so our ARES group has a county-wide exercise coming up in about 5 weeks and im trying to figure out the best approach for our primary field station. we're going to be set up at a park for potentially 24-36 hours and i've been going back and forth on the power situation for a while now.

right now i'm thinking a 100ah LiFePO4 battery as the main source with a small honda eu2200i as backup but my concern is whether the generator noise is going to be a problem for the HF stuff. last time we ran a genny near the radio it was picking up all kinds of hash on 40m. i know bonding and filtering helps but how much of a pain is this in practice when you're setting up fast under field conditions.

also the antenna situation — i was planning to do an EFHW for 40/80 with the 9:1 unun up in a tree, probably 60-65 feet on the long end. anyone done this for extended emcomm ops and found it lacking, like did you wish you had something more robust. the other option i keep thinking about is just bringing the trap vertical but that means more stuff to haul and set up.

not really asking about the radio itself we've got that sorted, just the antenna and power side of things is where i keep second guessing myself

the generator noise thing is real and honestly the bonding fix works better in theory than when you're rushing a setup in a field. what we ended up doing for our group's go-kit is just keeping the eu2200i at least 50 feet away from the operating position if terrain allows, run a longer extension cord, and use it primarily to top off the lithium battery rather than running the radio directly off it. the radio stays on the battery the whole time and you just run the genny for maybe an hour here and there to keep it charged. that alone got rid of like 90% of the noise issues we were seeing on 40m without having to mess with ferrite chokes on every cable.

as for the EFHW — totally fine for what you're describing. i've done 36 hour shifts on one and it does the job. the 9:1 unun does run warm if you're pushing power for a long time so just keep an eye on that. the trap vertical isnt worth the hassle IMO unless you're specifically trying to do something the wire antenna cant, which for basic NTS or emcomm voice traffic you probably arent.

yeah the honda eu series is pretty clean as far as generators go but even those put out enough noise to mess with receive on lower HF bands if its sitting anywhere near the antenna feedline. the isolation thing the other guy mentioned is probably the easiest fix in a field scenario.

one thing i'd add — if your 80m operation is going to matter at all during the exercise, do a quick test of that EFHW at home before you go. some of those 9:1 unun kits you build or buy cheap have iffy cores and on 80 specifically the efficiency can drop off a cliff. i've seen guys show up to an exercise thinking they have 80m capability and their SWR is a mess because the unun is lossy as heck. nothing worse than finding that out during the actual event.