The 20P5 is the 20 Volt 200 mA version of the 10P13 and is an output valve, designed for television service in both audio and frame timebase circuits. The 2.6 Watt output would have been more than adequate for domestic use. The cathode resistor is given as 180 Ω and the anode load is 5,400 Ω.
The anode has flat sides normal to the electron flow.
The thin glass tube envelope is 20 mm in diameter and, excluding the B8A base pins, is 61 mm tall.
References: habits article & 1040 Type 20P5 was first introduced in 1948.
Absolute Maximum Operating Conditions¶
Updated April 05, 2011. shape:thin.glass.tube construction:all.glass type:beam.tetrode age:1940.1950 base:b8a heater:200ma pins:8 pin:1.h pin:2.a pin:3.ic pin:4.ic pin:5.g2 pin:6.g1 pin:7.k pin:8.h