Bottom line guys is that just because you are not transmitting does NOT mean that you can compromise the quality of your antenna system. That antenna is your gateway to the ADSB signals that are in the airwaves around you..compromise that and you compromise both the amount of signals that you hear as well as the quality of those signals compared to the surrounding noise/other signals etc.
The front end (business end) of many of these ADSB receivers is very broad (meaning not very selective signal wise) so if you use less than the optimum antenna system connected to it then you are simply not going to see the results that you are looking for. Mobile phone antennas are not the way to go !!!!
Go buy the right tools (antenna, coax, etc) for the job then once you have the correct basics in place then you can work on enhancing the system by adding different types of antennas/preamps/front end filtering etc...all designed to add capability to that all important antenna system. I have been a ham radio operator for many years..specializing in frequencies from VHF and up to over 2 Ghz which is higher than the ADSB freqs that are in use currently.
Just because you dont live in an optimum location (up high on a hill) such as Cairns doesnt mean you cant get a lot of extra performance out of the system you have and still get much better better results than you probably first thought possible
