I have a different anomalous ground condition. I have recently moved from
NJ to the Atlanta area and am in the process of setting up a shack. I am on
the air with wire antennas, but the shack is still in chaos. I am in a
ground level basement. The house power panel is about 3 feet to the left of
the station, and the house ground rod is just outside the house behind the
power panel. It has the telephone ground etc attached to it. I can't tell
how long the rod is as a concrete apron was poured around if as part of a
pool installation. The station ground goes out through a conduit and
attaches to the power ground. I don't have much faith in the performance of
the rod as an RF ground, but at least I am in compliance with the electrical
code.
The story is too long to tell, but involves worries about coupling into RX
antenna ports when using a Beverage or other antenna. No sign of problem
there, but by chance I touched the tip connector of a cable connected to the
antenna jack of a backup second transceiver/amp combination and was
surprised to hear some nice sweepstakes signals. They were about 5 s-units
down from the reading on the main setup. In investigating I find that I can
short the transceiver coax and the signals go away, but if I touch the coax
tip to even the ground post on the transceiver I can hear signals. And if I
touch it to the single point ground I am using--which is about four feet
from the power ground--I get even better signals. Just to make sure this was
not a ground conductor inductance issue, I did the experiment while
listening to a broadcast station. The ground makes a nice broadcast band
antenna, and the signals are quite a bit stronger than those I get by
touching the tip of the coax myself.
I have made resistance checks between the power panel box and the station
ground and see 0 ohms, to I don't think this is an issue of the box not
being connected to the ground rod.
I disconnected all the other leads coming to the transceiver to make sure
the chassis wasn't picking up RF from something plugged into it--no change.
It sounds to me like the power neutral must be bringing in this noise, but
maybe I am off base.
Just for the heck of it I drove in two rods about 1 foot away from the power
rod in a small open area not covered by the cement apron and tied them to
the station ground with no effect.
I'm not certain it would have any effect, but I thought about connecting a
radial field to try to get a better RF ground than provide by rods, but I am
not sure that would help if pickup is pouring off the power neutral, and
unless I can convince the wife to lay radials on the concrete and across a
pool I can't do this anyway.
Can anyone give me ideas as to what might be going on and how/if to try to
cure it?
Bob W2WG
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|