"Homebrew you say? But did you DESIGN it yourself?"

Raymond A. Heising  (1922)

That is a question we get fairly regularly when we tell the other fellow that our rig is homebrew.  I often get the feeling that the question stems from a certain insecurity -- the guy who asks it may feel a bit insecure because the "rig" he is running is completely commercial and his only role in its production was to flash a credit card number.  

But lately I have been reading through Jim Williams' wonderful book "Analog Circuit Design -- Art, Science, and Personalities" and I can see that there may be something to this question. 

It was the chapter by Barrie Gilbert that made me think more about this. Barrie is the legendary designer for whom the Gilbert Cell is named.  This circuit is at the heart of the NE602 chip that many of us used to build our first "Neophyte" receivers and other homebrew rigs.  Barrie's chapter is entitled "Where do Little Circuits Come From."  Uh oh. 

Barrie grew up in the post-war United Kingdom.  He father had been killed in a German bombing raid. As a kid, he built crystal radios and, with his brother, "shortwave sets" on softwood bases.  He used a TRF receiver that employed Manhattan-style construction.  Barrie, it seemed, was one of us.  

But then, he suddenly seemed more advanced.   He wrote:  

"Later, I began to build some receivers of my own but stubbornly refused to use circuits published in the top magazines of the day, Practical Wireless and Wireless World.  Whether they worked as well or not they had to be "originals" otherwise, where was the satisfaction?  I learned by my mistakes but grew to trust what I acquiered in this way:  it was 100% mine, not a replication or mere validation of someone else's inventiveness."  

Wow, that is certainly hardcore.  I will note,  however,  that in getting back to the the question about whether I have "designed" the rig myself, I have NEVER had the questioner come back to say that HIS rig was homebrewed from HIS OWN original design.  Never.  Not once. 

And I will note that building a rig from the schematic is an enormous challenge.  It is not easy.  It is not the mere replication of someone else's inventiveness.  Anyone who thinks it is easy should try to homebrew a simple direct conversion receiver.  They will discover that it is NOT easy. 

I guess this comes down to what we mean by "homebrew."  I prefer to stick to the old ham radio meaning of the term:  It is homebrew if it was built at home, even if it is built from a schematic done by someone else. When Jean Shepherd built his Heising Modulator, was he working off a schematic from a ham radio magazine?  He almost certainly was.  But he gathered the parts, laid out the chassis, and put the circuit together.  Most importantly, when trouble cropped up, he was able to step in and make the needed corrections.  Was his modulator "homebrew?" Of course it was.  Did he design it himself?   No, his name was not Heising! 

More than 100 people built our SolderSmoke Direct Conversion Receiver.  We resisted pressure to turn this project into a kit.  The folks who built it worked off schematics that we had prepared.  They gathered the parts and built their own circuit boards, Manhattan style. They struggled to get the whole thing to work, to make sure the VFO was on the right frequency and at the right level, that the AF amplifier was not oscillating.  Were these receivers "homebrew?"  Of course they were. 

Jim Williams warned that Analog Circuit Design was "A wierd book."  He strongly discouraged collaboration between the authors, and noted that this would probably result in "a somewhat discordant book."  We see that discord in the hardcore position taken by Barrie Gilbert.  Many of the other designers seem to take a more flexible, less austere position.  Some even seem to downplay the role of mathematics.  

I think Barrie had a right to be proud of his fundamentalism.  But not all of us are capable of that.   Writing in Jim Williams' book,  Samuel Wilensky sums it up nicely: 

"I classify analog designers into one of two categories.  There are those who do truly original work, and these I consider the artists of our profession.  These individuals, as in most fields, are very rare.  Then there are the rest of us, who are indeed creative,  but do it by building on the present base of knowledge."   

Some Great Analog Pictures from MIT Building 20 and other Analog Locations

Here is a picture of Jim Williams taken through a Tektronix oscilloscope camera.  I never used one of these things, but Dean KK4DAS did.  Here are the details of the shot: 

I took this great photo of Jim Williams with a Tek scope camera sometime around 1977 or so. There was no digital (or analog) manipulation. It was a simple double exposure. I first shot a scope waveform, then just to see what would happen, I pulled the camera off the scope, stuck it Jim’s face and snapped another shot before pulling the film. I never expected it to look this good….a view from inside the oscilloscope!

Here is the collection of pictures that this 'scope shot came from: 

https://lensprojects.com/analog-history/

Thanks to Len Sherman for the pictures.  On his site you will see, among other things, the upside down Christmas Tree of dead parts, and Bob Pease's Volkswagen Beetle. 

More info on MIT's Building 20: 

https://en.wikipedia.org/wiki/Building_20

Jim Williams -- Analog Man -- Book Review: "Analog Circuit Design -- Art, Science, and Personalities"

 

Jim Williams at his bench.  Note the mess. 

The Bob Pease book that KD4EBM gave me led me to the Jim Willams book entitled Analog Circuit Design -- Art, Science, and Personalities.  I'm only about a quarter of the way through it, but I can already tell that it is great.  Get this book.   Make room on your shelf.   

Jim was the editor, and it is a collection of contibutions made by a many different analog luminaries.  Curiously, none of the bios show that there are any hams among them (but the articles of many of them seem to hint at ham radio backgrounds).  MIT shows up a lot in the bios.  Jim notes in the very first line of the preface that "This is a weird book."   He talks about how it came together -- he met with the contributors and each of them pledged NOT to consult with the others about what they would write.  Jim notes that the result is "a somewhat discordant book," that "Hopefully would lend courage to someone seeking to do analog work." " The single greatest asset a designer has is self knowledge."  "Take what you like, cook it any way you want to, and leave the rest."  Indeed. 

I found that Jim's own contributions were among those that I liked the most. He writes about "analoggery" and "digital fakery"  but then acknowledges that this is a "good natured" controversy.  He notes that "no true home is complete without a lab" (a shack?) and that "no lab is complete without an HP series 200 oscillator."  His bio reveals that he lived in California with his family and "14 Tektronix oscilloscopes."   In a chapter entitled "Should Ohm's Law be Repealed?" Jim describes the very early influence of a neighbor, Dr. Stearn,  who owned a Tek 535.  It allowed them to see into circuits:  "You knew the excitement Leeuwenhoek felt when he looked in his microscope."  But that was not always enough:  Jim tells how Stearn once successfully troubleshot one of Jim circuits simply by running moistened fingers over circuit while watching the scope. 

Tom Hornak also really struck a chord with me. He writes of things that happened in the year "10 BT" (Before Transistors).  He talks about how he and a childhood friend had trouble understanding the differences between voltage and current.  "We found someone who knew the right answer, but he did not help us too much. Instead of using a simple analog such as a phasor diagram, he started to talk sine and cosine. We accused him of not knowing the answer either, and covering up his ignorance my muttering mumbo-jumbo."  Tom explaines:  "I know that trying to 'understand electricity' early in life had a lasting benefit to me. I got used to 'seeing electricity' in analogs and I am still seeing it that way. I believe every electronic circuit designer could benefit from thinking in analogs, and it is never too late to start. This belief made me write this chapter."  

Barrie Gilbert -- the man credited with inventing the Gilbert Cell (the heart of the NE602) -- has a chapter in the book.  He writes of circuits "laid out Manhattan-style" and "built on softwood bases." He hombrewed a very early TV receiver. He tested AF amplifiers "by placing a finger on the grid of the first tube."  (We recommended something similar with the SolderSmoke Direct Conversion Receiver, but some builders seemed not to believe that this would work!)    

It is undoubtedly a tragedy that we lost both Jim Willams and Bob Pease in June 2011. Jim died of a stroke at age 63; Bob died of a possible heart attack or stroke while driving home from Jim's memorial service. But here we are in 2025 still talking about their work and their books. In a certain sense they live on through their writing.  This is a lesson and an inspiration for those of us who sometimes get a bit down by the vagaries of AI and the algorithms:  We never know when -- perhaps long after we are gone -- someone might come across something we have written and find inspiration there.  

Three cheers for Jim and Bob.   

https://soldersmoke.blogspot.com/2025/10/troubleshooting-analog-circuits-by-bob.html

https://www.jameco.com/Jameco/workshop/inthenews/pease.html?srsltid=AfmBOoqCC_QLhohtE3--OhGRLuQ0kQDyAq0rDsRhkdQDeIeZmGZs7nvN

https://www.edn.com/analog-engineering-legend-bob-pease-killed-in-car-crash/

A Knack Victim's Midlife Crisis

Thanks to Steve WA0PWK for sending us this Jim Williams cartoon.  

Been there, done that. It doesn't mean you are a bad person.

Fixing TEK 465 Oscilloscopes

I'm having TeKnical difficulties.  My beloved Tek 465 'scope quit on me.  I'd been running it continuously for a day or so, watching the output on my BITX VFO.  Then, suddenly, it blew the 1.5 amp fuse.  I replaced the  fuse, but afterwards the trace was gone and the "Low Line" light was acting weird -- on when it should have been off, then flickering.   I consulted with Alan Wolke.  He happened to be out at TEX HQ in Beaverton, Ore.  He provided some good suggestions, but before I had a chance to try them, the trace came back.  I attributed this good luck to the Radio Gods being pleased with Alan's presence in Beaverton... but my reprieve was short-lived.  Trace went out again today. 

I found this video of the legendary Jim Williams (RIP) fixing a Tek 465.  (Check out Jim's junk box!)
I'll start by checking the Tantalums.  I may get lucky. 

If anyone has any other suggestions, send them this way.  The Tek scope may be old, but it is a COMPLICATED piece of gear... 

Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20

Troubleshooting and Simulations

Alan, W2AEW, roams the Northeast USA as a Field Application Engineer for Tektronix. This week he sent me an e-mail with some words of wisdom about simulations and troubleshooting. Thanks Alan!

An excerpt from Alan's e-mail:

Funny you mentioned about LTSpice, and wanting to have that puff of soldersmoke whenever you place a component. It reminds me of something that I'd often tell new-hire engineers. Many times, engineers fresh out of school have never touched a resistor - they've often spent their entire education doing bookwork and simulations. I would always caution engineers about this, and try to illustrate that the simulation is only as good as the model you give it. If you ask the simulator to exercise the model in a way it wasn't designed for, it won't tell you that, it will just lie to you. YOU have to be smart enough to recognize the lie. For example, the simulator has no problem putting 10,000 amps through a 1N914A diode - it doesn't know that you'll let the smoke out of it! The simulator must be considered a tool, just as you VOM, scope, counter, finger, nose, etc. are all tools. Each can give you valuable information (and can lie to you). You have to learn to know what you can believe, and what you have to question - and you need to develop ways to look at strange behavior in a number of ways to figure out what is happening.

It reminds me of a story that Jim Williams wrote many years ago (you mentioned Jim Williams in a previous SS episode). He described how, as a child, he was playing with circuits at his neighbor's, and using his (neighbor's) oscilloscope to examine a circuit he was working on. He was getting all kinds of strange behavior, and couldn't make heads or tails of what he was seeing with the scope, VOM, etc. The neighbor (who was definitely afflicted with the Knack) came by and, with moistened fingers, probed around in his circuit for a few minutes. He then grabbed a small value capacitor and soldered it judiciously in the circuit, and everything worked fine. Jim was flabergasted and demanded an explanation. The neighbor said that he suspected that the circuit was oscillating at several hundred MHz, and used his finger's capacitance/loss/etc. to damp this behavior. He continued to explain that since the oscillation frequency was so high, the scope couldn't "see" it. Jim complained that this "wasn't fair"! The neighbor concluded the lesson about how important it is to not-only understand what our tools can do for us, but it is really more important to understand their limitations - because it is when we ask a tool to do something that it can't do, it often won't complain, it will lie. The same holds true for nearly every tool we use, and is a lesson well learned. This story is included in his chapter entitled "Should Ohm's Law Be Repealed?" in his book, "Analog Circuit Design: Art, Science and Personalities" from 1991.

Alan has a lot of great stuff on his web site. Check it out:
http://www.qsl.net/w2aew/