The VP23 is a battery HF pentode for use in portable radio receivers and transmitters. The main design feature is battery economy. The VP23 was used in military equipment and designated ARP12 and later the CV1331.
The tubular envelope, covered in screening paint, has no marking on the reverse.
The top mica. Sadly almost no detail of the construction can be seen.
The wide glass tube envelope is 30 mm in diameter and, excluding the MO base pins, is 81 mm tall.
References: Data-sheet & 1043. Type VP23 was first introduced in 1938. See also1938 adverts.
