so i've had my FT-857D for probably 6 years now and just got around to doing the mars/cap mod and enabling the extended receive. took me maybe 20 minutes once i actually found the right pads to short and stopped second guessing myself. used the mod guide over on mods.dk which i think most people know about already.

the extended rx is honestly pretty nice, picking up stuff down in the lower HF range and even poking around some of the utility freqs is fun when bands are dead. the TX mod i mostly did because our local ARES group sometimes operates on freqs just outside the ham bands during activations and it's a pain not being able to hit those.

my question is more about whether anyone's done the fan mod on the 857 too. mine gets warm running digital modes for any extended period and i know there's a resistor swap you can do to make the fan kick in earlier or just run constantly. anyone done that and did it help? the fan noise doesnt bother me at all, i just dont want to cook the finals on a long FT8 session

yeah i did the fan mod on mine probably 3 years ago. its just a resistor swap on the main board, R1005 i think but dont hold me to that, been a while. dropped it from like a 47 ohm to something much lower so the fan runs basically all the time at a low speed. makes a difference when doing JS8Call for a couple hours, the heatsink stays noticeably cooler. the fan itself is pretty quiet at that speed so it doesnt bother me. only thing id say is just be careful pulling the board out, those ribbon cables are not very forgiving and i nicked one slightly and had a minor panic. all good but just take your time.

the mars mod is fine but if youre doing emcomm stuff and need out of band TX regularly id honestly just look at getting a used commercial radio down the road. not knocking the 857 at all i love mine, but trying to do serious cross-band or NVIS work outside normal allocations on a modded ham radio is kind of a gray area depending on your coordinator. anyway on the fan thing — some guys also just prop the radio up so theres more airflow underneath. low tech but combined with the resistor mod it makes a noticeable difference. also make sure your power supply isnt running hot too, sometimes people blame the radio when the whole shack needs more ventilation