Re: MONSTER 100kW VTTC - Building now!

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: David Sharpe <sccr4us-at-erols-dot-com> 

Hi Boost

Tesla list wrote:

 > Original poster: Boost <boost-at-newmail.ru>
 >
 > Hello Tesla list
 >
 > .<<SNIPPO>>
 >
 > Hehe ! =))) Yep, sure, you're using two 5868 tubes with this specs:
 >
 > Fmax = 100 MHz
 > Va max = 4000 V
 > Pa max= 450 W
 > Vg max = -500 V
 > Pg max = 50 W
 > Ig max = 180 mA
 > Ik max = 700 mA
 >
 > And run them at 12 kW ! =)))))))
 > Don't Make Me Laugh!
 > __________

I ran two 752B's level shift push pull at 6.8kV (measured) and 2.5A
plate current peak (measured).  This is a peak input power of better
then 30kW ( 6.8*2*2.5 ) on two tubes that for normal ICAS service
would be good for ~1.6kWDC input.  Yes they got orange hot in
<5 seconds, but circuit failure was NOT the tubes, the tank capacitors
failed (casings split).  Was getting spark length of better then 18" up
to point of tank cap failure.

If staccato mode (duty cycle) control is used, and thermal time delay
of tube's plate structure is exploited, 10X continuous power ratings as
pulse power could be reliably handled for weeks.  This is same
process that allow megawatt pulse powers out of microwave tubes
with only 10kW CW ratings (also running a 0.1% duty cycle).

Regards
Dave Sharpe, TCBOR/HEAS
Chesterfield, VA. USA