I have experienced the same problem at my station. 10-160 meter vertical, LMR600 coax, Morgan RF Systems M-300 coaxial arrestor, HF-Auto Tuner, LA-1K Amp. I had the most trouble when operation on 75 meters. High SWR, Overdrive, TX delay. Mark told me to remove the arrestor and so far the problem has not repeated.
Mike
