If traveling to Mexico there is one of the autoformer companies that makes a buck/boost box, (most of them are boost only) not sure which brand does both, Franks or Power Max (Checked Franks and it only boosts, does not buck could not find a listing for Powermax)
Did find this though.. Sounds like it might do the job.. But.. Well.. Make your own judgement, this is a 6KVA unit, max consumption (100 amps times 120 volts = 12000 or 12 KVA) on a motor home.. If you are 30 amps (3.6KVA) this one will do the job, it also takes care of the 240 volts common in some countries, Can not fix 50 Hz though.
