Sensibly equivalent¶ to:
The L63 was an Octal based general purpose amplifier triode from M-OV. It featured the then new standard 6.3 Volt heater. This was a low power heater insulated with alumina.
The L63 was a 'me too' straight copy of the American 6J5, intended initially for overseas markets where American-type valves were in demand. However, it was used in Britain too, especially by manufacturers of export equipment. It was never intended for UK domestic radios.
The ML4, already available in a 6 V version (ML6, or ML6C for SW oscillators), was far superior to the L63.
The wide glass tube envelope is 28 mm in diameter and, excluding the IO base pins, is 83 mm tall.
References: Private communication, datasheet & 1043. Type L63 was first introduced in 1938.
Absolute Maximum Operating Conditions¶
Updated April 03, 2015.