[amsat-bb] Re: FT-8800R new toy

[Ari Kosonen]

2011/3/13 Bob- W7LRD <w7lrd at 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)