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filipsPL / autowx2

The program for scheduling recordings and processing of the satellite and ground radio transmissions (like capturing of the weather APT images from NOAA satellites, voice messages from ISS, fixed time recordings of WeatherFaxes etc.) :earth_africa: :satellite:
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Dongle shift is calculated but not always used #64

Open filipsPL opened 5 years ago

filipsPL commented 5 years ago 
2019-01-22 20:40  SDR device found!  
2019-01-22 20:40  Recalibrating the dongle...  
-0.179
2019-01-22 20:40  Using the good old dongle shift (a): 0 ppm
somkar1 commented 5 years ago

For me also dongle shift is not working. It is not even finding new dongle shift and later when I checked in detail, the kal is not finding any frequencies many times. I tried on debian and also on raspberry 3 b+ both same thing happening.

filipsPL commented 5 years ago

and what is the output of the kal itself? Does it work for you?

somkar1 commented 5 years ago

There are two problems. One is Kal itself doesn't work at times which only its author can solve.

Our problem is calibrate.sh is only run and not the calibrate_full.sh. So there is no dongleshift.txt or gsm_channel.txt files to start with.

channel=$(cat $channelFile) is empty as in autowx2 config file only calibrate is run and calibrate_full is commented by default.

Kal doesn't find anything if the -c $channel is empty. Hence calibrate.sh fails to find the shift.

When manually run output is

$ kal -s GSM900 -e 74 -g 49.6 2 Found 1 device(s): 0: Generic RTL2832U OEM

Using device 0: Generic RTL2832U OEM Found Rafael Micro R820T tuner Exact sample rate is: 270833.002142 Hz [R82XX] PLL not locked! Setting gain: 49.6 dB kal: Scanning for GSM-900 base stations. GSM-900: chan: 25 (940.0MHz + 733Hz) power: 4392752.42 chan: 27 (940.4MHz + 797Hz) power: 3285022.45 chan: 29 (940.8MHz + 824Hz) power: 2098686.73 chan: 30 (941.0MHz + 1.355kHz) power: 2575591.98 chan: 66 (948.2MHz + 145Hz) power: 1585427.24 chan: 69 (948.8MHz + 956Hz) power: 2206713.86 chan: 70 (949.0MHz + 971Hz) power: 4093341.39 chan: 77 (950.4MHz + 1.527kHz) power: 1795610.18 chan: 78 (950.6MHz + 1.143kHz) power: 2098148.96 chan: 81 (951.2MHz + 1.701kHz) power: 4590153.19 ...chan 124 Difference of offsets between channels is >1kHz. This likely means that the correct PPM is too far away and you need to provide a rough estimate using the '-e' option. Try tuning against a local FM radio or other known frequency first.

So this is what calibrate_full will get if we remove the comment. But calibrate_full won't have entered anything on to dongshift.txt($shiftfile) anyway so even if we run calibrate_full.sh still it won't work.

timeout 100 kal -c 27 -g 49.6 -e 0 2 Found 1 device(s): 0: Generic RTL2832U OEM

Using device 0: Generic RTL2832U OEM Found Rafael Micro R820T tuner Exact sample rate is: 270833.002142 Hz [R82XX] PLL not locked! Setting gain: 49.6 dB kal: Calculating clock frequency offset. Using GSM-900 channel 27 (940.4MHz) Tuned to 940.400000MHz (reported tuner error: 0Hz)

Hence calibrate.sh fails as there is no value given for -e $recentShift (which will be zero).