Re: More RFI filter testing...


This makes a lot of sense, but haven't we already known the gap to 
be a huge source of high frequency noise?.  What if we focussed 
on designing filters specifically for the spark gap.  What about 
placing a small value capacitor directly across the spark gap with 
minimal wire length.  All it would take is a couple of those small 
MMC caps.

Maybe it would be necessary to have a capacitor from each side of 
the gap connected to RF ground.

Just an idea.

Matt Behrend


> My latest theory of the minute is....
> 	The pulse seems completely unrelated to the primary coil or other
> primary
> parts.  It appears that the pulse is caused by the actual arc at the
> spark
> gap.  The heavy wiring in that area, just serves as an antenna to
> transmit
> these 1GHz+ signals.  I suspect the gap stores energy as capacitance
> across
> the gap.  When conduction starts, the arc becomes a super high power
> high
> frequency transmitter for about 20nS.  Apparently, this initial arc can
> occur by itself without starting the primary circuit into conduction. 
> Ie.
> it can occur so fast the primary circuit will be unaffected by the fast
> local arc of the gap.  I must assume this is common to any spark gap
> system
> and not just Tesla coils.  This is good in that it may have more data
> about
> it somewhere.  Unfortunately, the power, speed, frequency, and connected
> metal parts will make this thing bazaarly difficult to stop or even
> shield
> against!
> 	So to make a long story short.  It looks like the initial gap
> capacitance's stored energy is going into the initial arc at the gap and
> feeding a tremendous amount of power into the arc for about 20nS.  That
> power is being converted to very powerful, high-frequency RF.  Since the
> arc size is about 1/4 inch, I assume the frequency extends well into the
> low number of GHz region...
> Cheers,
> 	Terry