Hi all, and ingenious suggestion there from fil. As I understand it, using several antennas and a switching system would work. But if you try to combine the signals from more than one antenna, the phasing of the signals from the different sources, albeit only a few feet apart, would be thrown out and either negate each other or act as an echo. I did buy a very high quality ex Govt./ military quality phasing harness from Haydon Comms, who advertise in Radio User, fitted with N-connectors, but still haven't had time to get around to having a play with it. Still using the bog standard (but self water-proofed) antenna outside on the roof very successfully, the SSE 1090 and Watson Radar Extender antennas sitting in their boxes, waiting for me to make up feeder leads from RG213 (the Westflex 103 is so stiff) and attach them to the roof.