Sensibly equivalent¶ to:
The N30 by Marconi is a Catkin external anode audio output valve.
It would have been used as the audio output stage of an all-mains receiver. The design is dated to 1934 and is a series 2 Catkin. The N30 was a version of the MPT4 but with a 13V 0.3A heater, intended for use in AC/DC sets.
The thin metal tube envelope is 18 mm in diameter, with the metal base 28 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