[amsat-bb] Re: Yubileiny downlink spectrum overlaps AO-51 downlink
G0MRF at aol.com
Mon Jun 2 12:31:48 PDT 2008
In a message dated 02/06/2008 16:25:21 GMT Standard Time, oz1my at privat.dk
Please this is just a technical matter :-)
Here this afternoon with Yubileiny AOS at 1430 UTC and
AO-51 with AOS at 1441 UTC in Copenhagen, the downlink
spectrum of Yubileiny was strong when listening to
the AO-51 frequency.
Oh dear, no frequency co-ordination!
A week or so ago I looked at the transmission from Yubileiny and it was
almost constant amplitude over a 4800Hz bandwidth slowly reducing beyond that.
If you allow for the practical width of our IF filters and the fact doppler
can shift the frequencies by +/- 10kHz, at 435MHz, then Yubileiny and AO-51
will encounter each other from time to time.
Thankfully the orbits are very different so it's a minor (but avoidable)
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