[amsat-bb] Need help decoding EO-79 packets.

Mike Rupprecht mail at mike-rupprecht.de
Thu Apr 21 16:33:09 UTC 2016

Hi Jeff,

if you use soundmodem by UZ7HO you don't need AGW Packet Engine.

Firstly start soundmodem software, then AGW Online KISS OR use the QB50p1
Online decoder.
If it's connected you should see a green light.

If you successfully decode a packet you should see something like this in

2: <NON-AX25 frame Len=125> [18:29:19R]
2: <NON-AX25 frame Len=125> [18:29:29R]
2: <NON-AX25 frame Len=125> [18:29:39R]
2: <NON-AX25 frame Len=125> [18:29:49R]

73 Mike

-----Ursprüngliche Nachricht-----
Von: AMSAT-BB [mailto:amsat-bb-bounces at amsat.org] Im Auftrag von Jeff A.
Gesendet: 21 April 2016 17:18
An: amsat-bb at amsat.org
Betreff: [amsat-bb] Need help decoding EO-79 packets.

I have been trying for weeks to set up a system to decode telemetry packets
EO-79 (QB50P1) without success. As I am new at dealing with data from
satellites that is not already handled by a dedicated program such as
FUNCube Dashboard, which handles Doppler tracking and packet decoding all by
itself, I'm still kind of lost as to how all the required components are
supposed to come together.

If I can figure out EO-79, goes my thinking, then I can go on to tackling
other BPSK 1200 baud birds such as the XW-2 constellation. I will list what
I'm doing below; if someone can please give me a sanity check it would be
greatly appreciated.

- Receiver: FUNCube Dongle Pro+, SDR# outputting to a virtual audio cable.
- SATPC32 tracking EO-79, correcting for Doppler, and controlling SDR#.
- AGW Packet Engine set up with "Sound Card" TNC (the other end of the
virtual audio cable), dual port, 1200 baud for each channel.
- AGW Online KISS set up to connect to the Packet Engine. WINSock remote
port 8000.
- Soundmodem by UZ7HO on the same port 8000 and listening to SDR#, which is
set for USB, 4kHz bandwidth. SATPC32 is keeping the packet traces in the
center of the 4kHz passband, and I can see the traces appearing in the
waterfall in Soundmodem. The modems in Soundmodem (2 channels) are set for
BPSK 1200 baud, and the reticules match up exactly with the traces I can see
in the waterfall.

And Soundmodem refuses to decode a single #$%&ing thing. There is an
occasional "<NON AX.25 FRAME>" that shows up in the list, and Online KISS
will show a bunch of garbage, but this mostly occurs when there is nothing
in the waterfall at all.

Several sites have said that I'm to connect something to something else
using virtual serial ports, but none of them have really given me a straight
answer as to where to connect what to what.

What am I doing wrong here? Any advice would be ridiculously appreciated.


J. Boyd, JR2TTS/NI3B
the2belo at msd.biglobe.ne.jp
Twitter: @Minus2_C

Sent via AMSAT-BB at amsat.org. AMSAT-NA makes this open forum available to all
interested persons worldwide without requiring membership. Opinions
expressed are solely those of the author, and do not reflect the official
views of AMSAT-NA.
Not an AMSAT-NA member? Join now to support the amateur satellite program!
Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb

More information about the AMSAT-BB mailing list