so this has been driving me crazy for about two weeks now. picked up a used 7300 from a guy at the club, worked fine for the first few days then just started outputting low power across the board. doesnt matter what band, 40m 20m 10m all the same, just sits around 20w when the dial is set to 100w.

i already went into the menus and looked at the ALC settings, didnt seem obviously wrong. RF gain is all the way up. tried a different antenna and dummy load just to rule out the obvious stuff. the radio doesnt throw any error codes and the display looks totally normal. SWR reads fine into the dummy load. its just... weak.

my first thought was the PA transistors but i wanted to see if anyone had run into this specific thing before i start poking around inside with a meter. the previous owner said he never had issues but you know how that goes. anyone seen this on a 7300 specifically?

had almost the exact same thing on a friends 7300 last year. turned out to be the driver stage, one of the small transistors before the finals was running hot and not driving the PA properly. the finals themselves tested fine which is kind of counterintuitive because most people jump straight to blaming the PA transistors.

before you open it up though, go into the menu and find the RF power calibration section, theres a way to check if the radio thinks its actually outputting 100w internally vs what youre seeing at the connector. if the radio thinks its doing full power but the wattmeter says otherwise, that rules out a software/settings issue pretty definitively and points you toward hardware. also worth checking the voltage at the finals with a meter under load if you can get to the test points, icom put some decent documentation out on that.

long shot but did you check if it's still in some kind of low power mode from a contest or something? i know the 7300 can be set to a reduced output and it's not super obvious on the display. my buddy handed me his once at a field day and i thought something was broken, spent like 20 mins before someone pointed at the power setting on screen that i'd just skipped over. probably not your issue since you already looked around but worth a quick sanity check before digging into hardware.