Robertdkeys@aol.com writes:
> 1) 48VDC on the main power busses.  You would
>    need to build a 48vdc power supply at around
>    100 amps and run it off of 220 power like
>    from a dryer outlet circuit or somesuch.

FWIW...it seems that there are large quantities of gear converting something 
sane to -48vdc on eBay.  Mostly small stuff, but fairly often there 
something out of a telco rack somewhere that is heavy duty. 

Ken