i thought short wave went up to 29,999 kHz? tahstw hat it does on my sw radio. -fonzy
You could be right. My Sony only goes up to 26100 kHz, though, which is where I got the figure from. Feel free. GrahamN 19:52 Jan 23, 2003 (UTC)
I have a digital one(not DAB, digital dial) i think the MW one is wrng too. as it goes up to 17,010 khz on mine, then sw starts on 17,011 starts. - i dont really know enough about radio btu i am shore that sw goes up to 30 Mhz. -fonzy
The current American AM band extends from 540 to 1700KHz wheras the official European MW band is from 531 to 1602 KHz also in both cases there are stations operating "just" outside the official band so the defacto band goes from 520 to around 1720 KHz (confusingly some older European radios mark dial position in metres instead) Officially "Shortwave" (HF) covers the range 3 to 30 Megahertz however there is no (legal) shortwave BROADCASTING above 26.1 MHz (remember the radio spectrum is used for many other things besides broadcasting) also Most people consider the bands between the top end of the meduimwave band and 3 MHz to be "shortwave" even if they are not officially classed as such. Most "Shortwave" radios only cover the most popular broadcast bands (some only cover the "49 Metre"/6 MHz broadcast band) Some treat Shortwave as a single "band" while some (particualrly analouge tuned) radios split it up into smaller ranges (often marked "SW1" "SW2)" etc to make tuning easier.
Does this help? It's a bit surprising that the definitions seem so vague. GrahamN 20:16 Jan 23, 2003 (UTC)
All thsi conflicting data hurts my head :-s, we need someone who really is an expert on this. -fonzy
How about if we round the numbers off and qualify them with "approximately"? GrahamN
Yes do taht for now might be good to put an HTML comment on the paeg saying if you deffently know what it should be please say. -fonzy
The trad. modulation used for telegraphy (carrier either on or off) is called CW. Although the amplitude is modulated per se (0 or 100%), the term AM is never used for this. I have thus removed the following sentence:
Not all morse telegraphy is "CW" Some is "MCW" "FSK" etc Actually even "CW" is a bit of a misnomor. It should really be termed "ICW" (interrupted continous wave)
The term "commercial radio broadcasting" in this context is rather confusing (Long wave is used for commercial radio broadcasting in Europe, Africa, Asia,.....) Since the majority of Longwave and Shortwave (as well as much Mediumwave) broadcasting is infact NON-commercial. Also Long wave is NOT used for broadcasting in "Australasia". In the 1930's when the ABC was being established in Australia t was originally proposed that LW should be used but a for various reasons mix of MW and SW (and later FM etc) was decided upon instead.
Tagged with globalize/north america for these reasons:
Virtually every paragraph discusses the USA and/or Canada in depth, but only in a few places in the article are other countries mentioned by name. The article needs a substantial overhaul if it is to be more representative of the global audience of Wikipedia, per MOS. -- B.D.Mills ( T, C) 01:00, 13 November 2008 (UTC)
I live in the USA. Right now I hear radio stations broadcasting on long wave AM, for example 180 KHZ. Surely part of this article is in error. ( EnochBethany ( talk) 18:52, 11 September 2012 (UTC))
An encyclopedia would certainly mention the kind of stereo already specified and in current enforcement by the U.S. Government. This is "AM Analog Stereo", which has no connection to the AM digital stereo already covered in the article. And to address the international nature of Wikipedia articles, most countries have implemented "AM Analog Stereo" in a small minority of their stations as well. What should be noted in the article is that the kind of AM Stereo on the books is virtually the same for both the U.S. and practically all other countries. That kind of AM Analog Stereo is "C-QUAM". Another easily sourced information on the difference between "AM Analog Stereo" and "AM Digital Stereo", is that the "C-QUAM" flavor of "AM Analog Stereo", besides being the only flavor of AM Analog Stereo authorized by governments around the world, also has no licensing fees, unlike the popular AM Digital Stereo. Ohgddfp ( talk) 11:55, 15 August 2013 (UTC)
Are there any radio engineers reading this who think that this statement is misleading? In my view "heterodyning", and the selected sources, are being misused in this context. Sum and difference frequencies (sidebands) are generated when a signal is amplitude modulated, but that is more of a consequential effect of the amplitude modulation than a principle by which to amplitude modulate, as this statement would suggest. Wildbear ( talk) 00:15, 22 September 2013 (UTC)
Mixing is probably most general, as it means nonlinearly combining two signals (in audio it means linearly, but that's different). AM modulating is bilinear mixing a baseband signal with a carrier oscillator signal. Heterodyning is mixing an RF signal with a local oscillator signal of a frequency different from the RF carrier frequency. Homodyning is mixing an RF signal with a local oscillator signal of same frequency as the RF.
Recently an editor added this unsourced paragraph on a quirk in vacuum tubes discovered when Crystal Gayle records were played in the 1980s to the "Vacuum tubes" section. While this is interesting and entertaining, I feel in addition to not being notable enough, it is off topic for this section and this article. The "Vacuum tubes" section is about the historical introduction of vacuum tubes to radio around 1920, so a minor quirk in modern tubes does not belong here. In addition I am not sure it belongs in this article; perhaps it would be more appropriate in Vacuum tube, Triode, or Radio broadcasting -- Chetvorno TALK 23:00, 19 April 2015 (UTC)
See also http://www.mwlist.org/mwlist_quick_and_easy.php 84.80.54.162 ( talk) 17:32, 7 July 2016 (UTC)
There is a statement, with {{ citation needed}}: Finally, the 10 kilohertz minimum separation between stations in the United States limits fidelity to sounds much lower than the upper limit of human hearing, and the advent of high-fidelity recording equipment has created a demand for high-fidelity radio. First, it doesn't say which part of the statement needs a citation, but the statement itself is questionable. While 20Hz to 20kHz is the common frequency range for describing audio equipment, most people's hearing drops of closer to 15kHz. The highest note on the usual piano, from Piano_key_frequencies, is 4186Hz. There isn't much music up there, though the harmonics of some notes make it sound a little nicer. The problem is more that both transmitters and receivers aren't well designed, to save on costs, to get the most out of the available bandwidth. Gah4 ( talk) 18:29, 14 February 2017 (UTC)
The next paragraph seems to suggest that the FM broadcast band shift in 1946 is responsible for the delay until the 1970's of FM's dominance. That seems hard to believe. Car radios were AM only for many years, and many home and portable radios also were for many years. But for people who wanted to listen to high fidelity audio, FM broadcasting was the first choice much earlier. Some people in 1946 had useless radios, though. Gah4 ( talk) 18:29, 14 February 2017 (UTC)
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i thought short wave went up to 29,999 kHz? tahstw hat it does on my sw radio. -fonzy
You could be right. My Sony only goes up to 26100 kHz, though, which is where I got the figure from. Feel free. GrahamN 19:52 Jan 23, 2003 (UTC)
I have a digital one(not DAB, digital dial) i think the MW one is wrng too. as it goes up to 17,010 khz on mine, then sw starts on 17,011 starts. - i dont really know enough about radio btu i am shore that sw goes up to 30 Mhz. -fonzy
The current American AM band extends from 540 to 1700KHz wheras the official European MW band is from 531 to 1602 KHz also in both cases there are stations operating "just" outside the official band so the defacto band goes from 520 to around 1720 KHz (confusingly some older European radios mark dial position in metres instead) Officially "Shortwave" (HF) covers the range 3 to 30 Megahertz however there is no (legal) shortwave BROADCASTING above 26.1 MHz (remember the radio spectrum is used for many other things besides broadcasting) also Most people consider the bands between the top end of the meduimwave band and 3 MHz to be "shortwave" even if they are not officially classed as such. Most "Shortwave" radios only cover the most popular broadcast bands (some only cover the "49 Metre"/6 MHz broadcast band) Some treat Shortwave as a single "band" while some (particualrly analouge tuned) radios split it up into smaller ranges (often marked "SW1" "SW2)" etc to make tuning easier.
Does this help? It's a bit surprising that the definitions seem so vague. GrahamN 20:16 Jan 23, 2003 (UTC)
All thsi conflicting data hurts my head :-s, we need someone who really is an expert on this. -fonzy
How about if we round the numbers off and qualify them with "approximately"? GrahamN
Yes do taht for now might be good to put an HTML comment on the paeg saying if you deffently know what it should be please say. -fonzy
The trad. modulation used for telegraphy (carrier either on or off) is called CW. Although the amplitude is modulated per se (0 or 100%), the term AM is never used for this. I have thus removed the following sentence:
Not all morse telegraphy is "CW" Some is "MCW" "FSK" etc Actually even "CW" is a bit of a misnomor. It should really be termed "ICW" (interrupted continous wave)
The term "commercial radio broadcasting" in this context is rather confusing (Long wave is used for commercial radio broadcasting in Europe, Africa, Asia,.....) Since the majority of Longwave and Shortwave (as well as much Mediumwave) broadcasting is infact NON-commercial. Also Long wave is NOT used for broadcasting in "Australasia". In the 1930's when the ABC was being established in Australia t was originally proposed that LW should be used but a for various reasons mix of MW and SW (and later FM etc) was decided upon instead.
Tagged with globalize/north america for these reasons:
Virtually every paragraph discusses the USA and/or Canada in depth, but only in a few places in the article are other countries mentioned by name. The article needs a substantial overhaul if it is to be more representative of the global audience of Wikipedia, per MOS. -- B.D.Mills ( T, C) 01:00, 13 November 2008 (UTC)
I live in the USA. Right now I hear radio stations broadcasting on long wave AM, for example 180 KHZ. Surely part of this article is in error. ( EnochBethany ( talk) 18:52, 11 September 2012 (UTC))
An encyclopedia would certainly mention the kind of stereo already specified and in current enforcement by the U.S. Government. This is "AM Analog Stereo", which has no connection to the AM digital stereo already covered in the article. And to address the international nature of Wikipedia articles, most countries have implemented "AM Analog Stereo" in a small minority of their stations as well. What should be noted in the article is that the kind of AM Stereo on the books is virtually the same for both the U.S. and practically all other countries. That kind of AM Analog Stereo is "C-QUAM". Another easily sourced information on the difference between "AM Analog Stereo" and "AM Digital Stereo", is that the "C-QUAM" flavor of "AM Analog Stereo", besides being the only flavor of AM Analog Stereo authorized by governments around the world, also has no licensing fees, unlike the popular AM Digital Stereo. Ohgddfp ( talk) 11:55, 15 August 2013 (UTC)
Are there any radio engineers reading this who think that this statement is misleading? In my view "heterodyning", and the selected sources, are being misused in this context. Sum and difference frequencies (sidebands) are generated when a signal is amplitude modulated, but that is more of a consequential effect of the amplitude modulation than a principle by which to amplitude modulate, as this statement would suggest. Wildbear ( talk) 00:15, 22 September 2013 (UTC)
Mixing is probably most general, as it means nonlinearly combining two signals (in audio it means linearly, but that's different). AM modulating is bilinear mixing a baseband signal with a carrier oscillator signal. Heterodyning is mixing an RF signal with a local oscillator signal of a frequency different from the RF carrier frequency. Homodyning is mixing an RF signal with a local oscillator signal of same frequency as the RF.
Recently an editor added this unsourced paragraph on a quirk in vacuum tubes discovered when Crystal Gayle records were played in the 1980s to the "Vacuum tubes" section. While this is interesting and entertaining, I feel in addition to not being notable enough, it is off topic for this section and this article. The "Vacuum tubes" section is about the historical introduction of vacuum tubes to radio around 1920, so a minor quirk in modern tubes does not belong here. In addition I am not sure it belongs in this article; perhaps it would be more appropriate in Vacuum tube, Triode, or Radio broadcasting -- Chetvorno TALK 23:00, 19 April 2015 (UTC)
See also http://www.mwlist.org/mwlist_quick_and_easy.php 84.80.54.162 ( talk) 17:32, 7 July 2016 (UTC)
There is a statement, with {{ citation needed}}: Finally, the 10 kilohertz minimum separation between stations in the United States limits fidelity to sounds much lower than the upper limit of human hearing, and the advent of high-fidelity recording equipment has created a demand for high-fidelity radio. First, it doesn't say which part of the statement needs a citation, but the statement itself is questionable. While 20Hz to 20kHz is the common frequency range for describing audio equipment, most people's hearing drops of closer to 15kHz. The highest note on the usual piano, from Piano_key_frequencies, is 4186Hz. There isn't much music up there, though the harmonics of some notes make it sound a little nicer. The problem is more that both transmitters and receivers aren't well designed, to save on costs, to get the most out of the available bandwidth. Gah4 ( talk) 18:29, 14 February 2017 (UTC)
The next paragraph seems to suggest that the FM broadcast band shift in 1946 is responsible for the delay until the 1970's of FM's dominance. That seems hard to believe. Car radios were AM only for many years, and many home and portable radios also were for many years. But for people who wanted to listen to high fidelity audio, FM broadcasting was the first choice much earlier. Some people in 1946 had useless radios, though. Gah4 ( talk) 18:29, 14 February 2017 (UTC)