[amsat-bb] (no subject)
archie.hackett at hotmail.com
Tue Nov 13 01:18:03 PST 2007
... and here are the results of the Norwegian jury ...
(Our dear American friends won't recognise that phrase - but the "Eurovision" crowd will).
After reading all sorts of wierd and wonderful comments on the Amsat-bb re: data modes on analogue satellites - (including SSTV and the infamous "pesky" 31) - I decided to throw caution to the wind and try to jump through the hoop by myself.
Being an AO-7 afficiondo - (look it up in the dictionary!) - the logical choice was AO-7, not least due to it's orbit - (slow doppler) - and mode - downlink lower than uplink -
(you'll need to think! about that one).
I set up 2 x 386 machines running MixW V12, 2 instances of ITUNE and the FT-290/790 pair.
I'd already built special interfaces to allow me to regulate the audio on both PC's + adequate filtering - audio and RF.
The first thing I noticed was that a pair of EARS (!!!) works better than the "theoretical" one true rule, in practice - especially on modes like RTTY where you have two tones. It's easier to tune in PSK with a single line on the MixW waterfall display. To it's discredit, MixW can't decide which way to go for "auto-tuning" the last few hundred hertz - to it's credit, give it a little kick up the bum - (manual tuning)- and it copies perfectly.
I missed the callsign ... LA2Q something-or-other ... due to QRM ...(just kidding!!!).
(The next bit is "aimed" at the Europeans).
Obviously, most people are *NOT* going to bother to set up for digital on an analogue satellite - which would entail organising both a TX and RX system but it shouldn't be a problem to switch to a digital mode to just TX ... and since I already have a dual system operating ... I would appreciate a report if you hear me. (I'll *ONLY* be on AO-7 mode-B).
Remember !!! ... due to the different QTH's = different rates of doppler !!! ... I will need to "tune-in" on your signal so send your callsign several 'thousand' times.
For those that are absolutely bone idle and can't be bothered to switch to a digital mode it is possible to give me a report on SSB if you hear any "snoring" noises.
PSK31 does !!! work on the higher frequencies on satellites but it takes a little more practice than just the normal wailing into a microphone emulating a cow in labour.
AAAAAAWWWWWWWLLLLLLLLLEEERRRRRRRRR ... (swish) ... (swish)
The good news - (for the South Africans, the good gnu's).
If PESKY31 will work on AO-7 it will most certainly work on P3E - and save a lot of bandwidth while it's at it.
73 John. <la2qaa at amsat.org>
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