I’ll start with I’m fairly new to this. I built a ADS-B receiver on a Raspberry Pi 2B running Raspbian Buster running the flight aware add on with a FA Pro Plus receiver connected directly to the Pi 2B, with a home made cantenna connected via a 3ft F to SMA cable. I’ll also add since the Pi 2B does not have built in Wifi I’m using a Edimax EW-7811Un 2.5Ghz WIFI dongle also directly connected to the Pi 2B.
This setup seems to work pretty well.
I decided to add a 2nd receiver to pick up UAT as I have a few GA airports within 20 miles.
The second receiver I built a 2nd cantenna (for 978Mhz) connected via 3ft F to SMA cable to a FA 978/1090 filter, connected to a FA Pro receiver connected via a USB extension cable. I installed dump978, serialized the receivers, enabled UAT.
My antennas are at the same height roughly 24" apart.
The issue I noticed is adding the UAT receiver dropped my 1090 plane count about 25%.
If I unplug the 978 receiver, my 1090 plane count returns to normal, if I plug it back in, it drops again.
I tried both a 1ft and 3ft USB extension cable on the 2nd receiver with the same results.
I searched the board and saw similar topics but none with any definite cause or fix.
I did a scan on both receivers and there is high noise from 860Mhz to 894Mhz on the 1090 receiver (FA Pro Plus) and from 862Mhz - 878Mhz on the 978 receiver (FA Pro)
I attempted tom move the 978 receiver (FA Pro) to a 2nd Raspberry Pi, by installing dump978-fa there and pointing Skywawre978 on the Pi 2B to it as the feed but while I did see UAT traffic on the local
/skyaware978 dash of the Pi 2B, the data never made it to FA.