[amsat-bb] Re: Russian speaking QRM on AO-51 Rev: 13642
glasbrenner at mindspring.com
Sat Feb 3 10:54:46 PST 2007
> Yeah, but PL on stops non-hams from expending battery power.
> wb4gcs at amsat.org
Correct, but not quite that simple. The PTT part of PL hasn't been in use
much for a host of reasons that I will not go into now. We could go back to
it now, but I've asked the command stations to hold off until a few more
pieces of software are ready, partially to retain continuity. Jim White is
working on a program to fulfill an idea of mine that will allow a uplink
with PL to turn on the downlink transmitter, then immediately switch to the
no PL audio path. The repeater and downlink will then be on for n number of
minutes with no PL required. After n minutes the downlink times out and
another PL'ed uplink will start the loop over again.
This will allow us to do several important things simultaneously. We will be
able to save battery power when the satellite is not over users, but at the
same time we will not have the same degree of logjam problems because the PL
will only be required once or twice per pass. Also as long as one person is
PL capable, everyone in the footprint can play whether or not they have a PL
capable radio. We'll also be able to hear the QRM and work around it and get
rid of it.
With this system anyone will be able to use the satellite given one PL
equipped station in the footprint. As common as it may seem to have PL here
in the US, this will allow access to more operators worldwide, as well as
allow more operators to afford the 2nd radio sometimes required to do full
duplex. 2m FM HTs without PL can be had for practically nothing now.
I think this is the best possible combination of both modes of operation.
73, Drew KO4MA
AMSAT-NA Vice President of Operations
AMSAT LM 2332
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