Owensy,
I tried my aerial in the loft with USB extenders, but this did not seem to work well, as I kept on loosing communication with RB and had to unplug the USB & reconnect again, to see aircraft.
So I eventually tried extending the aerial cable and put it back in the loft, as an experiment. To extend the cable I went to Maplin and bought some cheap cable RG174 @99p a metre, an SMA coupler, BNC X2 & SMA to BNC X2. This extended my range beyond belief for £18 and it was instant.
See attached DO12 excel file to show the increase.
CAM