The CV5109 (commercially the GE10) is a saturated emission diode primarily for use as a control element in AC stabiliser circuits.
The CV5109 has a directly heated tungsten filament and to ensure that it operates with saturated current the anode voltage must be 100 Volts or more. The characteristic that makes it suitable as a control element is the large change in anode current for a small change in filament voltage.
The base connections marked j indicates a short circuit between pins 3 and 4. This enables the equipment to be designed such that if the valve is removed the equipment will shutdown.
The KB/RC identifies this valve as being made to specification K1001 or K1006, the B denotes qualification by a UK authority and the RC identifies the maker as Ferranti, Chadderton, Oldham.
The anode cylinder secured at the top and the single strand filament running through the centre.
A closer view.
Thanks to R J Sutherland for supplying the information.
The wide glass tube envelope is 27 mm in diameter and, excluding the IO base pins, is 60 mm tall.
References: Private communication & data-sheet. Type CV5109 was first introduced in 1957. See also1957 adverts.
