so we have a county-level emcomm exercise coming up saturday and ive been going back and forth on power for probably two weeks now. the plan is to set up a full station at the fairgrounds, run HF and VHF simultaneously, probably 100w on HF and whatever the 706 pulls on 2m. last exercise we used a honda eu2200 and it was fine but the noise floor was kind of rough even with the inverter type — not terrible but definitely noticeable on 40m when propagation was quiet.

ive got a 100ah lifepo4 now that i didnt have last time and im seriously considering just running off that with a 30a balmar charger keeping it topped if needed. should handle a few hours no problem if im not transmitting constantly. the antenna situation is where i get more unsure — i have a 40-10 EFHW that i can get up maybe 25 feet with a painters pole, and a buddipole that honestly ive never been totally happy with but its fast. thinking about bringing both and using the EFHW for HF work and the buddipole as backup or maybe for a second operator position.

anyone dealt with generator noise specifically on 40m during a field exercise? wondering if separation actually helps or if its mostly a lost cause with a small genny that close

generator separation absolutely helps but you need more than you think. at field day a few years back we had the eu2000 (older version, same basic deal) about 30 feet from the HF station and still had some hash coming in. moved it to maybe 60 feet with the cord run along the ground and it cleared up noticeably. the other thing that made a huge difference was a common mode choke right at the rig — just wound some of the power cable through a mix31 toroid, maybe 8-9 turns. killed a lot of what was getting in on the dc side.

your lifepo4 plan sounds smarter honestly if you can make the capacity work. 100ah at 12.8v nominal is what, about 1280wh theoretical, real world maybe 900-1000wh usable before you'd want to back off. at 100w out youre pulling maybe 22-25a on transmit, way less on receive. if your duty cycle is reasonable you could probably go 4-5 hours easy without touching the charger. i'd bring the honda as insurance but run off the battery primary, keep the genny away from the antenna farm and just use it to top up between nets if needed.

the EFHW vs buddipole thing — i'd go EFHW without hesitation for actual HF work. buddipole is convenient but its a compromise in every direction. get the wire up as high as you can and you'll hear the difference immediately.

we ran into this exact same generator noise problem at a RACES drill last spring, the little inverter gennys are better than a cheap chinese unit but theyre not silent by any means. one thing we tried that worked pretty well was just routing the feed line away from the generator and power runs — like actively keeping them separated, not just coiled up near each other. seems obvious but in a hurried setup its easy to just throw everything together.

also — not sure what your feedline situation is on the EFHW but if youre using RG-8X or something light, throw a few turns through a snap-on ferrite at the rig end. makes a dumb amount of difference for common mode stuff coming in off the coax shield. i think i used a mix-43 clamp-on, whatever i had in the box.

good luck with the exercise, those fairground setups are always kind of a mess logistically lol