so we've got a county-wide ARES exercise coming up and i'm running the portable HF station this time around. ive done this before but never as the primary operator, usually just helping whoever's in charge haul gear. this time its on me to get everything working.

my plan right now is an IC-7300 running off a Honda EU2200i with a 40m NVIS dipole up maybe 15-20 feet on a couple of painter poles. should be fine for the intrastate traffic we're doing. my concern is the generator noise - last time somebody ran an EU2200i near an HF rig it put a nasty buzz on the audio and S3-ish noise floor on 40. we ended up running off a battery instead. but we need to run for like 8+ hours potentially and i dont have enough battery capacity for that at 50-75w output.

thinking about running the genny further away and using a longer power cable, maybe 25-30 feet of 10 gauge, and seeing if that cleans things up. also wondering if a good line filter on the DC side would help or if the problem is more RF getting into the feedline. the dipole will be maybe 40 feet from the generator physically so that might be the bigger issue. anyone dealt with this and found something that actually works versus just band-aids?

the EU2200i RFI issue is pretty well documented, the problem is usually conducted noise on the AC line getting into your power supply and then onto the DC rail. physical separation helps some but honestly the bigger fix ive seen work is a good line filter on the AC input of whatever supply you're using and making sure your DC common is properly bonded. Astron and similar linear supplies tend to be way quieter on the DC side than switchers too, so if youre running a switching supply thats worth looking at. also make sure your coax shield is actually grounded at the rig end and not just floating - i've seen that make a huge difference in what the noise floor looks like.

the 40 feet of separation should help with direct RF pickup from the genny, Honda's are pretty clean RF-wise compared to the cheap inverter gens, most of the problem really is conducted. 25-30 feet of power cable wont hurt but its probably not the main fix by itself.

we ran almost this exact setup at a Field Day site two years ago, EU2200i feeding an Astron RS-35A and then the 7300. put the genny about 50 feet upwind (for the exhaust obviously) and ran 12ga extension to the supply. noise was totally acceptable, S1 or under on 40m. the key thing we did was keep the power cable bundled tight and ran it away from the coax, not parallel to it. whenever the two cables crossed we did it at 90 degrees. might sound fussy but it made a noticeable difference when we were troubleshootng it.

for 8 hours at 50w youre probably burning around 2-2.5 gallons depending on load, the EU2200i holds about a gallon so plan accordingly. also worth having a backup battery just in case you need to go QRP for a stretch while you refuel, switching the rig off mid-exercise is a pain.