Rich said:
>no, I thought he said only one of the two tubes was bad.<
Major confusion here........I thought he needed to replace both of them. From
what Karl Arne said, it sounds a bit as if the 4X500 is 4-250/4-400 with a
different base and an external anode. That makes them sound attractive, except
for the fact that the shape of them is awkward - the anode cooler comes down
very close to the glass envelope. I've a vague memory that they were originally
meant for use in FM BC tx's, with a copper pipe tank circuit, down which the
air was blown, but memory may be playing tricks. However, such a tank circuit
would cool them effectively, although you'd need another fan on the bottom for
the filament seals. They came out in about 1946/7 time.
Still sounds like a major mechanical project on a TL922.
73
Peter G3RZP
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
|