Mullard PM256 Power Triode

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2-volt Heater Battery Output Triode

This is a 1930s version of this valve, with the markings on the top of the valve and no anode line on the side of the base (compare with the 1927 PM254). It is a 5 watt power triode valve for audio output. 6 volt, 250 mA filament. PM252 and PM254 are 2 and 4 volt filament equvalents. The PM256A was a slightly inferior valve (lower gain and anode voltage) but had 6 watts anode dissipation.

PDF Data Sheets PM252, PM254, PM256, PM256A