AM expanded band

The extended mediumwave broadcast band, commonly known as the [AM] expanded band, is a broadcast frequency allocation. It moves the upper limit of the AM bandplan from 1605 to 1705 kHz. 

History

The band became officially available around 1993, but only in ITU region 2 (the Americas). It is popular with micro-broadcasting for having less interference due to fewer signals than the standard/legacy AM band.

Though supported on most modern AM radio receivers sold in the Americas, this band is usually unavailable to older receivers except for those with substantial extended coverage. On such radios, the 1600–1700 segment was labeled "Police", since it was the original police radio band. In the U.S., coverage on newer radios is mandated by the Federal Communications Commission (FCC), invoking the All-Channel Receiver Act.

Regional use

Americas

In the United States of America, the Federal Communications Commission voted to support an expanded band on April 12, 1990.^[1] The FCC granted "stereo preferences" to commercial broadcasters intending to use AM stereo when issuing licenses for the band. However, such stations have never been required to broadcast in stereo. With the content of the AM band evolving more toward talk radio than music, it is unlikely that the FCC would take any action against an extended-band station only broadcasting in monophonic sound.

The standard for FCC licensed expanded band stations has been to broadcast omnidirectionally with ten kilowatts of power in the daytime and one kilowatt at night—except for stations that use antennas with higher than normal efficiency or those multiplexed with an existing station on a different frequency. In those cases, they are, by FCC Part 73 rules, authorized for less than one kilowatt at night, generally limiting such stations to 281 millivolts per meter per kilowatt at one kilometer, the minimum efficiency for a Class B station. One station, KVNS 1700 kHz, licensed to Brownsville, TX, operates at 12% less than the standard (8.8KW Day and 880 watts at night) due to treaty obligations with Mexico.

Because 1610 kHz (the top or right-most channel on analog radios) had previously been used for Travelers' Information Stations (TIS) as 530 kHz — the bottom or left-most channel — still is (though 530 is NOT a FCC US AM Broadcast channel, some TIS stations were displaced for new expanded-band stations. There are no AM stations in the United States licensed to 1610 kHz ^[2]

While 1710 kHz appears on many radios, it is unused even by TIS stations, except for a group (WQFG689) licensed with a waiver to the County of Hudson in New Jersey. This is because TIS stations are authorized under Part 90 of the FCC rules which deal with all two-way radio [except marine (Part 80) and ham/amateur radio (Part 97)] and not Part 73 or 74 which are the broadcast rules.

Mexico has a total of four radio stations licensed for the expanded band: XEUT-AM 1630, XEARZ-AM 1650, XEANAH-AM 1670, and XEPE-AM 1700. XEARZ (5 kW) and XEPE (10 kW) operate with nighttime power greater than 1 kW.^[3] These stations were authorized before changes in 2014 set aside the AM expanded band, along with 106-108 MHz on FM, for social community and social indigenous radio stations.

Greater Europe

Although the extended band is not officially allocated in Europe, it is used by a number of "hobby" pirate radio stations, particularly in the Netherlands, Greece, and Serbia, and it was used in the past by Vatican Radio (on 1611kHz).

Australia

In Australia, many commercial radio broadcast licences have been authorised for the extended band.

The vast majority of licences have never been used. Due to a number of factors, few Australian stations in this band have many listeners.

Japan

AM expanded band in Japan is up to 1629 kHz. 1620 kHz or 1629 kHz is normally used on Highway advisory radio and/or Roadside Station along strethces on major expressways in their country. Many Japanese AM radios can tune up to 1629 kHz, it can be found on Japanese car stereos and many radios, walkman, etc. 1611 kHz is rarely used in Japan, and it appeared on many Japanese radios.

The Philippines

In the Philippines, the first AM expanded band radio station in low power format broadcasting in Marikina City is DZBF DEL Radio - Radyo Marikina 1674 kHz started in July 25, 1996.

References

External links

• FCC document on AM expanded band
• A proposal to use the expanded MW band for international broadcasting in Australia and NZ