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.
Our other Mazda 215SG is fully metalised.
The other side of the envelope is not silvered and the electrodes are visible. Note the rectangular anode and concentric grids whilst still having the bakelite top cap assembly of the early 1930s.
The balloon envelope is 42 mm in diameter, and excluding the B4 base pins is 110 mm tall.
References: Data-sheet & 1040. Type 215SG was first introduced in 1929.
Absolute Maximum Operating Conditions¶
Updated April 03, 2015. 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