The CV1732 is electrically equivalent to the commercial ML4. Made by M-OV it carries the GEC logo used to denote professional valves. With the tubular envelope it is most probable that this was a late manufacture valve for replacement purposes.
The CV1732 was used as an RF oscillator, as a single-valve phase splitter, and as a driver for larger valves. The CV specification shows that the UK Government purchased these valves for the General Post Office (GPO) who at the time also controlled the telephone system.
The anode is made from a plate that has been stamped, folded and ultimately fixed by notching. The same method that was used for miniature valves. The grid can be seen to be a fine wire held in notches in the support rods. Again a product of mass production. The cathode is a rectangular tube that has been spray coated with emissive material.
The GEC logo on paper stuck to the glass. Inside the flat box nature of the anode can be seen.
The wide glass tube envelope is 32 mm in diameter and, excluding the B5 base pins, is 93 mm tall.
