[GreenKeys] REC-10 Loop Supply Wiring Diagram

[Jeffrey D Angus]

On 12/16/2013 10:13 PM, Jim Haynes wrote:
> So it would be a good idea to replace the selenium stack
> with a silicon rectifier bridge. 
Be advised that doing so will substantially increase the output
voltage if the equivalent series resistance that the selenium
rectifiers have is not added in series with the new silicon diodes.

It also limits the ripple current the transformer has to deal with.

Measure the DC voltage at the connector first. Then calculate
the required dropping resistance and wattage accordingly after
replacing the selenium stack with something like four 1N4007
diodes.

Seeing an 10% or more increase by changing selenium rectifiers
(or tube rectifiers) to silicon is one of the things I have to correct
when working on vintage gear that someone went "solid state
happy" with to bring the B+ back down to the design values.

Also: The condensers may need replacing as well. Use a 200-220
uF electrolytic for the main filter cap, and 177VAC (or higher)
rated motor run capacitors for the 2 and 10 uF units. Pay particular
attention to the 2 and 10 uf values as they are critical.

Jeff-1.0
wa6fwi