Sensibly equivalent¶ to:
The UAF42 is an early all glass valve introduced in 1948 together with the EAF41 and consists of a single diode and a variable μ RF amplifier pentode in a single envelope.
The valve is screened and the envelope has the moulded glass pip for pin registration in the metal skirt of the base. The first B8A valves had metal skirts fitted with built in locating pips and spigots to guide the valve into its base.
By the early 1950s the B8A valves were being phased out in favour of B9A and B7G based valves.
Like the EF91 the inside of the glass is coated to reduce the release of gas during the life of the valve.
The thin glass tube envelope is 20 mm in diameter and, excluding the B8A base pins, is 53 mm tall.
References: Data-sheet & 1040. Type UAF42 was first introduced in 1948.
Absolute Maximum Operating Conditions¶
Updated July 10, 2020. shape:thin.glass.tube construction:all.glass type:diode.pentode age:1940.1950 base:b8a heater:100ma pins:8 pin:1.h pin:2.a pin:3.a(d) pin:4.g3 pin:5.g2 pin:6.g1 pin:7.k.s pin:8.h