Thanks Derekl
I am planning to take your advice but the problem I have is that very few antennas call themselves "Amateur 2m band antenna" and I am trying to decipher the names - with my knowledge that is no easy feat!!!
A discone antenna is a bit of a belt and braces approach, I do have the room and it lets me off the hook, having to pick a specific antenna - and getting the wrong one. Better to spend a few quid more and cover all bases.
I am interested in ACARS reception, but I do live quite near my local airport and do pick up most things from a "rubber duck"
Thanks for your help