FlightAware Discussions

Dual FA bandpass filter

Does anyone know the specs for the FlightAware dual UAT + ADS-B filter? Is it the original filter with a new label? (The part number is the same: PCT-BPF-980-1150.)

From a retailer here in Australia I ordered what I thought would be a 1090MHz filter (which reportedly passes 980-1150MHz) but what turned up was a combined 978MHz + 1090MHz filter - not the same item shown on their website. I’m curious as to what its working range is, mainly because 978MHz isn’t used in Australia for ADS-B related activities.

I got the same antenna here from FA.

I suspect it is the same internally as the original was a series coupled high-pass and low-pass filters with quite a wide pass-band.

Depending where you are located, the 900MHz band uses a down link that goes up to 960MHz, that filter won’t help.

Australian Mobile Frequencies

It is the same product. The label (only) has been updated.

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Although the filter has a male connector on one side and a female connector on the other side, are the electrical characteristics symmetrical? in other words, does it make a difference which side is connected to the antenna and which is connected to the receiver?
Are the filter characteristics available such as center frequency and bandwidth, etc.?
Thanks.

As above, the FA filter is made using two filters in series - a high-pass and a low-pass.
It makes no difference which you filter first, so no, it doesn’t matter which way you insert it in your feed.

As for the filter characteristics, have a look at this thread - FlightAware ADS-B filter VNA measurements.

For clarification (or to be pedantic) the filter is a ‘wide band-pass’ design, not a ‘dual band-pass’ design (as per the title of this thread).

Thank you for your swift answer with link (FlightAware ADS-B filter VNA measurements) to filter plot with some data.
To summarize, the VNA display shows that the BW is 230.99 MHz, the center is 1.0726 GHz.