[Amps] Utilization of old TV transformer

[Fuqua, Bill L]

I used TV power transformers in the past when I was much younger. I usually got around 1200volts DC at 300 or so ma. MAX with a voltage doubler. 
These were black and white TV transformers, perhaps your is from an early color TV which would have a higher rating. 

73
bill wa4lav

________________________________________
From: amps-bounces at contesting.com [amps-bounces at contesting.com] On Behalf Of Vic K2VCO [vic at rakefet.com]
Sent: Friday, March 19, 2010 3:32 PM
To: Amps reflector
Subject: [Amps] Utilization of old TV transformer

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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