working on a 500T with issues in the MPX section (well, actually its a 440T with the guts of a 500T). I have never seen anything like the issue it's having so I am looking for suggestions. Basically, I am able to hear what I think is the 19KHz Tone, the L channel comes through clear with the stereo beacon lit but the right is a mess of noise and a tone that seems to be residual from 19khz and is based on the signal strength and Z403 alignment. The board was doing this before I put new caps in it, unfortunately, FM tuners are my weakest point.