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

Gregg Wonderly greggwon at gmail.com
Sun Mar 13 15:40:33 PDT 2011


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.kosonen at gmail.com> wrote:

> 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)
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