How to verify a working FA 978MHz antenna?

FlightAware ADS-B Flight Tracking
1

I live in the Chicago NW suburbs, and recently purchased the new FlightAware 978 Mhz antenna for the upcoming release of PiAware with UAT978 support. When I set it up, however, I was surprised to find no UAT signals in my area.

Are there any other users in my area with no signals? Is there a map of 978-only coverage or activity so I can see if my equipment is functional?

I purchased some new connectors for the antenna, but I’ve even swapped out the cabling from my functional feeder as a test and I still get no results:

New N-to-SMA connectors
https://www.amazon.com/gp/product/B01MFHRW4N
https://www.amazon.com/gp/product/B06WVTHGM2

On a whim I plugged the 978 antenna into a dongle configured for 1090 and got 60 planes immediately… not sure if that is supposed to happen or not.

978 feeder I’m testing: https://flightaware.com/adsb/stats/user/fauser#stats-100115

piaware log excerpt, configured currently for 1090+978:
Apr 6 15:26:08 piaware piaware[464]: 3700 msgs recv’d from dump1090-fa (1171 in last 5m); 3700 msgs sent to FlightAware
Apr 6 15:26:08 piaware piaware[464]: 1 msgs recv’d from dump978-fa (0 in last 5m); 1 msgs sent to FlightAware
Apr 6 15:31:08 piaware piaware[464]: 4949 msgs recv’d from dump1090-fa (1249 in last 5m); 4949 msgs sent to FlightAware
Apr 6 15:31:08 piaware piaware[464]: 1 msgs recv’d from dump978-fa (0 in last 5m); 1 msgs sent to FlightAware
Apr 6 15:36:08 piaware piaware[464]: 6035 msgs recv’d from dump1090-fa (1086 in last 5m); 6035 msgs sent to FlightAware
Apr 6 15:36:08 piaware piaware[464]: 1 msgs recv’d from dump978-fa (0 in last 5m); 1 msgs sent to FlightAware

2

Which dongle are you using?

Maybe you have the dongles mixed up?

3

I have an older Orange Prostick and and Nooelec dongle. I started by configuring only 1 dongle for 978 only based on the commands provided in the 3.7 announcement. Tried both radios individually, but neither dongle showed results.

To rule out a bad Pi I later configured two dongles for 1090 + 978 using the commands to set serial numbers and assign devices to the programs. I am getting results from the 1090 radio and antenna but not the 978 radio and antenna.

4

With UAT it’s going to be even more important to have the antenna where it can see all around.

If the weather is bad then you will likely have far less UAT signals, maybe even none.

2 Likes
5

I see it get down to zero on days when it snows or the weather is bad (wet and windy) for a while.

6

Agreed and understood… it started in my attic but I’ve since brought it down to troubleshoot. Since I’ve confirmed a working radio and working cable now, I’m going to put it back up there.

7

You should probably also experiment with using both of the dongles you mentioned.

If you have strong noise in the area the dongle without integrated LNA might be better for reception.

1 Like
8

https://flightaware.com/adsb/stats/user/jeffs992#stats-108359

I’m near KLOT, new UAT antenna in my attic, orange dongle, dedicated RPI. 2-3 planes. Often 0. I’ve played with gain (my 1090 optimal gain is 44), but really doesn’t make a difference to UAT at least where I am. I am under the MDW Class C and ORD Class B so that probably limits the number of little guys nearby.

Everything looks right radio-wise, I think UAT is just not that common where I am. Which surprises me because I have UAT in my plane (Bonanza). Love to keep comparing notes, fauser. Thx.

9

One consideration is that the gain is much lower for UAT. I have a RPi for UAT with an orange FA dongle set to gain 14. Below are today’s signal levels for UAT

image
image828×431 191 KB

10

Well, you have an external preamp as well for that.

Still trying 28 on the orange FA dongle is a good idea.

1 Like
11

The summer weather is bringing out more of the UAT 978 aircraft. My site in Baltimore sees a few dozen planes per day on 978, a few hundred on a fine weekend. The same site records 4,500 daily on 1090 MHz so clearly Mode S is dominating the ADS-B scene.
Thirty day daily aircraft count from 978 only:image

12

I am the OP for this discussion and I realized I never came back to update this post. I ended up moving my FA-branded filter from my 1090 receiver (blue stick) to my UAT receiver (orange stick) and it made a big impact. There still aren’t that many UAT signals around, but there are enough that I’m no longer questioning if the equipment works.

There are rarely planes flying after sundown so the piaware software restarts itself several times overnight.

uat-rate
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