so ive been putting this off forever but finally got around to doing the MARS mod on my IC-7300 last weekend. pretty straightforward once you find the right jumper, took maybe 20 minutes including the time i spent second-guessing myself and looking at the service manual three times. expanded TX works fine, not that i actually need it day to day but its nice to have.

while i had it open i also reflashed the firmware to the latest version which i somehow hadnt done in like two years. the waterfall does seem a little smoother? hard to say if thats placebo or real. the DSP filter changes in the newer firmware are supposed to be improved but honestly on SSB i cant tell a huge difference. FT8 is FT8, doesnt matter.

what i really want to do next is look into the modifications people have done for the noise blanker — ive seen some threads on other sites about tweaking the NB aggressiveness but im not sure if thats a software thing or if theres actual hardware involved. anyone done anything along those lines on the 7300 specifically? my noise floor here is pretty brutal from a neighbors solar inverter and the stock NB only does so much.

the NB on the 7300 is mostly DSP-driven so there isnt a ton you can do on the hardware side without getting into territory that would probably make things worse. what i did find that actually helped was playing with the NB depth and width settings in the menu — most people leave them at default and they're honestly not optimized for inverter-type noise which tends to be more periodic than impulse noise the blanker is really tuned for.

if you havent already, try setting NB width to around 3 and depth somewhere in the 8-10 range and see if that does anything. also the notch filter in auto mode can sometimes catch inverter harmonics better than the blanker depending on the frequency. i spent a while messing with this when my neighbor put in a solar setup and that combo helped more than i expected. still not perfect but workable on 40m which was the worst band for me.

yeah i did the mars mod on mine about a year ago, same experience, no big deal. one thing i'll say is make sure you documented which jumper you moved because i almost forgot and had a mild panic moment when i was thinking about sending it in for the display issue i had later. icom service would have flagged it immediately.

for the noise problem honestly have you tried a bandpass filter on the input? i know its not a rig mod exactly but i threw a 40m BPF in line when i was having similar issues from some switching supply in my own shack and it cleaned things up more than anything i did in the menu settings. just a thought.