I have old germanium transistor from computers that were dumped
in the 70's.
The Hfe varies between 50 to 150.
The Vbe varies between 110 and 230.

A couple of these have a short between collector and emittor,
below 1 ohm.
(The intention was to make an oscillator under 1 V. The reference
I got from this group were sine oscillators. The circuit that I
are going to try is a blocking oscillator that hopefully
convert 1 to 6/7 volts to replace a 9V battery.)
--
Don't praise the day before the evening. One swallow doesn't make spring.
You must not say "hey" before you have crossed the bridge. Don't sell the
hide of the bear until you shot it. Better one bird in the hand than ten in
the air. First gain is a cat purring. - the Wise from Antrim -

On Wed, 06 Mar 2024 12:52:14 +0100, albert@spenarnc.xs4all.nl wrote:

>I have old germanium transistor from computers that were dumped
>in the 70's.
>The Hfe varies between 50 to 150.
>The Vbe varies between 110 and 230.
>
>A couple of these have a short between collector and emittor,
>below 1 ohm.
>(The intention was to make an oscillator under 1 V. The reference
>I got from this group were sine oscillators. The circuit that I
>are going to try is a blocking oscillator that hopefully
>convert 1 to 6/7 volts to replace a 9V battery.)

Those shorts can be cleared by a high voltage pulse of short duration.
Charge up a 1uF cap to 500V and apply it across the relevant terminals
or between the case and the relevant terminal. You probably have tin
whiskers and zapping them in this way is the most effective way of
dealing with it.

On 3/6/24 22:58, Cursitor Doom wrote:
> On Wed, 06 Mar 2024 12:52:14 +0100, albert@spenarnc.xs4all.nl wrote:
>
>> I have old germanium transistor from computers that were dumped
>> in the 70's.
>> The Hfe varies between 50 to 150.
>> The Vbe varies between 110 and 230.
>>
>> A couple of these have a short between collector and emittor,
>> below 1 ohm.
>> (The intention was to make an oscillator under 1 V. The reference
>> I got from this group were sine oscillators. The circuit that I
>> are going to try is a blocking oscillator that hopefully
>> convert 1 to 6/7 volts to replace a 9V battery.)
>
> Those shorts can be cleared by a high voltage pulse of short duration.
> Charge up a 1uF cap to 500V and apply it across the relevant terminals
> or between the case and the relevant terminal. You probably have tin
> whiskers and zapping them in this way is the most effective way of
> dealing with it.

I'd be surprised if you could bring Ge transistors back to life
by such treatment. Sure, you'll blow the whiskers, but the
transistor goes with it.

Jeroen Belleman

On 2024-03-06 16:58, Cursitor Doom wrote:
> On Wed, 06 Mar 2024 12:52:14 +0100, albert@spenarnc.xs4all.nl wrote:
>
>> I have old germanium transistor from computers that were dumped
>> in the 70's.
>> The Hfe varies between 50 to 150.
>> The Vbe varies between 110 and 230.
>>
>> A couple of these have a short between collector and emittor,
>> below 1 ohm.
>> (The intention was to make an oscillator under 1 V. The reference
>> I got from this group were sine oscillators. The circuit that I
>> are going to try is a blocking oscillator that hopefully
>> convert 1 to 6/7 volts to replace a 9V battery.)
>
> Those shorts can be cleared by a high voltage pulse of short duration.
> Charge up a 1uF cap to 500V and apply it across the relevant terminals
> or between the case and the relevant terminal. You probably have tin
> whiskers and zapping them in this way is the most effective way of
> dealing with it.
>
A microfarad at 500V is 125 mJ. That'll blow a crater in the active device.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

On Wed, 6 Mar 2024 17:38:59 -0500, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

>On 2024-03-06 16:58, Cursitor Doom wrote:
>> On Wed, 06 Mar 2024 12:52:14 +0100, albert@spenarnc.xs4all.nl wrote:
>>
>>> I have old germanium transistor from computers that were dumped
>>> in the 70's.
>>> The Hfe varies between 50 to 150.
>>> The Vbe varies between 110 and 230.
>>>
>>> A couple of these have a short between collector and emittor,
>>> below 1 ohm.
>>> (The intention was to make an oscillator under 1 V. The reference
>>> I got from this group were sine oscillators. The circuit that I
>>> are going to try is a blocking oscillator that hopefully
>>> convert 1 to 6/7 volts to replace a 9V battery.)
>>
>> Those shorts can be cleared by a high voltage pulse of short duration.
>> Charge up a 1uF cap to 500V and apply it across the relevant terminals
>> or between the case and the relevant terminal. You probably have tin
>> whiskers and zapping them in this way is the most effective way of
>> dealing with it.
>>
>A microfarad at 500V is 125 mJ. That'll blow a crater in the active device.
>
>Cheers
>
>Phil Hobbs

Must be 0.1uF then. Or 0.01. There's bound to be someone on YT that's
done it.

On Wed, 06 Mar 2024 23:25:21 +0000, Cursitor Doom <cd@notformail.com>
wrote:

>On Wed, 6 Mar 2024 17:38:59 -0500, Phil Hobbs
><pcdhSpamMeSenseless@electrooptical.net> wrote:
>
>>On 2024-03-06 16:58, Cursitor Doom wrote:
>>> On Wed, 06 Mar 2024 12:52:14 +0100, albert@spenarnc.xs4all.nl wrote:
>>>
>>>> I have old germanium transistor from computers that were dumped
>>>> in the 70's.
>>>> The Hfe varies between 50 to 150.
>>>> The Vbe varies between 110 and 230.
>>>>
>>>> A couple of these have a short between collector and emittor,
>>>> below 1 ohm.
>>>> (The intention was to make an oscillator under 1 V. The reference
>>>> I got from this group were sine oscillators. The circuit that I
>>>> are going to try is a blocking oscillator that hopefully
>>>> convert 1 to 6/7 volts to replace a 9V battery.)
>>>
>>> Those shorts can be cleared by a high voltage pulse of short duration.
>>> Charge up a 1uF cap to 500V and apply it across the relevant terminals
>>> or between the case and the relevant terminal. You probably have tin
>>> whiskers and zapping them in this way is the most effective way of
>>> dealing with it.
>>>
>>A microfarad at 500V is 125 mJ. That'll blow a crater in the active device.
>>
>>Cheers
>>
>>Phil Hobbs
>
>Must be 0.1uF then. Or 0.01. There's bound to be someone on YT that's
>done it.

..... and wouldn't you know it - there is! This fellow uses 1000V,
though:

https://www.youtube.com/watch?v=xFwDXIYgBvQ