30MHz Spark Gap Testing - Is this real??

From:  Greg Leyh [SMTP:lod-at-pacbell-dot-net]
Sent:  Monday, April 06, 1998 4:13 AM
To:  Tesla List
Subject:  Re: 30MHz Spark Gap Testing - Is this real??

Terry wrote:

>         What are the implications if this is true?  If the primary circuit is doing
> all of its work at ~50MHz and at hundreds, if not thousands, of amps at that
> frequency, everything changes!  The conductors must be short, wide, copper
> strips.  The capacitors must be able to withstand even greater stresses than
> we ever imagined.  And the spark gaps... who knows?  This would imply that a
> much better spark gap or other switching system may give much better
> performance.  EMI becomes a major concern.

The sharp, high spikes in your waveforms look familiar; 
I have seen those on most of my scope msmts in and around
the primary vault, even when measuring points on the 60Hz
circuits.  I had been attributing this to switching noise
capacitively coupled from the rotary gap, since my scope
sees them even with the input leads shorted!  Wrapping the
scope (Fluke 123) in Al foil had helped somewhat.

What type of sensor are you using for the current msmt?
Wideband CT?  Shunt?

One possible verification of the signal fidelity is to
short the scope input _at the sensor_ and see if the 
signal persists.  You probably have already done this.

The main reason that I am skeptical is my present coil
seems to work at about 70% efficiency, with primary ckt
plumbing that is expecting most of the power to be at
38 kHz.  My primary would be hopelessly sloppy at 50MHz.