The V240C/2K is a velocity modulated oscillator or Heil Tube designed for operation in the range of 3.95 to 4.05 GHz. The output is 350 mW and the V240C/2K is a direct equivalent of the CV2189 and this exhibit carries both Type designations.
The attached data-sheet includes a cross sectional diagram of the internal structure.
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.
This exhibit is marked with GPO for the UK General Post Office. This was a Government controlled body responsible for all UK telecommunications. Point to point links used microwave stations for bulk traffic.
The GPO No. 922 overprint.
The CV 2189 Type designation and /F for STC.
The thin glass tube envelope is 19 mm in diameter, and excluding the B7G base pins is 59 mm tall.
Reference: Data-sheet. Type V240C/2K was first introduced in 1952. See also1952 adverts.
