[GreenKeys] Western Union Rectifier 69-B

[David Burns]

Derek...
     When Western Union stopped supporting their own machines 
(non-Teletype) in 1966, I received one of their Model 100 machines 
(surplus) with exactly this power-supply for the local loop!  Mine had 
solid-state diodes instead of the 83 tube, but it looks like you have 
-the real deal- here!  (Wish I still had mine from 50 years ago!)

     The power supply I received had a larger (physically) adjustable 
resistor.  The one wired into my machine was probably a 20 or 25 watt 
resistor.  Mine was adjusted for 60 ma for my particular machine (and it 
was inside the machine, not strapped to the top of the supply as yours 
is)  If you adjust yours for 60 ma and it doesn't get too hot, you're 
good to go, right?

     Mine had the metal capacitor, and in 1966, it worked fine.  I 
seriously doubt the exact value is crucial...you just want the bulk of 
the full-wave rectification ripple knocked out of the output waveform.  
I'd check the old metal one for a value printed on the side.

     Bear in mind that the 83 tube (if you're going to use it ....and I 
would!) should be operated with the base down, I believe

     Looks Like Fun!!

..Dave in Boston