Thanks Allocator,
Just tried the frequencies, and still get white noise, so I hold the big hill responsible. Anyway, thanks for the links, very interesting stuff.
I have been using the ANRB for little under a year now, and my interest just grows - my five year old son has also recently begun to take an interest. When we were spotting planes today I asked him if he would like to be a pilot one day, and he said "Sorry daddy, but planes are too big for me to drive !".
All the best,
John with Charlie