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Re: MMC Question. (& gap size)

Original poster: Mddeming@xxxxxxx In a message dated 8/11/06 12:23:20 A.M. Eastern Daylight Time, tesla@xxxxxxxxxx writes:
Gary's comments regarding gap width is right on. You can get away
with near or at resonant values for the tank cap, but if one wrong
thing occurs like a failed gap or incorrect gap setting, it can be
the demise of the NST. Thus, the recommendation for LTR (as it won't
rise above the C limited voltage in both situations).

Well, vacation starting tomorrow. I'm going fishing!!!

Take care,

Hi Glen, Bart, All,

While on the subject of gap size, it is worth noting that the "effective size" of the gap can change over time, which is why adjustability is necessary, and another reason why LTR is a good idea: 1) A new, smooth, shiny copper gap set at 4mm has a different firing voltage than it does after oxidation from firing, even though the distance stays the same. In a multi-pipe gap, there are more surfaces involved, and the resulting difference can be even greater. 2) The gap that performed ideally when tested in a cool, dry shop in spring may show very different behavior outdoors on a hot, muggy day in summer. Blowing air at 10C (50F) across a gap has different quenching characteristics than air at 30C (86F). 3) Pits and scratches that develop over time on the facing surfaces of the electrodes will also affect the breakdown voltage of the gap.

Just a few more wrinkles not in the simulation programs (yet :^))

Matt D.