I recently purchased a Jammer tester off Chris. The thing works because my Rx-65 goes crazy when I turn the thing on but my blinder doesn't make a sound at all . To make matters worse, I tested it on my next door neighbours blinder and That doesn't make a sound either. I've tested it at all different angles, positions, distance's on mine and my neighbours and it does not make a single sound. Both units power up correctly with a tone and the green light is on. Does anybody know whats going on??