so ive been sitting on doing the mars/cap mod on my FT-857D for probably two years now and last saturday i finally just did it. pulled the radio apart, found the diodes, clipped D900 like every guide says and put it back together. took me like three hours because i kept second guessing myself and re-reading the same forum posts over and over.

anyway it works, i can now TX outside the ham bands which was mainly the point because i do some MARS stuff with my local group and the workaround we had before was kind of a pain. audio sounds the same to me on HF, havent noticed any difference in receive either. one thing i wasnt expecting is it seems like the ALC behavior changed slightly on 10m but that could just be me imagining things, hard to say.

anybody else done this and noticed anything weird after? also thinking about doing the internal speaker mod at some point because that stock speaker is genuinely awful. or just live with it and use headphones i guess

yeah did mine about four years ago, same diode. never had any issues and the radio has been solid. the ALC thing on 10m youre probably not imagining it completely — i noticed something similar but it was within spec when i actually measured it so i stopped worrying. the 857 ALC can be a little twitchy anyway especially up high in frequency, stock or not.

the speaker mod is definitely worth doing if you spend any real time listening on it without headphones. i used a small 8 ohm driver from an old portable radio and it made a noticeable difference. just make sure whatever you drop in there fits without touching the board, clearance is tighter than it looks once you route the wires. honestly the hardest part of that whole mod is just not stripping the tiny screws getting the case off for the third time

i always get nervous reading about people clipping diodes on their radios lol. did this on a 897D back in the day and it was fine but i still held my breath for about a week after. good documentation on that mod exists at least, some of the other mods floating around out there for various rigs the instructions are just... not great. like someone typed it up from memory and never proofread it.