No antenna is at DC ground, if it is going to function as an antenna. As far
as static building up on the outer braid of coax, if you have your antenna
firmly mounted to the pipe metal to metal, then grounding the pipe at the
bottom is as close to "grounded" as you are going to get, and this will
ground any "ground" radials that are not active elements of the antenna, and
usually put the shield of the coax at ground, also. There is a more
important reason to ground the antenna pipe, and thereby the shield of the
coax. It keeps local electrical noise and interference from penetrating into
the coax , and raising the noise and interference in the reciever. The
signals you are trying to pick up on the scanner or radio are hundreds of
times weaker than a lot of local noise is, and the noise will tend to
over-ride the signal if this is not attended to. (the coax actually acts
like an antenna when the shield is not at ground).
This will tend to severely limit your hearing range on the radio ,
especially in locations that are rife with electrical noise , like in the
city, near a factory, etc, etc, etc
"Bob Parnass" wrote in message
news
On Wed, 20 Aug 2003 22:37:52 -0700, Jason Wagner wrote:
... On the other hand, I do like the idea of having static build up
on coax bled to ground. But does this product really work? Anyone
using
them?
If you want to avoid building up a static charge
on your antenna, use an antenna that is at "DC ground."
Discones and Ventennas are not at DC ground.
I have a few of the spark gap arrestors like those
you cited. It takes a high voltage to jump the air gap
inside them. Using a more sophisticated receiver protector
with a gas cartridge will discharge the voltage to ground
at a lower voltage level than an air gap and provide more protection.
I use an older Alpha Delta Transi Trap on my shortwave receiver.
It contains a replaceable gas plug. A newer version is
show at http://www.alphadeltacom.com/tt3g50.html
Disconnect your scanner from the antenna when not in use,
especially during lightning season.
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Bob Parnass, AJ9S GNU/Linux User http://parnass.com