so ive been running my IC-7300 for about three years now mostly for FT8 and some SSB contesting and i always had this nagging feeling the frequency stability wasnt quite where i wanted it especially when the rig first warms up. you know that first 10-15 minutes where everything drifts around a little before it settles.

anyway i finally pulled the trigger and did the TCXO-15 upgrade and i gotta say the warmup drift is noticeably better. like i used to watch my dial freq creep maybe 20-30hz over the first few minutes and now its pretty much locked from the moment i key up. not sure if this matters much for FT8 since the software handles a lot of that correction but for things like WSPR where you want to be spot on it feels like a real improvement.

the install itself wasnt bad, main thing is just being careful with the tiny connector and not stressing the board. took me maybe 45 minutes including the time i spent second guessing myself and looking at the service manual twice. just wondering if anyone else has done this and whether they noticed anything else change — some people say it affects phase noise slightly but i honestly cant measure that at home so i dunno.

yeah i did the same mod about a year ago and the warmup stability thing is real, not your imagination. i run a lot of weak signal VHF stuff and it made a genuine difference for me. the phase noise improvement is supposedly measurable but i think you need pretty serious test equipment to actually see it in practice, most of us wont notice it in real world operating.

one thing i will say is if you're doing the mod anyway, its a good opportunity to check the general condition of the board and make sure your thermal paste on the finals hasnt dried out or whatever. mine had gotten a bit crusty and i figured while i was in there id deal with it. just something to consider if you havent been inside the rig before.

been thinking about this mod for my own 7300 but honestly for the casual operating i do im not sure i'd notice. does it affect anything on receive side or is it purely a transmit/frequency reference thing? i get confused about where the TCXO actually sits in the signal chain