Sensibly equivalent¶ to:
The DD41 Mazda valve contains a pair of independent signal diodes with an internal screen and external metalisation. Clearly this valve was designed to operate to screen the signals present as much as possible.
Such a valve could be used as AM demodulators. It is probable that this valve was designed to operate above the then customary 455 KHz IF frequency.
The HL41DD was used in the 1948 Murphy television receiver V114 as a noise suppressor and pulse separator.
The reverse is plain zinc paint.
The classic envelope is 32 mm in diameter and excluding the MO base pins is 68 mm tall.
References: Datasheet, 1040 & 1043. Type DD41 was first introduced in 1938.
Absolute Maximum Operating Conditions¶
Updated October 17, 2018. shape:classic construction:pinch type:double.diode age:1930.1940 base:mo heater:4.0v pins:8 pin:1.h pin:2.k(2) pin:3.a(2) pin:4.s pin:5.a(1) pin:6.m pin:7.k(1) pin:8.h