curiousmarc
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Another vintage components donation
🕑 Added 2022-01-28 07:22:50 +0000 UTCA viewer that wishes to remain anonymous rescued a batch of old components from the dumpster of his company. And they are quite interesting. They are mostly from the early 60's. Early Germanium semiconductors for the most part, mostly professional / higher end. I don't have much Germanium stuff in my collection, so this turns out to be a great addition. They'll come in handy to repair the early transistorized HP stuff from the1960's.
See this really early Germanium transistor, an OC47. The case is actually a glass ampoule, painted black. Low-numbered, obsolete OC-series transistors are the first ones I ever played with when I was exploring electronics as a kid.
Some early transistors from the General, more serious looking.
Some were high end semiconductors for the time, like this DG-2400 transistor from Delco. I did not know they could make a 120V 25A Germanium transistor. Of course it is slow, and gain is low, but still. That was probably not cheap, my guess is military or aerospace use.
There was a nice collection of early power zeners, like this 50W one.
Here is another one, also 50W, high voltage, in a curious looking transistor package.
Here are some early mesa transistors for logic switching. Mesa transistors were the 2nd generation of transistors. The first generation were alloyed ones, like the ones used in the 50's in our IBM 1401. These ones from TI are in a match package. Most of these early fast transistors were very fragile, withstanding only a few volts or a few mA.
And the one from Motorola is in a candy wrap. Definitely meant for low cost.
Look at these cute Germanium SD-1 diodes!
The gem of the donation was actually a batch of tubes, namely Nixie tubes. New in the box, from National and Burroughs.
The Nationals were classic Nixie tubes, with quite modern looking digits, and the ones from Burroughs are top view style. They will also come in pretty handy with the 1960's HP instruments. And I'm sure I'll make some kind of indicator with them.
This Daven component is unusual. It's a constant impedance attenuator. 150 Ohms in, 150 Ohms out, -2 to -18 dB to a few 100 kHz. And if you turn it full CCW, it turns completely off.
There were also two fast DAC chips from the 1994 that Ken Shirriff reverse engineered in no time:
You can read about what Ken found about this chip (basically, everything), on Twitter:
https://twitter.com/kenshirriff/status/1484243975468847105
But a component collection is completely useless unless it's organized. And most of the time, you won't have the exact part, but need to find an equivalent. So I need to research all of the important parameters for the label. Quite a large amount of work to get there. But then I can zero in on an equivalent in a matter of minutes.
Well, thank you very much anonymous donor, I am glad these were rescued from the landfill. Well done!
Marc
Comments
CuriousMarc
Thanks Jac, I did not know. But it would make sense, as the first number in a tube number would be the filament voltage! I certainly remember the BC series!
Jac Goudsmit
I seem to remember the O in OC was really intended to be a zero, indicating that the filament voltage was zero because unlike a tube, a transistor had no filament. Later on, they changed transistor names in Europe to use A (e.g. AC126) for Germanium, B (e.g. BC238) for Silicon. The second letter was the purpose of the transistor: C was general purpose, D was high power, F was high frequency etc.
CuriousMarc
Yes I think the OC series is European and originated with Philips. My first transistors were the OC72, in an elongated metal can resembling the shape of this glass one. They were part of an old "learn electronics" toy kit that my neighbor gave to me. You could build a whole AM radio with a few transistors!
