" Uncle Peter" wrote in message
news:HVKDc.1192$Rr2.241@lakeread03...

"Telamon" wrote in message
...
In article sBEDc.1168$Rr2.4@lakeread03,
" Uncle Peter" wrote:

How does the antenna differentiate between "noise" and a valid
signal?



SNIP


Fundamentally, you want the entire antenna system to reject common mode
noise since to a local antenna this is the mode in which, the local
noise will couple to the antenna. You will want to use an antenna that
is balanced (Hertzian) instead of unbalanced (Marconi). You might also
want to consider using an antenna type that responds more to the
magnetic field component of the radio wave instead of the electric.
These two suggestions encompass the fact that most of the local noise
energy reaching and coupling to the antenna is a common mode electric
field and since the far field broadcast signals you want to receive is
composed of both electric and magnetic the later will be enhanced at
the expense of the former.

The connection from radio to antenna is best shielded so you would use
coax. You could use a balance line but they are harder to acquire, use,
and still will not work as well as coax shielding against local noise.

The antenna would be located as far from the majority of local noise
sources as possible on the property. Distance reduces the coupling to
local noise sources.

--
Telamon
Ventura, California

You'd also have to decouple the coax shield from the antenna to
prevent signals or noise from carried on the outside of the shield
common-mode fashion from being coupled back into your
remotely located antenna.

Pete

Quite true.