articles | RaytheonVT127
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Sensibly equivalent¶ to:- CV1127 - Pen46 |
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The VT127 is an early television line output pentode valve. In line scan duty high surge voltages appear, this valve can withstand an anode surge of 3,000 Volts.
The box anode is supported on ceramic insulators. The two inner grids are supported on notched copper rods. The suppressor grid appears to be beam plates in this valve. The Pen46 has a wire wound third grid.
Some of the (earlier) Mazda 'Pen' series were true pentodes (eg. AC/Pen, AC2/Pen) while others (later) were definitely beam tetrodes (eg. AC4/Pen, AC5/Pen). It is quite possible that both varieties of Pen46 were made. Basically, in the early 1930s Mazda pentodes were the best in Europe, far surpassing M-OV's efforts in this direction. By the later 1930s, M-OV and RCA had co-operatively developed a family of beam tetrodes which were significantly better than the best Mazda pentodes. Mazda gradually climbed onto the beam tetrode bandwagon but, whereas M-OV proudly advertised their 'KTs', Mazda concealed the change to beam valves from all but the technical cognoscenti.
Given that only Mazda made valves on the Mazda Octal (MO) base and that this is made in the USA and has a UK Government code it was probably made during WWII.
The classic envelope is 50 mm in diameter and, excluding the MO base pins, is 118 mm tall.
References: Private correspondence.
Pin Connections
The box anode is supported on ceramic insulators. The two inner grids are supported on notched copper rods. The suppressor grid appears to be beam plates in this valve. The Pen46 has a wire wound third grid.
Some of the (earlier) Mazda 'Pen' series were true pentodes (eg. AC/Pen, AC2/Pen) while others (later) were definitely beam tetrodes (eg. AC4/Pen, AC5/Pen). It is quite possible that both varieties of Pen46 were made. Basically, in the early 1930s Mazda pentodes were the best in Europe, far surpassing M-OV's efforts in this direction. By the later 1930s, M-OV and RCA had co-operatively developed a family of beam tetrodes which were significantly better than the best Mazda pentodes. Mazda gradually climbed onto the beam tetrode bandwagon but, whereas M-OV proudly advertised their 'KTs', Mazda concealed the change to beam valves from all but the technical cognoscenti.
Given that only Mazda made valves on the Mazda Octal (MO) base and that this is made in the USA and has a UK Government code it was probably made during WWII.
The classic envelope is 50 mm in diameter and, excluding the MO base pins, is 118 mm tall.
References: Private correspondence.
Pin Connections
Given that only Mazda made valves on the Mazda Octal (MO) base and that this is made in the USA and has a UK Government code it was probably made during WWII.
The classic envelope is 50 mm in diameter and, excluding the MO base pins, is 118 mm tall.
References: Private correspondence.
Pin Connections
References: Private correspondence.
Pin Connections
Pin Connections
