[eagle] Re: what is going on?, some technical content at last.
kk7p at wavecable.com
Tue Jul 15 20:01:53 PDT 2008
> AO-40 was heavily promoted in QST and downlinks were 10 dB stronger than
> AO-13 so activity went up.
Yep, sometimes I heard 4 or 5 stations in addition to the Colorado
continuous SSTV downlink! And LEILA stepping on everything it could find
(except the SSTV downlink :-(
> I don't know how long it would have lasted. One
> interesting fact was that the AO-13 70 cm downlink worked much better in Los
> Angeles than the 2 meter downlink. Ambient noise was about 15 dB lower.
AO-40 had downlinks strong enough to actually use. AO-13 was definitely
for weak-signal operation and needed serious antennas. Karl's analog
HELAPS was realy pushing the envelope to get near 100 kHz bandwidth. An
SDX could do it easier - but we really need to prove the SDX can
tolerate the radiation and recover from a hit. A reliable narrowband
transponder is to be preferred over an unreliable wideband transponder
:-) The original Eagle proposal, if memory serves me correctly 9it
often does not) was to have a linear transponder and the SDX was goign
to be an experiment on the 2 meter downlink, 50kHz wide or so, with a
bypass at the IF so if it became unreliable we could still get
engineering beacon data on that downlink. A coded S-band downlink is
probably even better, though, based on AO-40 experience.
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