FlightAware Discussions

Only 3 Others Positions detected

I only have 3 postions with 10 messages sent to FA in 4 days.

Sun Apr 28 14:19:43 2019 EDT dump1090-mutability v1.15~dev starting up.
Using sample converter: UC8, integer/table path
Found 1 device(s):
0: Realtek, RTL2838UHIDIR, SN: 00000001 (currently selected)
Detached kernel driver
Found Fitipower FC0012 tuner
Max available gain is: 19.20 dB
Setting gain to: 19.20 dB
[FC0012] no valid PLL combination found for 1090000000 Hz!
Gain reported by device: 19.20 dB

Statistics: Sun Apr 28 14:19:44 2019 EDT - Sun Apr 28 15:19:44 2019 EDT
Local receiver:
8620867584 samples processed
0 samples dropped
0 Mode A/C messages received
95591817 Mode-S message preambles received
61616767 with bad message format or invalid CRC
33974874 with unrecognized ICAO address
11 accepted with correct CRC
165 accepted with 1-bit error repaired
-5.9 dBFS noise power
-5.9 dBFS mean signal power
-5.1 dBFS peak signal power
0 messages with signal power above -3dBFS
Messages from network clients:
0 Mode A/C messages received
0 Mode S messages received
0 with bad message format or invalid CRC
0 with unrecognized ICAO address
0 accepted with correct CRC
0 accepted with 1-bit error repaired
176 total usable messages
21 surface position messages received
61 airborne position messages received
0 global CPR attempts with valid positions
0 global CPR attempts with bad data
0 global CPR attempts that failed the range check
0 global CPR attempts that failed the speed check
0 global CPR attempts with insufficient data
1 local CPR attempts with valid positions
0 aircraft-relative positions
0 receiver-relative positions
81 local CPR attempts that did not produce useful positions
60 local CPR attempts that failed the range check
0 local CPR attempts that failed the speed check
0 CPR messages that look like transponder failures filtered
0 non-ES altitude messages from ES-equipped aircraft ignored
176 unique aircraft tracks
174 aircraft tracks where only one message was seen
CPU load: 33.1%
740091 ms for demodulation
436812 ms for reading from USB
15681 ms for network input and background tasks
Sun Apr 28 15:23:10 2019 EDT Caught SIGTERM, shutting down…

Sun Apr 28 15:23:10 2019 EDT Waiting for receive thread termination
Reattached kernel driver

i have no idea why i have 0 tracked aircraft.

Change your dongle. Fitipower is NOT suitable for 1090 MHz.
Use one with RTL2832U + R820T2


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Fitipower FC0012 frequency range is 22 - 948.6 MHz, not enough for 1090MHz ADS-B.

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That tuner does not work well, it’s not suited to receive ADS-B.

3 dongles i would recommend:

rtl-sdr v3 (https://www.rtl-sdr.com/buy-rtl-sdr-dvb-t-dongles/)
(for maximum performance you can later get a fitting LNA https://www.rtl-sdr.com/new-product-rtl-sdr-blog-1090-mhz-ads-b-lna/)

Flightaware Pro Stick Plus (https://www.amazon.ca/FlightAware-Stick-Receiver-Built-Filter/dp/B01M7REJJW/)

AirNav Flightstick (https://www.radarbox24.com/store)
(currently out of stock i believe)

Note that all dongles i listed use an SMA connector.

i bought RTL2832U+R820T.

could it be a bad install where fitipower was choosen by mistake in pi during dump1090 or piaware install?

could the device do dump978 if it is not R820T?

Thanks for prompt replys

No, The tuner chip FC0012 or R820T are hardware chips, which cannot be selected by software. Only one of the two is provided in any dongle.

It is your seller who sent you wrong dongle: advertised R820T, but sold Fitipower

ill be back once i receive the dongle

got lots of signal using SharpSDR on windows at 1091 mHz

Signal or noise? :slight_smile:

Are you sure you can tell the difference?

Also note that you can receive a little bit at that frequency and the 3 positions are most likely real signal.
But the reception is very very very bad with the Fitipower chip.

:+1: :+1: :+1:

The above comments about the FC0012 not being suitable for ADS-B are correct.

The PLL error means that the FC0012 was never actually tuned (the tuning code bails out before programming the tuner at all) so whatever signal you are hearing is basically random noise from whatever mode the tuner happened to power up in / whatever the last frequency setting was. This probably also explains the “signal” you see in sharpsdr. FWIW ADS-B signals are not very visible on a a waterfall display (they are bursty and quite wideband) - if you see a strong vertical line on the waterfall display, that’s not ADS-B.

Unfortunately I think 978MHz is outside the tunable range of the FC0012 as well.

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If the PLL doesn’t lock (or doesn’t lock reliably), you have no way of knowing what frequency you are receiving.

I’ve never had the pleasure of FC0012, so no idea what’s inside the dongle, but those loaded with the 820 are very sensitive to low voltage supply. Try a ‘better’ PSU and see if you can get the tuner to lock.

The 820T datasheet claims 42MHz to 1002MHz, but obviously we can squeeze more that out of them.
Perhaps the FC0012 will surprise us.

It’s not that the PLL isn’t locking, the driver isn’t even trying to program it.

see https://github.com/osmocom/rtl-sdr/blob/master/src/tuner_fc0012.c#L231

Oh, I see your point.
Reading that code suggests changing the reference crystal to 36MHz (from 28.8MHz) may put 1090 into a valid range. Amusing to try, but I’ve seen one claim that the FC0013 goes to 1100MHz, so that’d be an easier start point.
The manufacturer claims the FC0013 & FC0014 can receive GPS (1575MHz).
This review of the FC0013 suggests poor performance on 1090MHz using the supplied antenna (no surprise there), but a decent antenna may give vastly better results. I say ‘vastly’, because GPS operates below the noise floor and any receiver capable of pulling useful data from that weak a signal could be really impressive for ADS-B.