[HomeBrew] Germanium Power Transistors

[Philip Atchley]

Hi Dick et al.

I "grew up" with electronics in the 50's and '60s,
cutting my teeth on tubes
in the early '50s and later "solid state".  It's
pretty simple really.
"Practical" germanium transistors were invented and
sold commercially before
silicon units were.  And not just in "power"
applications either.  So far as
I know, all the earliest "solid state" consumer 
products used germanium
devices, up through the mid '60s anyway (look at the
Zenith Transoceanic
1000 and 3000 series radios).  They were also
frequently used in power
applications like the output section of auto radios
(which still often used
12 Volt tubes for the other stages), inverters for
high Voltages etc.
However, those early devices WERE NOT as reliable as
first touted, being
very heat sensitive and easily damaged, and they also
turned "leaky" very
easily.  The first silicon devices were expensive
compared to the germanium
devices, but as soon as manufacturing techniques
allowed it they were very
quickly incorporated into the latest consumer products
which often "touted"
"Silicone transistors" in their ad copy.  And with
good reason as they were
far superior.

Now, as an aside.  How many on this list remember the
CK-722?  As a young
man I saved my pennies and bought one, only to blow it
out on my first
project, an Xtal radio with one CK-722 for a headset
amplifier 8^(

73 de Phil,  KO6BB
DX begins at the noise floor!

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Merced, Central California,    37.3N  120.48W  CM97sh


> This question is for the old timers.  That is, for
those post tube, pre
> integrated circuit era,
>
> Why did early power circuits use Germanium rather
than Silicon
> transistors?
>
> I recently came across a couple power boards that
are full of them.  Do
> they
> have any practical modern application?
>
> Dick W5TA