Realise this is off-topic, but why are you hanging out in such a dangerous place QDMx3?
North Devon is very uncrowded generally, so I reckon it's unlikely one will bump into anything, even at 500 feet. And you see a lot more from that height. No point flying a cub at 2,000 feet. That's practically stratospheric!
Anyway, posted this question on the military board and they said no frontline jets are fitted with TCAS yet, so bang goes that theory.
QDM