Author Topic: Identifying a transistor  (Read 568 times)

MordechaiBenZev

Identifying a transistor
« on: January 22, 2022, 09:35:17 AM »
There are some transistors up for sale right now on Ebay that have a package I haven't seen before. A cross between a TO-1 and TO-5.  This one is billed as an OC71N...but I can't tell the manufacturer.  Is anybody familiar with this? 


mozz

Re: Identifying a transistor
« Reply #1 on: January 22, 2022, 11:19:51 AM »
SFT?
  • SUPPORTER

MordechaiBenZev

Re: Identifying a transistor
« Reply #2 on: January 22, 2022, 11:41:59 AM »
I always thought the SFT packages were a bit more elongated.  This looks a touch more like a TI 2G3xx series.  In any case it looks like the "OC71N" is a post-production restamp, but I may well be wrong about that.

tonyharker

Re: Identifying a transistor
« Reply #3 on: January 22, 2022, 02:39:39 PM »
Genuine OC71s (Mullard/Philips) were always in a black glass package. This one appears to be a remarked something.  Looks like an AC128 package. Telefunken?

Rob Strand

Re: Identifying a transistor
« Reply #4 on: January 22, 2022, 05:22:05 PM »
In the pic here you can see a large logo on one side.  I can't quite make it out.

https://www.radiomuseum.org/tubes/tube_oc71.html


[Actually it says manufacturer SI under the pic]
« Last Edit: January 22, 2022, 05:31:05 PM by Rob Strand »
Send:     . .- .-. - .... / - --- / --. --- .-. -

PRR

Re: Identifying a transistor
« Reply #5 on: January 22, 2022, 05:26:10 PM »
I don't think "TO1" was ever a formal standard. It was retro-fitted to several existing similar commercial packages after JEDEC got their transistor staff organized. "TO-1" may be flat or dome on top, straight or flanged on bottom. It is probably the product of a button-shank machine, adapted as each maker saw fit.
  • SUPPORTER

duck_arse

Re: Identifying a transistor
« Reply #6 on: January 23, 2022, 09:51:00 AM »
it looks as tho the case has an emitter tag, in which case it would appears to be over the collector pin. I've only ever seen germs pin-marked on the collector, I think.
up, higher.