Sensibly equivalent¶ to:
The PM3 was introduced in 1926 as a general purpose triode with a μ of 14. The filament current, initially 0.1 Amp was later reduced to 0.075 Amps as in PM3. This exhibit draws 0.07 A at 4.0 V.
The base has the vertical line indicating the anode pin. There is no indication that this line ever had white paint in the groove as some Mullard valves had.
The balloon envelope is 45 mm in diameter and, excluding the B4 base pins, is 91 mm tall.
References: 1931 data-sheet & 1004 Type PM3 was first introduced in 1926.
Absolute Maximum Operating Conditions¶
Thanks to Andy Cowley for supplying the above PDF datasheet.
Updated April 04, 2015. shape:balloon construction:pinch type:triode age:1920.1930 base:b4 heater:4.0v pins:4 pin:1.a pin:2.g1 pin:3.f pin:4.f