In my 8660C RF plugin, the output is present, but VERNIER control cause about 40 dbm swing from max to min position. Meter show just a 0,5 dbm swing, and needle is around center scale. I have already tried to replace some cards (A3,A10, ecc..) taken from an worked unit, but with no success. Is this a common fault for that unit? Any suggestion?
Thanks.