For sat ops mobile, you will get the most success out of a 1/4 wave antenna on a good ground plane. It will give you a hemispherical emission pattern so that any direction in LOS is equally covered.
Gregg W5GGW Sent from my iPhone On Mar 13, 2011, at 4:28 PM, Ari Kosonen <ari.koso...@gmail.com> wrote: > 2011/3/13 Bob- W7LRD <w7...@comcast.net> > >> Not wanting to reinvent the wheel. Anyone using the FT-8800R mobile for >> satellites have any hints or sugestions, antennas etc. Email direct-thanks. >> > Hi, > > I am using FT-8900R (practically same as '8800 plus 6m and 10m) for working > satellites > from my car. My antenna is a Diamond NR770 dualband whip on the trunk lid of > my car. > While this setup is ok for usual mobile FM operation and APRS, it is > probably not optimal > for satellite ops. I have got better results on satellites with a dual band > mag whip on the roof the my car. Especially when the satellite is below ~60 > degrees it can be reached easily when > I can hear it (thanks to 50 watts on the uplink). When the sat is higher > than that the whip > is not so good. > > I have been working mainly on AO-51 and I have preprogrammed the > uplink/downlink > channel pairs with different doppler values so it is easy to follow the > sweet spot while > the sat first approaches (above the nominal frequency on downlink) and the > starts to fly > away (below the nominal freq). Programming goes easily with FTB8900 software > by > G4HFQ. As same channel pairs are available both on the left and right side > of the > radio, I usually transmit and listen on the left side of the radio and try > to listen my > own signal on downlink with the right side of the rig. With a single mobile > whip > the sensitivity of the downlink rx is usually not good enough during the > transmission. > This might be better with separate antennasa for uplink and downlink. > > I have planned to use my Arrow yagi with FT-8900R. As the Arrow's diplexer > is rated only > max 10 watts, I bought 100w rated separate diplexer to be used with '8900 > instead. > But I have not tried this combination yet. > > 73 de Ari OH3KAV / OH7KA > Tampere, Finland (grid: KP11) > _______________________________________________ > Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. > Not an AMSAT-NA member? Join now to support the amateur satellite program! > Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb _______________________________________________ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
