The Tungsram VP2D is a battery vari-μ RF pentode. This Type was produced with both B4 and B7 base caps. The B4 version was issued in 1938 with the B7 the following year.
The metalising carries the identification and the words Barium Tube. Barium Azide was the first successful method of producing oxide coated filaments but was messy. Here the name is used as a brand identifier as the Azide process had been superseded long before 1938.
The plain reverse carries the number 803
The classic envelope is 46 mm in diameter, and excluding the B7 base pins is 106 mm tall.
Reference: 1043. Type VP2D was first introduced in 1937.
Absolute Maximum Operating Conditions¶
Updated August 05, 2015. shape:classic construction:all.glass type:pentode age:1930.1940 base:b7 heater:2.0v pins:7 pin:1.m pin:2.a pin:3.g3 pin:4.f pin:5.f pin:6.- pin:7.g2 pin:tc.g1