The V231C/1K is a velocity modulated oscillator or Heil tube. It is designed to provide a local oscillator operating, within a suitable cavity, at 3.06 to 3.18 GHz with an output of 50 mW. The cathode current is 45 mA and the resonator voltage is between 180 and 240 V.
The C in the designation indicates that it is designed for narrow electronic tuning rather than wide mechanical tuning which is indicated by an A in the Type designation. In the case of the V231C/1K the electronic tuning range is ±8 MHz.
This valve was made in England but carries the American ITT company name - the actual manufacture would be at the STC plant in Footscray, Kent.
The following is an extract from an STC catalogue and appears just below the table that gives the above information. This tube was developed for local oscillator use in S-band radar and provides a minimum output of 40 mW in the frequency range 3.04 to 3.12 Ghz and may be electronically tuned over a range of 10 MHz. The inexpensive cavity with which it is used is compact in design and both mechanical tuning and power output control are achieved by simple screw adjustments.
The resonator connects to the external disc. Note the evacuation pip on the side.
Another view.
The thin glass tube envelope is 19 mm in diameter and, excluding the B7G base pins, is 58 mm tall.
