▼ Menu

W81

Sensibly equivalent to:
7H7 W143 W148
See also:
Olympia Show 1947
    
Extras ▼

 

The W81 is a variable μ amplifier pentode on a Loctal (B8B) base. Use would be at RF or IF frequencies in receiver equipment. The W101 is the same valve but fitted with a 100 mA heater (at 19 Volts).
The Osram paper label shows the BVA logo.
The wide glass tube envelope is 32 mm in diameter, and excluding the B8B base pins is 59 mm tall.
Reference: 1040. Type W81 was first introduced in 1947.

 

Pin Connections
B8B
1
2
3
4
5
6
7
8
h
a
g2
g3
s
g1
k
h

 

Absolute Maximum Operating Conditions
Pentode
Vh
Ah
Va
Vs
Vg
mAa
mAs
ra
gm
6.3
0.3
250
100
-3.6
9.6
3.6
-
2.8
Updated April 12, 2013.
Return to Main Index