[Date Prev][Date Next][Thread Prev][Thread Next] - [Date Index][Thread Index][Author Index]

(no subject)




... 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.

Conclusion.

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@amsat.org>
_______________________________________________
Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author.
Not an AMSAT-NA member? Join now to support the amateur satellite program!
Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb



AMSAT Top AMSAT Home