12-11-2014, 10:02 AM
I would say, get the schematic and go by it.
I do not have 640B sch, and 640 might not be the same.
And you have to measure the transformer's leads to see where the centertap is or where the field coil comes in.
Unless someone knows off hand.
I do not have 640B sch, and 640 might not be the same.
And you have to measure the transformer's leads to see where the centertap is or where the field coil comes in.
Unless someone knows off hand.
