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40 uses for Germanium Diodes (1950) [pdf] (pocnet.net)
53 points by kalium-xyz 38 days ago | hide | past | favorite | 24 comments

I fell in love with Electronics at 16 precisely because of these kind of books that 60's printed full of them. I discovered them in my father's book collection in early 90's and these were my "drug gateway" to my programming career.

Having electronics and hardware background made my programming so much easier as it was easier to understand some concepts and choices that to "pure software" engineers appeared weird.

These days I love to combine hardware and software integration and boy oh boy, it pays so much better. Not many programmers out there that will offer a bill acceptor and/or magnetic card reader integration for a POS solution when your local restaurant wants to modernize their shop.

Show these kind of books to your kids, you'll never know where the rabbit jumps from.

I have a collection of old printed databooks and application notes from semiconductor manufacturers such a Analog Devices, Philips and Motorola (back when they produced silicon). A lot of the devices are obviously obsolete but the principles from the design examples are still valid.

Hasn’t Stripe and others cannibalized the POS market? I figured that market would be saturated. Being another software/hardware guy the various POS systems Always seemed an interesting market. Do you do lot of custom work building custom POS?

Always. Clients always like their solution to be personalized for their specific needs. No 2 shops are alike even if they are across each other on same street. Usually the custom work comes in form of: a). hardware used hence interfacing with it is custom and b). reports as each client has its own idea of how data should look in front of their eyes.

One niche use that I know of that lives on to this day for germanium diodes is in analog guitar effects.

The reason is twofold: germanium diodes generally have a softer turn-on than silicon diodes, and they have a lower forward voltage drop than silicon diodes.

This makes them useful in audio applications for clipping circuits (more sensitive and warmer sounding distortion), but also in simple one-diode envelope-detector circuits. One rather famous guitar compressor effect from the 1970s (the 'Orange Squeezer') used a germanium diode as an envelope-detector in this manner.

> germanium diodes generally have a softer turn-on than silicon diodes

This a million times, and it also applies to germanium transistors too. I keep reading that all it needs to emulate the germanium sound in a guitar fuzz made with silicon transistors is adding a small cap between base and collector, which is only part of the story: those are non linear devices, and there's a non trivial difference between Ge and Si V/I curves, which translate into different sound which can't be emulated just by adding a cap. A softer curve creates a much gentler distortion which doesn't ruin the sound when playing chords for example.

Another famous guitar effect example is the germanium "fuzz face" pedal, which are still in production today.

You can get an idea of this kind of fuzz sound in the song "Spirit in the Sky" by Norman Greenbaum.

The librarians date it 1951. https://www.worldcat.org/title/40-circuits-using-germanium-d... It is no 102 of Bernards radio books series. List and many other scanned books at https://www.americanradiohistory.com/Bookshelf_Bernards_Baba...

Thanks for posting the link to the bigger list of books. I just love this stuff. I remember some of these from my childhood and my father's collection. +1 for posting this!

No copyright date appears in this document, but it was apparently published before 1963 (since it lists a U.S. address that uses a postal zone rather than a ZIP code).

Sylvania's 1N34 diode became available in 1946[1], so the document may date from as early as then.

[1] https://en.wikipedia.org/wiki/Diode#Solid-state_diodes

I was looking through this magazine for inspiration for a fun project. I've been a hobbyist for 40-something years, and still like to daydream about 'cool things to build'. Then one of the projects caught my eye, and I saw a real-world/real-use for it related to Amateur Radio. And then I saw more, and more!

At the end, I see that a fellow Amateur Radio was a previous owner. So it has me more interested now.

Thanks for sharing.

My first ever electronics project was a radio that used an 1N34 diode in 1974. Worked beautifully and that's what launched my interest in electronics and then computers.

I was sad recently to find that Digi-Key doesn't stock germanium diodes. My 200-in-1 kit I had as a kid had a couple of germanium diodes in it; I guess you could substitute Schottky Si diodes in most if not all of the circuits in its manual. I guess Schottkys have higher reverse leakage, but that doesn't always matter.

taydaelectronics.com lists 1N34s in their catalog, although they are out of stock at the moment. 28 cents each.

(I usually check Tayda first, before ordering from Mouser/Digikey. Often cheaper, although parts take a little longer to arrive.)

On page 18 they power a relay directly from an antenna. This seems a little optimistic to me, or perhaps they had very low-power relays back then?

>Transmitter Failure Alarm

You would have it installed near your high power transmitter. Having worked on high power AM transmitters, the fences surrounding the antenna can pick up the signal and corroded joints act as a detector, the result is the fence becomes a receiver. So I have no doubt a relay could be powered.

What? Does the fence itself vibrate and reproduce the sound? Or do you need to complete the circuit using the fence as the detector?

I'm not entirely sure what process is converting to sound, but the metal fence makes a great antenna and we are talking about 10's of feet from the antenna with 500 kW AM at 200 kHz going into it.

It could actually have been arcing:


Does anyone know where other books from this series can be found?

Not sure if it contains other books from the series, and it has been likely posted already a hundred times, however here is a huge list with some interesting subdirs filled with books also pertaining electronics, ham radio etc.


Attics and cellars of retired, or more likely deceased, engineers probably. Most such books were never in ordinary libraries and would be discarded when the new edition came out. The American Radio History [1] web site looks like a good place to start.

I have Babani's 1st and 2nd Book of Transistor Equivalents and Substitutes [1] and several National Semiconductor data books and application books from the 70s, '80s and '90s.

I almost never refer to them any more but they were so central to my life as an electronics engineer that I can't bear to throw them out.

[1] https://www.americanradiohistory.com/Bookshelf_Bernards_Baba...

I recently picked up some at a Radio Rally (Hamfest), you might find some gathering dust in the corner of a university or government electronics lab if they have not already gone in the trash.

You only need one use to justify germanium: Fuzz.

I like to plant them and grow Geraniums.

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