Sensibly equivalent¶ to:
The VT-103 is the American Government designation for the commercial 6SQ7 and both Type designations appear on the steel envelope.
Internally the VT-103 is a double diode triode sharing a common cathode, designed in the early 1940s specifically for superhet receiver use. The diodes are signal detector and AGC rectifier, while the triode is the first stage audio voltage amplifier feeding a single audio output valve.
The RCA logo and Made in USA.
The thin metal tube envelope is 25 mm in diameter and excluding the IO base pins the valve is 51 mm long.
References: Datasheet, 1040 & 1043. Type VT-103 was first introduced in 1938.
Absolute Maximum Operating Conditions¶
Updated January 09, 2017. shape:thin.metal.tube construction:glass.disc type:double.diode.triode age:1940.1950 base:io heater:6.3v pins:8 pin:1.m pin:2.g1 pin:3.k pin:4.a(d2) pin:5.a(d1) pin:6.a pin:7.h pin:8.h