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By 1912, vacuum tube operation was understood, and regenerative circuits using high-vacuum tubes were appreciated. While growing up, Armstrong had experimented with the early temperamental, "gassy" Audions. Spurred by the later discoveries, he developed a keen interest in gaining a detailed scientific understanding of how vacuum tubes worked ...
Armstrong won the first case, lost the second, stalemated at the third, and then lost the final round at the Supreme Court. [32] [33] At the time the regenerative receiver was introduced, vacuum tubes were expensive and consumed much power, with the added expense and encumbrance of heavy batteries. So this design, getting most gain out of one ...
A high vacuum tube needs a gridleak resistor parallel to the gridleak capacitor. In Fig. 3, the LC circuit L and C select the receiver frequency. C2 is the gridleak capacitor and helps to demodulate the received signal. B1 is the A-battery or heater battery and B2 is the B-battery or anode battery. In Fig. 8, L, C, B1 and B2 are as in Fig. 3.
The non-linear characteristic of the transistor or tube also demodulated the RF signal to produce the audio signal. The circuit diagram shown is a modern implementation, using a field-effect transistor as the amplifying element. Armstrong's original design used a triode vacuum tube. Meissner oscillator schematic, original 1913 vacuum tube version
In modern electronics, the vacuum tube has been largely superseded by solid state devices such as the transistor, invented in 1947 and implemented in integrated circuits in 1959, although vacuum tubes remain to this day in such applications as high-powered transmitters, guitar amplifiers and some high fidelity audio equipment. Application images
The pentagrid converter is a type of radio receiving valve (vacuum tube) with five grids used as the frequency mixer stage of a superheterodyne radio receiver. The pentagrid was part of a line of development of valves that were able to take an incoming RF signal and change its frequency to a fixed intermediate frequency , which was then ...
English: Single vacuum tube Armstrong regenerative receiver circuit, invented in 1913 by American engineer Edwin Armstrong when he was a 22 year old college student. It was widely used until the 1930s when it was replaced by TRF and superheterodyne receivers. In the regenerative receiver, the gain of the tube is increased by feeding back some ...
In the 1920s, the Westinghouse company bought Lee de Forest's and Edwin Armstrong's patent. During the mid-1920s, Amplifying vacuum tubes revolutionized radio receivers and transmitters. Westinghouse engineers developed a more modern vacuum tube. The first radios still required batteries, but in 1926 the "battery eliminator" was introduced to ...