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