Sensibly equivalent¶ to:
The N30 is from the second series of M-OV Catkins and has an opaque enamelled top envelope.
The N30 was a version of the MPT4 with a 13 V 0.3 A heater, intended for use in AC/DC sets.
The visible envelope is in fact a precision shaped copper anode that is sealed to the lower glass envelope.
The large wide base hides a rubber sealing ring that helped to reduce microphonic effects.
The thin metal tube envelope is 18 mm in diameter and, excluding the B7 base pins, is 103 mm tall.
References: Data-sheet. Type N30 was first introduced in 1934. See also 1934 adverts.
Absolute Maximum Operating Conditions¶
Updated January 03, 2022.