[amsat-bb] Re: Working SO-50

[Eric Knaps, ON4HF]

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


http://www.on4hf.be


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
>
>
>
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