The P3580 is an audio output pentode for use in universal mains sets ie with or without mains transformers from a time when DC mains still existed.
Made by the Austrian company Triotron it was produced with the Ct8 base and the B7 for the British market.
The output is 4 Watts with a 320Ω cathode resistor and an anode load of 4,500Ω
The classic envelope is 49 mm in diameter, and excluding the B7 base pins is 113 mm tall.
References: 1043. Type P3580 was first introduced in 1936.
Absolute Maximum Operating Conditions¶
Updated December14, 2012. shape:classic construction:pinch type:pentode age:1930.1940 base:b7 heater:200ma pins:7 pin:1.- pin:2.g1 pin:3.g2 pin:4.h pin:5.h pin:6.k.g3 pin:7.a