Topband: Another Antenna Question
Mike(W5UC) & Kathy(K5MWH)
w5uc at suddenlink.net
Tue Aug 21 21:09:18 EDT 2007
While searching for information about RX antennas, I ran across
K7TKR's page and ultimately his receive antenna comparison.
http://www.k7tjr.com/rx1comparison.htm
Having to make the most of a small lot, only two antennas appear to
be a choice; the K9AY array, and two verticals spaced fairly
closely.(1/8 WL or less) Per Lee's chart, the pair of verticals has
a RDF of 9.03, and the K9AY antenna has a RDF of 7.2, a difference
of 1.83. This brings my first question which is: How much difference
in performance will that variation in RDF make?
The second question comes from modeling a two vertical array in
EZ-Nec. By experimenting with EZ-Nec I have determined that I can
vary the F/B of a two vertical array by varying the length of the
delay line, and ange of radiation of the antenna. Additionally, if I
understand the calculation of RDF, RDF can be manipulated by varying
the F/B of the antenna. Thus the second question; How do I
determine what reasonable and practical numbers are for calculating RDF?
This brings the 3rd and final question. Are my methods, as described
above, flawed?
73,
Mike, W5UC
"age & treachery will overcome youth & skill"
http://www.suddenlink.net/pages/w5uc/
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