Author Topic: Identify this Germanium transistor???  (Read 999 times)

aran.e666

  • Stompbox Star
  • ***
  • Posts: 180
  • Aran
    • View Profile
Identify this Germanium transistor???
« on: May 11, 2017, 11:15:49 AM »
hey guys,

long time since i posted here but i'm back. I'm asking this here as i'm really not too sure where else i can ask this question :D

anyways, so recently i acquired some nice USAF stamped 2n404's from Ebay. i noticed however one transistor was very dirty and also in a different style package when i was testing the hFE. either way, i still tested it. i think it measured 470 hFE  :o (yes, i know it's not true hFE but still much higher than the 404's i tested). that's when i noticed that there were more of the same transistor. i found one that was fairly clean. its made by RCA and says 'CIA' (or C1A) with what looks like '3621A'. yes, i know, CIA isn't Central Intelligence Agency but just some identification tag probably. my question is - what is this? are there any similar transistors? i ask because i can't find any info on it. maybe i didn't look hard enough which is why i'm asking here for someone to point me in the right direction.

~Aran
Guitar is love, guitar is life.

jimilee

  • Electron Doctor
  • *****
  • Posts: 7254
  • Jimi Lee
    • View Profile
Pedal building is like the opposite of sex.  All the fun stuff happens before you get in the box.

flanagan0718

  • Electron Doctor
  • *****
  • Posts: 2674
  • Mike
    • View Profile
    • Custohm Electronics
Re: Identify this Germanium transistor???
« Reply #2 on: May 11, 2017, 11:54:32 AM »
This might not help but i figure it might be good to have  ;)

https://drive.google.com/file/d/0Bycv0SjnxaR5b3Y1ampRT3kyUE0/view?usp=sharing

aran.e666

  • Stompbox Star
  • ***
  • Posts: 180
  • Aran
    • View Profile
Re: Identify this Germanium transistor???
« Reply #3 on: May 11, 2017, 12:07:12 PM »
thanks for the replies guys, much appreciated.

i searched in the discontinued transistors and i found a '2N3621' but it seems its not the same

as for the small signal transistors pdf, yeah, its actually nice to have as i never thought to search for it before.

i'm sure we will figure it out :D
Guitar is love, guitar is life.

flanagan0718

  • Electron Doctor
  • *****
  • Posts: 2674
  • Mike
    • View Profile
    • Custohm Electronics
Re: Identify this Germanium transistor???
« Reply #4 on: May 11, 2017, 12:38:05 PM »
I actually have an ass load of Germs to go through if i find any in my stash ill let you know.

ASS LOAD


aran.e666

  • Stompbox Star
  • ***
  • Posts: 180
  • Aran
    • View Profile
Re: Identify this Germanium transistor???
« Reply #5 on: May 11, 2017, 12:44:11 PM »
that pic reminds me of an old teacher i had. he came from Canada to the UK for a year to teach electronics. he had this cabinet in his classroom so he decided to show me inside when he found out i love electronics. it was filled with this HUGE collection of germaniums :D
Guitar is love, guitar is life.

aran.e666

  • Stompbox Star
  • ***
  • Posts: 180
  • Aran
    • View Profile
Re: Identify this Germanium transistor???
« Reply #6 on: May 21, 2017, 01:38:23 PM »
bump

still no info at all
Guitar is love, guitar is life.

EBRAddict

  • Solder Ninja
  • ****
  • Posts: 385
  • Strictly bush league
    • View Profile
Re: Identify this Germanium transistor???
« Reply #7 on: May 21, 2017, 07:50:36 PM »
This ham operator has a 1957 and a 1960 RCA product sheet for discretes:
http://n4trb.com/AmateurRadio/SemiconductorHistory/SemiconductorDocuments.htm

I didn't look carefully but I didn't see anything with 3-6-2-1-A or partially in that sequence. It looks like all their transistor products start with "2N"



midwayfair

  • Electron Doctor
  • *****
  • Posts: 7026
  • Jon P
    • View Profile
    • Midway Fair
Re: Identify this Germanium transistor???
« Reply #8 on: May 22, 2017, 08:16:40 AM »
It's not germanium. There are plenty of silicon in the TO-5 package.

Anything with 4 numbers after the 2N is going to be silicon, and you can be reasonably sure that anything in a TO-5 package is intended for medium voltage applications (think 50-100V).

It's probably a 7, not a 1.
http://alltransistors.com/transistor.php?transistor=3412
Myself's music & things I make: http://jonpattonmusic.com. My band: http://midwayfair.org. PCBs of my designs from: http://www.1776Effects.com (Bearhug Comp & Cardinal Harmonic Trem); http://www.jmkpcbs.com (Hamlet+ delay & Blue Warbler envelope vibe); Snow Day OD/Flabulanche: www.madbeanpedals.com

aran.e666

  • Stompbox Star
  • ***
  • Posts: 180
  • Aran
    • View Profile
Re: Identify this Germanium transistor???
« Reply #9 on: May 23, 2017, 08:29:46 AM »
thanks for the replies,

i'l have to look at that site and see if i can see anything myself.

also Midwayfair, i never actually thought of it like that. i took a look at the datasheet and it makes sense. i suppose it would make sense that it is a 7 too. i would test it to see if it's npn but for some reason the transistor socket on my DMM is blocked up.

i also got in touch with the semiconductor museum and this is what they had to say: "The other unit, type "3621A" is similar to many other RCA "in-house" numbers made for a specific customer, often a computer manufacturer.    I haven't seen the CIA text before, so this type might be actually a special order for the CIA."

i suppose the only real way to know would be to contact RCA but considering they shut down in the 80s makes it impossible. another thought i had was asking the original seller where he got them from buy he said he bought them from someone years ago.

i would still love to know what the CIA means. i think its just RCA's markings as most of my RCAs have random letters on them.



Guitar is love, guitar is life.