The CV5729 (6CD6G) is specified for line timebase output in VHF television receivers with wide deflection angles and a screen size of up to 17 inches. With 700 Volts on the anode and a peak surge of 6 kV it can operate with up to 15 Watts anode dissipation. The 50CD6G differs only in heater rating.
The 6CD6G can also be used as an audio output beam tetrode. The values given are for single ended use. The data-sheet has more information on its use for audio. For triode connected Class A push pull a pair could deliver 4.8 Watts. As a beam tetrode the pair in Class A are specified for an output of 13.5 Watts.
Peter Farrow has used these valves in an audio amplifier to produce around 50 Watts of audio in a parallel push pull circuit.
This valve can also be used as a series pass element in a stabilised power supply.
The Brimar brand on the base cap. The box anode has side flanges to assist with heat dissipation.
A closer view reveals that this valve has been made with a double set of cathodes and inner grids. The beam plate and anode are common. The inner grids are wound on copper supports.
Top view: showing the three insulated hairpin heaters in each cathode.
Lower view: This clearly reveals that the main assembly was jig assembled before being spot welded to the supports set into the pinch.
The classic envelope is 50 mm in diameter and, excluding the IO base pins, is 129 mm tall.
References: Data-sheet & 1040. Type CV5729 was first introduced in 1952. See also1952 adverts.
