----- Original Message -----
From: "Tom W8JI" <w8ji@w8ji.com>
To: "topband" <topband@contesting.com>
Sent: Tuesday, August 19, 2014 10:08 PM
Subject: Re: Topband: Skimmer calibration
BC antennas have the elaborate radial system in order to get that
groundwave while the typical on ground ham vertical loses a lot of the
0-10 degree (or more) radiation. Go to the beach to get it back.....or go
with elevated radials.
That just isn't factual at all. Radials under the vertical antenna have
virtually no effect on wave angle unless they are sparse and grossly
unbalanced, allowing them to radiate like a low horizontal antenna.
Radials change the efficiency, not the pattern, unless the radials radiate
like a dipole.
73 Tom
Note that I didnt say anything about changing the pattern, just the energy
included at low angles and where the efficiency starts at the base and at
the often poorly understood Fresnel Zone if you really want more power in
those low angles and not heating worms or sand granules.
Carl
KM1H
_________________
Topband Reflector Archives - http://www.contesting.com/_topband
|