Yes I've read the manual. What is the proper behavior of the 6600M ATU. In either Memory or Manual mode, if I press and hold the ATU button it looks to toggle between Tune and Bypass. In the TUNE mode if I press and release the ATU button, the MOX, TUNE and ATU buttons light up red for a half second or less but the ATU does not seek a tune solution. I hear no relays chattering and there is no change of SWR. I get the same results on both ANT 1 and ANT 2 and have tried on different antennas. The un-tuned SWR I am starting with is in the 2.5-5:1 range depending on the antenna, band and frequency. What am I doing wrong / missing?