The CL202 is a French valve made by Metal. The electrodes are obscured by the silver magnesium gettering. Looking up from the base the electrodes can just be seen. The form is a horizontal cylindrical anode with a single filament strand. The classic R-type pattern.
There are faint etched markings on the bulb that give the makers name and the type designation. No further details are available.
The CL202 probably dates from the early middle 1920's and is a dull emitter.
The base shell is of nickel and the simple brass split pins fix into a composition insulator.
The balloon envelope is 39 mm in diameter, and excluding the B4 base pins is 81 mm tall.
Absolute Maximum Operating Conditions¶
Updated May 01, 2013. shape:balloon construction:pinch type:triode age:1920.1930 base:b4 pins:4 pin:1.a pin:2.g1 pin:3.f pin:4.f