Sensibly equivalent¶ to:
This Mazda HL210 has curved cuts in the base pins and etched lettering on the dome.
The HL210 is a general purpose battery triode with a two volt filament.
The lettering is difficult to see but is all present.
The balloon envelope is 45 mm in diameter and, excluding the B4 base pins, is 90 mm tall.
References: Datasheet. Type HL210 was first introduced in 1929.
Absolute Maximum Operating Conditions¶
Updated September 01, 2019. shape:balloon construction:pinch type:triode age:1920.1930 base:b4 heater:2.0v pins:4 pin:1.a pin:2.g1 pin:3.f pin:4.f