbao harbor.

Apex Surplus in Los Angeles

The Polaroid camera for the Tek 'scope was pretty cool.  And the comments about the Simpson 260 made me feel good about finding one at a recent hamfest, but I don't think mine is an extremely rare Model 2.   

Who is the Man in the Portrait in Artie Moore's Shack?

 

Who is this person?   He is in a prominent position in Artie Moore's very early radio shack.  Artie was obviously big on labeling things, and there is a label under the picture but I can't make it out.  What do you folks think?  Who is this?  

https://soldersmoke.blogspot.com/2023/04/artie-moore-and-titanic.html

Four Old BBC Shows on Radio: Hams, Physics, and Antique Wireless

The first one, about ham operators in general, is pretty depressing. Then it goes downhill as they shift to those who are listening to baby monitors and cell phones.  Yuck. 

The second one seems to show some physicist having understandable difficulty explaining particle-wave duality in a short TV segment.  

There is a short bit (that I didn't quite get) about the BBC's "Teddy Bear's Picnic."  

The final one is about Gerald Wells and his Antique Wireless Museum in South London.  Note the white coat -- clearly a boffin.  For a while I confused him with Rupert Goodwins G6HVY (similar white coat, but a different bloke).  

Early (1912?) Ham Station

 

Perhaps a bit overdressed by today's standards, but he's got a familiar look on his face.  Confidence and pride in his rig, and a steely determination to make contacts with it.  

If you zoom in you can see the crystal and the cat's whisker. 

More on this here: 

http://uv201.com/Photo%20Pages/ham_3.htm?fbclid=IwAR10Lbi2CAsYeiBDUjWb5KIQrh1SJVGwDyL2_1ZrkPk1VbllAUbeahwxsAI