so it started with just wanting to extend the TX range on my 857 because i do some MARS/CAP stuff and needed the out of band capability. did the standard mars mod which is just moving a couple diodes on the board, pretty straightforward if you've got steady hands and can read the service manual.

but then i figured since i already had the thing apart i might as well look into the collins filter mod everyone talks about for SSB. dropped in a YF-122C and honestly the difference on a crowded band is pretty noticeable, voices just kind of separate better and the muddiness on weak signals is reduced. not a night and day thing but definitely worth it if you do a lot of HF contesting or DX.

the part i wasnt expecting was how deep you can go with this radio. theres a whole community of people who have done the RX preamp mods, noise blanker tweaks, even some guys reflashing the firmware on the DSP section although i havent touched that yet and im not sure i want to. anyone else gone further with theirs or have opinions on whether the DSP stuff is worth messing with? feels like the kind of thing where you can really brick it if something goes sideways

yeah the collins filter is the one mod i always recommend when someone asks about improving that radio. the stock filter is honestly pretty mediocre for a rig in that price class. i put the YF-122S in mine which is the narrower one and use it primarily for CW, works great. for SSB i agree the C is the better choice.

on the DSP reflash stuff - i'd leave it alone. talked to a guy at the hamfest last year who tried it based on some instructions he found on a dead forum link and ended up with a radio that would boot but had no audio output whatsoever. yaesu wanted something like 200 bucks just to look at it. the performance gains people claim from that are pretty marginal anyway compared to the filter swap which is a real tangible improvement.

i did the mars mod on mine a while back and it went fine but i was sweating the whole time lol. my soldering iron is kind of old and the tip is not in great shape so i was terrified of bridging something. ended up fine but i should probably just get a decent hakko before i try anything more invasive.

curious about the preamp mod though - is that the one where you're adding an external LNA or is there something you can do internally? i mostly do 2m weak signal stuff with mine when im not on HF so any receive improvement on VHF would be interesting to me