so ive been putting off the extended TX mod on my FT-857D for like two years now because honestly the whole diode removal thing seemed scarier than it actually ended up being. finally sat down last weekend with a decent soldering iron and some magnification and just did it. took maybe 45 minutes including the time i spent second-guessing myself and re-reading the procedure three times.

the actual mod is pretty straightforward once you get the bottom cover off and locate D3007, just remove it and youre transmitting on the extended ranges. but here's the thing nobody really mentions — my power output on 60m dropped noticeably compared to what i was seeing on 40 and 17, and im not sure if thats expected behavior for this radio or if i maybe disturbed something nearby while poking around in there. anybody else notice that? also the fan seems to kick on a bit earlier than before but that might just be me being paranoid about it now that ive had the thing open.

either way im glad i finally did it. been wanting to work some of the oddball frequencies for MARS and just general experimentation. if anyone's been thinking about doing this mod and has a steady hand its really not that bad, the service manual is pretty clear once you track down the right version of it.

the power drop on 60m is normal for that radio, its not just you. the 857 was never really optimized for those channels from the factory and even with the mod the PA just doesnt love that part of the band. i measured mine with a Bird and its consistently a few watts down compared to 40m at the same power setting. nothing you did wrong.

the early fan thing though, id keep an eye on that. might just be confirmation bias like you said but could also be a cold solder joint somewhere that's adding resistance and generating a little extra heat. worth reflowing anything you touched while you had it open just to be safe.

did basically the same thing on mine about a year ago, went fine. one thing i did after the TX mod was also swap out the stock electrolytic caps on the audio board while i had it open — there are a few that are known to drift on older units and it made a noticeable difference in receive audio quality, kind of tighter and less mushy sounding. probably not worth opening it back up just for that but if you ever go in again for something else its cheap insurance. total cost was maybe 4 dollars in caps from mouser.