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Re: 304tl experiments...
Original poster: FutureT@xxxxxxx
In a message dated 3/23/07 10:39:58 PM Eastern Standard Time,
tesla@xxxxxxxxxx writes:
This reminds me. I had an idea. What about using an
interrupter with a suitable SCR, with some good
isolation between the SCR and the interruptor. If you
ran this on a CW system, would you have the freedom to
try out different bps and pulse width similar to an
SSTC? You wouldn't have to worry about zero crossing
since the filter cap (if it was plenty large enough)
could deliver the energy you needed for many duty
cycles?
-Brett
Brett,
By interrupter do you mean the staccato control timing
signal controlling the SCR? I might not be understanding
exactly what you're suggesting.
An SCR requires the removal of the positive voltage (for
a sufficient time duration) before the SCR can turn off.
A different device other than an SCR would need to be
used unless an SCR is available which can turn off
within one RF cycle. When I did my duty cycle
control experiments (which required shutting off the
oscillation during positive plate voltage times), I used
grid controlled staccato and supplied a sufficiently
negative voltage to the grid to cut off oscillation despite
the oscillator "wanting" to keep running. This strong
negative grid voltage could possibly destroy the tube I think.
An interupter such as a mechanical rotary switch could
be put in series with the SCR anode, but then the SCR wouldn't
be needed.
A hydrogen thyratron should work in place of an SCR, but
there may be some suitable solid state devices available in
today's world, which can handle the voltage and current,
and turn off fast enough.
John
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