so ive been running my IC-7300 stock for about two years now and honestly its a great radio out of the box, no complaints. but ive been reading forever about swapping out the stock roofing filter situation and whether it actually makes a difference on a crowded band. ended up pulling the trigger on the FL-5000 optional filter last month and did the install myself, which took maybe 45 minutes if you count the time i spent second-guessing myself before opening it up.

honestly the difference on 40m during a contest weekend was pretty noticeable, at least to me. adjacent signal rejection felt tighter. hard to say if that's placebo or real but i was pulling calls out of the noise that i was struggling with before. could also be atmospheric conditions that day who knows.

anyway the mod itself is dead simple, just the filter and some care not to strip those tiny screws. wondering if anyone else has done this and whether they went further with any other mods — ive seen some posts about the TX EQ settings and the DSP tweaks but havent messed with that stuff yet. also curious if anyone has done the hardware AGC mod that floats around on the forums, never been fully clear on whether thats actually worth the hassle or if the software DSP handles it fine these days.

did the same filter about a year ago and yeah it does make a real difference, not placebo. the stock filter is fine for casual operating but once you're in a pileup or a contest environment you really start to notice where the 7300 falls short compared to a radio with a proper narrow roofing filter from the factory. the FL-5000 doesnt fully close that gap but it helps.

as for the AGC mod — i looked into it pretty deep and ended up not doing it. the consensus i kept seeing was that the 7300's DSP is doing so much of the heavy lifting anyway that hardware AGC tweaks can actually introduce some weird artifacts if you don't get the time constants exactly right. i messed with the AGC settings through the menu instead and found a combination that works pretty well for SSB. theres a thread on the 7300 yahoo group from like 2019 that has a really good breakdown of the attack and decay values people have settled on.

TX EQ is worth spending an afternoon on for sure, even if you dont do any hardware stuff. just playing with the bass and presence settings through the menu made my audio reports way better on SSB. running a decent mic helps too obviously but the built in EQ on that radio is actually pretty flexible once you dig into it.