The N30 by Marconi is a Catkin external anode audio output valve.It would have been used as the audio output stage of an AC/DC or Universal 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: Data-sheet Type N30 was first introduced in 1934. See also 1934 adverts. |