Dual FA bandpass filter

[Barny70]

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.

[anon69157259]

I got the same antenna here from FA.

[geckoVN]

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

[ericcarlson]

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

[n112]

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.

[geckoVN]

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).

[n112]

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.