Originally Posted by
kb2vxa
One last thing, I have a bad feeling about this, the last time I heard a tuner "singing" it was internal arcing, the internal balun screaming in pain. This was surprising at first, an MFJ "3KW" tuner arcing with only 100W of AM, modulation struck the arc followed by the hiss of carrier arcing inside the balun. It was more the antenna system than the tuner, a 160M sloping open delta fed with open wire ladder line. It turned out the line was a half wave on the 75M AM Gangsta band sending the high RF voltage at the antenna feed point down to the tuner, baluns like current feed, voltage feed kills them. This is where the old Johnson Matchbox shines over today's tuners, it has a balanced output and one leg can be shorted to ground for unbalanced output, it laughs at high voltage.