Talk:AM broadcasting

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

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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:

... for radio telegraph communication early in the 20th century ...

Okay. I think we really could use an article on radio telegraphy, are you up to it? I had thought that it was on AM frequencies; I remember hearing lots of Morse Code on medium and shortwave as late as the mid 1970s, was that something different from what is ususally called radio telegraph? -- Infrogmation

The point is it is not "AM" (as in amplitude modulation), so it is not "AM radio". Even though it happened to occur in bands also used for AM. My suggestion is that the term "AM radio" should mean "public broadcasting using amplitude modulation", while "AM" should mean "amplitude modulation" in the more technical meaning. Morse using CW is neither. Sorry, I don't know too much about radio telegraphy history and such, so all I can contribute would be a silly stub. -- Egil 18:14 Feb 4, 2003 (UTC)

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)

frequencies

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.

Globalize

Tagged with globalize/north america for these reasons:

• The first licensed commercial radio services began on AM in the 1920s. XWA of Montreal, Quebec (later CFCF) was the first commercial broadcaster in the world, with regular broadcasts commencing on May 20, 1920. The first licensed American radio station was started by Frank Conrad, KDKA in Pittsburgh, Pennsylvania. -- No mention of any other countries.
• In North American broadcasting practice, transmitter power input to the antenna for commercial AM stations ranges from about 250 watts to 50,000 watts. (rest of paragraph omitted to save space). -- No mention of the broadcasting practices for any other region.
• As a result, many broadcast stations are required as a condition of license to reduce their broadcasting power significantly (or use directional antennas) after sunset, or even to suspend broadcasting entirely during nighttime hours. -- Not clear from the article if this is specifically North American practice or is found everywhere.
• In the United States and Canada, some AM radio stations are granted clear channel status... -- No mention of the practices in any other country.
• The hobby of listening to long distance signals is known as DX or DX'ing, from an old telegraph abbreviation for "distance". Several non-profit hobbyist clubs are devoted exclusively to DXing the AM broadcast band, including the National Radio Club and International Radio Club of America. -- No mention of this hobby in other regions, but is instead stated as if this is the terminology everywhere.
• AM radio is broadcast on several frequency bands. The allocation of these bands is governed by the ITU's Radio Regulations and, on the national level, by each country's telecommunications administration (the FCC in the U.S., for example) subject to international agreements. -- Example is USA only. No other examples for any other country given.
• However, in the late 1960s and 1970s, top 40 rock and roll stations in the US and Canada such as WABC and CHUM transmitted highly processed and extended audio to 11 kHz, successfully attracting huge audiences. In the UK during the 1980s, BBC Radio 4 (a largely speech channel) had an FM location, whereas BBC Radio 1, a music channel, was confined to AM broadcasts over much of the UK. Frequency response is typically 40 Hz–5 kHz with a 50 dB S/N ratio. -- North American perspective again. Also notable for one of the very few places in the whole article that even mentions any broadcasting practice outside of North America.
• The limitation on AM fidelity comes from current receiver design. Moreover, to fit more transmitters on the AM broadcast band, in the United States maximum transmitted audio bandwidth is limited to 10 kHz by an NRSC standard adopted by the FCC, resulting in a channel occupied bandwidth of 20 kHz. -- USA perspective, other viewpoints absent.
• In the United States, iBiquity's proprietary HD Radio has been adopted and approved by the FCC for medium wave transmissions, while Digital Radio Mondiale is a more open effort often used on the shortwave bands, and can be used alongside many AM broadcasts. -- No mention of the practices elsewhere, yet again.
• While FM radio can also be received by cable, AM radio generally cannot, although an AM station can be converted into an FM cable signal. In Canada, cable operators that offer FM cable services are required by the CRTC to distribute all locally available AM stations in this manner. In Switzerland a system known as "wire broadcasting" transmits AM signals over telephone lines in the longwave band. North american perspective. Also notable as one of the few places that mentions a country outside North America.
• Some microbroadcasters and pirate radio broadcasters, especially those in the United States under the FCC's Part 15 rules, broadcast on AM to achieve greater range than is possible on the FM band. No mention of the practice elsewhere.

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)

link title[ ] —Preceding unsigned comment added by 78.187.53.71 (talk) 12:38, 6 December 2008 (UTC)