[amsat-bb] International Space Station-Bounce on 1296 MHz

Les Rayburn les at highnoonfilm.com
Mon May 27 14:27:43 PDT 2013

Many of you may have read about the successful QSO between DJ5AR and 
Jan, PA3FXB using the ISS as a
passive reflector, similar to airplane scatter or EME.

Using EME protocols and periods of 30 seconds, they completed the QSO 
using CW. This involved modifying
satellite tracking software, and compensating for the Doppler shift. You 
can read details and hear audio files on
DJ5AR's blog here:


This is quite an accomplishment, but I instantly began to wonder if it 
couldn't also be pulled off with much simpler
equipment using WSJT software such as FSK441 (commonly used for rapidly 
moving meteor scatter QSO's).
Doppler shift would not be a problem, even with the quick moving ISS, 
since the software is already optimized for
short transmission periods.

It might be necessary to modify the standard messaging to allow for a 
complete QSO exchange to happen faster,
or to shorten the periods to 15 seconds.

432 MHz has already proven to be very productive for airplane scatter, 
so I also wondered if 432 might be a good
band for this type of experimentation. Lots of satellite operators are 
already equipped to operate on 432 and to track
the ISS in real time with their antennas.

I'd love to hear some discussion about the possibility of this. It could 
open up a lot of potential grid squares on 432 and 1296
simply using FSK441.

Another problem to be solved is classifying the propagation mode in LoTW 
and other logging software. Would this be considered "airplane scatter" 
or would we have to invent a whole new name for this?

Congratulations to both hams for this accomplishment!

Les Rayburn, N1LF
121 Mayfair Park
Maylene, AL 35114

6M VUCC #1712
AMSAT #38965
Grid Bandits #222
Southeastern VHF Society
Central States VHF Society Life Member
Six Club #2484

Active on 6 Meters thru 1296, 10GHz & Light

More information about the AMSAT-BB mailing list