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Re: AO-7 requirements




>
> >Leo operation may have to be done mobile using mag-mounted whips?
>
> Probably OK as long as they are 5/8 wave with some gain.  The little
stubby
> 18" whips don't really cut it.
>

Emil, I'm guessing you haven't ever tried this. The 5/8 wave stinks for
mobile satellite work due to it's pattern being focused on the horizon. It's
not enough gain on the horizon to work, and too big of a null overhead to
work well there (primarily as a receive antenna, you can get up to the bird
on just about anything). A single 1/4 wave whip on 2m works great on the
uplink, and the same antenna performs ok as a 3/4 wave on the 435 downlink,
with even a little gain overhead.

With a good receiver AO-27 is very workable above 15 degrees on a single 2m
1/4 wave for both uplink and downlink, although you might have to weather
some fades. Add a preamp and SO-50 is better and AO-27 is solid.

Ed, if you can whip up a 3 or 4 element UHF beam you can aim out the window,
you'll triple your fun! I hope you give it a shot. NX7U could probably give
you some advice on a primo mobile setup. I'd really advise to try to do
something full duplex on the FM birds, and if on a whip, with a preamp. If
you do have to work half duplex, pick a frequency uplink that seems to
correspond to a clear downlink, away from the center of the passband, and
call CQ, tune around for replies, and mention "half-duplex". I often try to
schedule gas stops, meals, and other stops around satellite passes so I can
use the arrow, or at least a 4 element UHF only arrow on receive. Enjoy, and
I hope to hear you from Florida.

73, Drew KO4MA

PS I still have a long way to go before I get up in numbers like Randy,
N7SFI, but last count was 72 grids activated on LEO sats. It's a blast.


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