Tim Wescott writes:

It seems like a 60Hz to 400Hz converter would be a common accessory in
avionics shops -- or do they go for avionics prices?

I suspect most provide a few watts; at best tens of same.

--
A host is a host from coast to
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433