so ive been running an old TS-570 for probably 8 years now and always told myself i didnt need to upgrade. buddy of mine kept showing off his 7300 at every club meeting and i finally caved last month when i saw a decent used one come up on qrz classifieds.

first thing i noticed honestly was just how much easier the waterfall makes everything. i know thats what everyone says but its genuinely kind of hard to go back once you've used it for a while. was spinning the VFO on the 570 basically by feel and memory and now i actually see whats happening on 40m which is kind of embarrassing to admit took me this long to experience.

the audio is also noticeably better both TX and RX, had a couple guys comment on it unsolicited during rag chews which i wasnt expecting. still getting used to the touchscreen menus, some stuff is buried kind of weird but im getting there.

one thing though - im getting a weird low hum on receive on 160m specifically. doesnt seem to be RFI from the shack, already checked that, and it goes away if i disconnect the antenna. tried a different feedline run too. anyone dealt with something like that or should i just be looking at my antenna system more carefully before i blame the radio

congrats on the 7300, its a solid radio. the 160m hum thing is almost certainly not the radio itself, icom's done a pretty good job shielding those. my first guess would be common mode noise coming down the feedline - 160 is brutal for that because the wavelength is so long it picks up all kinds of garbage. a stack of mix-31 toroids clamped near the radio end of the coax fixed a similar issue for me on 80m. also worth checking if the hum frequency corresponds to anything in your house, like 60hz or 120hz harmonics, could point you toward a specific appliance or switching supply thats coupling in somewhere.

the waterfall thing is real btw, i resisted for years and now i genuinely dont know how i found signals without one

yeah i went through almost the same thing swapping from an older kenwood to the 7300, the learning curve on the menus is real but after a month or so it just clicks. for the hum have you tried running the radio on battery temporarily just to rule out your AC line? i had a ground loop issue once that only showed up on the lower bands and it drove me nuts for weeks before i figured out it was my shack power strip doing something weird