Re: design ideas needed


Tim Wescott wrote:
> bill.sloman@xxxxxxxx wrote:
> -snip-
>
> > The whole circuit will tend to ring at this resonant frequency as soon
> > as the gap has broken down.
> >
> In fact, in the very early days of radio there were no vacuum tubes and
> the high-tech transmitters used the negative resistance of the arc to
> create a sustained oscillation. AFAIK this was _not_ just a spark-gap
> transmitter exciting a resonant filter; it was a true oscillation that
> depended on the arc as an active element.

Arcs do tend to have a slightly negative incremental resistance - and
that could have been enough to offset the resistive losses in the coil.
There might have been some mildly odd effects as the arc current went
through zero, but your conducting channel is running at about 6000K and
won't cool off much while the current is changing polarity.

-------------
Bill Sloman, Nijmegen

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