I notice that there are two Item #5 chokes - one in the oscillator section, and one in the power supply section. (Since they have the same Zenith part numbers, they must be identical.) My guess is that their purpose is to block RF interference from getting into the plate supply - which could come from the set's front-end or the vibrator?
Whichever choke is open, you could measure the inductance of the other one, but I doubt the values are very critical. At least for troubleshooing purposes, I think you could just jumper the open choke. Then replace it later if necessary.
Doug
:I'm resurrecting a Zenith 6v-27 battery farm radio, and U have an open rf choke item 5 on the Beitman diagram, Zenith part # 20-88. Does anyone have any idea what the specs on that coil were? were they similar to item 4,
:Zenith part # 20-82 antenna choke? Thanks, Leno