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Old January 13th 06, 06:31 PM posted to rec.radio.amateur.antenna
kl7r
 
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Default 2nd Floor grounding

There are grounds and there are are grounds.

Lightning ground
House wiring safety ground
Antenna counterpoise (ground)
Ham shack common RF bus ground

If you live in an apartment building or if you use soundcard modes you
will soon find out that using the building's electrical safety ground
as your antenna's counterpoise is a bad thing.

Dont try to use an endfed wire antenna in an apartment.
You will be unhappy if you try to use your TV and soundcard speakers as
your antenna counterpoise.

I came to the conclusion that balanced antennas are the answer.

Put up a dipole or, better yet, a loop antenna.
Balanced antennas have their "ground" as part of the antenna itself.

I personally have never used a balun at the antenna but have used
choke baluns near the rig and have used 4:1 baluns at the tuner.
I often use an antenna tuner and ladder line so am not so sure that a
balun at the antenna is a good thing under those conditions.

I have experimented with "artificial grounds"
They are just a series L-C circuit that you insert between your
station common RF bus and your counterpoise system.
Series LC circuits act like a short when tuned so the idea is that
when your station counterpoise system is tuned with the series
LC circuit, your station bussbar ground will have the highest current
path to counterpoise system ground

You can make an RF current meter with a diode a toroid
a little magnet wire and a volt meter.

MFJ artificial grounds or tuned counterpoise tuners have you
tune for max current through the series LC circuit.

I have found that max current through the series LC circuit is not
always the best setting for getting minimum rf in the shack. I
use my soundcard speaker amp as my canary - tune the
counterpoise for least audio out of the speakers.

KL7R

PS, I live in a rain forest. I dont know a thing about lightning
grounds.