where to find germanium TO-220 PNP NPN

[Jay1028]

Have a KLH21 with bad outputs. They are TO-220 germanium types.
Can't find gemaniums anywhere. Any ideas what to do?
Thanks

 

[Doug]

whats the part numbers?

 

[Watson A.Name - \Watt Sun, the Dark Remover\]

Have a KLH21 with bad outputs. They are TO-220 germanium types.
Can't find gemaniums anywhere. Any ideas what to do?
Thanks

Germanium transistors cannot be passivated like silicon, so they have to
be packaged in a hermetically sealed package. If a germanium device was
mounted in a TO-220 epoxy package, the plastic would contaminate the
chip and it would soon quit working.

 

[Jay1028]

The parts are house numbered. I can't cross them to anything.

 

[Watson A.Name - \Watt Sun, the Dark Remover\]

The parts are house numbered. I can't cross them to anything.

Are they so shorted that you can't measure any of their junctions? You
should be able to measure one and you will find that the junction will
have about 0.6V across it, hence it's a silicon device.

Measure the supply voltage and get some high power silicon transistors
in the TO-220 package that have a higher voltage rating than the supply
voltage. Or maybe change to the TO-3P plastic package, which is rated
for more than a hundred watts with a decent heat sink.

 

[mike]

The parts are house numbered. I can't cross them to anything.

Paraphrasing the thread so far...
Help me find germanium transistors.
What are the part numbers?
I'm not tellin'...

Don't suppose it's ever occurred to you that some of us might have
salvaged germanium transistors from old gear and stashed them away.

I probably can't help cause the ones I saved look like a TO-220
with a tab out each side instead of the top.
mike




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[Pi]

Germanium transistors cannot be passivated like silicon, so they have to
be packaged in a hermetically sealed package. If a germanium device was
mounted in a TO-220 epoxy package, the plastic would contaminate the
chip and it would soon quit working.

So how can Germanium be used in plastic TO housings? Must they always
be in glass? I have ann application requiring germanium in TO92, a
special component that will be build as special. I am wondering how
this could be done?

Regards,

Pieter Hoeben

 

[Watson A.Name - \Watt Sun, the Dark Remover\]

So how can Germanium be used in plastic TO housings? Must they always
be in glass? I have ann application requiring germanium in TO92, a
special component that will be build as special. I am wondering how
this could be done?

Regards,
Pieter Hoeben

I have never seen or read of any germanium device being packaged in a
package that had the chip in contact with the plastic or silicone
package, as is usually done with silicon devices.

Some manufacturers, Raytheon may have been one, made very small
germanium transistors for hearing aids. I have read that Raytheon later
made the CK722 and its sisters in a smaller package that was then
repackaged in the normal CK722 package so that it conformed to their
product line. Check out the X-ray picture on this web page
http://www.semiconductormuseum.com/CK722/index.htm
And this web page http://www.ck722museum.com/page6.html
So you may be able to find germanium transistors that will fit in the
space of a TO-92 package.

See these URLs for more info.

 

[legg]

Have a KLH21 with bad outputs. They are TO-220 germanium types.
Can't find gemaniums anywhere. Any ideas what to do?
Thanks

There were very few TO220 parts in existence when the KLH21 desk-top
FM radio was made, but germanium transistors were common. Power stages
often used TO-1 or X-04 germaniums for a couple of watts output.

Please copy the part number of the suspect device or indicate the
part's location / ID in the schematic.

A bad output is a symptom that can be caused by faults anywhere or
everywhere in this unit. Troubleshooting a radio will generally
involve starting at the INPUT to the device.

RL

 

[legg]

There were very few TO220 parts in existence when the KLH21 desk-top
FM radio was made, but germanium transistors were common. Power stages
often used TO-1 or X-04 germaniums for a couple of watts output.

Please copy the part number of the suspect device or indicate the
part's location / ID in the schematic.

A bad output is a symptom that can be caused by faults anywhere or
everywhere in this unit. Troubleshooting a radio will generally
involve starting at the INPUT to the device.

My mistake. The preceding comments are more applicable to earlier
models.

The KLH21 was made in '78. TO220 plastic silicon transistors were
commodities by then, and germanium parts of any shape or size were
unlikely to see power applications in a new product (still common in
rf and in portable products then).

RL

 

[Michael A. Terrell]

There were very few TO220 parts in existence when the KLH21 desk-top
FM radio was made, but germanium transistors were common. Power stages
often used TO-1 or X-04 germaniums for a couple of watts output.

Please copy the part number of the suspect device or indicate the
part's location / ID in the schematic.

A bad output is a symptom that can be caused by faults anywhere or
everywhere in this unit. Troubleshooting a radio will generally
involve starting at the INPUT to the device.

RL

Sams photofact 1357-SED has the schematic and was published in 1973. i
don't have a copy in my collection.

 

[Jorgen Lund-Nielsen]

Have a KLH21 with bad outputs. They are TO-220 germanium types.
Can't find gemaniums anywhere. Any ideas what to do?
Thanks

Maybe there a confusion between "german" and "germanium"???

I have never seen a TO-220 Germanium, but a lot of
Silicium TO-220 with the "European-German" notation BDxxx or so.
And i know some K&H-Active Speakers from the mid/end of
the sixties which already uses silicium transistors
(RCA-Series 40406-40411 i think to remember).
I don't think that K&H uses germanium again in newer designs.
I would expect that the BD243B-BD244B types of transistors
would do the job as they are state of the art in the mid seventies.
Google for BD243 and you find the farichild data sheet.

Jorgen

 

[mc]

Maybe there a confusion between "german" and "germanium"???

I have never seen a TO-220 Germanium, but a lot of
Silicium TO-220 with the "European-German" notation BDxxx or so.
And i know some K&H-Active Speakers from the mid/end of
the sixties which already uses silicium transistors
(RCA-Series 40406-40411 i think to remember).
I don't think that K&H uses germanium again in newer designs.
I would expect that the BD243B-BD244B types of transistors
would do the job as they are state of the art in the mid seventies. Google
for BD243 and you find the farichild data sheet.

You may be right. "Silicium" is called "silicon" over here...

 

[Jorgen Lund-Nielsen]

You may be right. "Silicium" is called "silicon" over here...

And "Silicon" here means the opaque glue for the bathroom or to
glue glass to build an aquarium or so...

Funny translation errors ;-)

Jorgen

 

[mc]

And "Silicon" here means the opaque glue for the bathroom or to
glue glass to build an aquarium or so...

Ah! That is what we call "silicone".

"Silicon" = Si, the element

"Silicone" = large molecule Si compounds

At least in American English, today, at the current phase of the moon

 

[Watson A.Name - \Watt Sun, the Dark Remover\]

And "Silicon" here means the opaque glue for the bathroom or to
glue glass to build an aquarium or so...

Funny translation errors ;-)

Jorgen

We call it silicone glue or silicone seal, also RTV which was GE's
abbreviated term, Real Time Vulcanizing.

 

[Hal Murray]

We call it silicone glue or silicone seal, also RTV which was GE's
abbreviated term, Real Time Vulcanizing.

How about Room Temperature Vulcanizing

 

[Watson A.Name - \Watt Sun, the Dark Remover\]

How about Room Temperature Vulcanizing

Oops. Yeah, that sounds more like it.

 

[Fred Abse]

How about Room Temperature Vulcanizing

Correct. How about Dow Corning, rather than GE, too?

 

[Jim Adney]

Correct. How about Dow Corning, rather than GE, too?

I think it was actually GE. Both are now heavily into silicone
products, but D-C is probably more commonly associated with them.

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