FlightAware Discussions

978 Mhz decoder


I left the 978 decoder running for an hour with no luck to get anything on the screen.

any hint?

$ rtl_sdr -f 978000000 -s 2083334 -g 48 - | ./dump978
Found 1 device(s):
0: Realtek, RTL2838UHIDIR, SN: 00000001
Using device 0: Generic RTL2832U OEM
Found Rafael Micro R820T tuner
Exact sample rate is: 2083334.141630 Hz
[R82XX] PLL not locked!
Sampling at 2083334 S/s.
Tuned to 978000000 Hz.
Tuner gain set to 48.00 dB.
Reading samples in async mode…


I’m using the same a VHF/UHF antenna that works fine for 1090 Mhz on the same dongle.


Wait for the new dump978-fa to be announced on Friday.
It should be a lot more reliable than the older dump978 (I have to restart mine every hour).

Mostly low flying, GA aircraft use UAT 978. The range is considerable lower than ADSB-1090Mhz.

This is my airspy setup on 1090 Mhz

This is my rtl-sdr setup on UAT 978 (I’ll change it to airspy shortly)

The Antennas are basically in the same location. Both setups use hab/nevis amps with cavity filters and LMR400 coax.

Had UAT running here with a home-made antenna tuned for 1GHz, maybe received 1-2 flights per day a few months ago. Interesting was picking up some weather data from the nearby airports I wasn’t expecting. Had an earlier dump978 running on an RPI2b, needed to be re-started every day so added a chron. Was expecting more traffic being close to the US border, might be more traffic now though and looking forward to checking out the new software release when available.

1 Like

Thank you Jon for the details. appreciated.


Anyone in Greater Seattle Area managed to get a single 978Mhz message?

I don’t understand what could be the issue!!