Vacuum Tube - 35Y4, Rectifier, Half Wave
New-Old-Stock (NOS) tube.
The 35Y4 is a half-wave high-vacuum rectifier designed for use in a-c/d-c receivers. The heater is tapped to permit operation of a panel lamp. It is recommended that the plate be connected to the heater tap so that the plate current will pass through the panel lamp and the tapped section of the heater.