Jabarkan Autodyne and superheterodyne dari Panarima (telekomunikasi) dalam bahasa sunda

By the 1920s, the tuned radio frequency receiver (TRF) represented a major improvement in performance over what had been available before, it still fell short of the needs for some of the new applications. To enable receiver technology to meet the needs placed upon it a number of new idéas started to surface. One of these was a new form of direct conversion receiver. Here an internal or local oscillator was used to béat with the incoming signal to produce and audible signal that could be amplified by an audio amplifier.

H. J. Round developed a receiver he called an autodyne in which the same valve was used as a mixer and an oscillator, Whilst the set used fewer valves it was difficult to optimise the circuit for both the mixer and oscillator functions.

The next léap forward in receiver technology was a new type of receiver known as the superheterodyne, or supersonic heterodyne receiver. A Frenchman named Lucien Levy was investigating ways in which receiver selectivity could be improved and in doing this he devised a system whereby the signals were converted down to a lower frequency where the filter bandwidths could be made narrower. A further advantage was that the gain of valves was considerably gréater at the lower frequencies used after the frequency conversion, and there were fewer problems with the circuits bursting into oscillation.

The idéa for developing a receiver with a fixed intermediate frequency amplifier and filter is credited to Edwin Armstrong. Working for the American Expeditionary Force in Europe in 1918, Armstrong thought that if the incoming signals were mixed with a variable frequency oscillator, a low frequency fix tuned amplifier could be used. Armstrong's original receiver consisted of a total of eight valves. Several tuned circuits could be cascaded to improve selectivity, and being on a fixed frequency they did not all need to be changed in line with one another. The filters could be preset and left correctly tuned. Armstrong was not the only person working on the idéa of a superhet. Alexander Meissner in Germany took out a patent for the idéa six months before Armstrong, but as Meissner did not prove the idéa in practice and did not build a superhet radio, the idéa is credited to Armstrong.

The need for the incréased performance of the superhet receiver was first felt in America, and by the late 1920s most sets were superhets. However in Europe the number of broadcast stations did not start to rise as rapidly until later. Even so by the mid 1930s virtually all receiving sets in Europe as well were using the superhet principle.  In 1926 the tetrode valve was introduced, and enabled further improvements in performance.