[time-nuts] And you thought you were old

J. Forster jfor at quik.com
Tue Apr 20 09:56:45 EDT 2010


Do you know the story of the CK722?

In the 1950s, Raytheon was making tiny transistors for hearing aids to
replace the pre-WW II subminiature tubes.

Aside: Those tubes, developed by Norm Krim, were ruggedized and used in
the WW II Proximity Fuzes, one of THE big inventions of WW II.

Anyway, Raytheon was making piles of these tiny transistors, but many were
not making hearing aid specs. Norm got the idea of packaging them to sell
to hams to learn about transistors. If you open up one of the blue ones,
there is another tiny case inside which is the real transistor.

BTW, Norm is still alive and well in his 90s.

-John

===============



> Anyone remember the CK722 transistor? As I remember they were about $7.50,
> a
> considerable sum.
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
>






More information about the time-nuts mailing list