David Johnston posted:I do not understand why it is thought that a 773 has a higher voltage motor than other Lionel locomotives of the same era.
Well, the owner's manual for the 773 (page 1) says:
"The normal operating voltage of the 773 locomotive ranges from 12 to 20 volts, depending upon the train load, and its current consumption, including the smoke generator and the reversing E-Unit is from 3 to 4 amperes."