so we have a county ARES drill coming up saturday and im trying to nail down the power situation before i haul everything out there. been running a 100ah lifepo4 with a 40a charger off the truck for the last couple drills but this one is supposed to go 18 hours which is longer than usual and im not sure the battery alone is gonna cut it especially with two radios running, a laptop, and we might be adding a winlink station this time.

the EC wants to bring a generator but last time we used a cheap harbor freight unit the RFI was just unbearable, like full S9 noise floor on 40m and it basically killed HF ops. i know you can filter them but nobody had anything with them that day. was thinking maybe a honda eu2200i or similar inverter type would be cleaner but i havent personally tested one on HF. anyone actually run HF next to one of those and can tell me what the noise floor looked like?

also on the antenna side, thinking about putting up a 40m NVIS setup since we're doing intrastate stuff, probably an end fed halfwave or maybe just a simple inverted V dipole. the site is a fairgrounds with decent open space so getting some height shouldnt be a problem, have a couple of 31ft jackite poles. just not sure if EFHW or dipole is gonna be easier to deal with for multiple operators who may not be super experienced with tuners and stuff.

the honda eu2200i is night and day compared to the harbor freight stuff, i ran one about 15 feet from my ic-7300 last summer at a field day site and 40m was totally workable, maybe s1-2 background noise which is honestly better than my shack at home with all the switching supplies. the trick is still grounding the generator frame and running the radio off a separate battery that the genny is charging rather than directly off the genny output, that little bit of isolation helps a lot. some guys add a line filter on the ac output too but honestly with the honda i didnt feel like i needed it.

for your antenna question i'd just go with the inverted V dipole, fed with coax, resonant on 40m. EFHW is great but you're adding a matchbox into the equation and if something goes wrong or someone bumps it you're troubleshooting a transformer on top of everything else. dipole is harder to get wrong and for NVIS you want the apex as low as you can stomach anyway, like 25-30ft is actually fine. the jackite poles will work perfect for that.

yeah the inverter generators are way better for RFI, we tested a yamaha ef2000is against a conventional open frame unit a while back and the difference was pretty dramatic. still worth having a clamp meter or at least a handheld with you to sweep around the generator before you commit to a frequency, interference can still do weird things depending on the site and what else is running.

one thing id add - 18 hours with two rigs and a laptop is gonna be more than most people expect. if youre running an icom 7300 or similar at even 50w tx youre looking at maybe 20-25A peaks on transmit and like 2-3A on receive, plus whatever the laptop pulls. just make sure youre actually doing the math on your ah budget and not just guessing because ive seen batteries get pulled down way faster than expected when winlink starts doing long bursts. having the genny as a backup charger is smart, just dont count on it as your primary from the start or you'll run into fuel logistics issues if the drill goes long.