Hi, Your R741 number was the Rogers chassis number used in models 630,640 650, 660 and 680 radios.
Your radio is a lot older, 1930-31 24 (224) tubes were used at that time and not a lot later. I have schematics for those radios.
You need to check for voltages with a multimeter. The two large pins on the 80 should be getting a 5 volt filament voltage. It could also have an open filament.
You need to be careful as the filter capacitors will probably be bad and will damage the power transformer. There are two 4 mfd and two 2 mfd caps in the radio power supply. The other paper caps in the radio will probably need replacing also.
Ed, Warkworth, Ontario
