recently obtained a germanium part - Page 1
Forum section: electronics / beginners

author: LaserTazerPhaser
author_rank: Regular Contributor
timestamp: June 08, 2019, 09:16:46 pm
content: Whats the year it was likely manufactured? It appears to have solder on leads but diode test showed Vc-b 0.138v and Vce seems to be high for germanium type.

author: Audioguru
author_rank: Super Contributor
timestamp: June 09, 2019, 12:39:24 am
content: That antique transistor is between 50 years old to 60 years old. Kiss it goodbye then bury it.

author: LaserTazerPhaser
author_rank: Regular Contributor
timestamp: June 09, 2019, 03:23:29 am
content: Isn't the die sealed off from corrosion?

author: amyk
author_rank: Super Contributor
timestamp: June 09, 2019, 04:10:33 am
content: Do any of them have the usual yyww date codes?I would guess late 60s/early 70s. Pictures of some others I can find online have 70s date codes.

author: Tomorokoshi
author_rank: Super Contributor
timestamp: June 09, 2019, 04:56:13 am
content: A HEP series transistor? Now that's cool!

author: soldar
author_rank: Super Contributor
timestamp: June 09, 2019, 09:11:44 am
content: I would not throw them away if they are not damaged as they have historical value.If they arepoint contact transistorsthey are easily damaged by shock or vibration.Germanium transistors were very subject to temperature. Today they really are only of historical value or to repair transistor devices, like radios, from that time.

author: Ian.M
author_rank: Super Contributor
timestamp: June 09, 2019, 10:35:47 am
content: There are very few things a Ge power transistor is good for nowadays, apart from repairing antique equipment. One application that may be worth experimenting with is an ultra-low voltage Joule Thief. Of course it wont start at as low a voltage as a modern energy harvesting IC . . .

author: LaserTazerPhaser
author_rank: Regular Contributor
timestamp: June 09, 2019, 01:01:38 pm
content: What were those 2khz F(t) germanium TO-3 transistors used for?

author: Gyro
author_rank: Super Contributor
timestamp: June 09, 2019, 06:49:50 pm
content: Quote from: soldar on June 09, 2019, 09:11:44 amThe last time I used a Germanium transistor, it was an OC71 style glass encased one - I used it as the sensor for a precise aquarium thermostat, higher temperature coefficient than Silicon and nice fish friendly package. It was glued into the end of a plastic tube with aquarium safe silicone. It was still going strong after 20+ years.

author: Canis Dirus Leidy
author_rank: Regular Contributor
timestamp: June 09, 2019, 08:00:21 pm
content: Quote from: LaserTazerPhaser on June 09, 2019, 01:01:38 pmIt's enough for voltage regulator. Or even for audio amplifier:(Schematic was taken fromVWM60 service manual)

author: emece67
author_rank: Frequent Contributor
timestamp: June 09, 2019, 10:06:41 pm
content: .

author: David Hess
author_rank: Super Contributor
timestamp: June 10, 2019, 02:50:51 am
content: Quote from: Ian.M on June 09, 2019, 10:35:47 amThey make great pass elements for very low dropout voltage regulators. And they are useful for a very low input voltage inverter which is even better than a Joule Thief.

author: Seekonk
author_rank: Super Contributor
timestamp: June 10, 2019, 03:59:32 pm
content: I still have a batch of GT-109 from General Instrument, 67 date code if I remember. Must be at the end of production because they finally got very good at it. Leakage compares to silicon. I have people that prize these because they make excellent FUZZ boxes. One guy said he has bought all sorts of germanium and never found any as good as mine.

author: exe
author_rank: Unknown
timestamp: June 10, 2019, 07:58:05 pm
content: I have a few (may be 10-20, not many) old USSR transistors. I want to build something with them, but can't figure what. Probably, I should just throw them or give away.

author: Macbeth
author_rank: Super Contributor
timestamp: June 10, 2019, 08:45:35 pm
content: Quote from: Gyro on June 09, 2019, 06:49:50 pmThe OC71 is my most memorable transistor. Because as a child in the '70s I made theLadybird Radioand wired the OC71 backwards and it released the magic smoke. That was my first hint at the brutality of getting things wrong in electronics.But the unpowered germanium diode crystal set went so well...!

author: soldar
author_rank: Super Contributor
timestamp: June 11, 2019, 01:19:16 pm
content: OC71 and AC126. I remember them like it was yesterday and probably still have a few lying around.

author: Gyro
author_rank: Super Contributor
timestamp: June 11, 2019, 01:24:09 pm
content: Ah, the joys of scratching the paint on the side of an OC71 and finding out whether you'd scored a cheap OCP71 or just a white paste filled one.

author: Ian.M
author_rank: Super Contributor
timestamp: June 11, 2019, 02:44:12 pm
content: Then there was the joys of trying convert an OC71 to an OCP71 by trying to centrifuge the white paste down into the bottom of the envelope to get it clear of the junction!

author: bob91343
author_rank: Super Contributor
timestamp: June 11, 2019, 04:47:56 pm
content: I am impressed with the number of those who still have germanium parts. I recently repaired an HP counter that had a shorted 2N404. As it happened, my hoarding aspect meant that I still had some stock of the exact part. The counter has been working great for a while now. Model 5245L.I have several drawers labeled Obsolete Transistors that include germanium as well as early silicon. I am mentally unable to toss them, although I don't imagine they will ever get used.A friend recently obtained a couple of brand new CK722s in their original packaging. Those were, to my knowledge, the first commercially avaialbe transistors. Most of them wouldn't work.