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Re: Microwave oven transformer - tube coil



Brad:
	There are so many big triodes around that it is hard to
answer your question.  Don't remember any big ones at Fair Radio.
As noted in an earlier posting, you can get new 833A's for about
$110 each, which are equivalent to about three 810's in power
handling capability.  Would work nicely at 3000 volts on the plate(s).
I have RCA transmitting tube manuals here, and any of the ARRL
handbooks up to the middle 70's have extensive tables of transmitting
tube characteristics.  My suggestion would be to look around for what
BIG (physically) tubes you can find which you have reason to believe
are good, and then check on the characteristics.
	One thing you will need, in addition to plate transformers,
is a suitable filament transformer.  Lot of those tubes use 10 volts
on the filaments, at 4.5 amps for the 810, 10 amps for the 833
a's.
	That 2600 volt 120 ma transformer only puts out 300 watts
at ratings, perhpas twice that overloaded for short periods.  If
you're into "big power" you'll need bigger plate transformers.  I
think you can get a 2500 volt 1 amp transformer for under $200 from
some of the advertisers in QST, but don't have an ad handy to check
on.  Guys still build big linear amplifiers, and there are suppliers
for the power supply components.
Ed Phillips