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: Datasheet. Type N30 was first introduced in 1934.
Absolute Maximum Operating Conditions¶
Updated December13, 2012. shape:catkin construction:pinch type:pentode age:1930.1940 base:b7 heater:300ma pins:7 pin:1.- pin:2.g1 pin:3.g2 pin:4.h pin:5.h pin:6.k pin:7.a