[GreenKeys] enlighten me regarding Model 19 rectifier

[epvgk at limpoc.com]

Ok, I don't have this thing in my possession yet, but looking through the
documents and pictures it appears there is a REC-30 module which looks like
it weights about as much as my car. Seems to be a thyratron based rectifier/
regulator circuit, plus a big transformer with a bunch of different taps for
different input voltages, etc. 

What is it for? The printer and TD seem to have plain 115VAC motors. I naively 
assumed I could just string the TD, 15, and keyboard in series with my 
existing loop and fire away. Is the purpose of the REC-30 just to provide a
local loop supply so you can, say, print from a tape, or punch from the 
keyboard, without needing an external loop supply? And maybe also step down
AC mains voltage so you can run the 115vac motors off 220? 

I'm sure the mercury vapor tubes are pretty to watch, but I feel like I'd
be happier putting the 150 lbs of steel in a closet somewhere and using
my existing loop supply. 

eric