Sensibly equivalent¶ to:
The DH63 is a double diode triode and was designed for receiver audio use.
The diodes would be for signal and AGC rectification and the triode would act as AGC amplifier or first audio amplifier.
There is no direct brand indication but the etched lozenge is clearly a M-OV design.
The top section is the voltage amplifying triode. The anode is formed as a central cylindrical space with side flanges to dissipate the generated heat.
The classic envelope is 38 mm in diameter and, excluding the IO base pins, is 99 mm tall.
References: Data-sheet, 1040 & 1043. Type DH63 was first introduced in 1937. See also 1937 adverts.
Absolute Maximum Operating Conditions¶
Updated December07, 2019.