The CV1120 is a UK government procurement specification that was made by various suppliers. The commercial equivalent was the SU2150A from Cossor and this hand assembled saddle construction proved the most reliable in service.
The maximum reservoir capacitor is 0.25 µF, and the minimum series resistance is 10 kΩ.
The KB/JD identifies this valve as being made to specification K1001 or K1006, the B denotes qualification by a UK authority and the JD identifies the maker as Elliott Bros. (London) Ltd, Borehamwood.
The cylindrical anode is supported on glass rods fixed in the pinch.
The anode fixing flanges and top cap connection.
The cathode tube and a second support pass through the anode and as a consequence the cathode is not central.
The lower end of the cathode together with the insulated heater.
The classic envelope is 47 mm in diameter at its widest and excluding the B4 base pins the valve is 111 mm high.
