Original poster: Jim Lux <jimlux@xxxxxxxxxxxxx> At 08:27 PM 1/21/2007, you wrote:
Original poster: "resonance" <resonance@xxxxxxxxxxxx> I'm all ears. | Can you suggest a nice surplus tube that would handle 10 kVA at around 7.2 kV?
What's your price range for the tube? And, what kind of life do you want on it?
There's lots of high power tubes out there in things like induction furnaces, dielectric welders, radio stations, etc. Some of them get pulled and replaced on a regular maintenance schedule. There's someone on the list who, I think, works with these things and can probably suggest part numbers.
brand new, you're probably talking $1K to $2K (just casually running through a list of transmitter tubes at RF Parts, all those 3CX and 4CX tubes in the 10kW range are around there...)
The YU-191A, YD-1172 etc, are typical water cooled industrial triodes. 15kW or there abouts, 6kV anode voltage. I've seen them in used, but low hours, for around $1500 each.
I'm thinking of a small 7.2 kV, 10 kVA pole xmfr for power. Perhaps two big 10 kVA tubes running at 20 kVA into a 24 inch dia. coilform approx 72 inches long. 34 x 8.5 inch toroid. Perhaps with John's stattaco controller on the tubes.
In general, one big tube is cheaper than multiple small tubes, unless there's some peculiar economy of scale with the small tubes.
Don't forget that a 10-20 kW tube is going to need a pretty hefty filament supply. It's those 10 V at 100 Amp kinds of things that bite you.
One can, of course, buy a 100kW or a 500kW tube (as used by "Border Blaster" radio stations)