RadioBanter - View Single Post

January 31st 05, 02:51 AM

On 30 Jan 2005 17:14:42 -0800, wrote:
I would be using 8 inches as the diameter.

Hi Brad,

Well, you sure pegged it down for being Fat. However, this is not
particularly useful for just the FM Band. A fat antenna has useful
properties as being wide banded (which means you suffer nothing from
it being obese), and this would roughly equate to many times as wide
as the FM band. (Another)However, receive antennas are not
particularly demanding as long as they are high enough to see the
antenna that is transmitting. In that regard, and as a rule of thumb,
your antenna can see as far in miles as the square root of twice its
height in feet (hope that is not too alien from business math). If
you figure how high the other (transmitting) antenna is, you can add
those two mileages to compute your listening range.

Example: your Fat vertical antenna is 25 feet high (above the ground -
on the peak of your roof for instance) and the transmitter antenna is
on a hill 250 feet high. That computes to your antenna being able to
see about 7 miles and the transmitter being able to see 22 miles.
Hence you would be able to hear that program being broadcast from as
far as 29 miles out (barring obstructions like mountains in the way).

73's
Richard Clark, KB7QHC