[amsat-bb] GTO-Track

Brad, K1GTo brad at k1gto.com
Thu Oct 19 14:07:05 PDT 2006

I've started designing a simple Java application that will run on a Nextel
phone (should actually run on any java phone) that will automate the
frequency shifting necessary to have a QSO on a Linear/transponder

I know that I'm nowhere near as experienced as most of the guys on here, so
I wanted to run a few things by you, so you can tell me if it is a good
idea, or how it might be improved. 

In the first Phase, the application will use an internet connection to
connect to a running Predict server (that's the Linux satellite tracker
program). The application that runs on the phone will interface to predict
to obtain Doppler shift information about the satellite currently selected,
based on the QTH coordinates programmed into Predict. 

As the satellite approaches and then departs, the application on the phone
will, via an ICOM CI-V interface, shift the frequency such that the operator
doesn't have to touch the dial (once its set where he wants it). 

In order to be most useful, I'm thinking that the operator should scan
around on the RX frequency and find a spot, whether it's an open frequency
for calling CQ, or a frequency where someone else is calling CQ and they
want to respond. 

By selecting that RX frequency, the application will make calculations and
properly adjust the receiver such that the correct input frequency is used.
In effect, the application will pair up the correct TX and RX frequencies so
that you transmit on the input frequency that corresponds to the output
frequency, with Doppler, and everything else factored in. 

That was sort of question 1 there, is that how it ought to work? 

Then the next part of the question would be: Should the application leave
the RX frequency constant, not adjusting it whatsoever for any Doppler, etc,
and only adjust the input frequency? 

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