The CV499 (commercially the 5B/256M) is a beam tetrode for use at up to 60 MHz. The prototype was the VX7050. The anode dissipation is 25 Watts for this small transmitting PA valve.
The KB/F identifies this valve as being made to specification K1001 or K1006, the B denotes qualification by a UK authority and the F identifies the maker as STC, Paignton.
The seam of the anode and above the lower mica can be seen the beam plates and the two aligned wire grids.
A closer view of the aligned grid windings. The control grid has copper supports.
The STC LOgo and the commercial Type designation of 5B/256M. The locating pip for the B8B or Loctal base is on the right.
The base of this all glass valve showing the spigot key and depression for the locking spring.
The wide glass tube envelope is 29 mm in diameter and, excluding the B8B base pins, is 76 mm tall.
