[Milsurplus] Variable Hertz AC Supply--Used For What?

[Don Merz]

What good is this thing? It's an AC supply--looks to be in the 4-5 amp range made by Pacific Electronic Enterprises as their model PD-250D AC Power Source. Voltage seems to be variable from 0-150VAC and frequency is variable from about 40hz to 500Hz. Metered. Solid construction. Solid State. 

Whyforisthis? I was thinking that maybe it could be used to power 400hz aircraft dynamotors. But surely their startup current would crush this thing?

Any ideas? I just want to sell it but I am not sure who would be interested in it!

73, Don Merz, n3RHT