Since we are now able to receive APRS packets in their original format we can think about setting up a network server where Xastir can connect to and grab the packets. Step 3: Fire up a server where Xastir can connect to This can be done by invoking sed like this: sed -u -r 's/^.//'.
To be more precise - we just have to strip the first 6 characters from evey line and then we are done. The output is VERY close to the original APRS format.
#LOGILINK RTLV CODE#
If you dig deeper in the internet then you will discover that multimon-ng is used to decode pager masseges, DTMF codes, morse code and much more.
So lets try another decoder: multimon-ng.Īfter having it downloaded, compiled and installed (like shown on their website) we can start it together with rtl_fm like -f 144800000 -s 22050 -o 4 -g 100 -C - | multimon-ng -a AFSK1200 -A -t raw - multimon-ng (C) 1996/1997 by Tom Sailer HB9JNX/AE4WA (C) 2012-2014 by Elias Oenal available demodulators: POCSAG512 POCSAG1200 POCSAG2400 EAS UFSK1200 CLIPFSK AFSK1200 AFSK2400 AFSK2400_2 AFSK2400_3 HAPN4800 FSK9600 DTMF ZVEI1 ZVEI2 ZVEI3 DZVEI PZVEI EEA EIA CCIR MORSE_CW DUMPCSV SCOPE Enabled demodulators: AFSK1200 Found 1 device(s): 0: Realtek, DVB-T Dongle, SN: 00000991 Using device 0: Dexatek DK DVB-T Dongle (Logilink VG0002A) Found Fitipower FC0013 tuner Oversampling input by: 12x. If we take a closer look then we can see that all the data is here but it would be too much effort do rebuild the original fromat from this output. OK - not bad, but it doesnt look like the specified format of APRS that is sent over the air. Rtl_fm -f 144800000 -s 22050 -o 4 -g 100 -C - | multimon -a AFSK1200 -t raw /dev/stdin multimod (C) 1996/1997 by Tom Sailer HB9JNX/AE4WA available demodulators: POCSAG512 POCSAG1200 POCSAG2400 EAS AFSK1200 AFSK2400 AFSK2400_2 HAPN4800 FSK9600 DTMF ZVEI CCIR SCOPE Enabled demodulators: AFSK1200 Found 1 device(s): 0: Realtek, DVB-T Dongle, SN: 00000991 Using device 0: Dexatek DK DVB-T Dongle (Logilink VG0002A) Found Fitipower FC0013 tuner Oversampling input by: 12x.