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Re: Dramatic Performance Drop After 5 Seconds?
> Original Poster: "William Parn" <parn-at-fgm-dot-com>
>
>
> Greets All,
>
> My coil when at 3/4 to full power will run really nice for
> 1-5 seconds and all the sudden the 12" - 14" streamers turn
> into little 1/2" streamers, and the sound changes to a real
> tinny sound. If I wait a few minutes and turn back on, it
> repeats.
>
> I cleaned and checked to spark gap really well and the same
> thing still happens.
"Fizzle out" is a common problem with medium power coils, particularly ones
where the spark gap design is not adequate for the power being used.
I just responded to a post from Ron West asking pretty much the same thing.
I've seen fizzle-out happen under two conditions:
1. Static gap not being ventilated actively enough, so that ions
and metal vapour are lingering and preventing quenching. This
can happen very, very quickly, and I'd bet it's the cause. In
severe cases, the gap arc will actually start to look more like a
jacob's ladder flame than the correct blue-white welding-spark
appearance. This is a good clue that you're reaching power levels
where a rotary gap would work best.
2. Caps warm up and change the tank frequency, detuning the coil. If
your MMC gets warm in a few seconds, it's not designed
properly. I suspect this is not the case, but it's worth
feeling the temperature after a run to rule this out.
Either of these can happen very quickly, or very slowly, depending on the
degree of severity of the problem.
-Adam
adamsmith-at-mediaone-dot-net