Hi,can anybody help.i have a gti 1500,its fine when the sun is out and the ground is dry.Its also fine when the ground is damp for about an hour,then it starts to false.I have to have sensitivity down to 6 and still it will sound off when there is nothing there.I have changed the coil,the batteries.can these detectors be serviced.The last time this happened the detector went barmy giving a constant falsing like it was on a big tin can,even when you put the coil in the air.I ended up chucking the coil and it was fine with the black one on.Months later I'm getting slight falsing when the ground is damp.i have tried it without the coil cover and still the same.Today i went out for two hours in the sun and dry and not a whisper,sensitivity at 7.Any ideas,I'm lost.also yes i have tried changing frequency and resetting the detector.it looks like my gti don't like the wet weather.Guess the AT PRO will have to come out to play when it rains.