New user random dump1090 output

[Grayarea]

I downloaded the current fr24 raspberry image and installed it on my new Pi4.

Initially I got tracks from aircraft about 300km away, after a few hours of use it stopped tracking anything.

I have a the following jetvision kit;

• ADS-B Dongle RTL2832/R820T2
• ADS-B Antenne SCO-1090 MHz for 1090 MHz inclusive 10m antenna cable
• MCX Pigtail for the direct connection to our Diamond Crown ADS-B Dongle
• Mounting bracket

Antenna is mounted on top of my no longer used tv pole, and there is 15 meters of cable.

Before I mounted the antenna it was indoors and it picked up close planes on my PC using the windows version of dump1090.

I have installed the graph1090 package (thanks!) and it show only sporadic data ADS-B message rate (message received 1.6m only) and ADS-B track seen (single message 30) ADS-B Maxima (messages local 1600.o u) this is the only data I have seen since installing graph1090.

How should I troubleshoot this?

How does dump1090 handle the frequency drift on the rtl usb fob?

In windows on SDR# I had to use --ppm 54 to get 1090 data on the 1090 band.

I have a Nooelec NESDR SMArt v4 SDR - Premium RTL-SDR w/ Aluminum Enclosure, 0.5PPM TCXO, SMA Input. RTL2832U & R820T2 on order as a spare and as it has a temp stabilised tuner I thought it would be better than the jetvision unit.

================================================== ================================================== ==============================================

/run/dump1090-mutability seems to have no real data except stats.json, which has this currently;

"latest":{"start":1586946984.2,"end":158694698 4.2, "local":{"samples_processed":0,"samples_droppe d":0 ,"modeac":0,"modes":0,"bad":0,"unknown_icao":0, "ac cepted":[0],"strong_signals":0},"cpr":{"surface":0,"airbor ne" :0,"global_ok":0,"global_bad":0,"global_range":0, " global_speed":0,"global_skipped":0,"local_ok":0,"l ocal_aircraft_relative":0,"local_receiver_relative ":0,"local_skipped":0,"local_range":0,"local_s peed ":0,"filtered":0},"altitude_suppressed":0,"cpu ":{" demod":0,"reader":0,"background":0},"tracks":{"all ":0,"single_message":0},"messages":0},
"last1min":{"start":1586946984.2,"end":1586946 984. 2,"local":{"samples_processed":0,"samples_droppe d" :0,"modeac":0,"modes":0,"bad":0,"unknown_icao":0, " accepted":[0],"strong_signals":0},"cpr":{"surface":0,"airbor ne" :0,"global_ok":0,"global_bad":0,"global_range":0, " global_speed":0,"global_skipped":0,"local_ok":0,"l ocal_aircraft_relative":0,"local_receiver_relative ":0,"local_skipped":0,"local_range":0,"local_s peed ":0,"filtered":0},"altitude_suppressed":0,"cpu ":{" demod":0,"reader":0,"background":0},"tracks":{"all ":0,"single_message":0},"messages":0},
"last5min":{"start":1586946984.2,"end":1586946 984. 2,"local":{"samples_processed":0,"samples_droppe d" :0,"modeac":0,"modes":0,"bad":0,"unknown_icao":0, " accepted":[0],"strong_signals":0},"cpr":{"surface":0,"airbor ne" :0,"global_ok":0,"global_bad":0,"global_range":0, " global_speed":0,"global_skipped":0,"local_ok":0,"l ocal_aircraft_relative":0,"local_receiver_relative ":0,"local_skipped":0,"local_range":0,"local_s peed ":0,"filtered":0},"altitude_suppressed":0,"cpu ":{" demod":0,"reader":0,"background":0},"tracks":{"all ":0,"single_message":0},"messages":0},
"last15min":{"start":1586946984.2,"end":158694 6984 .2,"local":{"samples_processed":0,"samples_droppe d ":0,"modeac":0,"modes":0,"bad":0,"unknown_icao ":0, "accepted":[0],"strong_signals":0},"cpr":{"surface":0,"airbor ne" :0,"global_ok":0,"global_bad":0,"global_range":0, " global_speed":0,"global_skipped":0,"local_ok":0,"l ocal_aircraft_relative":0,"local_receiver_relative ":0,"local_skipped":0,"local_range":0,"local_s peed ":0,"filtered":0},"altitude_suppressed":0,"cpu ":{" demod":0,"reader":0,"background":0},"tracks":{"all ":0,"single_message":0},"messages":0},
"total":{"start":1586946984.2,"end":1586946984 .2," local":{"samples_processed":0,"samples_dropped":0, "modeac":0,"modes":0,"bad":0,"unknown_icao":0, "acc epted":[0],"strong_signals":0},"cpr":{"surface":0,"airbor ne" :0,"global_ok":0,"global_bad":0,"global_range":0, " global_speed":0,"global_skipped":0,"local_ok":0,"l ocal_aircraft_relative":0,"local_receiver_relative ":0,"local_skipped":0,"local_range":0,"local_s peed ":0,"filtered":0},"altitude_suppressed":0,"cpu ":{" demod":0,"reader":0,"background":0},"tracks":{"all ":0,"single_message":0},"messages":0}


rtl_test shows this;

-----
Lost samples in the first 2 seconds after starting the test are common and not a problem!
Starting 30 second rtl_test, standby!
-----
Found 1 device(s):
0: Realtek, RTL2838UHIDIR, SN: 00000001

Using device 0: Generic RTL2832U OEM
Found Rafael Micro R820T 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
[R82XX] PLL not locked!
Sampling at 2400000 S/s.

Info: This tool will continuously read from the device, and report if
samples get lost. If you observe no further output, everything is fine.

Reading samples in async mode...
Allocating 15 zero-copy buffers
lost at least 168 bytes
Signal caught, exiting!

User cancel, exiting...
Samples per million lost (minimum): 1
-------
Test finished!
More than 2 lost samples per million or other errors probably mean the receiver isn't working correctly.
Try another power supply before condemning the receiver though!
-------
-------
No undervoltage detected, looking fine!
If the dongle is not directly plugged into the Raspberry Pi, lack of power/voltage could still be an issue.
Even without detected undervoltage a better power supply can often improve reception!
For optimum performance i would recommend the Official Raspberry Pi power supply.
-------

[Grayarea]

I am also getting this in the fr24feed log every 10 minutes now;

2020-04-15 11:36:17 | [reader][w]Global timeout exceeded, 0 msgs, 0 resyncs, reconnecting
2020-04-15 11:36:17 | [reader][i]Connection terminated
2020-04-15 11:36:17 | [main][i]Terminating child process 23353 with SIGTERM
2020-04-15 11:36:23 | [reader][i]Connecting to DVBT receiver via (exe:///usr/bin/dump1090-mutability --gain -10 --raw --mlat)
2020-04-15 11:36:23 | [reader][i]Connected to the receiver, configuring
2020-04-15 11:36:23 | [reader][i]Configured, processing messages

MLAT takes up to 3 hours to come up.

[Oblivian]

Yep, Dump1090 auto configures to centre on 1090 (generally)

Try re-configuring it, Set as beast-tcp and start dump1090 as a service
sudo systemctl dump1090-mutability start
Then restart fr24feed

The image is pretty buggy at not actually starting dump1090 properly via the command as you see it trying in your log (or leaving it crashed in background)

The other gotca...

MCX Pigtail

That will likely have an SMA on 1 end? check it. One could be a RP-SMA, which may mean you have no centre pin anymore

[Grayarea]

Thanks for the help Oblivian.

I changed to beast-tcp in the fr24 feeder status web page and restarted.

sudo systemctl dump1090-mutability start gives this error;

Unknown operation dump1090-mutability

New error in fr24 logfile;

2020-04-15 12:13:34 | [reader][i]Connecting to unknown receiver via (tcp://192.168.1.170:10000)
2020-04-15 12:13:46 | [feed][n]ping 9
2020-04-15 12:13:47 | [feed][n]syncing stream result: 1
2020-04-15 12:14:06 | [reader][e]Could not connect to tcp://192.168.1.170:10000

Is there instructions on changing dump1090 to a service I could follow?

[Oblivian]

oops
sudo systemctl start dump1090-mutability


And the port should be set to 30005

so receiver: beast-tcp
host: 127.0.0.1:30005

Or cheat, and run it auto.
https://github.com/wiedehopf/adsb-sc...or-dump1090-fa

Which will give you a nicer map and so on

[Grayarea]

OK, I installed dump1090-fa and reinstalled graph1090.

So far no change to the lack of dump1090 data output, /run/dump1090-fa looks like the old dump1090-mutibility did.

MCX Pigtail, the cabling has not changed from last night when it was working, so I don't think that is it. Also checked plug and female end on the pcx and male on the cable.

fr24feed is still killing the connection every 10 minutes.

I cannot find a log file for dump1090-fa other than the json files in /run/dump1090-fa.

Is it worth increasing the logging on dump1090-fa to get a better picture of what is going on?

Should I purge dump1090-mutability?

[Grayarea]

I see from other sticked posts that USB ADS-B dongle being attached to the pi directly is not recommended. On the build your own page this is not defined, what sort of powered USB hub is recommended?

[Grayarea]

After all of the twiddeling I can see that the stats.json now has some data in it. I however am not really sure how to intereprate it;

"last1min":{"start":1586963852.4,"end":1586963 912. 4,"local":{"samples_processed":144048128,"sample s_ dropped":0,"modeac":0,"modes":12,"bad":4,"unknown_ icao":8,"accepted":[0,0],"noise":-45.1,"strong_signals":0},"remote":{"modeac":0,"mod es":0,"bad":0,"unknown_icao":0,"accepted":[0,0]},"cpr":{"surface":0,"airborne":0,"global_ok":0, "g lobal_bad":0,"global_range":0,"global_speed":0,"gl obal_skipped":0,"local_ok":0,"local_aircraft_relat ive":0,"local_receiver_relative":0,"local_skipped " :0,"local_range":0,"local_speed":0,"filtered":0}, " altitude_suppressed":0,"cpu":{"demod":1113,"reader ":857,"background":361},"tracks":{"all":0,"sin gle_ message":0,"unreliable":0},"messages":0},
"last5min":{"start":1586963612.4,"end":1586963 912. 4,"local":{"samples_processed":719978496,"sample s_ dropped":0,"modeac":0,"modes":16,"bad":7,"unknown_ icao":9,"accepted":[0,0],"noise":-45.1,"strong_signals":0},"remote":{"modeac":0,"mod es":0,"bad":0,"unknown_icao":0,"accepted":[0,0]},"cpr":{"surface":0,"airborne":0,"global_ok":0, "g lobal_bad":0,"global_range":0,"global_speed":0,"gl obal_skipped":0,"local_ok":0,"local_aircraft_relat ive":0,"local_receiver_relative":0,"local_skipped " :0,"local_range":0,"local_speed":0,"filtered":0}, " altitude_suppressed":0,"cpu":{"demod":5480,"reader ":4245,"background":1786},"tracks":{"all":0,"s ingl e_message":0,"unreliable":0},"messages":0},
"last15min":{"start":1586963012.4,"end":158696 3912 .4,"local":{"samples_processed":2159935488,"sampl e s_dropped":0,"modeac":0,"modes":16,"bad":7,"unknow n_icao":9,"accepted":[0,0],"noise":-45.1,"strong_signals":0},"remote":{"modeac":0,"mod es":0,"bad":0,"unknown_icao":0,"accepted":[0,0]},"cpr":{"surface":0,"airborne":0,"global_ok":0, "g lobal_bad":0,"global_range":0,"global_speed":0,"gl obal_skipped":0,"local_ok":0,"local_aircraft_relat ive":0,"local_receiver_relative":0,"local_skipped " :0,"local_range":0,"local_speed":0,"filtered":0}, " altitude_suppressed":0,"cpu":{"demod":16237,"reade r":12566,"background":5294},"tracks":{"all":0," sin gle_message":0,"unreliable":0},"messages":0},
"total":{"start":1586961632.3,"end":1586963912 .4," local":{"samples_processed":5472124928,"samples_dr opped":0,"modeac":0,"modes":2310,"bad":1532,"unkno wn_icao":778,"accepted":[0,0],"noise":-45.0,"strong_signals":0},"remote":{"modeac":0,"mod es":0,"bad":0,"unknown_icao":0,"accepted":[0,0]},"cpr":{"surface":0,"airborne":0,"global_ok":0, "g lobal_bad":0,"global_range":0,"global_speed":0,"gl obal_skipped":0,"local_ok":0,"local_aircraft_relat ive":0,"local_receiver_relative":0,"local_skipped " :0,"local_range":0,"local_speed":0,"filtered":0}, " altitude_suppressed":0,"cpu":{"demod":41252,"reade r":31861,"background":13430},"tracks":{"all":0, "si ngle_message":0,"unreliable":0},"messages":0}

[Grayarea]

Is there any methodology of tuning --ppm for dump1090-fa?

I have altered it to the value that gave 1090 on the 1090 band in SR#, but the temp is different (lower) where the PI is currently.

Does anyone know if the jetvision ADS-B dongle is supposed to have a temp compensated tuner?

[abcd567]

Problem seems to be somewhere in your hardware (antenna, antenna location, cable, connectors, dongle, power supply etc etc). Changing ppm or switching decoders from dump1090-mutability to dump1090-fa is NOT going to solve the hardware problem.

Another source of problem may be strong interfering signals from a nearby Cell/Mobile phone tower. If this is the case, you will need a Filter.

Although ppm adjustment improves reception, but it does not have big effect on maximum range/plane count, so do not give too much importance to it.
Most users use the default ppm setting and never bother to adjust it, and their receiver performs very good.

[wiedehopf]

Well mutability had no samples processed.
dump1090-fa is processing samples now.

I'd say either you have some RP-SMA issues going on (wrong connector with the pin missing).
Or for some reason the antenna you have isn't being powered resulting in zero signal.


You shouldn't need to change PPM at all.
ADS-B isn't so picky about that up to a certain range (200 ppm or sth).
Most likely your issue lies elsewhere.

[Grayarea]

I have pulled the cable from the loft down to my PC, with no changes the PC using the same ADS-B fob, same cabling and aerial, running dump1090 found aircraft immediately.

So this leave Pi4, power supply.

I have a powered USB hub on order, so we will see if that changes anything.

PPM measured in SDR# is 53.

[Grayarea]

Here is a sample from the PC stats;

Statistics as at Wed Apr 15 19:28:34 2020
15031 sample blocks processed
73 sample blocks dropped
0 ModeA/C detected
471375 valid Mode-S preambles
2 DF-?? fields corrected for length
0 DF-?? fields corrected for type
1294 demodulated with 0 errors
17 demodulated with 1 error
10 demodulated with 2 errors
4 demodulated with > 2 errors
1325 with good crc
0 with bad crc
0 errors corrected
0 with 1 bit error
0 with 2 bit errors
1325 total usable messages

[ylis]

In your first post you stated

ADS-B Antenne SCO-1090 MHz for 1090 MHz inclusive 10m antenna cable
Antenna is mounted on top of my no longer used tv pole, and there is 15 meters of cable.

Have you joined the TV cable and the the Jetvision cable ?
What cable did you bring down from the loft to the PC ?

[Grayarea]

My house is a long sloped roof so 10 meters was not enough, I ordered a 5 meter sma extension cable to extend the antenna cable.

The entire cable run is the same for the original installation and the PC downstairs, no changes were made other then rerouteing the existing cable.

PC and Pi4 are side by side, PC running dump1090 works fine, Pi4 running dump1090-fa/dump1090-mutability does not. Same cable, same antenna, same ADS-B fob. I plug and unplug.