Sensibly equivalent¶ to:
This battery double diode triode has a very low filament consumption. This suggests an oxide coated filament. It would have been used for detection, AGC detection and first audio amplification in radio receivers. Possible portable military equipment. The MO (Mazda Octal) base dates it as 1938 or after.
The classic envelope is 32 mm in diameter and, excluding the MO base pins, is 77 mm tall.
References: Datasheet, 1040 & 1043. Type HL23DD was first introduced in 1938.
Absolute Maximum Operating Conditions¶
Updated February 20, 2013. shape:classic construction:pinch type:double.diode.triode age:1930.1940 base:mo heater:2.0v pins:8 pin:1.f(-) pin:2.- pin:3.a pin:4.- pin:5.a(d2) pin:6.m pin:7.a(d1) pin:8.f+ pin:tc.g1