Sensibly equivalent¶ to:
The Mazda 215SG is a screen grid valve or tetrode. It was designed for RF amplification in radio receivers. The screen provides isolation between the grid and anode circuits and enables greater individual stage gains to be achieved without instability.
This exhibit is fully metalised but our other Mazda 215SG has a clear bulb and the construction is visible.
The reverse is just plain grey zinc paint.
The balloon envelope is 45 mm in diameter, and excluding the B4 base pins is 113 mm tall.
References: Datasheet & 1040. Type 215SG was first introduced in 1929.
Absolute Maximum Operating Conditions¶
Updated April 22, 2014. shape:balloon construction:pinch type:tetrode age:1920.1930 base:b4 heater:2.0v pins:4 pin:1.g2 pin:2.g1 pin:3.f pin:4.f pin:tc.a