The SP215 is an HF pentode for two volt battery sets. The SP215 is a straight pentode and the VP215 has a variable μ characteristic.
The reverse of the envelope is plain zinc paint.
The balloon envelope is 45 mm in diameter, and excluding the base pins is 101 mm tall.
References: Datasheet, 4022 & 1043. Type SP215 was first introduced in 1934.
Absolute Maximum Operating Conditions¶
PDF scanned from an original document held by the museum
Updated March 18, 2014. shape:balloon construction:pinch type:pentode age:1930.1940 base:b7 heater:2.0v pins:7 pin:1.m pin:2.g1 pin:3.g3 pin:4.f pin:5.f pin:6.- pin:7.g2 pin:tc.a