I have a D&A PDX-400 and the SWR trimmer (small tuner knob) in the back had went bad and I replaced it with a new trimmer but it still didn't fix the problem. The SWR between the radio and the linear is sky high. Before the stock one went bad it was always good. Any ideas of what's going on with it or how to fix or bypass this completly and get a good SWR between the radio and linear?? It worked Excelent befor the trimmer went bad. Output was 800-850 watts. Any help would be very much appreciated.