Re: Valves

There are a number of tubes that are available from the medical MRI market 
that should do to replace the spark gap.  The YC-156  (3CPX5000A7) comes to 
mind.  This tube has a max plate voltage of 6500 volts can handle  4 amps 
continuous or up to 64 amps in a pulse mode.  The tube requires no socket, 
is a triode and needs about -100 vdc to cut it off.   Norm

At 07:24 AM 9/26/99 -0600, you wrote:
>Original Poster: "Bill the arcstarter" <arcstarter-at-hotmail-dot-com>
>Mark Finnis <mefinnis-at-medicine.adelaide.edu.au> wrote:
> >>Original Poster: "Jim Lux" <jimlux-at-jpl.nasa.gov>
> >>
> >>Except that a thyratron really is a "latching" kind of tube (think of it
> >>as
> >>a SCR) as opposed to an amplifier (like a triode or tetrode).  I believe
> >>that Richard Hull did some stuff using thyratrons as a replacement for the
> >>spark gap though...
> >
> >My limited knowledge tells me this means it "stays switched-on" once fired,
> >until the forward current source disappears that is.
> >
> >How would this work with our RF cap oscillations ?
>These tubes have a deionization time.  If the current stays zero for roughly
>the deionization time, then the tube will switch to a nonconducting state.
>I would think that the period between zero crossings for a tesla coil LC
>oscillation would be faster than the deion time, and the tube would
>therefore stay on for the entire oscillation envelope.
>But I could be wrong.  Depends on the tube.  I know the H filled ones are
>faster than mercury vapor tubes, but more than that I don't know.
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