We're deep in a valley, and have always had major problems with weak signals, so I fitted a masthead amp a few years back. Recently I've had to change PVRs, and the new one is struggling: it comes up with a picture, then freezes. I got a new masthead amp, but it's made no difference. I've decided step one is to move the amp from its current position - maybe 20 feet from the aerial - to the aerial itself. The only remaining question being, which amp do I install? The old one, which I've noticed is 27db, or the new one, which is 13db? Anyone have any idea?