Sensibly equivalent¶ to:
The VP4B is a variable μ pentode for RF and IF amplifier use. The VP4 was introduced by Mullard in 1933, the B variant being introduced in 1935.
This exhibit typifies the pentode challenge to the screen-grid in the second IF position of cheaper superhet receivers. Although not the equal of the (then) latest American types, it audibly outperformed screen-grids such as the VMS4B when the radio was sited close to the transmitter. Note the style of marking and the texture and light colour and of the gold spray paint. These are characteristic of Mullard production immediately before WWII.
The classic envelope is 40 mm in diameter and, excluding the B7 base pins, is 100 mm tall.
References: Data-sheet, 1040 & 1043. Type VP4B was first introduced in 1935.
Absolute Maximum Operating Conditions¶
Thanks to Andy Cowley for supplying the above PDF datasheet.
Updated October 07, 2020.