Pw... I know about HF, etc. LATCC sectors use VHF transmitters far remote from Swanwick, eg Davidstow Moor in Cornwall. These transmitters are used to provide service to aircraft over huge areas and it just struck me that 5 watts erp is a bit weeny! (I'm a licenced radio amateur as well as being an ATCO so have a fair knowledge of radio communications). I have an amateur radio 2m (145mHz) walkie-talkie which runs 5 watts and short of sticking its aerial into a portable radio I can't cause any QRM with it. That's why, even more so, I don't understand the person in Warminster getting ATC transmissions on his radio (if that's what they were).