I have an old TV power transformer that I am thinking about using as a plate
transformer
for a medium-power amplifier (2 x 813).
It weighs between 15 and 20 pounds and the stack is 3.25" x 4.5" x 4".
It has a hv winding for 680v at 290 ma and four filament windings which I
wouldn't use.
The total VA output of all the windings is 313. But remember this rating
assumes
continuous duty.
The amplifier will be used on CW, so the duty cycle will be about 50%. I would
need to use
either a doubler or tripler circuit to get a reasonable voltage for the 813's.
My guess is that a doubler would give me about 1900v which would probably drop
to about
1700 under load. If the 813's were loaded to 400 ma that would be 680 watts
input.
With a tripler I could get 2800v which would probably drop to 2400. At 360 ma
plate
current that gives me 864 watts input.
My feeling is that the transformer would be OK with the first configuration,
but the
second would be too much for it.
Do you agree? Or should I forget about using this transformer and look for a
better fit?
The fact that it's free is a big incentive.
--
Vic, K2VCO
Fresno CA
http://www.qsl.net/k2vco/
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