ADS-B Dual 978 MHz + 1090 MHz Band-Pass SMA Filter

This is an excellent filter. Especially considering the price. The name "ADS-B 1090MHz" leads one to believe it's only for 1090MHz but it is actually a rather wide bandpass filter covering 978MHz as well. I measured this unit on my Site Master S120 in gain/insertion loss mode (didn't feel like setting up the HP SA and sweeper) and my results are similar to a previous reviewer. Approximately 1.6 dBm loss at 978MHz and 1.1 dBm loss at 1090MHz. Attached photos show the results. (Don't mind the squigglies on the screen - the LCD was damaged due to cold weather.) Subtract 2.0dBm from the values on the screen to account for cable and connector losses. 3dBm edges are at 943 and 1183 and 20 dBm down are at 906 and 1233 so it's got fairly steep skirts. In practice it works well and I found that using this filter and the FlightAware SDR stick with the built-in LNA captured significantly more aircraft than a basic NooElec Nano2+.That said, it would be better to have a narrow filter with about 5MHz bandpass at 1090 and a separate narrow filter with 5MHz bandpass at 978. Why? Well, the SDR's have no front-end filtering and with a bandwidth of 943 to 1183MHz everything in that range is presented to the SDR device including transponder outputs and all kinds of other aviation related signals we don't care about which can overload the input of the SDR.Even though it's a very wide-band filter and I'd prefer to have a more narrow 1090MHz specific filter, I give it five stars because the build quality is good, it works better than anything else available in this price range, and it's an amazing value. Until I find some narrow 978 and 1090 specific filters this is what I recommend.

This filter works great. I have a TRS tower not half a mile from my Antenna & when I went to put an amp on my ADS-B antenna my reception just died. It was believed that I was amplifying the RFI & overloading. So, placed this little gem from the antenna and then on the way to the receiver I placed the amp - now I'm really pulling in the signals. Maybe, doubled my reception range? If not doubled, pretty darn close. If you want to do ADS-B in a serious way, this is a must have. The price is fair for the results it brings.Placement is as follows: ANT - THIS FILTER - AMP - RECEIVERUPDATE: This filter has died. Far to early & out of warranty/return eligibility. It worked so well for awhile but I can't afford to replace this filter every other or every few months.UPDATE: After trying to get this resolved (see comments) I gave up. I tried again here towards the end of July. I got to talk to people! In a nutshell, it was my fault it died. I didn't realize that these are NOT WATERPROOF - I was using mine outside on the antenna's mast. Even so, they wanted to send me a replacement. It just arrived & I wanted to update my review. So, do not place these filters outside without some sort of WATERPROOF protection! TYVM FlightAware!

I've been enjoying learning more about ADS-B and have had fun putting together a Raspberry Pi running PiAware to see what's flying by my window. While the plan is to ultimately mount an antenna outside, I'm first learning/tweaking the setup indoors with a 1090 antenna propped up against the interior of a window.As I live in a congested urban area, and I happen to know there's a cell tower about 2500 feet from my house, I figured I'd try out the SMA filter *despite* my already owning the FlighAware ProStick Plus with the built-in filtering. Putting the SMA filter own increased the traffic I could pick up by a factor of two, and it extended my visible range by about 1.4 nm.The range and numbers are much greater when I do a comparison while my hand holds the antenna outside the window. Once mounted externally I'll have a much fuller view of the regional sky.

Insertion loss is is -1.35 dB at 1090 MHz. The filter response is good, with the passband spanning from 942 to 1187 MHz. I would like to see lower insertion loss, and would be willing to trade that off for filter response. I use the FlightAware 5.5 dBi (i.e. 3.3 dBd) antenna, fed with 40 feet of LMR-600. The combined insertion loss of the filter and the feed line cancels most of the gain of the antenna. The -1.35 dB insertion loss of the filter cuts down the number of aircraft observed each day from just over 600 aircraft per day to just under 500 aircraft per day. I'd run without the filter if I didn't have a 500-watt transmitter antenna 12-feet away from the ADSB antenna. The attached plot (performed with a normalized and calibrated spectrum analyzer) shows that the filter does function quite well at the job it was designed to perform.

I bought the orange SDR a few years back to identify the traffic landing in front of my balcony at the airport a few miles away. I was happy seeing ten to twenty in front of me. I live in a high rise in a valley and can't have a visible "good" antenna. I changed out to the blue stick and my numbers went to 30 to 50. I added the filter and now I get 70 to 130 at a time and even see trafic 150+ nm away over Mexico.I'm adding a 978 for GA traffic and ordered another filter to go with it.

I bought this filter to see if I could improve my Fliteaware blue dongle and tuned antenna with LNR400. I guess my limits aren't due to cell towers or other RF overloading my blue dongle because the filter reduced my reception envelope by 5 - 10%. I use adsbSCOPE v 2.7 to plot max range envelopes. Comparing my before and after envelopes (with the insertion of the Band-Pass filter), I can say the filter only degraded my location. YMMV Your mileage may vary...+++UPDATE - I broke the code. Tuned 1090 Antenna with LNR400 > (this) ADSB Band Pass filter > LNA4ALL (low noise amp) > blue dongle. Now I am starting to blow out my envelope :)