so ive been chasing this one for about three weeks now and im starting to lose my mind a little. my 7300 started dropping output maybe a month ago, used to put out a solid 100w on all bands, now im seeing maybe 30-35w on 20m and it gets worse as i go higher, like on 10m im barely getting 15w out. SSB and CW both affected.

before anyone says ALC — yes i checked. ALC is not pegging, its behaving normally. drive level looks fine on the screen. ive reseated all the internal connectors i can get to without going too deep, checked the fan is spinning, radio doesnt feel like its overheating. SWR is fine, antenna hasnt changed. tried two different dummy loads.

did the usual reset to factory defaults, no change. firmware is current. the weird thing is if i drop power to like 25w it seems... almost more stable? like the ratio of actual output to what im asking for gets a little closer but still not right. it just feels like somethings degrading in the PA stage but i dont want to assume that and go chasing ghosts. anyone dealt with this on a 7300 specifically?

had almost the exact same thing happen to mine about a year and a half ago. turned out to be one of the finals starting to go — i think it was one of the RD70HVF1 transistors but honestly i sent it to a shop so i cant say for certain which one was the culprit. the symptom was pretty much what you're describing, worse on higher bands, output kind of tapered off slowly over a few weeks before i noticed it properly.

the shop said one transistor was leaky and the other was still okay but they replaced both as a pair which makes sense. cost me a bit but the radio has been solid since. if youre handy with RF work you could probably scope the drain voltages on the finals and see if something looks off, but if you're not set up for that it might just be worth sending it in. icom's service network isnt that bad depending on where you are.

check the LPF relays too before you commit to PA work. i know it sounds boring but those relays can get flaky and cause weird band-dependent power issues that look like a finals problem but arent. theres a known thing on some early production 7300s with the relay contacts getting oxidized. you can sometimes hear a faint click that sounds slightly different on the affected band when you TX. probably not your issue if its affecting multiple bands but worth a look since its an easier fix than pulling the finals.