Twin-grid vacuum tube
Hugo Tetrode was born in 1895.
Hugo Tetrode died in 1931.
A tetrode is an electronic tube with four electrodes; cathode, grid, screen, and plate.
a tetrode is used when you need a screen grid tube, but a suppressor grid tube can't be used.OK, but the question was "why use a tetrode instead of a triode?"So, the answer...1. A tetrode has a higher voltage/power gain than a triode.2. A tetrode has less anode-grid feedback capacitance than a triode, and can operate in common-cathode radio frequency circuits without the neutralisation (or other corrective circuitry) that is needed by a triode.
Tetrode original paper: Die chemische Konstante der Gase and das elementare Wirkungsquantum I don't know about Sackur
Tetrode; a type of vacuum tube
Giulio Cottini has written: 'Il teorema di Tetrode'
Yes. It was an early attempt to improve high-frequency operation.The device had the usual emitter-base-collector construction, but with *two* base connections, one at either side.In operation, a reverse bias applied to one of the base connections forced the current flow towards the other base, giving an artificially-narrow current path.This reduced capacitances in the device, giving higher operating frequencies.Concurrent, and later, developments gave greatly imrpoved perfomance from the conventional "triode" construction, so tetrode transistors became obsolete.Be aware that the tetrode transistor is basically a triode (three-electrode) device, unlike the vacuum tube tetrode, which has four terminals and gives radically different characteristics from the triode vacuum tube.
The screen grid shields the control grid from the plate, reducing capacitance and the Miller Effect, improving performance at high frequencies.It *also* greatly increases the intrinsic ("natural") gain.This is the amplification factor, "mu".A triode has a maximum mu of around 100, and as little as 2.0, depending on the valve type.A tetrode/pentode has a mu in excess of 500, often in the thousands.However, you won't usually find a specification for mu in tetrode/pentode data sheets, as it's impractical to design circuits with this amount of gain.Around 300~350 is the practical maximum.
The correct schematic symbol for a tetrode tube includes the usual elements for a vacuum tube - a cathode, anode, grid, and screen grid. The grid is depicted as a single line inside the tube with an arrow pointing towards the cathode. The screen grid is often shown as a grid between the control grid and the anode.
P. J. C. Tetrode has written: 'Prae-adviezen over de vraag, Welke zijn de oorzaken en de beteekenis van den tegenwoordigen hoogen rentestand, ook in verband met de ontwikkeling van de welvaart?' -- subject(s): Economic history
A tetrode valve is a type of vacuum tube that contains four active elements: a cathode, an anode (or plate), and two control grids. The first control grid modulates the flow of electrons from the cathode to the anode, while the second control grid, known as the screen grid, helps to improve performance by reducing capacitance effects and increasing gain. Tetrode valves are commonly used in audio amplifiers and radio frequency applications due to their efficiency and improved linearity compared to earlier triode designs. They played a significant role in the development of early electronics before the advent of transistors.