Sensibly equivalent¶ to:
The K50N is a Mullard PM12M suppleid to Ever Ready. It is an variable μ RF tetrode known at the time as a screened grid valve because the screen grid took the form of an enclosing cage.
The reverse is plain metalising paint.
The balloon envelope is 42 mm in diameter, and excluding the B4 base pins is 106 mm tall.
References: Datasheet & 1043 Type K50N was first introduced in 1937.
Absolute Maximum Operating Conditions¶
Thanks to Andy Cowley for supplying the above PDF datasheet.
Updated November 27, 2014. shape:balloon construction:pinch type:tetrode age:1930.1940 base:b4 heater:2.0v pins:4 pin:1.g2 pin:2.g1 pin:3.f pin:4.f pin:tc.a