List of North American broadcast station classes Warning: You are not logged in. Your IP address will be publicly visible if you make any edits. If you log in or create an account, your edits will be attributed to your username, along with other benefits.Anti-spam check. Do not fill this in! ===Station class descriptions=== All domestic (United States) AM stations are classified as '''A''', '''B''', '''C''', or '''D'''. <ref>{{cite web | url = https://www.fcc.gov/media/radio/am-clear-regional-local-channels#CLASSES | title = AM Station Classes, and Clear, Regional, and Local Channels | website = fcc.gov| date = 11 December 2015 | publisher = Federal Communications Commission | access-date = July 5, 2019 }}</ref> * '''A''' (formerly '''I''') β [[clear-channel station]]s β 10 kW to 50 kW, 24 hours. **Class A stations are only protected within a {{convert|750|mi|km|0|abbr=off|adj=on|sp=us}} radius of the transmitter site. **The old Class I was divided into three: Class I-A, I-B and I-N. [[NARBA]] distinguished between Class I-A, which were true clear-channel stations that did not share their channel with another Class I station, and Class I-B, in which a station operated with 50 kW at night but shared its channel with at least one other I-B station, requiring directional operation. This distinction was superseded by the [[Regional Agreement for the Medium Frequency Broadcasting Service in Region 2]] (Rio Agreement), which instituted the current class system. **The former Class I-As are omnidirectional, with the exception of 870 WWL New Orleans and 1030 WBZ Boston, which use directional antennas to put a better signal over their largest population areas. **Most former Class I-Bs are directional at night, although a few are also directional during days. (A handful of I-Bs did not have to use directional antennas: 680 KNBR San Francisco, 810 WGY Schenectady, 850 KOA Denver, 940 XEQ Mexico City, 1070 KNX Los Angeles and 1070 CBA Moncton. KNX and CBA were far enough apart that both could operate without using a directional antenna. XEQ is far enough from Montreal that it did not need a directional antenna. KNBR and KOA are the only Class Is on their frequency but share those frequencies with several Class II-Bs.) **Former Class I-N stations exist only in Alaska, where they are too remote to interfere with other clear-channel stations in the contiguous 48 states. They are only held to Class B efficiency standards (although higher efficiency is acceptable). **No new Class A stations are licensed in the conterminous United States, although the FCC states it may be possible to license additional Class A stations in Alaska. * '''B''' (formerly '''II''' and '''III''') β regional stations β 250 W to 50 kW, 24 hours. **Stations on the [[AM expanded band]], 1610 kHz to 1700 kHz, are limited to 10 kW days and 1 kW nights, non-directionally. **Several expanded band stations operate DA-N or even DA-2 with up to 10 kW during all hours, after providing proof that such operations will not cause co- or adjacent-channel interference. **If under 250 W at night, the antenna must be efficient enough to radiate more than 140.82 mV/m at 1 km. * '''C''' (formerly '''IV''') β local unlimited-time stations β 250 W to 1 kW, 24 hours. **Class C stations that were licensed at 100 W are [[grandfather clause|grandfathered]]. **Rare Class Cs operate with directional arrays, such as [[KYPA]] and [[KHCB (AM)|KHCB]]. * '''D''' (formerly '''II-D''', '''II-S''', '''III-S''') β current and former [[daytimer]]s β Daytime 250 W to 50 kW, nighttime under 250 W or off-air. **[[Field strength]] is limited to 140 mV/m (millivolts per meter) at 1 km. **No new class D stations are licensed, with the exception of Class B stations that are downgrading their nighttime operations to Class D (i.e., less than 250 W). The station's daytime operation is then also reclassified as Class D. **If a Class D station is on the air at night, it is not protected from any co-channel interference. * '''TIS'''/'''HAR''' β [[travelers' information station]]s / highway advisory radio stations β Up to 10 W transmitter output power. Stations within [[National Park Service|US national parks]] are licensed by [[National Telecommunications and Information Administration|NTIA]] and not the FCC. * '''Unlicensed broadcasting''' β (see [[low-power broadcasting]]) β 100 mW DC input to final amplifier with a {{convert|3|m|ft|0|abbr=off|adj=on|sp=us}} maximum length radiator, no license needed, may be measured at edge of campus for school stations and neighborhood broadcasters. '''Notes:''' * In the Western Hemisphere ([[ITU Region|ITU region 2]]), [[medium wave]] AM broadcasts are on channels spaced 10 kHz apart from 530 kHz to 1700 kHz, with certain classes restricted to subsets of the available frequencies. * With few exceptions, Class A stations can be found only on the frequencies of 540 kHz, 640 to 780 kHz, 800 to 900 kHz, 940 kHz, 990 to 1140 kHz, 1160 to 1220 kHz, and 1500 to 1580 kHz. The exceptions are cited in relevant international treaties. * While US and Canadian Class A stations are authorized to operate at a maximum of 50,000 watts day and night (and a minimum of 10,000 watts at night, if grandfathered), certain existing Mexican Class A stations, and certain new Cuban Class A stations are authorized to operate at a higher power. Certain Mexican Class A stations are authorized to operate at less than 50,000 watts at night, if grandfathered, but may operate at up to 100,000 watts during the day. * Class B and D stations can be found on any frequencies from 540 kHz to 1700 kHz except where frequencies have been reserved for Class C stations. * Class C stations can be found in the lower 48 US states on the frequencies of 1230 kHz, 1240 kHz, 1340 kHz, 1400 kHz, 1450 kHz, and 1490 kHz (commonly known as "graveyard" frequencies). Other countries may use other frequencies for their Class C stations. * American territories in ITU region 3 with AM broadcasting stations ([[Guam]] and the [[Northern Mariana Islands]]) use the 9 kHz spacing customary to the rest of the world. All stations are class B or lower. * Canada also defines Class CC ([[Carrier Current]], restricted to the premises) and LP. (less than 100 watts)<ref>{{Cite web |url=http://spectrum.ic.gc.ca/engineering/engdoc/baserad.zip |title=Industry Canada Broadcasting Database |access-date=2011-01-29 |archive-url=https://web.archive.org/web/20131207042211/http://spectrum.ic.gc.ca/engineering/engdoc/baserad.zip |archive-date=2013-12-07 |url-status=dead }}</ref> * TIS stations can be found on any frequency from 530 kHz to 1700 kHz in the US, but may only carry non-commercial messages without music. There is a network of TISs on 1710 in New Jersey. * [[Low-power AM]] stations located on a school campus are allowed to be more powerful, so long as their signal strength does not exceed roughly 14 to 45 Β΅V/m (microvolts per meter) (depending on frequency) at a distance of 30 meters (98.4 ft) from campus. ====Former system==== AM station classes were previously assigned [[Roman numerals]] from I to IV in the US, with subclasses indicated by a letter suffix. Current class A is equivalent to the old class I; class B is the old classes II and III, with class D being the II-D, II-S, and III-S subclasses; and class C is the old class IV. The following conversion table compares the old AM station classes with the new AM station classes: :{| class="wikitable" |- ! Old Domestic Station Class ! New Domestic Station Class |- | I | A |- | II | B |- | III | B |- | IV | C |- | II-S | D |- | III-S | D |- | II-D<br />(Daytime Only) | D |} Summary: Please note that all contributions to Christianpedia may be edited, altered, or removed by other contributors. If you do not want your writing to be edited mercilessly, then do not submit it here. You are also promising us that you wrote this yourself, or copied it from a public domain or similar free resource (see Christianpedia:Copyrights for details). Do not submit copyrighted work without permission! Cancel Editing help (opens in new window) Discuss this page