[amsat-bb] Re: AO-07 Downlink Antenna
w9ae at charter.net
Sat Feb 3 12:49:23 PST 2007
Im having really poor luck with my inverted V antenna.. its not very
high up but only on a very high pass will it hear the beacon on 29.502.
What is every one else using?
During field day I've had success on AO-7 Mode A using a 10m inverted
Vee with the apex 12 feet high. That's 3/8 wavelength high which is the
best height for satellite reception. More gain near the horizon where
the path is longest, but no nulls at high elevation. The inverted Vee
seems to be fairly omnidirectional in the azimuth plane, compared to a
flat dipole which has nulls at the ends.
A horizontal full wave loop will give better reception at low elevations
(where you need the most gain), but worse reception at high elevations.
I've been meaning to put the Vee up at home. I even have an ARR 10m
preamp to put at the feedpoint, and a PTT-activated coaxial relay to
prevent me from accidentally transmitting into the preamp. Just have to
get around to it...
Wayne Estes W9AE
Oakland, Oregon, USA, CN83ik
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