starman wrote in message ...
Alan J Giddings wrote:
Hello,
Can anyone offer me a little advice on the grouding of my SW
receivers? I have a couple old Soviet SW radios, a Sony SW77, Sangean
ATS909 and a new Degen 1102. I want to make a ground that will work
well with any of these receivers. What material is best? Copper,
Iron, Steel etc? A rod or plate? What is the best type of cable to
use as a lead-in to the receiver? Is there an ideal length?
Depending on where the radio will be the lenght could be anything from
5ft to 30ft. Any advice is much appreciated.
Thanks,
Alan
Myself, I hardly think it's worth the trouble with most portables. If
you see an improvement, it will probably be in the LW/MW spectrum. On
the higher HF bands, there is little help in adding a ground unless
you have some kind of wierd antenna issue, or little antenna at all. I
bet you will notice little difference in most cases, unless your
antenna is small and lame. A ground is not required for quiet radio
reception. In fact, ground is a noise source. I use no outside
grounding at all to my shack. I have outside grounds, but they are a
lightning return. Most of my antennas are complete, and require no rf
ground to properly function. The only one I have that does, is a 160m
inverted L. It requires an rf ground at the base of the antenna to
provide the "lower half". All my others are dipoles, yagi's, etc, that
are complete antennas in themselves and require no extra rf ground.
This is the preferred route to go if possible.
The second kind of ground is called an RF ground. This helps to reduce
noise on the antenna system from sources in your house like televisions,
computers and other applicances. This is harder to do well. I suggest
you look at the following website for more information on building a low
noise antenna system. Good luck.
Maybe semi-misleading...It's the improved decoupling of the feedline
from the antenna that reduces the noise level. "noise ingress" Not
the grounding itself, although the grounding helps in the decoupling
of the line. Ground is a noise source. An RF ground should be under an
antenna to provide it's "lower half" if it requires it. IE: 1/4 wave
vertical, etc.. So if you use a balanced antenna that requires no
"lower half", IE: 1/2 wave dipole, 1 wave loop, etc, you need no rf
ground at all. MK
http://www.anarc.org/naswa/badx/ante...e_antenna.html