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RE: Re: TH-D7 Deficiencies



I use two memory slots for each satellite.  One for the uplink, one for the
downlink.  When I want to work a bird, I copy the downlink memory slot into
the VFO (F -> VFO) so that I can change it to adjust for doppler.  I do not
change the uplink frequency like Bob said since the 2m uplink doesn't have
much of a doppler shift.  The 440 downlink is what you need to worry about.

73!

A.J. Farmer, AJ3U
http://www.aj3u.com


-----Original Message-----
From: owner-AMSAT-BB@AMSAT.Org [mailto:owner-AMSAT-BB@AMSAT.Org] On Behalf
Of Robert Bruninga
Sent: Monday, July 12, 2004 8:57 AM
To: w8aas@comcast.net
Cc: amsat-bb@AMSAT.Org
Subject: [amsat-bb] Re: TH-D7 Deficiencies


>>> Dave Taylor <w8aas@comcast.net> 7/10/04 7:45:41 PM >>>
> What I do is program the Doppler frequencies for uplink 
>and downlink separately.  It works, but has two drawbacks:
>
> - It uses 10 memories instead of 5.
> - It increases the workload during a pass, 
>   because you have to change two channels and switch 
>   bands twice for each doppler change.

But there is no reason to do that.  The 2m uplink only has a
peak doppler of 2500 Hz above say 5 deg elevation
and so there is no reason to tune the uplink for a handheld.
Below 5 deg elevation, most handheld operators are never
going to be able to see the bird and if they do, the bird
is 6 dB further away than it is at 25 deg, and the chance that 
their 5W could be heard anyway is quite small...

Dont bother with uplink tuning.  ALso, the Satelite RX is
broaderband than terrestrial receivers to allow for being
2.5 KHz off and still be in the passband...

de Wb4APR, Bob
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