ERR TXF error message received when attempting low power calibration. No power out on CW or SSB. I have studied the trouble shooting pages in the Owner's manual but cannot find the answer. Any suggestions please? Charles - M0BIN Sorry I should have stated that firmware revisions are: MCU 1.88 DSP 1.70 Using Elecraft Utility version 1.1.4.1 Charles - M0BIN