[amsat-bb] Re: Receiving RAFT on 216.98 MHz ?

[David Goncalves]

Doug,

If you look at the description on the RAFT1 website, you will notice that the
radar transponder, as it flies over the radar beam, will be downconverting the
216.98 (+/- doppler shift) radar signal to an audio tone on the 2
meter downlink.
This is the intended way to hear the 'ping'. You must be well timed
with your receiver, as the radar transponder is on a 1 minute timer
that must be commanded on by a command station. Hopefully, following
testing, a schedule can be setup so that many folks get a chance to
try this radar transponder out.

Heaingr the direct radar reflection 'ping' from off of the satellite
body is challenging for NAVSPASUR; for such a small cross section, I
don't know that it is likely that a amatuer would be able to do this -
but do try! Others may try hearing strong radar pings with the ISS,
Space Shuttle or other large orbiting bodies (like the moon!).

Lastly, one may listen to the 216.98 (+/- doppler shift) signal
transmitted from the radar transponder itself. There is no ping, just
a CW tone. AA2TX and others have determined that one may hear the 6mW
CW signal with a good omnidirectional antenna and a reasonably quiet
and sensitive receiver. A small group of us in the Boston area that
built the transponder eagerly await the launch, release and testing of
the satellite to listen to our creation. We are using a preamp, as a
weak signal will not impress my girlfriend :-)

Personally, I've a IC-375 220 allmode to hear it, but I live in a very
poor location for satellite reception. :-( One could also purchase and
rework a Hamtronics downconverter to use their 2M radio to hear the
signal. Hurry - the satellite will not be in orbit for long...

Hope this helps.

David Goncalves
W1EUJ

On 12/7/06, Douglas Quagliana <dquagliana at aol.com> wrote:
> A quick check around my radio shack confirms
> that none of my receivers will receive at or
> near 216.980 MHz.
>
> What were other amateurs planning to use to
> receive the pings from RAFT on 216.98? Is
> there a bargain-basement no-frills way to
> kludge something together to receive the
> signals?
>
> Douglas KA2UPW/5
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-- 
David Goncalves