Author: SM0TGU

Newsletter AMSAT-SM INFO nr: 3-4 2003 released.

Lite information om PcSat:

PCsat is doing fine and will continue in good Sun through New Years Eve. Seeing about 50 users per day and 30 per pass over the USA. Any packet station can copy her, just tune 145.825 and watch (1200 baud normal AX.25 packet).

To transmit though her, just set your unproto to UNPROTO APRS VIA WIDE, go to CONVERSE and type something to somone else you see. This is the same path as APRS users use terrestrially. (RELAY, PCSAT-1 and W3ADO-1 also work)

See also all captured packets on the downlink on http://pcsat.aprs.org

Sapphire (45) is 10 minutes behind PCsat in the same orbit. Her uplink is 145.945 and very weak downlink is on 437.095 +/- Doppler. Her digi callsign is VIA KE6QMD. ISS is not doing packet these days, but we can hope…

During travels, set your mobile to 145.825. When you hear one PCSAT pass, the next one is exactly 100 minutes later and the NEXT day the same pass is 30 minutes earlier. (And Sapphire is 10 minutes behind it but takes a UHF beam to hear it on 437.095, though it is easy to hit on 145.945..)

Klla: ANS 355

Hr kommer en frklaring frn AMSAT-India om vad som hnde med VuSat:
—-

Hi all,
I am sure many of you are curious to know about the
problem we had with vusat and subsequent delay in
launch. Here I would like to give a brief summary of
the problem for the sake of information:
During the final thermovacuum test of vusat there
was a high noise level observed. This resulted in
erratic behaviour of the transponder output. The
output gain varied too much upto about 10dBm or so.
You know we have 30dBm transponders onboard. The
problem could not be identified intime as ours was a
co-passenger with one another satellite called IRS-P6
which had to go on priority.
Presently the problem element has been
identified as a notch filter which was used for good
isolation between transponder output and telecommand
input. Again you know we have a telecommand at
149.522MHz pretty close to payload transponder output.
Incidentally this output filter was added at the last
minute, it was a commercial one and was not tested
properly. As the problem is now identified engineers
are working on the design of a new filter.
This filter is expected to be ready by the
end of December and will be subsequently integrated on
to vusat. The transponder chain will be tested before
the satellite goes into thermovac once again for
further tests. Hope this time there will not be any
problems.
ISRO has promised the launch of vusat with
the next main satellite on a polar orbit. We expect
this to happen in about a year s time from now.
-Nagesh, VU2NUD
Co-ordinator, Amsat-India

Klla: Amsat-India