[amsat-bb] Re: Yes, DStar can work on LEO,

[Patrick Green]

It's GMSK modulation.  I don't have the spec in front of me but I doubt
it'll run where there is any processing (preemphasis/deemphasis) is taking
place.  This is why I suggested using a linear transponder.  I realize that
D-star equipment would be unfriendly to the current operations of sats being
that there is no continuous tuning D-Star radio currently so using this
would most certainly would drift into other QSO's in progress.  Along with
that problem you have the inability to full duplex the QSO because someone
mentioned that the vocoder/decoder can be used only in one direction at a
time.  Seeing as this is a new mode and the equipment is expensive, I don't
see this being wildly popular that it'll "take over" the sats from their
usual operation.  A test at some point in the future would probably be good
to see if it can be done.  Perhaps Echo's B-side could be converted to pass
GMSK modulation?  Something for the programmers to think about.

73 de Pat --- KA9SCF.
Amsat #35741

On 2/26/07, Tony Langdon <vk3jed at gmail.com> wrote:
>
> At 09:14 AM 2/27/2007, Andrew Glasbrenner wrote:
> >Gentlemen,
> >
> >Please do not use FM on any of the transponder satellites, whether D-Star
> or
> >plain FM. FM of any kind is expressly unwelcome on AO-7 especially.
> >
> >If you would like to set up a test of D-Star via AO-51, please organize
> the
> >effort and send a request to schedule it to ao51-modes at amsat.org or to
> >myself directly and we will accommodate the test on a FM satellite, where
> FM
> >belongs. I think it'd be an interesting experiment.
>
> Umm, I thought D-Star was a digital mode, not riding on top of
> FM.  Is it transmitted as AFSK or is it modulated directly onto the
> carrier?  If it's the latter, then it wouldn't work on an FM satellite.
>
> 73 de VK3JED
> http://vkradio.com
>
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