so ive been running my 857D for about 3 years now mostly mobile and some portable ops and lately ive been noticing on 40m especially it just feels like its not pulling in the weaker stations as well as my buddy's IC-7300 does sitting on a desktop. now i know thats not a totally fair comparison since the 7300 has a better front end to begin with but still it got me thinking about whether there are any worthwhile mods for the 857 that actually make a real difference vs just being a rabbit hole.

ive read a few things about the collins filter mod and also some stuff about tweaking the noise blanker but honestly a lot of that info is pretty old and i cant tell whats still relevant. there was also something about replacing the stock BPF board but i dont remember where i saw that. anyone actually done any of this stuff and seen measurable improvement or is it more of a "feels better" kind of thing

not really trying to make it into a base station, just want to squeeze a bit more out of it for weak signal work on 40 and 80

the collins filter swap is legit if you do a lot of SSB, it tightens up the selectivity noticeably especially in crowded band conditions. did it on mine maybe two years ago and it wasnt that hard, just tedious. the difference on 80m phone in the evening when everyones piled in is real, not just placebo.

the receive sensitivity thing though i dunno. the 857 front end is what it is and short of a preamp inline i dont think youre getting dramatically better numbers out of it through internal mods. an external preamp like the SP-200 or even one of the cheaper chinese ones can help on 40 specifically but then you gotta be careful not to blow the front end with strong signals. its a tradeoff. honestly for portable use id just run it stock and accept the limitations before i started poking around inside on stuff that might not move the needle much

yeah comparing it to the 7300 is kind of a losing battle from the start, those are just different classes of radio. but the 857 can be nudged a bit. i did the ref osc mod a while back for better frequency stability which isnt receive sensitivity exactly but it does help when youre trying to zero in on a weak signal and youre chasing drift. small thing but combined with the optional filters it adds up.

one thing i will say is make sure your coax and connectors are clean first because ive seen guys spend hours on internal mods when the actual culprit was a dodgy PL-259 or a connector that had been sitting in a wet bumper mount. not saying thats your situation just worth ruling out before you start pulling boards