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Old August 10th 04, 05:58 AM
Harry Conover
 
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(Private) wrote in message . com...
Hello,

I am looking for some advice on if the ground system featured below is
sufficent or should be upgraded. It consists of:

- 3 ground rods 10' each around the tower (bonded together)
- 2 ground plates (one outside, one in the shack, also bonded
together)
- lightning arrestors and/or feedthrough adapters
- tower to mast ground
- interior coax switch (not shown)

I provided some pictures below:

http://www.telusplanet.net/~homac/exteriorground01.JPG

http://www.telusplanet.net/~homac/exteriorground02.JPG

http://www.telusplanet.net/~homac/exteriorground02a.JPG

http://www.telusplanet.net/~homac/exteriorground03.JPG

http://www.telusplanet.net/~homac/exteriorground04.JPG

http://www.telusplanet.net/~homac/interiorground01.JPG

http://www.telusplanet.net/~homac/interiorground02.JPG

I am looking for constructive feedback.....

Thank-you....

Lloyd


Hi Lloyd,

Looks like a nice installation, although your grounding rods might be
placed farther apart, or augmented by some heavy gauge radial wires
(depending on your local ground condictivity).

What I did note missing was the mention of 'lightning chokes' wound in
the coax lines decending from the tower. These are basic to lightning
protection for broadcasting towers, but I've rarely seen them
implemented by hams.

The idea of a lightning choke is to add a small amount of inductance
to the coax so that if a direct lighting strike happens, the
instantaneous current flowing though the outer jacked of the coax into
your lightning arresters will at least have some amount of impedance
limiting the current magnitude, thus reducing the probability of
destruction of both the coax and the the arrester itself.

These chokes are more often than not implemented by winding a dozen or
more turns of coax around a form (say a 4" diameter phenolic tube)
prior to the arrester or spark gap.

Harry C.