Hello Ib,
I agree with you. This is what I have in my Doppler.sqf file for SatPC32:
SO-50,436790,145850,FM,FM,NOR,0,0 SO-50,436795,145850,FM,FM,NOR,0,0
and in my SubTone.sqf:
SO-50,67.0,$3F,1 SO-50,74.4,$3E,3
This is for the Yaesu FT-847.
73, Eric.
Amateur Radio Station ON4HF Eric Knaps Satellite manager UBA
Op 3/12/2011 21:45, Ib Christoffersen schreef:
Working SO-50.
I think it is time to look at how one can operate over SO-50 and the problems that can be encountered.
First the normal and nominal data:
Uplink is at 145.850 MHz. Downlink at 436.795 MHz.
If it is not ON - use 74.4 Hz CTCSS tone to activate the transmitter for 10 seconds to have it on for nominally 10 minutes - when on use 67 Hz CTCSS tone during your transmission.
That was the intended normal operation.
Now to the deviations from the normal scheme.
The downlink frequency sometimes jump approximately 5 kHz. Therefore I have two different frequencies pairs to be used in SATPC32:
SO-50,436788.50,145849,FM,FM,NOR,0,0 SO-50,436795,145850,FM,FM,NOR,0,0
If you do not use Full Doppler Tracking it is not much of an issue. Just tune for best downlink.
Talking about SATPC32 here are the entries for the CTCSS tone:
SO-50,67.0,$3F,1 SO-50,74.4,$3E,3
The first data is for the ICOM IC-910 radio. If you use another radio please look at the information in SATPC32.
Next problem is the change of polarity of the downlink signal during a pass. The polarity changes during the pass. At least I have to switch polarity a few times from RHCP to LHCP to optimize the downlink signal. That has been confirmed by others. How it works using linearly polarized antennas I do not know - but I think there will be some fading.
And if that is not enough - at least here over Europe - we have to put up with QRM on the uplink from a lot of different sources like repeaters and people using our frequencies as cheap phone connections. The result of the QRM is that it sometimes is difficult to turn SO-50 on. Also the QRM may turn the transmitter off.
And since the inclination is not sun synchronous we have to live with a steady change of pass times over the year.
Some may think I am not a fan of SO-50. That is not the case. It is a very good satellite we got for free and it works very well. Already more people are using it over Europe after AO-51 is not with us any more. That just took a couple of days.
73 OZ1MY/Ib
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