Editing Intermediate frequency (section)

==Examples==
[[File:Radiola AR-812 superheterodyne ad.jpg|thumb|upright=1.3|The RCA Radiola AR-812<ref name="Malanowski_2011"/> used 6 triodes: a mixer, local oscillator, two IF and two audio amplifier stages, with an IF of 45&nbsp;kHz.]]
* down to c. 20&nbsp;kHz{{cn|date=July 2021|reason=The article [[Superheterodyne receiver]] originally stated this from 2006 to 2021<!-- https://en.wikipedia.org/w/index.php?title=Superheterodyne_receiver&type=revision&diff=89426788&oldid=89131394 -->, but without source}}, 30&nbsp;kHz (A. L. M. Sowerby and H. B. Dent),<ref name="Bussey_1990"/> 45&nbsp;kHz (first commercial superheterodyne receiver: RCA Radiola AR-812 of 1923/1924),<ref name="Malanowski_2011"/> c. 50&nbsp;kHz,<ref name="Bussey_1990"/> c. 100&nbsp;kHz,<ref name="Bussey_1990"/> c. 120&nbsp;kHz<ref name="Bussey_1990"/>
* 110&nbsp;kHz was used in European AM [[longwave]] broadcast receivers.<ref name="Langford-Smith_1941"/><ref name="Langford-Smith_1953"/>
* 175&nbsp;kHz (early wide band and communications receivers before introduction of powdered iron cores)<ref name="Langford-Smith_1941"/><ref name="Langford-Smith_1953"/><ref name="Bussey_1990"/>
* 260&nbsp;kHz (early standard broadcast receivers),<ref name="Langford-Smith_1953"/> 250–270&nbsp;kHz<ref name="Langford-Smith_1941"/>
* Copenhagen Frequency Allocations: 415–490&nbsp;kHz, 510–525&nbsp;kHz<ref name="Langford-Smith_1953"/>
* [[AM radio]] receivers: 450&nbsp;kHz, 455&nbsp;kHz (most common),<ref name="Langford-Smith_1953"/> 460&nbsp;kHz, 465&nbsp;kHz,<ref name="Bussey_1990"/> 467&nbsp;kHz, 470&nbsp;kHz, 475&nbsp;kHz, and 480&nbsp;kHz.<ref name="Ravalico_1992"/>
* [[FM radio]] receivers: 262&nbsp;kHz (old car radios),<ref name="Wiccanpiper_2004"/> 455&nbsp;kHz, 1.6&nbsp;MHz, 5.5&nbsp;MHz, 10.7&nbsp;MHz (most common),<ref name="Langford-Smith_1953"/> 10.8&nbsp;MHz,<ref name="Electra_Bearcat"/> 11.2&nbsp;MHz, 11.7&nbsp;MHz, 11.8&nbsp;MHz, 13.45&nbsp;MHz,<ref name="Pioneer_1987"/> 21.4&nbsp;MHz, 75&nbsp;MHz and 98&nbsp;MHz. In double-conversion superheterodyne receivers, a first intermediate frequency of 10.7&nbsp;MHz is often used, followed by a second intermediate frequency of 470&nbsp;kHz (or 700&nbsp;kHz with [[DYNAS]]<ref name="Telefunken_1996"/>). There are triple conversion designs used in police scanner receivers, high-end communications receivers, and many point-to-point microwave systems. Modern DSP chip consumer radios often use a '[[low IF receiver|low-IF]]' of 128&nbsp;kHz for FM.
* [[Narrowband FM]] receivers: 455&nbsp;kHz (most common),<ref name="Langford-Smith_1953"/><ref name="Hansen_ICS"/> 470&nbsp;kHz<ref name="Hansen_ICS"/>
* Shortwave receivers: 1.6&nbsp;MHz,<ref name="Langford-Smith_1953"/> 1.6–3.0&nbsp;MHz,<ref name="Langford-Smith_1941"/> 4.3&nbsp;MHz (for 40–50 MHz-only receivers).<ref name="Langford-Smith_1953"/> In double-conversion superheterodyne receivers, a first intermediate frequency of 3.0&nbsp;MHz is sometimes combined with a second IF of 465&nbsp;kHz.<ref name="Langford-Smith_1941"/>
* [[Analog transmission|Analogue]] television receivers using system M: 41.25&nbsp;MHz (audio) and 45.75&nbsp;MHz (video). Note, the channel is flipped over in the conversion process in an [[intercarrier method|intercarrier]] system, so the audio IF is lower than the video IF. Also, there is no audio local oscillator; the injected video carrier serves that purpose.
* [[Analog transmission|Analogue]] television receivers using system B and similar systems: 33.4&nbsp;MHz for the aural and 38.9&nbsp;MHz for the visual signal. (The discussion about the frequency conversion is the same as in system M.)
* Satellite [[uplink]]-[[downlink]] equipment: 70&nbsp;MHz, 950–1450&nbsp;MHz (L-band) downlink first IF.
* Terrestrial [[microwave]] equipment: 250&nbsp;MHz, 70&nbsp;MHz or 75&nbsp;MHz.
* [[Radar]]: 30&nbsp;MHz.
* [[Radio frequency|RF]] test equipment: 310.7&nbsp;MHz, 160&nbsp;MHz, and 21.4&nbsp;MHz.