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Re: RF Ground, House Ground, Ground....
Original poster: "Allanh by way of Terry Fritz <twftesla-at-qwest-dot-net>" <allanh-at-starband-dot-net>
If you look up proper grounding in an engineering book,
I used the Broadcast Engineers Hanbook, with a chart showing the ground
conductiviity value across the country. The standard measurement technique
is a pair of
copper rods, 1/2 " dia. and 4 feet long driven into the ground 3 feet,
separated by 3 feet. I tried this and came up with a reading close to the
book value for north Ga., that being 1000 ohms. You might like to try this
at your location.
----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
Sent: Wednesday, June 05, 2002 6:05 PM
Subject: Re: RF Ground, House Ground, Ground....
> Original poster: "Justin Hays by way of Terry Fritz <twftesla-at-qwest-dot-net>"
> Hi All.
> > I dont think that 6-8" is nearly enough. Im cutting it short with
> > 2 feet with my RF gnd, and i have 4 rods in the ground. My
> > secondary never arcs to my primary at the base, so that is a good
> > sign. I always thought that people put them in about 5feet or so
> > into the ground. I hope that you are not running a large coil off
> > of this small RF ground.
> > Steve Ward.
> It doesn't matter. You will notice very little difference in
> performance with a single 3 foot ground rod vs. several 5 foot ones
> tied together with 3" bar stock.
> The exception is if you live in very dry or sandy areas, where
> resistance of the Earth is abnormally high. In that case, I can see
> putting lots of effort into the grounding system.
> My best bud and I ran our 12" coil at 18kVA many times with a single
> 4 foot ground rod. Then we clipped the ground lead to the fence that
> ran around our entire backyard to see what would happen. The fence
> was your typical cyclone variety, metal poles every 8 feet. Average
> length of the entire structure is about 300 feet long, and the ground
> is always wet here in extreme South Texas. So we're talking dang near
> a perfect ground.
> There was no noticeable difference in coil performance before and
> after the ground was clipped onto the fence. Same arcs, 10-11 feet or
> I've noticed the same thing with every Tesla Coil that I have
> designed and made, over 25 of them. Ground matters very little when
> it comes to sparklength.
> > My secondary never arcs to my primary at the base, so that is a
> > good sign.
> That has everything to do with electrostatic field shape, input
> power, coil performance, and other things of more importance than
> If you're trying to kill radiated interference, grounding is a big
> issue. But if your sparks are shorter (or longer!) than you expected,
> I would tend to ignore the RF ground as long as it is reasonable. I
> mean, a wire laying on the ground probably will not work.
> Take care,
> Justin Hays
> Email: justin-at-hvguy-dot-com
> Website: www.hvguy-dot-com