Re: Tube coil makes sparks

>   So there is my report. Much work to do. The cancerous desire for more
> power was felt very early on. I know that 3 tubes will produce much more
> than 20" sparks, but a gentlemen at Elex electronic supplier mentioned
> the availability of 10,000 watt industrial oscillator tubes. ...

You might start looking around for a decommissioned plastic or wood welder.
The older ones used high power (many kW) RF to melt the plastic (or heat
the wood and adhesive). Generally, I think they ran at higher frequencies
(judging from the component sizes on one I saw) (probably 13 MHz ISM band),
however, you could probably use the tube at lower frequencies. The one I
saw (which was purchased as junk in an auction lot of lots of other things
like 100,000 trampoline springs) had a single fairly large tube in the
middle of a cabinet with a sort of weird rigid coaxial transmission line
(copper tube in the middle of a long thin aluminum sheet metal box )to
couple it to the workstation. The tube was probably 20 cm in diameter and
50-60 cm long. The power supply had a 50 amp 3 phase 240V  label on it. You
do the math.... A bunch o power. It eventually wound up in the dumpster, I

However, those big industrial tubes are big and tough and should make a
fine coil...