Be very careful when you put that pass cavity on the transmit side. When I was in Virginia I had a repeater on 147.06 and late at night I would get interference to it. Noticed the same to other repeaters in the area. Narrowed it down to a repeater that a cavity was placed on the transmitter side to help clear up some desense. Looking at the spectrum analyzer you can see when the transmitter would become active it would have a spur running from it assign frequency up the band to the public service area. This happpened when the transmitter was idle for a while. Removing the cavity cleared the problem.
Again be careful. David
