My thanks to Earl K6SE for publicising the Pennant antenna, which is
reminiscent of a short terminated vee or half-rhombic. It is actually a
very logical progression, come to think of it! I was about to try an EWE,
but this antenna looks even better. Before proceeding however, there are a
couple of points I want to clarify.
Firstly, wouldn't the omnidirectional response of the vertical section tend
to fill in the rear null, or is there a phasing effect at work here?
Secondly, the fact that antenna dimensions had to be adjusted to eliminate
reactance implies that the pennant is not a pure travelling wave antenna.
Could the reactance have been due to the vertical section, which is inductive?
Did you consider turning the pennant into a diamond (i.e. like a vertical
rhombic), where the open ends are brought back together? This would
eliminate the vertical section, and with it the above (admittedly
hypothetical) problems. It should also improve the efficiency.
Sorry for the questions. I would perform the modelling myself, but have
very little time at present, and suspect that Earl or someone else may
already have the answers.
73,
Peter VK3APN
pnesbit@melbpc.org.au
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