Running kalibrate-rtl to look for error offset for rtl device.

kal.out

506 pyramid:~/Projects/kalibrate-rtl (master %)$ src/kal --h
kalibrate v0.4.1-rtl, Copyright (c) 2010, Joshua Lackey
modified for use with rtl-sdr devices, Copyright (c) 2012, Steve Markgraf
Usage:
        GSM Base Station Scan:
                kal <-s band indicator> [options]

        Clock Offset Calculation:
                kal <-f frequency | -c channel> [options]

Where options are:
        -s      band to scan (GSM850, GSM-R, GSM900, EGSM, DCS, PCS)
        -f      frequency of nearby GSM base station
        -c      channel of nearby GSM base station
        -b      band indicator (GSM850, GSM-R, GSM900, EGSM, DCS, PCS)
        -g      gain in dB
        -d      rtl-sdr device index
        -e      initial frequency error in ppm
        -v      verbose
        -D      enable debug messages
        -h      help
507 pyramid:~/Projects/kalibrate-rtl (master %)$ src/kal -s GSM900
Found 1 device(s):
  0:  ezcap USB 2.0 DVB-T/DAB/FM dongle

Using device 0: ezcap USB 2.0 DVB-T/DAB/FM dongle
Found Rafael Micro R820T tuner
Exact sample rate is: 270833.002142 Hz
kal: Scanning for GSM-900 base stations.
GSM-900:
        chan: 14 (937.8MHz + 35.461kHz) power: 30374.59
        chan: 20 (939.0MHz - 21.902kHz) power: 16207.04
        chan: 31 (941.2MHz - 21.208kHz) power: 120861.56
        chan: 34 (941.8MHz - 5.378kHz)  power: 34297.31
508 pyramid:~/Projects/kalibrate-rtl (master %)$ src/kal -s GSM850
Found 1 device(s):
  0:  ezcap USB 2.0 DVB-T/DAB/FM dongle

Using device 0: ezcap USB 2.0 DVB-T/DAB/FM dongle
Found Rafael Micro R820T tuner
Exact sample rate is: 270833.002142 Hz
kal: Scanning for GSM-850 base stations.
GSM-850:
        chan: 185 (880.6MHz + 9.789kHz) power: 911549.11
        chan: 242 (892.0MHz + 9.373kHz) power: 443953.09
        chan: 244 (892.4MHz + 8.554kHz) power: 133959.20
509 pyramid:~/Projects/kalibrate-rtl (master %)$ src/kal -c 242
Found 1 device(s):
  0:  ezcap USB 2.0 DVB-T/DAB/FM dongle

Using device 0: ezcap USB 2.0 DVB-T/DAB/FM dongle
Found Rafael Micro R820T tuner
Exact sample rate is: 270833.002142 Hz
kal: Calculating clock frequency offset.
Using GSM-850 channel 242 (892.0MHz)
average         [min, max]      (range, stddev)
+ 9.371kHz              [9365, 9380]    (15, 3.910281)
overruns: 0
not found: 0
average absolute error: -10.505 ppm

Copyright (c) 2012, Steve Markgraf (steve@steve-m.de)
512 pyramid:~/Projects/kalibrate-rtl (master %)$ src/kal -c 185 -e -10.505
Found 1 device(s):
  0:  ezcap USB 2.0 DVB-T/DAB/FM dongle

Using device 0: ezcap USB 2.0 DVB-T/DAB/FM dongle
Found Rafael Micro R820T tuner
Exact sample rate is: 270833.002142 Hz
kal: Calculating clock frequency offset.
Using GSM-850 channel 185 (880.6MHz)
average         [min, max]      (range, stddev)
+ 128Hz         [124, 134]      (9, 2.320126)
overruns: 0
not found: 0
average absolute error: -10.146 ppm