so our ARES group has a county-level exercise coming up in about three weeks and im trying to figure out the best approach for our primary HF station. we've done these before but always just threw a honda eu2200i on the trailer and called it a day, except last time the noise floor on 40m was absolutely brutal and i spent half the drill chasing my tail trying to figure out if it was the genny or something else nearby.

thinking about switching to a lithium battery setup for at least the HF rig and keeping the generator for the other stuff (laptop, lighting, etc). i've got a 100ah lithium i use for portable ops and honestly at 100w it runs my IC-7300 for a good 4-5 hours without sweating it. the drill is supposed to be 8 hours though and i dont want to be scrounging around for charge halfway through.

also the antenna situation - last year we used a trapped vertical which worked okay but i keep thinking a linked dipole or even just a simple NVIS flat-top would do better for the intrastate stuff we're working. distance is mostly under 300 miles. anyone running similar setups for exercises like this, curious what actually works vs what sounds good on paper

the generator noise thing is real, we had the same issue with a predator 3500 and it was killing us on 40 and 80. what helped was running the rig off a battery that gets charged by the genny but keeping the genny itself physically as far from the antenna feedpoint as possible, like 50-60 feet if you can manage it, and making sure the chassis ground on the genny is actually bonded properly. a lot of guys skip that and then wonder why they have so much hash.

for your distance range yeah NVIS is the way to go, a flat-top dipole at like 25-30 feet on 40m is going to absolutely smoke a trapped vertical for anything under 300 miles. if you can stake it out between two trees or use a couple of fiberglass masts from SOTAbeams or even the MFJ push-up poles you're in good shape. linked dipoles are nice if you need multiband but for a dedicated exercise where you know the band plan ahead of time honestly a cut-to-frequency dipole is less fiddly.

on the battery side 100ah might be tight for 8 hours at 100w key-down but if youre doing actual voice comms traffic the duty cycle is way lower than that. probably fine. bring a second battery if you can, even an old AGM as backup doesn't hurt.

yeah i went through basically this same thing last fall. ended up running two 50ah lithiums in parallel for a 12 hour SET and it worked fine, never dropped below 12.4 or so. the genny noise is something i just gave up fighting and separated entirely, battery for the radio stuff full stop.

one thing i'll throw out - whatever antenna you end up with, spend time on the feedline. we had a bun in our coax at the connector that we didn't find until like hour three and it was making everyone miserable. now i pressure test every feedline before an exercise, just tape one end and blow into the other, if you feel resistance through the whole run the shield's intact enough. probably overkill but whatever.