Double-check that pic against an RCA datasheet. 35W4 heaters are pins 2/7 (6 as CT to cathode), plate 5, cathode 1. Your 3/4 for heaters is a common mixup with other tubes. Schematics don't lie.
Double-check that pic against an RCA datasheet. 35W4 heaters are pins 2/7 (6 as CT to cathode), plate 5, cathode 1. Your 3/4 for heaters is a common mixup with other tubes. Schematics don't lie.