Tim Williams wrote:
http://webpages.charter.net/dawill/t..._IndHeat1.html

Next, bigger power transformer and active device (aka transmitter tube).
Which reminds me, anyone have a 500-2000W tube on hand? Preferably not
forced-air or water cooled, but if so, then how about a blower for my pair
of 4CX250R's...
That's insane! Try some power FETs! They are ten times better than
tubes for this frequency range (50 - 100 KHz). You can get 600 V 30 A
transistors under $10. Want to compare the price with a 4CX250?

Running conservatively, you could get 4 KW out of such a transistor
(400 V, 10 A).

Jon