One of these meters you attach to your caravan ariel to help you find the strongest digital T.V.signal its suppoised to light up more of the green lights the stronger the signal they are on sale on E.bay for about £12.Are they any use ?
local "houses"; sorry its been a warm week-end!Our is a Lab gear one from TLC:
http://www.tlc-direct.co.uk/Products/MX27866R.html
It works pretty well most of the time in finding the best way to point the directional aerial before you initiate a "search" for digital channels.
It's used on the end of the coax cable that would plug into the TV [Status amplifier turned on]; find the best direction then unplug it and put the cable into the TV and initiate a channel "Search".
Sometimes there simply does not seem to be a "best" direction and your are back to looking at the local hoses.