so our ARES group has a county-wide exercise coming up in about 5 weeks and im trying to nail down my portable setup before then. ive been running a 100w HF station at home for years but doing this kind of extended field operation is new territory for me.

my current thinking is to bring my IC-7300 with a Chameleon MPAS Lite vertical and either run off my 40ah LiFePO4 battery or rent a small inverter generator. the exercise is supposed to be 8 hours continuous and there may be some periods of high traffic where im keying up a lot on SSB, so im not sure the battery alone is gonna cut it.

the other issue is antenna placement. the site is a county fairgrounds and theres a lot of chain link fencing and metal buildings around. i scouted it last week and theres maybe a 30 foot clearing on the south side away from most of the junk but i dont know if thats gonna be good enough for 40m work. was thinking about throwing a wire up between two masts if i can get permission but logistics of that get complicated fast.

anyone run an 8 hour field exercise with a 7300 before and have a realistic read on battery draw? ive seen the numbers on paper but real world duty cycle at an exercise is different than what the spec sheet tells you

yeah the 7300 at 100w is gonna eat you alive over 8 hours if youre doing any real SSB work. i did a similar thing at a RACES exercise two summers ago with a comparable radio and a 50ah AGM and i was sweating by hour 5. LiFePO4 is better but 40ah is still tight depending on your duty cycle.

rough rule of thumb im using now — figure about 20-22 amps at 100w transmit on SSB, maybe 2-3 amps receive. if your exercise has you talking a lot figure maybe 25-30% TX duty cycle over the whole thing and do the math from there. for me that works out to somewhere around 35-45ah for 8 hours which puts you right on the edge. i'd personally either bring a second battery or turn power down to 50w and see how that affects your signal reports — honestly on 40m most of the time nobody notices the difference in a local net situation.

on the antenna thing, chain link is annoying but not a dealbreaker. i've run a vertical in worse RF environments and still made contacts. if you can get 20-30 feet of separation from the fencing youll be ok for NVIS 40m work. the two mast dipole idea is better if you can swing it, even a simple inverted V off a 25ft mast in the clear would outperform the vertical there probably.

get the generator, seriously. i know everyone wants to go all battery and solar these days and thats fine for low power stuff but if youre running a full 100w HF station for 8 hours straight at an exercise where reliability actually matters, just get a Honda EU2200i or similar and be done with it. fuel it up, bring an extra gallon, done. no anxiety about state of charge, no voltage sag, no explaining to your EC why you went QRT because your battery died during a simulated disaster.

the quiet inverter generators are genuinely not that bad for RF either. i ran one about 15 feet from my station at Field Day and yeah i picked up a little noise on 40 but it wasnt terrible and moving it another 10 feet fixed most of it. run your power cable away from the antenna feedline and youre fine.