Warning – There are two secondary side windings. Each secondary has one blue and one green wire.
You will connect a green wire from one winding to the blue wire from the other winding. Follow the
directions carefully to make sure this happens. Should you instead connect a blue and a green wire
from the same winding, then you will surely blow a fuse!
1.
Cut the blue and green transformer wires (4 wires in total) to a length of about 8”.
2.
Remove 3/8” of insulation from the ends of the 2 blue and 2 green transformer wires.
3.
Select the inside blue and green wires as called out in Figure 3. Use your ohmmeter to measure
the resistance between these two wires. It should read open circuit if you have picked the right
blue and green wires.
4.
Form a twisted pair from these two wires. Twist the stripped ends of these wires together. See
Figure 3. Solder the twisted connection.
5.
Slide a 2” piece of 3/16” diameter (frosted) heat shrink tubing over the soldered joint, about half
on, and half off.
6.
Use the tip or the barrel of the soldering iron to shrink the heat-shrink tubing all along its length.
7.
Once the heat-shrink tubing has cooled, test your work by tugging on the heat shrink to assure
that it will remain in place.
8.
Twist together the insulated portion of the remaining blue and green transformer wires.
Twisting the pair reduces hum.
9.
Measure the resistance between the unconnected blue and green wires. It should be about 0.6
Ohms. If it’s less than 0.35 Ohms or more than 1 Ohm, then you may have a problem.
10.
Separately twist and tin each wire, preparing them for installation into the power supply in a
later step.
11.
We will not use the purple wire. Leave it close to full length, just cut the bare end and then
cover the end of the wire with a piece of electrical tape.
Transformer Installation
1.
Set the transformer into the chassis, wire side up, over the raised circle in the chassis floor. You
won’t bolt it into the chassis until after the shield has been installed.
2.
Twist the transformer primary leads (that’s the transformer wires with the FASTON connectors)
together to form a twisted pair. Slide the FASTON connectors from the toroidal power
transformer thru the switch cut-out in the front panel. Connect them to the indicated switch
terminals. Place black over black and white over white.
Figure 4-connecting up the power transformer