I got a 100W dummy load and the max power output I could get from the Icom 7300 was 75-80% using RTTY.
Next I checked the output of my MFJ power supply. Lo and behold the voltage out was only 13.0V with no power draw even though the knob was on the 13.8V detent. It is a fussy knob but I managed to raise it to 13.7V and test again - sure enough full power output on the 7300.
I think I’ll replace the power supply, I just don’t trust the voltage knob to stay put out of the detent.
#amateurRadio