AS a further point I believe I am correct that to detect both C/S transponders requires ground support in the form of a ground radar triggering the transponder to transmit. ADS-B from technical spec I think is the only standalone system with no ground support needed. I think if starting from nothing the cheapest is PAW see everything with ground support for FLARM and mode S bearing plus a transponder with ADS-B out covers all bases. An SE2 if a transponder is already fitted with no ADS-B. What do you all think?