9 hours ago
The 300 ohm line adjustment is used to set the primary of the transformer to a nominal voltage for any line voltage from 100 to 130 volts. Although that nominal voltage does not seem to be specified in the manual it should be 115 or 120 volts.
Dale H. Cook, GR/HP/Tek Collector, Roanoke/Lynchburg, VA
https://plymouthcolony.net/starcity/radios/