The 6JE6A is a purpose designed line output valve for colour television sets. Being an American Valve it will be optimised for 525 line systems.
The line output valve operates as a switch. The cycle of events starts with the valve being driven hard into conduction. This sends a current pulse to the scan coils and produces a linear ramp to deflect the beam across the screen. At the end of the line the valve is rapidly shut off. The collapse of the magnetic field in the scan coils generates a massive voltage spike. For the 6EJ6A the maximum value expected is 5,000 Volts.
The line output role was very demanding and the high heater power is to provide for the high peak cathode emission required in pulse service.
Line output valves were also well suited to being used as RF power amplifiers at up to 30 MHz. Many amateur radio linear amplifiers were built around this type of device. As a mass produced item they were considerably cheaper than the specialist, and thus low volume types, that were purpose designed for RF amplifier use.
The side view of the anode. The central box shape is supplemented by side wings to assist dissipate the heat generated in operation.
The base pins and bottom mica. Some supports are copper to help cool the attached grid.
A close-up of the bottom mica and components. The cathode is a wide flat tube with four thick heater wires passing through.
The wide glass tube envelope is 37 mm in diameter, and excluding the B9D base pins is 94 mm tall.
Reference: Datasheet. Type 6JE6A was first introduced in 1965.