🚀 go-pugleaf

In article <3sL6TB1w165w@inqmind.bison.mb.ca> bills@inqmind.bison.mb.ca (Bill Shymanski) writes:
>I have an old General Electric "Transistor Manual - 7th Edition", which
>looks like it was published in 1964 or so.   They have quite a few
>illustrations of the use of tunnel diodes.   Whatever happened to the
>tunnel (Esaki) diode ?

	Tunnel diodes can amplify, mix, and oscillate.  They operate
at sub-1V power supply levels, and at moderate (1 mA) currents.
Unfortunately, they are two-terminal devices (so they don't separate
the output signal from the input), and operate at such high frequencies
(2 GHz is typical) that UHF design rules should be used to ensure
acceptable results.

	Until relatively recently, every UHF TV tuner had a tunnel
diode local oscillator.   Silicon and GaAs FETs have taken over
from Ge (germanium, not General Electric) tunnel diodes.

	EEM lists several sources for tunnel diodes/back diodes.

American Microsemiconductor       (201) 377-9566
Diotec Electronics Corp.          (310) 767-1052
FEI Microwave                     (408) 732-0880
Germanium Power Devices           (508) 475-5982
Microphase                        (203) 866-8000
Relay Specialties                 (201) 337-1000
Solid State Devices               (714) 670-7734

	Of these, I think American Microsemiconductor is a
stockpiler of old parts, and Germanium Power Devices actually
manufacturers obsolete designs to order.

	John Whitmore