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Re: Weather/coil performance

Original poster: Terrell Fritz <terrellfone@xxxxxxxxxxxxxxxxxxxxxxx>


I think humidity affects the "surroundings" and its resistance more than the streamers (they exist in a super hot world that "does not care") or the coil (aside from "wet" cardboard). The path from the top of the coil back around to the secondary base - has to go through air, walls, land, concrete.... That circuit path is very important to the secondary's "loop resistance" and thus the "Q". That "external" coil oscillation path (resistance) is also very susceptible to weather and such.

So in bad weather (whatever that is), don't worry about the coil, but the surroundings... But in the bigger picture, once the arcs start, "Q" drops way down and it probably does not matter greatly. Pure electrostatic capacitive effects take over then. Unless the coil is wet or the external path is virtually destroyed, "Q" effects from weather should be fairly minimal. You might loose 10 to 20 % of streamer distance on a really bad day...



At 06:35 PM 1/24/2007, you wrote:
Original poster: Paul Nicholson <paul@xxxxxxxxxxxxxxxxxxx>

Mike (megavolts61) wrote:

> I just saw graphs of Pauls on the effects of humidity,
> and it seems there is a significant drop in the Q of a
> coil.

Humidity didn't seem to have an effect, so long as there
was no condensation.  As soon as temperature falls below
the dew point, condensation forms on surfaces within the
field of the coil and the Q falls.

Results from the outdoor coil measurements where curious,
with, at times, some fairly rapid Q variations.  It would
be nice to investigate these things further, but the
results we got stopped me worrying too much about the
fact that measured Q is always a lot less than predicted,
and that measurements vary from day to day.

Paul Nicholson
Manchester, UK.