Sensibly equivalent¶ to:
The Cossor 220PA is an audio output valve and proclaims the 'New Process' and thus is probably from the early 1930's when this type was first introduced. The electrodes are obscured but with a strong light the single triode section can be seen. This contrasts with our other 220PA that employs two sections in parallel and mica supports in a classic envelope.
The 220PA battery triode a popular type and had many equivalent types. The 220PA produced 0.18 Watts into a 9,000Ω load.
The dome carries the Cossor name, BVA logo, Made in England and V8 but does not have the Type designation etched in.
The classic envelope is 44 mm in diameter and excluding the B4 base pins it is 92 mm high.
References: Datasheet & 1043. Type 220PA was first introduced in 1931.
Absolute Maximum Operating Conditions¶
Updated August 24, 2015. shape:balloon construction:pinch type:triode age:1930.1940 base:b4 heater:2.0v pins:4 pin:1.a pin:2.g1 pin:3.f pin:4.f