[MrFixr55]

Try this:

+1 on radioRoslyn's info. take an ohmmeter and connect to pin 3 (screen grid and B+ for the rest of the radio) of the 42 socket, then idetify the speaker wire connected to it (the one that ohms at zero). that wire connects to the speaker connection that is common to the output transformer and the field coil. Then Ohm from Pin 2 (plate) of the 42 and identify that wire. That wire goes to the other connection for the output transformer primary. Ohm from Pin 1 or 4 (cathode) of the 80 rectifier to the remaining wire. It should be zero. Connect that to the remaining terminal of the speaker (the field coil).

Hope that helps.