For some reason I wasn't getting the normal output power from my Flex as the exciter to drive my THP 1.5 amp. I tried cycling power on the Flex and still no change. Finally for the heck of it I tried the frequency calibration on the Flex and then it went back to full output power. This happened one other time and I did the frequency calibration and once again it fixed it. Fast forward to tonight and one of my Flex Friend converts was on his radio and the power dropped driving his amp and he was flummoxed too. I then suggested the frequency calibration trick and he fixed it right away. Can anyone explain why this works? How can a frequency calibration tie into a power crow-bar circuit?