Sensibly equivalent¶ to:
The VR55 is a double diode triode RAF pre-WWII receiving valve. The design use was at the end of the IF chain where the diodes would demodulate the AM signal and rectify an AGC control voltage, and the triode would act as the first audio amplification stage.
The external screening metalisation precludes an inspection of the actual construction of the valve.
See EBC33 for the commercial equivalent.
The wide glass tube envelope is 28 mm in diameter and, excluding the IO base pins, is 82 mm tall.
References: Datasheet & 1040. Type VR55 was first introduced in 1938.
Absolute Maximum Operating Conditions¶
Updated February 16, 2013. shape:wide.glass.tube construction:pinch type:double.diode.triode age:1930.1940 base:io heater:6.3v pins:8 pin:1.m pin:2.h pin:3.a pin:4.a(d2) pin:5.a(d1) pin:6.- pin:7.h pin:8.k pin:tc.g1