Analysis of information sources in references of the Wikipedia article "Intermediate frequency" in English language version.
[…] As a result of the experience gained over a number of years in addition to the considerations stated previously the values selected for the intermediate frequencies of most commercial receivers have become fairly well standardized. For the majority of broadcast receivers tuning the bands 540–1600 Kc/s and 6–18 Mc/s, an i-f of about 455 Kc/s is usual. A frequency of 110 Kc/s has been extensively used in Europe where the long wave band of 150–350 Kc/s is in operation. Receivers for use only on the short wave band commonly the 40–50 Mc/s band generally use a 4.3 Mc/s i-f, and for the 88–108 Mc/s band they use 10.7 Mc/s. This latter value has been adopted as standard in U.S.A., and some other countries, for v-h-f receivers. […] Short wave receivers using 1600 Kc/s i-f transformers commonly employ two stages (3 transformers) although one stage is often used […] In wide band and communication receivers, two or more stages are commonly used. The intermediate frequency in general use is 455 Kc/s. Earlier receivers used 175 Kc/s but with the appearance of powdered iron cores and the development of high slope amplifier valves, the previous objection to the use of higher intermediate frequencies, i.e. lower gain, was nullified. […] It is recommended that superheterodyne receivers operating in the medium frequency broadcast band use an intermediate frequency of 455 Kc/s. This frequency is reserved as a clear channel for the purpose in most countries of the world. […] The European "Copenhagen Frequency Allocations" provide the following two intermediate frequency bands: 415–490 Kc/s and 510–525 Kc/s. […] An intermediate frequency of 175 Kc/s is also used. […] The American RTMA has standardized the following intermediate frequencies (REC-109-B, March 1950): Standard broadcast receivers—either 260 or 455 Kc/s. V-H-F broadcast receivers—10.7 Mc/s.[1][2] (See also: Radiotron Designer's Handbook)
[…] DYNAS system […] for car radio and home receiver applications […] system of FM-IF processing […] bandpass filters with a bandwidth down to about 20 kHz compared to 160 kHz for a conventional […] filter […] tracks the resonant frequency to the actual frequency […][5] (13+1 pages)
[…] Mixer […] perform frequency change so that multiply input FM signal by VCO output. F-91 introduce the secondary IF as 13.45 MHz. Band-pass filter […] has the same narrow bandwidth characteristic as the band-pass filter […] Input signal […] passed through the band-pass filter […] is multiplied by VCO output at mixer […] then change[d] to the original frequency. Original signal is detected by FM detector […] audio output is obtained. […] in spite of use the filter of fixed the center frequency, F-91 operate to the variable filter so that center frequency follow the input signal as equivalent. […][3][4] (4 of 40 pages) (NB. The Pioneer Elite F-91 and the very similar Pioneer Reference Digital Synthesizer Tuner F-717 (as sold in Japan) supported Active Real-time Tracing System (ARTS) in 1987, whereas the completely different but almost identically named Pioneer Digital Synthesizer Tuner F-717 and F-717L (as sold internationally in 1987) were based on the F-77 and did not support ARTS.)
[…] it can be assumed that the desired intermediate frequency is 465 Kc/s […] for this reason frequencies in the region of 450–465 Kc/s are very widely used […] Superheterodyne receivers, designed specifically for short-wave communication work, usually have a higher frequency for the I.F., from about 1,600 to 3,000 Kc/s, and may also incorporate double frequency changing. For example the receiver may change the incoming signal first to 3,000 Kc/s and then to 465 Kc/s or lower. […] Various frequencies are used for the I.F. amplifiers of radio receivers. A frequency of 110 Kc/s. has been widely used in Europe where the long wave band is in use. The gives extremely good selectivity but serious side band cutting. A frequency of 175 Kc/s. has been used for broadcast band reception both in America and Australia for a number of years but its use on the short-wave band is not very satisfactory. A frequency in the region on 250–270 Kc/s. has also been used to a limited extent as a compromise between 175 and 465 Kc/s. The most common frequencies for dual wave receivers are between 450 and 465 Kcs.[…] and, particularly if iron cored I.F. transformers are used, this frequency band is a very good compromise. For short-wave receivers which are not intended for operation at lower frequencies, an intermediate frequency of 1,600 Kc/s. or higher may be used. […] A frequency of 455 Kc/s. is receiving universal acceptance as a stanard frequency, and efforts are being made to maintain this freqeuncy free from radio interference. […](See also: Radiotron Designer's Handbook)
[…] As a result of the experience gained over a number of years in addition to the considerations stated previously the values selected for the intermediate frequencies of most commercial receivers have become fairly well standardized. For the majority of broadcast receivers tuning the bands 540–1600 Kc/s and 6–18 Mc/s, an i-f of about 455 Kc/s is usual. A frequency of 110 Kc/s has been extensively used in Europe where the long wave band of 150–350 Kc/s is in operation. Receivers for use only on the short wave band commonly the 40–50 Mc/s band generally use a 4.3 Mc/s i-f, and for the 88–108 Mc/s band they use 10.7 Mc/s. This latter value has been adopted as standard in U.S.A., and some other countries, for v-h-f receivers. […] Short wave receivers using 1600 Kc/s i-f transformers commonly employ two stages (3 transformers) although one stage is often used […] In wide band and communication receivers, two or more stages are commonly used. The intermediate frequency in general use is 455 Kc/s. Earlier receivers used 175 Kc/s but with the appearance of powdered iron cores and the development of high slope amplifier valves, the previous objection to the use of higher intermediate frequencies, i.e. lower gain, was nullified. […] It is recommended that superheterodyne receivers operating in the medium frequency broadcast band use an intermediate frequency of 455 Kc/s. This frequency is reserved as a clear channel for the purpose in most countries of the world. […] The European "Copenhagen Frequency Allocations" provide the following two intermediate frequency bands: 415–490 Kc/s and 510–525 Kc/s. […] An intermediate frequency of 175 Kc/s is also used. […] The American RTMA has standardized the following intermediate frequencies (REC-109-B, March 1950): Standard broadcast receivers—either 260 or 455 Kc/s. V-H-F broadcast receivers—10.7 Mc/s.[1][2] (See also: Radiotron Designer's Handbook)
[…] it can be assumed that the desired intermediate frequency is 465 Kc/s […] for this reason frequencies in the region of 450–465 Kc/s are very widely used […] Superheterodyne receivers, designed specifically for short-wave communication work, usually have a higher frequency for the I.F., from about 1,600 to 3,000 Kc/s, and may also incorporate double frequency changing. For example the receiver may change the incoming signal first to 3,000 Kc/s and then to 465 Kc/s or lower. […] Various frequencies are used for the I.F. amplifiers of radio receivers. A frequency of 110 Kc/s. has been widely used in Europe where the long wave band is in use. The gives extremely good selectivity but serious side band cutting. A frequency of 175 Kc/s. has been used for broadcast band reception both in America and Australia for a number of years but its use on the short-wave band is not very satisfactory. A frequency in the region on 250–270 Kc/s. has also been used to a limited extent as a compromise between 175 and 465 Kc/s. The most common frequencies for dual wave receivers are between 450 and 465 Kcs.[…] and, particularly if iron cored I.F. transformers are used, this frequency band is a very good compromise. For short-wave receivers which are not intended for operation at lower frequencies, an intermediate frequency of 1,600 Kc/s. or higher may be used. […] A frequency of 455 Kc/s. is receiving universal acceptance as a stanard frequency, and efforts are being made to maintain this freqeuncy free from radio interference. […](See also: Radiotron Designer's Handbook)
[…] As a result of the experience gained over a number of years in addition to the considerations stated previously the values selected for the intermediate frequencies of most commercial receivers have become fairly well standardized. For the majority of broadcast receivers tuning the bands 540–1600 Kc/s and 6–18 Mc/s, an i-f of about 455 Kc/s is usual. A frequency of 110 Kc/s has been extensively used in Europe where the long wave band of 150–350 Kc/s is in operation. Receivers for use only on the short wave band commonly the 40–50 Mc/s band generally use a 4.3 Mc/s i-f, and for the 88–108 Mc/s band they use 10.7 Mc/s. This latter value has been adopted as standard in U.S.A., and some other countries, for v-h-f receivers. […] Short wave receivers using 1600 Kc/s i-f transformers commonly employ two stages (3 transformers) although one stage is often used […] In wide band and communication receivers, two or more stages are commonly used. The intermediate frequency in general use is 455 Kc/s. Earlier receivers used 175 Kc/s but with the appearance of powdered iron cores and the development of high slope amplifier valves, the previous objection to the use of higher intermediate frequencies, i.e. lower gain, was nullified. […] It is recommended that superheterodyne receivers operating in the medium frequency broadcast band use an intermediate frequency of 455 Kc/s. This frequency is reserved as a clear channel for the purpose in most countries of the world. […] The European "Copenhagen Frequency Allocations" provide the following two intermediate frequency bands: 415–490 Kc/s and 510–525 Kc/s. […] An intermediate frequency of 175 Kc/s is also used. […] The American RTMA has standardized the following intermediate frequencies (REC-109-B, March 1950): Standard broadcast receivers—either 260 or 455 Kc/s. V-H-F broadcast receivers—10.7 Mc/s.[1][2] (See also: Radiotron Designer's Handbook)
[…] Mixer […] perform frequency change so that multiply input FM signal by VCO output. F-91 introduce the secondary IF as 13.45 MHz. Band-pass filter […] has the same narrow bandwidth characteristic as the band-pass filter […] Input signal […] passed through the band-pass filter […] is multiplied by VCO output at mixer […] then change[d] to the original frequency. Original signal is detected by FM detector […] audio output is obtained. […] in spite of use the filter of fixed the center frequency, F-91 operate to the variable filter so that center frequency follow the input signal as equivalent. […][3][4] (4 of 40 pages) (NB. The Pioneer Elite F-91 and the very similar Pioneer Reference Digital Synthesizer Tuner F-717 (as sold in Japan) supported Active Real-time Tracing System (ARTS) in 1987, whereas the completely different but almost identically named Pioneer Digital Synthesizer Tuner F-717 and F-717L (as sold internationally in 1987) were based on the F-77 and did not support ARTS.)
[…] DYNAS system […] for car radio and home receiver applications […] system of FM-IF processing […] bandpass filters with a bandwidth down to about 20 kHz compared to 160 kHz for a conventional […] filter […] tracks the resonant frequency to the actual frequency […][5] (13+1 pages)
[…] DYNAS system […] for car radio and home receiver applications […] system of FM-IF processing […] bandpass filters with a bandwidth down to about 20 kHz compared to 160 kHz for a conventional […] filter […] tracks the resonant frequency to the actual frequency […][5] (13+1 pages)
