| 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 frequency allocation which moved the upper limit of the AM bandplan from 1610 to 1700 kHz.
Contents |
The band became officially available around 1993 only in ITU region 2 (North and South America). It is popular with microbroadcasters 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 band. In the U.S., coverage on newer radios is mandated by the Federal Communications Commission (FCC), invoking the All-Channel Receiver Act.
In the United States, 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 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 and the AM band as more a band for talk radio than music, it is unlikely the FCC would take any action against an extended-band station only broadcasting in monophonic 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 (WQFG689) licensed with a waiver to the County of Hudson. This is because aeronautical radionavigation may use 1708 kHz,[1] and so like 87.9 FM it is not considered part of the adjacent radio broadcast band.
Although the extended band is not officially allocated in Europe, it is used by Vatican Radio and a number of "hobby" pirate radio stations, particularly in the Netherlands, Greece, and Serbia.
In Australia, 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 H3E emissions, as used by CHU in Canada on shortwave without reducing sound quality.
The vast majority of licences have never been used. Due to a number of factors, few Australian stations in this band have many listeners.