2013-07-26
I ordered and received an rtl-sdr stick ...
I ordered and received an rtl-sdr stick with an HF convertor and active antenna, planning to do some HF with it. For a simple test I tried to decode APRS messages, which has worked with the Noxon dab stick and rtl_fm/multimode. This new stick allows easy connection of external antennas through an SMA connector. Besides the cable to connect the HF convertor I also ordered an SMA - BNC cable which allowed me to connect other antennas, such as a 2 meter antenna. There were not a lot of APRS messages to test with, but eventually I found the working settings. This stick works better with automatic gain.koos@thompson:~/rtl-sdr$ ./src/rtl_fm -f 144800000 -s 22050 -o 4 -C - | multimon -t raw -a AFSK1200 /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 SCOPE Enabled demodulators: AFSK1200 Found 1 device(s): 0: Realtek, RTL2838UHIDIR, SN: 00000001 Using device 0: ezcap USB 2.0 DVB-T/DAB/FM dongle Found Rafael Micro R820T tuner Oversampling input by: 12x. Oversampling output by: 4x. Buffer size: 7.74ms Tuned to 145064600 Hz. Sampling at 1058400 Hz. Output at 22050 Hz. Exact sample rate is: 1058400.010094 Hz Tuner gain set to automatic. AFSK1200: fm PI1APU-0 to APND13-0 UIv pid=F0 >W3,NL7 PAradigm operation! AFSK1200: fm PD0PYL-0 to URPRW9-0 via PI1APU-0,WIDE2-1 UIv pid=F0 'z8%l .-/] AFSK1200: fm PI1APU-0 to APND13-0 UIv pid=F0 >W3,NL7 PAradigm operation! AFSK1200: fm PI1APU-0 to APND13-0 via WIDE2-1 UIv pid=F0 !5205.28NS00506.75E#PHG3440/Utrecht http://pe1mew.nl/pi1apu mail:pi1apu@pe1mew.nl AFSK1200: fm PD2WVH-0 to APU25N-0 via PI1APU-0,WIDE2-0 UIv pid=F0 >262031zDX: PI1FLD 52.21.08N 5.14.15E 49,3km 66. 22:27 AFSK1200: fm PI1APU-0 to APND13-0 UIv pid=F0 >W3,NL7 PAradigm operation! AFSK1200: fm PD2WVH-0 to APU25N-0 via PI1APU-0,WIDE2-0 UIv pid=F0 <IGATE,MSG_CNT=0,LOC_CNT=21 AFSK1200: fm PD2WVH-2 to APU25N-0 via PI1APU-0,WIDE2-0 UIv pid=F0 =5210.19N/00434.68E- {UIV32N} AFSK1200: fm PD0PYL-0 to URPRW9-0 via PI1APU-0,WIDE2-1 UIv pid=F0 'z8%l .-/]No timestamps, but there is not an awful lot of APRS traffic in this region.