978 MHz antenna for UAT


#1

If FlightAware were to offer a 978 MHz (only) antenna for UAT at a similar price point to our existing 1090 MHz antenna on Amazon USA ($39.95), would you buy one?

  • Yes
  • No
  • Not applicable to me (I don’t have a site in the USA)

0 voters


#2

Question is if will they interfere if installed close (same mast)?

Also it might be interesting if it will be a wide-band antenna (or not so wide, just to cover 978MHz and 1080MHz), that will feed two receivers via a active/passive splitter at the other end. This will simplify installation.
A 1030MHz central frequency, with 3dB fall at the +/-50MHz from center would be fine. 3dB loss is usually acceptable, most of the users here run the receivers with gains 10-20dB below the max (50dB), so they will just have to add 6-8db to that antenna setup (to include -3…-5dB from splitter).


#3

Most antenna have a near field effect that extends to around the signal wavelength (about 10inch for ADSB). In actual use you will probably not see much of a difference even if the antenna are placed side by side. I had multiple ADSB antenna within 2-3 inch of each other and didn’t see any major effects.

We did try some “dual band” antennas. They have their own problems (tuning two frequencies) and require more filtering (they pick up a lot of stray signals).

The poll question above is for a 978MHz antenna for the USA market. At the moment only the US has UAT planes. Also, FlightAware will develop the piaware solution for UAT. Right now the UAT sites are custom built and not the easiest thing to setup.


#4

David…would Flightaware also be sending out Feeders like you do for the 1090 MHz side? If not, it would be great if you sold the feeder kit.

I live on the perimeter fence of a GA only airport in the North Idaho back country and would love to see all the aircraft flying up here.

Edit: yes, I would buy one


#5

Yes I would buy one, instantly.
But lets talk a little bit more david.baker. I would assume that also a improvement in Dump978 is in order?
Right now my 978 monitoring activities are done with the installation of Dump1090 Mutability and the UAT data is going no where. I just purchased a FA Pro Stick (orange one) to dedicate to 978 UAT for my area. I hope there are plans in the future to improve Dump 1090 FA package so two dongles are used at one time.


#6

It certainly does go somewhere. I have a separate 978 antenna, Pi, and dongle feeding a dump1090-fa in net-only mode. The UAT 978 data I feed to FA shows up in Skyview and FA’s tracking logs. It’s quiet during the work week, but many 978-only GA aircraft show up here on the weekends, and in turn to FA’s track logs and in my aircraft counts.


#7

SMBurn,
So I can feed from my same location as a different site? If I did set my second Pi up as strictly 978 feeder then will that screw up my first site settings on Flightaware?

Thanks.
Glenn


#8

I feed my 978 stuff to dump1090-fa on port 30001, so it doesn’t appear as a separate site in FA stats. I’m guessing that running and claiming another piaware site instance is what you’re asking about, but I don’t have any experience with that. I trust somebody more knowledgeable with that will come along here.


#9

I have one site that is just for dump978.


Just run it in -net mode and feed it on port 30001.


#10

So that means three Pi? One for 1090, one for 978 and another one in -net mode to sum the signals?
Right now, with Joe’s script, I can run two receivers (978 and 1090) on only one Pi. But the 978 doesn’t get reported.

I would like an solution for the official software for the UAT to offer the option of adding the dump978 on the same Pi. And integrated in Flightfeeders. Maybe?

But yeah, firstly I would need a better antenna than what I have now.


#11

You can do it all in one RPI.
Just feed 1090 normally and feed 978 in on tcp 30001. My 978 traffic is uploaded to FA.

I just have it on a different one so I can see the difference.


#12

Yes, it’s doable, but the dongles must be re-serialized, if I recall correctly.


#13

Yes, it is easy, but only if they are identical. In my case, for 1090 I use a FA Pro stick and that already has a different serial than the generic one that I am using for 978.


#14

If you have more than one dongle then each will have a unique device ID.
You can set the one for dump1090. use setting rtlsdr-device-index

For rtl_sdr (the feeder receiver for dump978) you can use the -d command to specify the device ID.

As long as they are plugged into the same USB ports then they should come up as the same devices. If you set serial numbers then it makes it more deterministic.

You need to ensure that dump1090 is listening on tcp 30001 (AVR input). I have to look at my config for this(I can’t do that from my office PC). I don’t think that this is enabled by default in later versions.


#15

This is what I was planning, reimaging my second Pi with Pi aware, using the dongle I ordered for 978 UAT and just tell Dump 1090 to be in -net mode only or can my first Pi that is already running Pi Aware as a 1090 Flightaware feeder use the -net option in the config and still provide 1090 and 978 at the second time with both dongles installed and running?


#16

Would Flightaware also be sending out Feeders like you do for the 1090 MHz side?

I can’t say how many free UAT (978MHz) units we will send out. We already have a system for FBO to apply for free ADSB hardware. This will probably be extended to UAT also when everything is done.

This poll is for retailing the UAT antenna part. The rest of the prostick and filter parts are usable for both frequencies.

I would assume that also a improvement in Dump978 is in order? I hope there are plans in the future to improve Dump 1090 FA package so two dongles are used at one time.

Using multiple dongles on one Raspberry Pi is already possible. The setup is a bit hard to do at the moment and will be made much easier.

on flightaware.com/adsb/piaware/advanced_configuration
rtlsdr-device-index SD card installs only: for receiver-type “rtlsdr”, configures which dongle to use if there is more than one connected

So that means three Pi? One for 1090, one for 978 and another one in -net mode to sum the signals?

The plan is to make it so you can either have one dongle and select either ADSB or UAT. Or have two dongles installed and select to capture both. This would require an ADSB antenna , UAT antenna, 2 dongles hooked up to a single Raspberry Pi for the both option.


#17

That would be awesome. I had this setup working for while, but I was hampered by the lack of a good antenna.


#18

I was getting ready to say the same. Two dongles, one PI I have and I have the antennas already installed and ready to use. BTW for what it is worth, My Flightaware pro stick has arrived and just in
time for 978 use… I have two pro stick pluses and now the pro stick.


#19

I use the DPD 978Mhz antenna. It is a great antenna but far too expensive for most people. Something the price of the current 1090Mhz antenna would be great.


#20

The FA Pro stick has a 1090MHz filter inside, it’s not good for 978MHz.