Sensibly equivalent¶ to:
The HL133DD or HL133/DD is an indirectly heated double diode triode designed for use with series heater chains for AC, DC and car radio applications. In a superhet receiver the diodes would be used for signal detection and AGC voltage generation whilst the triode would be the first audio voltage amplifier stage.
The reverse is plain zinc paint metalisation.
The classic envelope is 32 mm in diameter, and excluding the MO base pins is 89 mm tall.
References: Datasheet & 1043. Type HL133DD was first introduced in 1938.
Absolute Maximum Operating Conditions¶
Updated March 20, 2017. shape:classic construction:pinch type:double.diode.triode age:1930.1940 base:mo heater:200ma pins:8 pin:1.h pin:2.k pin:3.a pin:4.- pin:5.a(d2) pin:6.m pin:7.a(d1) pin:8.h pin:tc.g1