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safir-M report and round-up




Report

1.      No beacons heard tonight at either 1747 utc or 1928 utc (both maxel
predicted times as I was in a New Years' party - hi).

Using TMD700E with TRACE ON in Packcom, 145.825 9k6, unattended rx. PACLEN
changed to 255; full packet was decoded.

However DK2SM Uli in JO42rl heard both times. Congratulations Uli! 

Round-up

2.      Email from aatis confirms best mode for DATA1 and DATA2 beacons is
KISS and Hex Decode:

copy:
Hi Andy,

sure can you decode the frames with a Hex Editor looking to the raw KISS 
stream. But it seems your received data contains errors. In addition, it is

necessary to watch the DATA0 frame also, to reduce the uncertainty due to
the 
bit0 ambiguity.

You find some information on our web page

http://hft.fh-pforzheim.de/download/aatis/

73  Henning DF9IC

That website also describes other dowmloadable programs - highly
reccommended.

3.      The errors DF9IC reefrred to have in part been noted by Masahiro
Arai in his posting to amsat-bb:

copy:

SAFIR-M is transmitting only even numbers due to bit0=0 problem now.
This means SAFIR-M may transmit incorrect data. Non hex code character
should change. If you find '@'(=40hex) in the telemetory, you must
change '@' to 'A'(=41hex).

The correct telemetry on Andy, G0SFJ's trace file at 1859utc 31/12/02
is 000000A0008D8A244B00. Another odd numbers may be in the telemetry.
The accident error is +1.

  trace data (hex)   30 30 30 30 30 30 40 30 30 30 38 44 38 40 32 34 34 42
30 30
  ascii              0  0  0  0  0  0  @  0  0  0  8  D  8  @  2  4  4  B 
0  0

  correct data (hex) 30 30 30 30 30 30 41 30 30 30 38 44 38 41 32 34 34 42
30 30
                                       ^^                   ^^
  corecct ascii      0  0  0  0  0  0  A  0  0  0  8  D  8  A  2  4  4  B 
0  0
                                     ^                    ^

4.      As Don, KD4APP    pointed out I also have to correct my earlier
posting - the DATA1 correct opening sequence in hex is:

D = 88 hex to dec /2
A =82 hex  to dec/2
T = a8 hex  to dec /2
A = 82 hex   to dec/2
1 = 62 hex   to dec/2

Convert these hex to decimal, divide by 2 and enter as ascii.  

73s to all

andy g0sfj
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