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Re: More RFI filter testing...
Terry,
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
<snip>
> 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
>