so ive been running my FT-857D for about 3 years now mostly mobile and it's been fine but ive always felt like the receive on 40m especially was a little soft compared to my buddies IC-7300 whenever we'd operate portable together. figured id look into the Collins filter mod and also ended up going down a rabbit hole on the IPO/AMP switching and noise blanker adjustments.

ended up doing the RX preamp tweak that floats around on eham, basically adjusting the bias on the front end slightly, and also added a Murata ceramic filter in the first IF stage which i got off a guy parting out a 756 Pro. wasnt cheap but the difference on a crowded 40m SSB segment is actually noticeable. the noise floor dropped maybe 2-3dB by my estimate which doesnt sound like much but in a pileup its a real difference.

also did the extended TX mod since im licensed for it anyway and the MARS/CAP mod was straightforward but thats pretty well documented everywhere. the IF filter thing took me a couple hours and a few choice words when i dropped a screw somewhere in the chassis.

anyone else done mods on the 857 family? curious if theres anything im missing that made a meaningful difference for you. ive seen people talk about the AGC mod but not sure if its worth the hassle on a rig thats already 10+ years old.

yeah the AGC mod is worth doing honestly. the stock AGC on those rigs is way too aggressive for weak signal work and once you slow it down a bit you can actually hear stations fading in rather than the rig just clamping down hard and releasing weirdly. there's a cap swap in the AGC loop, pretty sure its C1045 or somewhere around there, dont have the schematic in front of me right now. took me maybe 45 minutes and it changed how the rig felt to operate more than almost anything else i did to it.

the murata filter idea is interesting, i hadnt heard of pulling one from a 756 Pro for that purpose. what shape factor did you end up using and did you have to do any impedance matching or did it drop right in? asking because i have a 897D that has pretty much the same front end architecture and im always looking for an excuse to crack it open.

i did the mars mod on mine years ago thats about as far as i went lol. maybe im leaving performance on the table but the rig works good enough for what i do. the 7300 comparison is always gonna be rough because that ADC front end is just a totally different design philosophy, almost not fair to compare them. that said if youre getting real results on 40m in a pileup then hard to argue with that.