[Milsurplus] Ferro regulated PS for dyno spinner?

[Hue Miller]

I scavenged from an abandoned radio site, a GE built, ferroresonant 12V 35A DC supply.
It is a heavy sucker, maybe 45 lbs., and even has a choke inductor in it.
My question is, what happens when this kind of supply faces the heavy start load from
a dynomotor?  Does it also require a helper battery for dyno starting?
tnx
Hue Miller,   Newport, Oregon