Vacuum Tube - 6DA4-A / 6DM4, Diode, Damper
New-Old-Stock (NOS) tube.
The 6DM4 is a half-wave vacuum rectifier employing a T-9 envelope. It is designed specifically for use as a damper diode in horizontal-deflection circuits of black-and-white television receivers. Except for heater characteristics and heater warm-up time, the 6DM4 is identical to the 12DM4 and 17DM4.