so ive been putting this off for like two years but i finally opened up the 857 and did the extended TX mod. for those who dont know theres a diode on the main board — D2101 i think, or maybe D2103, i had to look it up twice — that when removed opens up the transmit range significantly outside the normal ham bands. obviously you need to actually be licensed for whatever youre doing with it but theres legit reasons to want this like MARS/CAP work or just testing into a dummy load across frequencies.

anyway the procedure itself isnt bad at all, the diode is surface mount so i was a little nervous but with decent iron and flux it came off clean. i also did the 1200hz shift mod for the internal keyer while i was in there because why not. the thing that surprised me is the radio actually feels a little more responsive on receive after all this, which makes zero sense and is probably just placebo, but whatever it feels better.

the only thing i messed with that i wish i hadnt is i tried to adjust the SSB TX bandwidth following some guide online and i think i made it slightly worse actually. not terrible but not quite right. might go back in and reset that to factory. anyone else done the audio bandwidth tweaks on this rig and had better luck?

yeah the D2101 is the right one on most of the 857D boards, at least on the ones ive seen. the D2103 thing throws people off because some older documentation had it wrong or was for a different revision.

on the SSB bandwidth thing — what guide were you following? theres a couple floating around and one of them has the trimmer pot labeled backwards compared to how it actually works on the board, so you end up going the wrong direction. i made the same mistake on mine and spent an hour wondering why my voice was getting thinner when i was trying to open it up. if you have the service manual the procedure in there is actually pretty clear, you just need a proper audio analyzer or at minimum a second radio to A/B against while someone talks into the mic. doing it by ear alone is rough.

the placebo thing on RX is real, i swear it happens every time i do any work inside a rig. open it up, change something completely unrelated to receive, and suddenly it sounds better. i think its just that you start paying more attention to it for a few days after.

i did the mars mod on my 7300 a while back which is different obviously but same general idea. that one you just hold a button sequence on powerup which is way less scary than touching SMD components. the 857 being older analog-ish design means theres more to actually physically change which i kind of respect even if its nerve wracking. good iron and flux is the right call, i use chisel tip for anything SMD these days, the fine conical tips always felt worse to me for small pads.