[GreenKeys] bulb voltage in model 28 lid

[Jack]

The Model 28 copy lights and the margin light (on the right) are all
6 VAC. You will sometimes find a 110VAC lamp in a 28 which
was used for a lot of purposes; it usually lights the red lense either
on the top left of the cover or the front left. 
If the machine has selective calling, the
lamp would indicate the machine has been "selected" for traffic. 
Sometimes a stuntbox contact controlled by a "space" function
bar operates the light every time a "space" is received...sort of a
rudimentary "activity" indicator. And, finally, the lamp might be
wired across the 110VAC bell. In a roomfull of TTY's, it
would be hard to figure out which one's bell is ringing, so they
place a lamp across it. The lamp could also be wired to
indicate the machine was out of paper. 
I am sure there were other innovative
uses. By the way, there are green and yellow "lenses" that
go in place of the typical red ones....but they are very rare.
I have seen standard "pilot light" assemblies used on the
top left...they give more horizontal visibility. 

Jack WA2HWJ