[Meteor-Scatter] Re: [Moon] First(?) 144-MHz-QSO via Reflexion on ISS

[Peter Sundberg]

Congratulations Bernd and Frank!!

As you point out, the signal levels are indeed ok, the problem lies in
tracking of doppler and the actual object in the sky. I am sure the angle
of the solar panels has some influence on the reflected signal, I hope
future tests might reveal to what extent this is true. 

It comes as no surprise that CW proved to be the best mode for you, the
doppler is so fast that machine modes will have difficulties decoding the
information. But with the myriad of different digital protocols available,
possibly one of them will be able to cope with the doppler issue. I am not
familiar enough with the properties of these protocols, but there's room
for some serious experimenting, thats for sure.

Again, congrats boys, well done!! 

73 de Peter SM2CEW
www.sm2cew.com
http://blog.sm2cew.com



At 16:58 2007-12-09 , DF2ZC wrote:
>Hello All,
>
>Triggered by Peter SM2CEW's tries to complete a QSO by using the ISS as a
>reflector Frank DH7FB and I decided to try that as well. From Peter's
>experience (and also Frank's when SWLing Peter's tries) we believed it would
>be worthwile considering BPSK63 as this would enable us to exchange all
>information within few seconds only (using the EME report and QSO rules).
>
>However with the first tries on 8 December we quickly had to realise the
>amazingly quickly changing large doppler makes use of this mode impossible
>and we returned back to good old CW since this is also copyable at such a
>situation when you are not 100% tuned on the signal. The second try today
>Sunday 9 December at ISS orbit 51845 starting with a common window at 1626Z
>we copied signals at elevations of > 20 degrees and within a minute
>exchanged all data. Signal reports were about S3...S5 (DF2ZC running only
>300 watts out). It was a tough task to follow the quick doppler changes and
>also adjust elevation and azimuth rotators. Two hands is at least one too
>few...
>
>That was a thrill! And now we are celebrating...
>
>And we will try more QSOs the coming days.
>
>btw http://www.n2yo.com/ gives a nice live google earth graphics display of
>ISS and other satellites.
>
>
>vy 73 Bernd DF2ZC (JO30RN)
>www.df2zc.de
>
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