[Tucker]

The audio output transformer on my 40-180 looks like it's been getting rather warm so I decided to replace it as long as I'm recapping the set.  I went with a Hammond 125C universal push pull transformer but I'm not sure that I understand the wiring diagram correctly. It appears that I would connect the secondary to pins 4&6 to get 12,800 impedance with an 8 ohm speaker.
The existing transformer appears to only have one primary wire coming from the power transformer. The Hammond has 3 wires on the primary side, a red, a blue, and a brown wire.  Not sure how that works ?
 
Here's a link to the transformer;  http://www.hammondmfg.com/125.htm 
 
And the schematic info;  http://www.nostalgiaair.org/PagesByModel...013332.pdf