so ive had my IC-7300 for about two years now and just last weekend i finally got around to doing the MARS/CAP mod to open up the TX range a bit. mostly wanted it for some EMCOMM stuff where we occasionally need to operate just outside the normal ham allocations during drills, and also just to have the flexibility honestly.

the mod itself was pretty straightforward, just the jumper on the board, took me maybe 20 minutes once i had the case open and could actually see what i was looking at. the icom service manual is pretty clear about which jumper to clip. transmit power seemed basically identical across the board after, no real change there, and the ALC is behaving normally as far as i can tell.

what im curious about is whether anyone has gone further than that — like the firmware stuff some guys talk about, or any other internal tweaks that are actually worth the trouble. ive seen some posts about modifying the noise blanker behavior but i cant tell if those are just placebo things or if there's real improvement. not looking to turn it into something it isnt, just curious what mods people have found genuinely useful vs. the stuff that sounds cool online but doesnt really do anything in practice.

the MARS mod is basically a no-brainer on that radio if you do any EMCOMM, good call. i did mine the day i got it out of the box honestly.

as far as going deeper — the one thing i actually found useful was tweaking the filter settings in the menu rather than hardware stuff. the 7300 has a lot of DSP headroom that most people dont bother dialing in. the NB on that radio is decent but its really sensitive to the threshold setting and most people just leave it on default which isnt always optimal depending on your noise floor. spend an hour playing with NB threshold and NR depth on a noisy band and you'll probably get more out of it than any hardware mod would give you.

the firmware stuff i've seen floating around is mostly sketchy third party things and i wouldnt touch it personally. icom pushes legit firmware updates and those are worth doing obviously, but the underground firmware mods seem like a good way to brick a radio you paid real money for.

yeah i did that mod too, mines been running fine for like 8 months since. one thing i noticed — and maybe this is just my unit — is that transmitting way outside the ham bands the final seems to run a little warmer so i try not to do it for extended periods. probably nothing to worry about but its in the back of my mind.

someone in my local club swapped out the internal fan on theirs with a slightly higher CFM unit because he does a lot of FT8 and was worried about thermals during long duty cycle stuff. said it made a noticeable difference. i keep meaning to check my temps more carefully during a long digital session but havent gotten around to it. not really a performance mod but kinda related i guess.