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field comms setup for county ARES exercise next month — generator vs battery question

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so we have a county-level ARES exercise coming up in about 5 weeks and im trying to figure out the best way to run our portable station for the full 12 hour op period. last time we ran off a Honda eu2200i which worked fine but hauling that thing plus fuel cans to a hilltop site is kind of a pain, and one of the guys in our group is pushing hard for a lifepo4 battery setup instead.

the issue is we're running two rigs simultaneously most of the time — an IC-7300 for HF and a TM-D710 for local VHF/UHF coordination, plus a small laptop for winlink and occasionally a second laptop. rough estimate puts us somewhere around 30-35 amps draw at moderate TX duty cycle. i did the math and even a 100ah lifepo4 gets you maybe 2-3 hours of real use at that load before you're babysitting the voltage. obviously you could chain batteries but that adds weight pretty fast.

antenna side we're planning a homebrew NVIS for 40/80 using about 130 feet of wire in an inverted V off a 31 foot Jackite pole. worked okay in testing but we're on a site with a lot of trees and the feedline run is kind of awkward. anyone done a similar setup and had issues with the feedline picking up noise from a generator running nearby? that was another complaint last time, we had some RFI from the eu2200i that took a while to track down.

would love to hear what other groups are doing for sustained field ops, especially if youve found a power solution that doesn't require a forklift to set up

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the generator RFI thing is real and honestly kind of annoying to chase down. we had similar issues with a eu2200i at a go-kit deployment last year. ended up being a combination of the feedline acting as a receive antenna for the inverter noise and a grounding issue with the genny itself. what helped us the most was running the coax feedline away from the generator at roughly 90 degrees for as far as practical, and adding a few turns of the coax through a mix 31 toroid right at the radio end. didnt eliminate it completely but got it down to where it wasnt really an issue on 40m.

on your power question, for 12 hours at 30+ amps you're not really getting away from a generator unless you want to haul like 400ah of batteries up a hill which sounds miserable. what we actually do for longer exercises is run the generator for the heavy lifting and keep a 100ah lifepo4 as a buffer/backup. generator charges the battery, battery runs the radios, generator noise is a little more isolated from the RF chain. works pretty well and if the genny craps out you still have a couple hours to figure it out.

the NVIS setup sounds solid, 40 and 80 inverted V off a jackite is pretty much the go-to for that kind of work. just watch your apex height if you're trying to stay truly NVIS on 40, lower is actually better for that mode which is kind of counterintuitive.

yeah 35 amp sustained for 12 hours is a generator situation, the math just doesnt work out for batteries alone unless money is no object and you have a truck to haul them. that said the hybrid approach the other guy mentioned is worth considering.

one thing i'd add — if you do stick with the eu2200i, look into whether your group has or can borrow a power conditioner or at least a good line filter between the generator and your equipment. some groups run a small UPS in line which sounds weird but actually helps a lot with the waveform quality from inverter gennys and also gives you that buffer so the radios dont see every little fluctuation. the honda units are pretty clean but under varying load they still arent perfect.

also for the feedline routing on that NVIS — how long is your feedline run? if you're going coax to a balanced antenna you probably already know about the common mode issues but its worth double checking that you have choking at the feedpoint and not just at the radio end. sometimes at a site with weird terrain and a bunch of metal around (like vehicles or a trailer) you get some unexpected coupling that moves around depending on where you park stuff.

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