Расширенный диапазон СРЧ: 1600-1700 кГц

Broadcast stations between 1600 and 1700 kHz
The extended mediumwave broadcast band, commonly known as the AM expanded band, refers to the broadcast station frequency assignments immediately above the earlier upper limits of 1600 kHz in International Telecommunication Union (ITU) Region 2 (the Americas), and 1602 kHz in ITU Regions 1 (Europe, northern Asia and Africa) and 3 (southern Asia and Oceania). In Region 2, this consists of ten additional frequencies, spaced 10 kHz apart, and running from 1610 kHz to 1700 kHz. In Regions 1 and 3, where frequency assignments are spaced nine kHz apart, the result is eleven additional frequencies, from 1611 kHz to 1701 kHz.

The extended band is not officially allocated in Europe, and the trend of national broadcasters in the region has been to reduce the number of their AM band stations in favor of FM and digital transmissions. However, new Low Power AM (LPAM) stations have recently come on the air from countries like Finland, Sweden, Norway, Denmark, the Netherlands and Italy. These frequencies are also used by a number of "hobby" pirate radio stations, particularly in the Netherlands, Greece, and Serbia. Vatican Radio for many years transmitted on 1611 kHz, before ceasing broadcasts on this frequency in 2012. Since 2014 a licensed Norwegian project has been broadcasting both Radio Northern Star and The Sea on 1611 kHz.

In 1979, a World Administrative Radio Conference (WARC 79) adopted "Radio Regulation No. 480", which stated that "In Region 2, the use of the band 1605 1705 kHz by stations of the broadcasting service shall be subject to a plan to be established by a regional administrative radio conference " As a consequence, on June 8, 1988 an ITU sponsored conference held at Rio de Janeiro, Brazil adopted provisions, effective July 1, 1990, to extend the upper end of the Region 2 AM broadcast band, by adding ten frequencies which spanned from 1610 kHz to 1700 kHz. The agreement provided for a standard transmitter power of 1 kilowatt, which could be increased to 10 kilowatts in cases where it did not result in undue interference.

Even before the formal adoption of the expansion, a 50,000 watt religious station located on the island of Anguilla, British West Indies, was broadcasting on 1610 kHz as "The Caribbean Beacon". This station dated to the early 1980s, and is no longer on the air.

In Argentina, the expanded band assignments are primarily in the region surrounding the nation's capital, Buenos Aires.

Canada has made an informal agreement with the United States to allow Canadian stations operating on 1610, 1630, 1650, 1670 and 1690 kHz to be located closer to their common border than would normally be allowed, in exchange for allowing the U. S. the same privilege on the other frequencies. Therefore, all of its limited number of expanded band stations currently operate on these frequencies.

There have only been a few expanded band stations established in Cuba. The most commonly used frequency is 1620 kHz, where multiple stations simulcast Radio Rebelde network programming.

Mexico has a total of four radio stations licensed for the expanded band prior to 2017: XEUT AM 1630, XEARZ AM 1650, XEANAH AM 1670, and XEPE AM 1700. Both XEARZ (5 kW) and XEPE (10 kW) operate with nighttime power greater than 1 kW. 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. With the exception of XEFCR AM in Reynosa, Tamaulipas, all of the stations since assigned to the expanded band have been community or indigenous stations: XECSCA AM, XECSCGU AM, XECSIA AM, XECSIB AM and XECSIC AM.

When the ITU approved the extension of the "top end" of the AM band to 1700 kHz in 1988, few consumer radios could tune higher than about 1620 or 1630 kHz. However, it was reported at the time that FCC "officials have been meeting with American manufacturers of radio receivers to make an early start on producing sets capable of receiving signals in the new band " and when the first U. S. expanded band radio station began operating in late 1995, it was estimated that by now there were 280 million radios capable of receiving the full expanded band. During the 1988 ITU conference, it was suggested that as many as 500 U. S. stations could be assigned to the new frequencies. The common FCC practice for station applications on the standard AM frequencies is to process the applications individually. For the expanded band, the Commission decided to allocate the entire band at once on a nationwide basis, after evaluating all of the stations which notified the FCC that they were interested in moving to the new band. Faced with the difficult task of evaluating hundreds of applications, the FCC developed a multi factored algorithm to rank the applicants. In addition to required separation standards, both within the United States and internationally, a major component of the evaluation was an individual station's "interference improvement factor", which was the degree to which a move to the expanded band would decrease the amount of interference on its vacated frequency, especially at night. The FCC summarized its primary considerations as "fulltime operation with stereo, competitive technical quality, 10 kW daytime power, 1 kW nighttime power, non directional antenna (or simple directional) and 400 800 km spacing between co channel stations". There was an outstanding question about the number of stations, based on the proposed standards, that could be accommodated on the new frequencies, with the FCC noting that an engineering firm, Cohen, Dippell and Everist, had "submitted an analysis to demonstrate that instead of 25 to 30 stations per channel their calculations show 'approximately 5 (certainly less than 10)' stations can be assigned per channel". However, a year later the Commission rescinded these assignments, after it was determined that there had been major flaws in the data used to evaluate the applications. A provision had been added to the Communications Act of 1934 in late 1991 which mandated that priority for expanded band assignments would be given to existing daytime only stations that were located in a community with a population over 100,000, and which also did not have any full time stations. The two authorized stations that met this standard became the first two to begin broadcasting on the new band: WJDM, 1660 kHz in Elizabeth, New Jersey (now WWRU in Jersey City, New Jersey) in late 1995, These two are the only expanded band stations in the United States authorized to use 10 kW at night. Other U. S. stations generally use ten kilowatts during the day and one kilowatt at night, with non directional antennas. An exception exists for stations that use antennas with higher than normal efficiency or those multiplexed with an existing station on a different frequency. KVNS in Brownsville, Texas, operates at 12% less than the standard (8.8 kW day and 880 watts at night) due to treaty obligations with Mexico, and WIGT in Charlotte Amalie, U. S. Virgin Islands, is licensed for 920 watts both day and night, due to similar treaty restrictions with respect to France's territorial holdings of Martinique and Guadeloupe. On March 22, 1996 the FCC announced a revised allocation table, consisting of 87 stations, but this too was eventually withdrawn due to errors. A third, and final, allocation, now approving 88 stations, was announced on March 17, 1997. In order to ease the transition, the FCC provided that both the original station and its expanded band twin could optionally operate simultaneously for up to five years, after which owners would have to turn in one of the two licenses, depending on whether they preferred the new assignment or elected to remain on the original frequency.> although an exception was made in the case of KYHN in Fort Smith, Arkansas, when the FCC approved its separate ownership, on the grounds that "Capstar's donation of the facility to MMTC, which planned to use KYHN to train women and minority group members in broadcasting and broadcast management, advanced the diversity goals set forth in the pending proceeding Promoting Diversification of Ownership in the Broadcasting Services". In general the FCC has refused to consider assigning any stations to the expanded band which were not included in the March 17, 1997 approval list. In 2006 an exception was made to this policy for WRCR in Ramapo, New York, which was allowed to move from 1300 to 1700 kHz, with the FCC stating that a "waiver is warranted to permit the licensing of a station that could provide full time local emergency radio service to Rockland County residents who would be at great risk in the event of a radiological emergency at the Indian Point facility".

Within Australia, the standard AM band transmitting frequencies of 531 to 1602 kHz are designated as the Broadcasting Services Band (BSB), while 1611 to 1701 kHz is designated as the "Mid Frequency" band. A limited number of stations operate under commercial licences on 1611, 1620 and 1629 kHz. The 1992 Broadcasting Services Act introduced "narrowband" station classifications, for broadcasts targeting specialized non general audiences, primarily in the larger cities, and a majority of stations assigned from 1611 to 1701 kHz are low powered (400 watts or less) Narrowband Area Service stations (MF NAS).

The AM expanded band in Japan extends to 1629 kHz. 1620 kHz and 1629 kHz are normally used by Highway advisory radio and/or Roadside Stations along stretches of major expressways. Many Japanese AM radios, car stereos and other receivers (walkman, etc.) can tune up to 1629 kHz. 1611 kHz is rarely used in Japan.

In the Philippines, the first AM expanded band radio station in low power format broadcasting in Marikina is DZBF, "Radyo Marikina 1674", started on July 25, 1996.