Tubes with 12 or 28 v Plates?

[Paul Litwinovich]

> Can anyone tell me what tubes are useful in a TX
> application that are also efficient with 12 or 28vdc
> plates?
>
> Cost and availability?
>
> Simple AM/CW HF TX designs?
>
> - Thanks! & 73, DavidC  K1YP

Dave,
12BE6, 12BA6, AND 12AT6  Were the common tube compliment of the 1960s hybrid
car radios. I mention hybrid because the audio output stages were germanium
and later silicon transistors. They are OK for receivers but you won't get
more than a fraction of a watt out of them. Quite a few tubes will work with
12 volts on the plate for oscillator or receiver functions. I've
successfully used tubes as old and simple as type 12 AKA UCX112  (from
1920s) to demonstrate oscillation up to about 3 MHz

Paul Litwinovich
N1MUC
C.E. WSHU/WSUF/WMMM