Humming from Progressive Industires EMS 50 amp system

I am not saying that what we did at work to reduce armature hum in relays is feasible in RV converters, I'm just relating what we had to do.

All of our 120vac relays had a thin piece of steel welded to the armature where it touched the coil core. We had thousands of relays in use on the street and we had complaints from folks living nearby. It seams that some folks are highly susceptible to the 60Hz sound.