Regarding Observation 11428924 …
Hello!
I just received this from TRANSIT 5B-5. (I’m still a beginner), but it seems shifted the signal. or am I wrong?
This looks like a SDR LO issue, you will need to find the correction and configure a PPM value.
Newer versions of rtl_test have the ability to measure the ppm value.
rtl_test -p10 if you use the docker satnogs solution, you need to run:
sudo docker exec <container name> rtl_test -p10
Keep this running for some time until it stabilizes and use the value found to enter in your satnogs client setup.
Found 1 device(s):
0: Realtek, RTL2838UHIDIR, SN: 00001470
Using device 0: Generic RTL2832U OEM
Found Rafael Micro R820T/2 tuner
Supported gain values (29): 0.0 0.9 1.4 2.7 3.7 7.7 8.7 12.5 14.4 15.7 16.6 19.7 20.7 22.9 25.4 28.0 29.7 32.8 33.8 36.4 37.2 38.6 40.2 42.1 43.4 43.9 44.5 48.0 49.6
Sampling at 2048000 S/s.
Reporting PPM error measurement every 10 seconds...
Press ^C after a few minutes.
Reading samples in async mode...
Allocating 15 zero-copy buffers
lost at least 120 bytes in buffer 0
real sample rate: 2048124 current PPM: 61 cumulative PPM: 61
real sample rate: 2047882 current PPM: -58 cumulative PPM: -1
real sample rate: 2047998 current PPM: -1 cumulative PPM: -1
real sample rate: 2048017 current PPM: 9 cumulative PPM: 2
real sample rate: 2047968 current PPM: -15 cumulative PPM: -2
Jan | PE0SAT
Thanks again for your help!
Since I’m not familiar with dockers and I dont want to break stuff…
Which one is the container?
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
15ff6f189940 librespace/satnogs-client:1.9.3 "satnogs-client" 33 minutes ago Up 33 minutes satnogs_satnogs-client
9e3c9271390a librespace/hamlib:4.0 "/docker-entrypoint.…" 33 minutes ago Up 33 minutes satnogs_rigctld
I was thinking the rigtctld but not sure…
Thanks again!
well I tried both… probably I don’t have the scrpt?
pi@srgs:~ $ sudo docker exec satnogs_rigctld rtl-test -p10
OCI runtime exec failed: exec failed: unable to start container process: exec: "rtl-test": executable file not found in $PATH: unknown
pi@srgs:~ $ sudo docker exec satnogs_satnogs-client rtl-test -p10
OCI runtime exec failed: exec failed: unable to start container process: exec: "rtl-test": executable file not found in $PATH: unknown
Just a feedback - I did a bit of research on this community and found an answer!
the command to run is: sudo docker exec -ti satnogs_satnogs-client rtl_test -p10
here the result:
sudo docker exec -ti satnogs_satnogs-client rtl_test -p10
Found 1 device(s):
0: RTLSDRBlog, Blog V4, SN: 00000001
Using device 0: Generic RTL2832U OEM
Found Rafael Micro R828D tuner
RTL-SDR Blog V4 Detected
Supported gain values (29): 0.0 0.9 1.4 2.7 3.7 7.7 8.7 12.5 14.4 15.7 16.6 19.7 20.7 22.9 25.4 28.0 29.7 32.8 33.8 36.4 37.2 38.6 40.2 42.1 43.4 43.9 44.5 48.0 49.6
Sampling at 2048000 S/s.
Reporting PPM error measurement every 10 seconds...
Press ^C after a few minutes.
Reading samples in async mode...
Allocating 15 zero-copy buffers
lost at least 44 bytes
real sample rate: 2047417 current PPM: -285 cumulative PPM: -285
real sample rate: 2047999 current PPM: 0 cumulative PPM: -141
real sample rate: 2047886 current PPM: -55 cumulative PPM: -113
real sample rate: 2047989 current PPM: -5 cumulative PPM: -85
real sample rate: 2048024 current PPM: 12 cumulative PPM: -66
real sample rate: 2048109 current PPM: 53 cumulative PPM: -46
real sample rate: 2047852 current PPM: -72 cumulative PPM: -50
I just have one last question: what I actually need to put in the satnog setup and where? the real sample rate?
To be honest my bet would be this signal in the observation is some aircraft acars signal and not the Transig 5B-5 signal. So don’t set frequency offset for this signal but use a known ! frequency for that.
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typo in the command, it should be rtl_test underscore
Keep it running for a longer time, but if this value is indeed around 50 then I wonder if this is a original RTL-SDR v4 and not a Chinese clone.
Thanks @pe2bz I totallly missed that option.
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