ADS-B antennas! I've experimented with all sorts over the years, but it's only since I started feeding data to more that one site that I've really been able to directly compare one against another.
What I have learnt is that cable loss is a huge factor and a fantastic antenna and a long co-ax results in disappointing performance. I don't currently have an external antenna, so all my testing is with indoor antennas at the moment. To-date, the best performing antenna I had was a very old SBS-1 mag-mount with about 3m of co-ax. However, even the cheapest and nastiest (and tiny) mag-mount antenna as provided with most DVB-T sticks and cut down to 68mm with it's 1m lead is almost as good as the SBS-1 antenna.
Having trawled the Internet, I now present the 'Tuna-tin Antenna' made from a 160gm tuna tin and an SO-239 chassis socket. It's certainly not an original idea so I don't claim any credit for this, but the performance even indoors is most pleasing. I've got about 2m of RG58A co-ax of uncertain parentage into a FlightAware Pro stick feeding to RadarBox24, FlightAware, RadarBox24 and PlaneFinder. The antenna is on top of a cabinet that is surrounded by brick walls and plasterboard with the silver foil backing (the photo on the window ledge is another Tuna-tin driving an SDRPlay SDR and Dump1090 into Virtual Radar giving similar results).
I am awaiting a 1090MHz filter because there is a fairly strong cell signal at around 950Mhz, but in the meantime I'm suitably impressed by the results.
Maximum range isn't breathtaking, averaging just over 100 miles in the Eastern sector and a bit less to the West, but the Tuna-tin is the best performing indoor antenna I have at the moment.
