Extended AM broadcast band
Encyclopedia
| 9 kHz spacing |
10 kHz spacing |
|---|---|
| 1602 | 1600 |
| 1611 | 1610 |
| 1620 | 1620 |
| 1629 | 1630 |
| 1638 | 1640 |
| 1647 | 1650 |
| 1656 | 1660 |
| 1665 | ------- |
| 1674 | 1670 |
| 1683 | 1680 |
| 1692 | 1690 |
| 1701 | 1700 |
The extended mediumwave broadcast band, commonly known as the [AM] expanded band, is a broadcast
Broadcast
Broadcast or Broadcasting may refer to:* Broadcasting, the transmission of audio and video signals* Broadcast, an individual television program or radio program* Broadcast , an English electronic music band...
frequency allocation
Frequency allocation
Use of radio frequency bands of the electromagnetic spectrum is regulated by governments in most countries, in a Spectrum management process known as frequency allocation or spectrum allocation. Radio propagation does not stop at national boundaries...
which moved the upper limit of the AM
AM broadcasting
AM broadcasting is the process of radio broadcasting using amplitude modulation. AM was the first method of impressing sound on a radio signal and is still widely used today. Commercial and public AM broadcasting is carried out in the medium wave band world wide, and on long wave and short wave...
bandplan
Bandplan
A bandplan or band plan is a plan for using a particular band of radio frequencies, that are a portion of the electromagnetic spectrum . Each bandplan defines the frequency range to be included, how channels are to be defined, and what will be carried on those channels...
from 1610 to 1700 kHz.
History
The band became officially available around 1993 only in ITU regionITU region
The International Telecommunication Union , in its International Radio Regulations, divides the world into three ITU regions for the purposes of managing the global radio spectrum...
2 (North and South America
Americas
The Americas, or America , are lands in the Western hemisphere, also known as the New World. In English, the plural form the Americas is often used to refer to the landmasses of North America and South America with their associated islands and regions, while the singular form America is primarily...
). It is popular with microbroadcasters
Microbroadcasting
Microbroadcasting is the process of broadcasting a message to a relatively small audience. This is not to be confused with low-power broadcasting....
for having slightly better propagation characteristics than the standard AM band.
Though supported on most (but not all) modern AM radio receivers sold in the Americas, this band is usually unavailable to older radio receivers except for those with substantial overcoverage. On such radios, the 1600-1700 segment was labeled "Police", since it was the original police radio
Police radio
Police radio is a communications radio system used by law enforcement agencies all over the world.Many such systems are encrypted to prevent eavesdroppers from listening in.-Portable radios:...
band. In the U.S., coverage on newer radios is mandated by the Federal Communications Commission
Federal Communications Commission
The Federal Communications Commission is an independent agency of the United States government, created, Congressional statute , and with the majority of its commissioners appointed by the current President. The FCC works towards six goals in the areas of broadband, competition, the spectrum, the...
(FCC), invoking the All-Channel Receiver Act.
Americas
In the United StatesUnited States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
, the FCC granted "stereo preferences" to commercial broadcasters intending to use AM stereo
AM stereo
AM stereo is a term given to a series of mutually incompatible techniques for wireless radio broadcasting stereo audio in the AM band in a manner that is compatible with standard AM receivers...
when issuing licenses for the band, however, such stations have never been required to actually broadcast in stereo. There is little commercial availability or demand for the required receivers, and many AM stereo stations have ended those broadcasts due to those factors. Since the advent of HD Radio
HD Radio
HD Radio, which originally stood for "Hybrid Digital", is the trademark for iBiquity's in-band on-channel digital radio technology used by AM and FM radio stations to transmit audio and data via a digital signal in conjunction with their analog signals...
and the AM band as more a band for talk radio
Talk radio
Talk radio is a radio format containing discussion about topical issues. Most shows are regularly hosted by a single individual, and often feature interviews with a number of different guests. Talk radio typically includes an element of listener participation, usually by broadcasting live...
than music, it is unlikely the FCC would take any action against an extended-band station only broadcasting in monophonic
Monaural
Monaural or monophonic sound reproduction is single-channel. Typically there is only one microphone, one loudspeaker, or channels are fed from a common signal path...
sound. Stations must broadcast at ten kilowatts in the daytime, and one kilowatt at night, and so there are no new low-power or clear-channel stations.
Because 1610 kHz (the top or right-most channel on analog radios) had previously been reserved for Travelers' Information Stations (TIS) as 530 kHz (the bottom or left-most channel) still is, some TIS stations were displaced for new expanded-band stations.
While 1710 kHz appears on many radios, it is unused even by TIS stations, except for a group
Single-frequency network
A single-frequency network or SFN is a broadcast network where several transmitters simultaneously send the same signal over the same frequency channel.-Overview:...
(WQFG689) licensed with a waiver
Waiver
A waiver is the voluntary relinquishment or surrender of some known right or privilege.While a waiver is often in writing, sometimes a person's actions can act as a waiver. An example of a written waiver is a disclaimer, which becomes a waiver when accepted...
to the County of Hudson
Hudson County, New Jersey
Hudson County is the smallest county in New Jersey and one of the most densely populated in United States. It takes its name from the Hudson River, which creates part of its eastern border. Part of the New York metropolitan area, its county seat and largest city is Jersey City.- Municipalities...
. This is because aeronautical radionavigation may use 1708 kHz, and so like 87.9 FM it is not considered part of the adjacent radio broadcast band.
Greater Europe
Although the extended band is not officially allocated in Europe, it is used by Vatican RadioVatican Radio
Vatican Radio is the official broadcasting service of the Vatican.Set up in 1931 by Guglielmo Marconi, today its programs are offered in 47 languages, and are sent out on short wave , medium wave, FM, satellite and the Internet. The Jesuit Order has been charged with the management of Vatican...
and a number of "hobby" pirate radio
Pirate radio
Pirate radio is illegal or unregulated radio transmission. The term is most commonly used to describe illegal broadcasting for entertainment or political purposes, but is also sometimes used for illegal two-way radio operation...
stations, particularly in the Netherlands
Netherlands
The Netherlands is a constituent country of the Kingdom of the Netherlands, located mainly in North-West Europe and with several islands in the Caribbean. Mainland Netherlands borders the North Sea to the north and west, Belgium to the south, and Germany to the east, and shares maritime borders...
, Greece
Greece
Greece , officially the Hellenic Republic , and historically Hellas or the Republic of Greece in English, is a country in southeastern Europe....
, and Serbia
Serbia
Serbia , officially the Republic of Serbia , is a landlocked country located at the crossroads of Central and Southeast Europe, covering the southern part of the Carpathian basin and the central part of the Balkans...
.
Australasia
In AustraliaAustralian Broadcasting Authority
The Australian Broadcasting Authority was an Australian government agency whose main roles were to regulate broadcasting, radiocommunications and telecommunications....
, many commercial radio broadcast licences have been authorised for the extended band.
However, they have restrictions not placed on licences for the standard mediumwave band: e.g. 5 kHz bandwidths and type
Types of radio emissions
The International Telecommunication Union uses an internationally agreed system for classifying radio frequency signals. Each type of radio emission is classified according to its bandwidth, method of modulation, nature of the modulating signal, and type of information transmitted on the carrier...
H3E emissions, as used by CHU in Canada on shortwave
Shortwave
Shortwave radio refers to the upper MF and all of the HF portion of the radio spectrum, between 1,800–30,000 kHz. Shortwave radio received its name because the wavelengths in this band are shorter than 200 m which marked the original upper limit of the medium frequency band first used...
without reducing sound quality
Sound quality
Sound quality is the quality of the audio output from various electronic devices. Sound quality can be defined as the degree of accuracy with which a device records or emits the original sound waves...
.
The vast majority of licences have never been used. Due to a number of factors, few Australian stations in this band have many listeners.