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YOU HAVE BEEN WARNED!

First Time Users May Be asked To Do A 1 Time Setup.
"Jack Painter" wrote in message
news:r4_Rc.12079$Yf6.1279@lakeread03...

"Harry Conover" wrote
(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.

Harry, that winding of coax may be useful as an RF choke, but it is most
certainly not a lightning choke, and will act more like an air-wound
transformer than anything else. Not only is this not specified for any
lightning protection systems, it is specifically warned against in many.

Jack Painter
Virginia Beach VA

Hello All. First let me comment that the lightning mitigation techniques
used are better than many ham installations. That being said, I would
increase the conductor size between the tower legs and the ground rods.
When I saw these, I thought a "fast acting fuse." The amount of current
that the tower can handle cannot be safely terminated to ground with smaller
conductors.

Also, the screw terminals need to be checked periodically because they will
loosen themselve due to "cold flow." Why not repace them with crimp types
and then solder the crimp with a torch as a back up? I am asuming that this
device is covered by something to protect it from rain, etc?

John-WA4JM, Dade City, FL, home to some of the most ferocious lightning
activity in the western hemisphere.