# old gold plated transistors



## kelly (Mar 4, 2013)

Found some interesting things as I was digging into some of my long forgotten stuff. These are from a circuit board of an old calculator. Most of the discrete components had gold plating on the ends, both inside and out. Tested a few in AP and the foils came off intack, nice thick plating. Just thought I'd pass this along incase anyone else has some old stuff, a quick scratch will tell. (I swear, someday I'm going to actually see the floor in my garage again.)


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## ilikesilver (Mar 4, 2013)

very cool


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## Findm-Keepm (Mar 4, 2013)

....only they are resistors, not transistors, and you'll find the "gold" is actually brass. 

Test with a drop of HCL and you'll see...

Cheers,


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## GOLDbuyerCA (Mar 5, 2013)

*Yet* the transistor is there, if we look close, as is several glass resistors, that are platted gold on the caps, and leads. in the late 70's, those glass resistors, of very high accuracy, were expensive, and yes, it is gold on them, i beg to differ FK , a lot of work though, and you need tens of pounds , good picture,


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## Findm-Keepm (Mar 5, 2013)

The items pictured are common film resistors - you can see the etch (spiral) around the body of the resistive element. One transistor is pictured with gold leads, but his comment on "old gold plated transistors" just doesn't hold water. Look at the surrounding resistors - all common carbon film resistors, known to have Zero PMs. The resistors that have had their coating scratched off to reveal the caps are not glass resistors - those use tensile methods of connecting the resistive elements, not crimps. I've spec'd and sourced many resistors for designs, and can speculate by the purplish brown coating that they are likely either Roederstein or Piher brand carbon film resistors. Nothing with PMs, but more like the below:

http://www.talonix.com/images/res/P62BB.jpg

Just trying to keep the forum clear of false hopes. There is one small TO-18 cased transistor pictured,. but not referenced by the OP. Most likely gold plate over Kovar, plenty of threads on that type/material.

Cheers


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## kelly (Mar 5, 2013)

Yes, you are correct, they are resistors not transistors. Thank you for that. However, they are gold plated, not brass. This came from a board out of an Olivetti calculator, circa 1969. As I said, I tested them and the foils came off intact.


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