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220PA

Sensibly equivalent to:
CV1022 K30G L2 LP2 LP2 P220 P220 PB1 PM2A VR22
See also:
CV1022 short entry - Cossor 2 Volt Range Advert - Cossor Mica Bridge Advert - QPP with Triodes
    
Extras ▼

 

The Cossor 220PA is an interesting audio output triode valve. A look at the envelope reveals two triode sections in parallel within the glass envelope in order to reduce the impedance and thus increase output. This was not uncommon in the early 1930's but this looks to be a much later valve in that it uses the mica bridge and classic envelope.
The filaments appear to be oxide coated and each section contains a single inverted V. Above the top mica are bright coil springs with hooks that hang from the top of the coil down through the middle and provide a tension force for the filament.
The 220PA battery triode was a popular type and had many equivalent types. The 220PA produced 0.18 Watts.
Power was a wet accumulator for the filament and a dry battery for the anode supply.
The classic envelope is 43 mm in diameter and excluding the B4 base pins it is 93 mm high.
References: Data-sheet & 1043. Type 220PA was first introduced in 1931. See also 1931 adverts.

 

Pin Connections
B4
1
2
3
4
a
g1
f
f

 

Absolute Maximum Operating Conditions
Triode
Vh
Ah
Va
Vg
mAa
ra
gm
2.0
0.2
150
-4.5
10.0
4000
4.0
Thanks to Frank Philipse for supplying the above PDF datasheet.
Updated July 05, 2022.
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