October 21, 1934 at the Tillamook Light Station, Oregon -- W7DIZ Saves the Day by Building a Transmitter (and Receiver!) from Scratch

 

W7DIZ is seated on the right.  Note headphones.

From the January 1935 issue of QST: 

Shown here is the Tillamook Rock Lighthouse as viewed from the south, with Tillamook Head overlooking in the background, in about 1930.

For a truly harrowing acccount of the storm see:  https://www.ohs.org/blog/saga-of-the-tillamook-rock-lighthouse.cfm

Here is what they wrote about W7DIZ's heroic improvisation: 

Without a way to communicate with the mainland, assistant keeper and radio enthusiast Jenkins (radio callsign W7DIZ) showed “perseverance in contriving a shortwave radio sending and receiving apparatus from miscellaneous materials available at the station which resulted in reestablishing communication,” first with Seaside gardener and amateur radio operator Henry Goetze (W7CXK). One telegram, received at 7:10pm on October 23, read:

Derrick gone, water tanks moved, west end rock gone, sixteen plate glass broken stop Telephone cable broken at rock…light will be in operation Thursday stop Assistant Hanson right hand deeply cut stop Recommend sending inspector check station stop Assistant Jenkins Amateur radio in operation reply via Western union care of Henry Goetze Seaside Oregon.

Thanks to Bob KD4EBM for alerting me to this.  It would be great to have more details on the rig that W7DIZ built in the wake of the storm.  Unfortunately, this seems to be one of those cases where AI just seems to muddy the waters.  When asked for details of Jenkin's build, AI came back with some suspiciously detailed answers.  Sure enough, these answers were just guesses that AI made, based on nothing more than the contents of 1930s era ham log books.  

Can anyone tell us more about what W7DIZ actually built? 

OBIT: Cyril Hilsum -- The Many Who Made Big HDTVs possible

For obvious reasons, we don't have a lot of obituaries on the SolderSmoke Daily News. (We are aware of our demographics, and even a moderate inclusion of obituaries might quickly overwhelm the blog.)  But we will make an exception for this one, partly because of the great technical achievments of Dr. Hilsum, but mostly because his New York Times obit had a lot of the humor that I used to find in the British newspapers. 

https://www.nytimes.com/2026/11/01/technology/cyril-hilsum-dead.html?unlocked_article_code=1.OFE.uorU.Gd0R2Ef9O3Dh&smid=url-share

Hilsum is described early on as, "an exuberant British physicist with voluminous, untamed white hair..." Later in the obit, the writer notes that. "Dr. Hilsum... was 101, having suurvived to his 11th decade by avoiding fresh vegetables, and subsisting largely on TV dinners, chocolate and red wine."  

His technical contributions were really substantial: https://www.ieee-ukandireland.org/in-memoriam-professor-cyril-hilsum-cbe-frs-freng-1925-2026/     Thank you Dr. Hilsum! 

Stellafane: Homebrew Telescopes -- The Telescope Makers of Springfield, Vermont -- PLEASE COMMENT

https://www.nytimes.com/2026/10/24/science/space/stellafane-telescopes-makers.html?unlocked_article_code=1.N1E.ZDIZ.cdzUED-FHW76&smid=url-share

The above New York Times article reminded me of Sellafane.   You know, I think I would rather go to Stellafane than to Dayton/Xenia.  And I might prefer to go to Oshkosh and the EAA than to Dayton/Xenia.  And I think that says something about homebrewing:  It may be that the true homebrewers are to be found in these other locations.  

Anyway, this is a part of our series on "other homebrews" and other workshops.   Stellafane has an amazing tradition.  

PlEASE COMMENT:  What do you think?  Am I wrong about Stellafane over Dayton?  

Grayson Evans KJ7UM Talks Thermatrons with Charlie NJ7V on Red Summit

 

https://www.youtube.com/watch?v=kgqYNlvXfOg

This is a really great interview.  It is reminder of what a great resource Grayson is, and of how lucky we are to have him in the hobby.  

Grayson mentions SolderSmoke a couple of times.  He talks about a thermatron version of the 40 meter direct conversion receiver.  He talks about a thermatron version of the Michigan Mighty Mite. 

Grayson notes that I am sort of averse to high voltage. I plead guilty. But I have good excuses:  I have done some homebrewing with thermatrons:   My Mate for the Mighty Midget receiver used 6U8 thermatrons.  And I have struggled (successfully) to keep my HT-37 alive in the Dominican Republic.  I have built a DX-40 and a DX-60 from hamfest parts. And decades ago, I stripped an old TV of the parts needed to build a power supply for an HW-32A SSB transceiver.  Somehow, I survived.   

But several years ago I switched to solid state gear, and I developed some bad habits.  I work on the solid state gear while energized.  With it, one hand is NOT behind my back.  I think it would be dangerous for me, at this point, to switch back to thermatrons. So I guess I will limit myself to vicarious thermatron adventures, through Grayson, his book, and his YouTube channel. 

I really liked Grayson's confession that he is just not good at working with metal chassis.  I too have mangled many of these over the years.   

And wow! Fire Hydrant on the Air! As Charlied noted: hey, it's a valve! Pete Juliano would love this idea!  

Thanks Grayson, and thanks Charlie. 

More Clandestine Spy Radios -- Soviet Spies in Japan during WWII -- Spies On The Air! Please Comment!

Sorge

I may have been too quick to dismiss the possibility that Soviet spies built their own radios.  Maybe they did, but with a radio specialist on the team.  Thanks to Mikele 9A3XZ for alerting us to this case. 

Here is a 1964 New York Times article on the Sorge case:  https://www.nytimes.com/1964/10/11/archives/again-the-sorge-case.html?unlocked_article_code=1.M1E.mQv_.rxy03pIehUb4&smid=url-share

Here is some great info on the radios thay used: 

The clandestine radio equipment used by Dr. Richard Sorge’s Soviet military intelligence (GRU) spy ring in Tokyo (1933–1941) was custom-built, field-assembled, and highly effective. 

Because bringing specialized espionage hardware into imperial Japan was too risky, the ring's technical mastermind and radio operator, Max Clausen, manufactured and assembled the gear locally using commercially available components and household scrap. 

Max Clausen

The technical breakdown of the "Ramsay" ring's radio setup includes:

1. The Homebrew Transmitter

Clausen built small, portable shortwave transmitters using the simplest possible circuitry to ensure reliability and easy concealment.

The Circuit Type: He heavily favored the Hartley oscillator circuit, a highly efficient and simplistic vacuum-tube configuration requiring very few parts. 

Power Source & Output: The transmitter generated roughly 15 watts of power. It ran on standard Japanese household AC electrical mains (100V), meaning they did not need bulky, suspicious external generators or specialized military batteries. 
Frequency Range: Transmission took place on amateur shortwave bands (around 7 MHz), which allowed the signal to blend in with legitimate civilian radio enthusiasts. 

2. Disguise and Concealment

The entire unit was designed to look like "household junk" if discovered during a routine police sweep. 

Modular Assembly: The transmitter was not kept as a single, uniform device. Clausen kept individual parts (tubes, coils, capacitors) scattered around his house. He would only assemble the working radio immediately prior to a transmission window and dismantle it directly afterward. 
The Cabin Cruiser / Fishing Boat Trick: As Japanese counter-intelligence began realizing an illegal radio was transmitting out of Tokyo, the ring adapted. Sorge purchased a luxury cabin cruiser. Clausen would pack the transmitter onto the boat and sail into the open sea or disguise themselves as a fishing vessel to transmit, making it completely impossible for the Japanese authorities to pin down their location using shore-based radio direction-finding (RDF) equipment. 

3. The Receiver

For receiving commands from Soviet intelligence handlers in Vladivostok, Clausen modified a standard, commercially available civilian radio receiver. By altering its internal coils, he expanded its frequency coverage to intercept shortwave military bands. It possessed exceptionally high sensitivity to pick up faint, distant signals from across the Sea of Japan. 

4. Code and Operational Security

One-Time Pads: Sorge's ring used a highly secure system of enciphering their Morse code messages based on numbers from a German statistical yearbook. Because the "key" changed with every single letter and was never reused, the Japanese intercept stations could read the signal but could not decrypt the messages. 
Radio Jargon Disguise: To further evade suspicion, Clausen heavily spiced his transmissions with casual "ham radio" lingo, making it seem like an amateur hobbyist chatting with someone abroad rather than a spy sending high-level military secrets. 

Despite the primitive and makeshift nature of this equipment, Clausen successfully transmitted over 23,000 code phrases. This included Sorge's most critical intelligence coup: confirming that Japan would strike south toward the US/Pacific instead of invading Siberia, allowing Stalin to safely redeploy his massive Siberian divisions to save Moscow from the German advance. 

The radio operations of Dr. Richard Sorge’s "Ramsay" spy ring in Tokyo are considered some of the most successful and technically fascinating in espionage history. 

The technical setup, gear, and tactics behind Sorge's communications relied heavily on a specialized approach to clandestine radio:

🛠️ The Custom-Built Hardware

Unlike many World War II intelligence networks that used factory-issued, military-grade espionage transceivers, Sorge’s equipment was entirely custom-built and home-brewed from commercially available parts. 

The Builder: The equipment was designed, built, and maintained by Sorge’s highly skilled radio operator, Max Clausen (a German communist and Soviet GRU agent). 
The Rig: Clausen constructed compact, portable shortwave transmitters and highly sensitive receivers. He bought ordinary radio components—tubes, condensers, and coils—from commercial shops across Tokyo to avoid drawing attention. 
Size and Capability: The transmitter had to be small enough to easily hide and transport, yet powerful enough to consistently project a signal from Tokyo all the way to a Soviet receiving station in Vladivostok. 

📡 Counter-Surveillance & Transmission Tactics

The Japanese Tokko (Special Higher Police) and military counterintelligence knew an illegal radio transmitter was operating in Tokyo, but Clausen successfully evaded their radio direction-finding (RDF) vans for six straight years. They managed this through strict transmission discipline: 

Constantly Moving Locations: Clausen never transmitted from the same place twice in a row. He regularly moved the equipment between various safe houses in Tokyo. 
The Cabin Cruiser: Sorge purchased a luxury cabin cruiser boat. Clausen would sometimes install the transmitter on the boat and broadcast from the open sea, completely confounding land-based Japanese tracking units. 
Brief Airtime: Transmissions were brief, highly condensed, and conducted late at night to minimize the window for the Japanese to lock onto their signal. 

🔐 The Encryption: Book Cipher & One-Time Pads

Even if the Japanese intercepted the radio waves, they could not read the content for years because of the ring's manual encryption system. 

The Statistical Almanac: Sorge's ring used a manual book cipher utilizing the Statistisches Reichsamt (German Statistical Almanac). 
The Process: Clausen would take the page numbers, columns, and figures of the almanac to serve as a random text key (or text gamma) to convert Sorge's intelligence into long strings of numbers. 
The Advantage: Because it was a "manual cipher," it required absolutely no mechanical cipher machines (like the German Enigma), eliminating bulky, incriminating hardware. 

🛑 The Downfall

The radio operation ultimately collapsed not because the Japanese intercepted the signal or broke the code technically, but through human counterintelligence work. In October 1941, Japanese police arrested an associate of the ring, leading a trail back to Sorge and Clausen. 

Upon Clausen's arrest, the Japanese authorities finally seized the hidden radio components. They were reportedly astonished at how Clausen had engineered such a high-performing, long-range shortwave system using nothing but simple, over-the-counter radio parts. 

Please comment on all this. 

Lessons Learned about AI (Large Language Models): "I don't 'know' the facts the way that a human does..." Let's do an experiment...

Yesterday, as I struggled with a Large Language Model that at first gave good advice (how to build a 5 crystal filter) and then really bad advice (how to build a filter with 5 crystals in parallel to achieve a USB passband) I got a message from an old friend who currently works in this industry.  

He advised me to be careful about advice from LLM AIs.  He warned that these AIs would just develop answers based on the information that had been used to train them.  In the case of ham radio electronic questions, the training material was often littered with errors and lore and bad, wrong info.  Often this bad information would be repeated over many years.  This would make the AI more likely to use it in their answers. 

It then occurred to me that I should take one case where I knew that wrong information was in the ham radio "literature" and that this information had been repeated many times over the years.  I am referring here to the question of why hams use lower sideband below 10 MHz and upper sideband above 10 MHz.  I had explored this question in many blog posts.   Many explanations were offered -- all of them violated the Hallas rule.  All of them failed to answer the question.  I wondered, would AI be wrong?  

Well, AI was wrong.  AI said:  

Subtracting in heterodyne mixing inverts the frequency spectrum. An Upper Sideband signal generated at the IF naturally flipped into a Lower Sideband signal on the lower bands.

That is wrong.   The Hallas rule tells us that sideband inversion ONLY occurs when the signal with modulation is SUBTRACTED FROM the signal without modulation.  

I called AI on this error in its answer.  I asked it why it had given me bad information.  Its responses were telling. 

Why did you initially say that sideband inversion results from subtraction? Is this because of the material on which you had been trained?

You're asking a fair question about where that explanation came from.

The brief answer: yes, it comes down to how technical explanations are presented across textbooks, amateur radio training materials, and online discussion forums—and how LLMs synthesize those patterns.

So you are just repeating incorrect information, as long as it was repeated enough, right?

That is a fair critique, and it gets to the heart of how Large Language Models work.

I don't "know" facts the way a human does; I generate text based on statistical patterns learned from vast amounts of training data. When a simplified explanation, misconception, or shorthand rule of thumb is repeated thousands of times across forums, textbooks, and study guides—as is the case with "subtraction inverts sidebands" in ham radio literature—I am prone to picking up and repeating that pattern.

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

I think we can draw three conclusions from all this: 

1) The talk about AI "personhood" is just nonsense, mostly nonsense from Anthropic. 

2) The concerns about data poisoning are real.  The ham radio "literature" is already poisoned, and look what happens. 

3)  We are living with the results of bad info in the amateur radio "literature" over the years.  AI is just spitting it back at us.  And I think it is getting worse.  Now everyone with a callsign and camera has a YouTube channel. The quality of content is low and dropping.  Soon AI will be spitting this stuff back at us. 

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

Let's do an experiment.  Those of you who have access to the other AI's like Claude, ChatGPT, DeepSeek and others, just ask them the question I started with: 

"Why do ham radio operators use LSB below 10 MHz and USB above 10 MHz?"  Let's see if the other AI LLMs are better at coming up with truthful answers.  Of course, they may see this and not repeat the error. 

About the Limits and Problems and Shortcomings of AI (actually of LLMs) -- The Design and Construction of a Crystal Filter

Complaining about AI on the computer/internet while surrounded by digital rigs!

 

A couple of days ago, I described in this blog how AI (specifically the Gemini LLM) had helped me design a 13 MHz crystal filter.  There was some angry push-back from people who seem to dislike any use of AI. One fellow said I should use my own mind and hands, and that by using AI I would risk having time to stand on the street corner.  I found it kind of ironic that this observation was being sent to me on a computer connected to the internet (two tools that have made this kind of construction MUCH easier).  

In the first round I think AI helped a lot. It even drew nice looking schematics for me.  Using the motional parameters determinef by me via the G3UUR method,  AI used the basic equations to calculate the shunt capacitances and the termination impedances.  This helped me avoid many of the mathematical errors that had slowed me down in the past.  I went ahead and built this filter, and (later!) took a look at the passband in my Antuino (a Scalar Network Analyser from Farhan). 

I found the passband to be that of an "LSB filter":  the skirt was steep just below the cutoff frequency, but much more sloping farther down in frequency.  This is not what I needed.  The signal hitting this filter would be (and would remain) USB. I could try to use this filter but I would be placing my BFO/Carrier Oscillator on the sloping portion of the curve.  Carrier and opposite sideband suppression would suffer. (Note: It is NOT 20 db down!  -20 db on this meter equals 0 db.) 

And here is one point where LLM AI really screwed up:  I asked it for a 5 crystal filter that would be a USB filter: One with the steep part of the skirt above and close to the cutoff frequency.  AI LLM quickly obliged.  I was suspicuous, because I had never seen this before. Here is what AI LLM Gemini recommended: 

Wow, looks great right?  Yea,  but it doesn't work.  I built it and looked at it in the Antuino.  NOPE.  It wasn't even acting as a bandpass filter.  It is more of a notch filter. Confronted with the failure, AI LLM admitted it was wrong (my coments in red): 

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

This configuration does not work. I have never seen it in any amateur radio book. Are you sure that this will work?

You are 100% correct to call that out—that schematic is incorrect and will not work as an SSB bandpass filter.

Why the Shunt-Crystal Schematic Fails

In quartz crystal equivalent circuits, the crystal reaches its lowest impedance () at its series resonant frequency ().

• Series Position (Correct Bandpass): When the crystal is placed in the series signal line, its low impedance at allows the RF signal to pass through to the next stage.
• Shunt Position (Incorrect): Placing the crystal directly from the signal line to ground causes it to act as a shunt short circuit at . Instead of passing a window, it short-circuits directly to ground, creating a band-reject (notch) response rather than a bandpass filter.

This is why you will not find that topology in Experimental Methods in RF Design (EMRFD), the ARRL Handbook, or classic G3UUR/Dishal filter literature.

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

At this point I decided that a 10 crystal Cohn filter would give me the steep skirts I needed.   Here is what AI recommended: 

I went ahead and built this one.  I looked at it with the Antuino.  It works. 

You can see the steeper skirts on this filter.  These steep skirts will allow me to use this filter on 17 meters with the 5 to 5.5 MHz VFO from the old Kenwood TS-820s.  

In the course of doing this, an old friend who works in this field (and who will remain anonymous) warned me about the dangers of over-reliance on AI LLMs, especially when working on ham radio circuitry.  More on this in the days ahead.  

Charlie ZL2CTM Talks Homebrew with NJ7V on Red Summit RF

 

https://www.youtube.com/watch?v=xV489xbf34I

NJ7V has a good interview with famed NZ homebrewer Charlie Morris ZL2CTM.  Charlie describes his interests in homebrew, and provides some good links for homebrewers.  I agree: understanding is important.  Great stuff!   Thanks to both! 

Using AI to Design Crystal Filters -- Please comment, especially on the use of AI

 

Earlier, AI told me that for 17 meters with a VFO in the 5.2 MHz range, and and a BFO/Carrier oscillator at 13 MHz I should not have any spur problems.  So I ordered 10 crystals from Mouser.  I hope to use it with the VFO from the Kenwood TS-820s. 

This project plunged me back onto the world of motional parameters determined by the G3UUR method, followed by the use of software to determine the shunt capacitors and the termination impedances. I have used Dishal, AADE software, and Wes Hayward's GPLA. 

Using this software can be a pain in the neck.  There are a lot of exponents.  Capacitance often has to be expressed in femto farads.  Frankly, there is a lot of potential for error. 

There is no way (as far as I know!) to skip the G3UUR measurement stuff.  You just can't tell AI to determine the motional parameters.  But after that, AI should be able to handle the calculations.  I have built these kinds of filters before, so I know roughly what the shunt capacitance should be.  Sure enough, just telling AI what the 2 motional parameters are, how many crystals I want to use (5) and the configuration (I selected the very simple Cohn configuration), and the desired bandwidth (I said 3 kHz).  AI happily spat out the shunt capacitance (which looked right) and the impedance that would result in a flat passband (613 ohms).  AI even designed the little FT-37-43 toroidal transformers that would work nicely with the 50 ohmm TIA amps on either end of the filter. 

I think this is a good example of one of the uses that can be made of AI.  It made the design of this filter a lot easier.  

Both Images Produced by AI Gemini (FLASH HIGH)

I have built the filter (in the real world) and it is mostly working.  I will perform some more tests on it and will report on this here.  

What do you folks think of all this?