FlightAware Discussions

Announcing the new 978 MHz antenna!

Thank you very very much for your offer, but I recently purchased and installed another FA 1090 antenna.

UAT traffic is very light here in Canada. I’m not sure it would be worth the time, effort, and money.

Thanks again, appreciated.

Fantastico!! ne avrò uno!

è fantastica l’antenna 978 MHz

I bought several highly-selective ISM band machined cavity filters and re-tuned them to 978 MHz. I’m using one in my UAT receiver and it blocks local 900-930 MHz signals by over 40 dB.
They are listed on eBay if you want one: 978 Cavity BPF.

Kind of an embarrasing thing happened to me regarding tracking UAT aircraft. Decided to raise the antenna by adding another 10ft mast about a week ago. I took off the feedline and found a long USB cable to run up the mast to the dongle, and used an N-SMA adapter to connect the antenna to the flightware filter then to the dongle. Plane count dropped to zero, nothing but a couple of pings all week. Really odd after removing feedline and raising the antenna…
Well I checked things over today and found I had used an N to RP SMA adapter accidentally. The RP adapter had no center pin in the male end… Replaced with the proper “regular” N-SMA adapter and just tracked a plane through the area up to CYWG almost to the ground.
WATCH THOSE ADAPTERS! :slight_smile:

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The prevalence of RP SMA stuff due to its use for wifi was really the bane of my existence in the early days of our ADS-B experiments.

Has anyone used this diplexer?

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This looks interesting

Has anyone tried this antenna? Just got my 1090 antenna and a raspberry pi zero up and running (mounted the pi right at the antenna) now looking into tracking 978 UAT also and while searching antennas I came across this antenna:

Thanks for any information.

I’m using the ADSBx Dual Antenna and the Stratux splitter/filters with two FA Orange sticks. I see no degradation in ADSB (250 nmi) and see occasional UAT out to 70 miles.

Burning in at my house before going up on a 4100’ mountain outside Yosemite overlooking the Central Valley.

Thanks W6cz!! Question though: Do you need two Orange Sticks? I was thinking I could do it all with one orange stick and a raspberry pi zero w and this antenna. Currently doing the 1080 with the FA 1080 antenna and the blue stick and no problem at all around 50% CPU. I was thinking I had room to add the 978 part and continue on.

Thanks Again!! Norman (KA1IJA)

You need a separate dongle to receive a 2nd frequency.

One dongle can only be tuned to one frequency at the same time.

The pi zero CPU isn’t fast enough to handle dump978-fa either.
(It might work, but surely not with anything else running.)

You need 2 dongles for the 2 frequencies. They are too far spread for one. I use Orange sticks because they don’t have an internal filter. Using a blue for 1090 might result in poor performance due to there being 2 filters in line. Maybe I should buy one and see

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After the LNA the additional attenuation of the SAW filter is not noticeable.
Performance should be equal or better.

Thanks Alot for the update!! I will order the parts now to get up and running with 978. May have to swap out the Pi zero for a Pi3.

@esmathews - I tested this antenna on my Rigol 815TG and got the same results (RL better than 20dB @ 978MHz). It is unusual to find an antenna that is resonant on only one frequency. Is there a built-in bandpass filter? Do you have any thoughts about using this antenna for transmitting on 978MHz? (outside of the US of course).