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Re: [TCML] Using tree as RF ground



Or....

You could forget the ground and just use the NST's as counterpoise. I did that one night with one of my coils. I had fired the coil at DC's place on his dedicated ground, and had the power ground link disconnected. The coil ran better than it ever ran before! (6" + 2x 12/60 NST) So sometimes that can work!

David Weiss




----- Original Message ----- From: "Jim Lux" <jimlux@xxxxxxxxxxxxx>
To: <tesla@xxxxxxxxxx>
Sent: Tuesday, September 25, 2012 2:31 PM
Subject: Re: [TCML] Using tree as RF ground


How big is your coil?

You're not putting up a vertical radio transmitting antenna, so a "earth" ground isn't all that important. What *is* important is that whatever is under the coil is connected to the bottom of the secondary. If your soil is highly conductive, then driving a stake into works ok, but there are much better ways to provide the RF return for your coil.

I'd look at getting some chicken wire to roll out and lay on the ground. The capacitive coupling from the mesh to the ground is pretty good, and, in any case, the mesh itself works as a better RF return than the soil. (unless you are in the proverbial hypersaline marshland.. for all we know, you're on the shores of bonny Salton Sea.. although a big tree would be unusual there)

The usual rule of thumb is that your counterpoise/ground mat should have a radius equal to the height of the top of your coil above it. So if your coil stands 4 feet high, you want about 4 foot radius. What I've done is stick the chicken wire to some cheap carpet (it makes it easier to roll up, and it provides a visual cue of "where NOT to stand"..)

I wouldn't hook up to the tree, unless you want to kill it.


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