View source for AM expanded band

The '''extended mediumwave broadcast band''', commonly known as the '''AM expanded band''', refers to [[broadcast|broadcast station]] [[frequency allocation|frequency assignments]] immediately above 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.
[[File:International Telecommunication Union regions with dividing lines.svg|right|thumb|250px|ITU regions and the dividing lines between them.
{{legend|#fd0|Region 1}}
{{legend|#0df|Region 2}}
{{legend|#d0f|Region 3}}
]]

==ITU Region 1==
{| class="wikitable" align=right border="1"
|-
!colspan="2"|ITU Region
|-
! 1 & 3<br>(9&nbsp;kHz<br>spacing)
! 2<br>(10&nbsp;kHz<br>spacing)
|-
| 1611
| [[1610 AM|1610]]
|-
| [[1620 AM|1620]]
| [[1620 AM|1620]]
|-
| 1629
| [[1630 AM|1630]]
|-
| 1638
| [[1640 AM|1640]]
|-
| 1647
| [[1650 AM|1650]]
|-
| 1656
| [[1660 AM|1660]]
|-
| 1665
| [[1670 AM|1670]]
|-
| 1674
| [[1680 AM|1680]]
|-
| 1683
| [[1690 AM|1690]]
|-
| 1692
| [[1700 AM|1700]]
|-
| 1701
| &nbsp;
|-
|}

===Europe===
The extended band is not officially allocated in Europe, and the recent trend in the region has been to reduce the number of AM band stations in favor of FM and digital transmissions. However, these frequencies are 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.<ref>[https://www.bamlog.com/darkcountries.htm "Silent MW Radio Countries"], compiled by Bruce Conti (bamlog.com)</ref>

==ITU Region 2==
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&nbsp;kHz to 1700&nbsp;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.<ref>[http://handle.itu.int/11.1004/020.1000/4.118.43.en.100 ''Final Acts of the Regional Radio Conference to Establish a Plan for the Broadcasting Service in the Band 1605-1705 in Region 2''] (PDF) (Rio de Janeiro, 1988. ITU.int)</ref>

===Anquilla===
Even before the formal adoption of the expansion, a 50,000 watt religious station located on the island of Anquilla, British West Indies, was broadcasting on 1610 kHz as "The Caribbean Beacon".<ref>[https://archive.org/details/MonitoringTimesJanuary1990/page/n7/mode/1up "What to Listen for in the 1990s"] by Don Bishop, ''Monitoring Times'', January 1990, page 6.</ref> This station dated to the early 1980s, and is no longer on the air.<ref>[https://archive.org/details/MonitoringTimesJuly2013/page/n13/mode/1up "The Fleet Is In: Angling for Radio Buoys"] by Mario Filippi, ''Monitoring Times'', July 2013, page 12.</ref>

===Canada===
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.<ref>[https://www.ic.gc.ca/eic/site/smt-gst.nsf/eng/sf10442.html ''Report on AM Broadcasting Possibilities in The Greater Toronto Area''], Government of Canada,  July 11, 2013 (gc.ca).</ref> Therefore, all of its limited number of expanded band stations currently operate on these frequencies.

===Cuba===
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.<ref>[https://www.bamlog.com/cubalist.htm "Cuba Radio Map"] (as of February 6, 2019) (bamlog.com)</ref>

===Mexico===
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. Both XEARZ (5&nbsp;kW) and XEPE (10&nbsp;kW) operate with nighttime power greater than 1&nbsp;kW.<ref>[http://www.ift.org.mx/sites/default/files/contenidogeneral/industria/memoriaam160518.pdf "Estaciones de Radio AM"] Instituto Federal de Telecommunicaciones, May 16, 2018.</ref> 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.

===United States===
====Background====
In the United States, implementation of the [[North American Regional Broadcasting Agreement]] in 1941 by the [[Federal Communications Commission]] (FCC) had established 1600 kHz as the upper limit for the standard AM broadcast band. Beginning in the 1930s adjacent higher frequencies had commonly been designated as a [[police radio]] band. Even after police radio transmissions were no longer made on this band, some county and city ordinances still forbade receivers capable of picking up transmissions on these frequencies,<ref>County of Los Angeles Code Chapter 13.10</ref> and they had reportedly been occasionally enforced to cite motorists in possession of amateur radio gear, or in extreme cases an AM radio installed in the vehicle as original equipment.{{CN|date=August 2018}}

A small group of frequencies, starting at 1665 kHz,<ref>[https://archive.org/details/radio_electronics_1985-05/page/n56/mode/1up "Servicing Cordless Telephones"] by Christopher Kite, ''Radio-Electronics'', May 1985, pages 77-80, 118.</ref> had been set aside for use by [[cordless telephone]]s, however in 1983 a higher allocation was assigned, and production after October 1, 1984 of handsets transmitting on the lower frequencies was prohibited.<ref>[https://babel.hathitrust.org/cgi/pt?id=osu.32435025410499;view=1up;seq=473 "Fourth Notice of Inquiry"] (FCC 88-72. Adopted February 25, 1988, released Jume 3, 1988), page 4511 (footnote no. 15).</ref> Therefore, by 1988 the frequencies from 1610-1700 kHz were largely unoccupied, with one major exception: 1610 kHz was one of two primary frequencies (along with 530 kHz) that had been assigned for use by hundreds of low-powered [[Travelers' information station|Travelers Information Stations]] (TIS). Moreover, the controlling licensing authority for these stations was not the FCC, but instead was the [[National Telecommunications and Information Administration]] (NTIA), so coordination between the two agencies was required. It was concluded that, for operation on 1610&nbsp;kHz, TIS and broadcasting stations were considered "co-primary" services, thus existing TIS stations were protected from having to move to new frequencies.<ref name="TIS">[https://babel.hathitrust.org/cgi/pt?id=uiug.30112059136157;view=1up;seq=41 "Travelers Information Stations"] (paragraph 24), Memorandum Opinion and Order, Docket No. 87-267, FCC 93-196, filed May 11, 1993, effective date June 11, 1993.</ref> The restriction imposed by having to protect existing TIS stations on 1610&nbsp;kHz had the practical effect of reducing by one the number of available expanded band frequencies, and currently there are no broadcasting stations licensed for this frequency in the United States.

The FCC gave approval for TIS stations to operate on 1620-1700, on a secondary basis, and it was informally suggested that, once most radios could tune to the higher frequencies, all of the TIS stations on 1610 kHz could be moved as a group to 1710&nbsp;kHz,<ref name="TIS"/>  however this was never implemented. (Currently 1710&nbsp;kHz is unused by TIS stations with one exception: a waiver has been granted to [[Hudson County, New Jersey]] to operate a [[single-frequency network]] (WQFG689)).<ref>[http://wireless2.fcc.gov/UlsApp/UlsSearch/licenseLocSum.jsp?licKey=2826342 Universal Licensing System: WQFG689] (FCC.gov)</ref>

====Preparation====
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..."<ref name="stage">[https://www.americanradiohistory.com/Archive-BC/BC-1988/BC-1988-05-23.pdf#page=55 "RIO is stage for AM spectrum conference"], ''Broadcasting'', May 23, 1988, pages 55-56 (americanradiohistory.com)</ref> 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.<ref name="first">[https://www.americanradiohistory.com/Archive-BC/BC-1995/BC-1995-10-09.pdf#page=66 "WJDM to be first on extended AM band"] by Glen Diskson, ''Broadcasting'', October 9, 1995, page 66 (americanradiohistory.com)</ref>

During the 1988 ITU conference, it was suggested that as many as 500 U.S. stations could be assigned to the new frequencies.<ref name="stage"/> On April 12, 1990 the [[Federal Communications Commission]] (FCC) voted to begin the process of populating the expanded band. Although some individuals had hoped the Commission would give preferences to minority-owner or daytime-only stations, it announced that the main priority would be reducing interference on the existing AM band, by transferring selected stations to the new frequencies. It was now estimated that the expanded band could accommodate around 300 U.S. stations.<ref>[https://www.americanradiohistory.com/Archive-Billboard/90s/1990/BB-1990-04-28.pdf#page=10 "FCC Votes To Proceed With AM-Band Improvement Plans"] by Bill Holland, ''Billboard'', April 28, 1990, page 10.</ref>

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)<ref>A "simple directional" antenna was defined as one that used no more than three towers.</ref> and 400-800 km spacing between co-channel stations".<ref name="migration">[https://babel.hathitrust.org/cgi/pt?id=ien.35559002137986;view=1up;seq=367 "IV. Migration to the Expanded Band"], ''Review of the Technical Criteria for the AM Broadcast Service'' (FCC MM Docket No. 87-267. Adopted September 26, 1991 and released October 25, 1991), pages 6302-6323.</ref>

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".<ref name="migration"/>

====Implementation====
In the fall of 1994, the FCC announced that, out of 688 applicants, a specially designed computer program (which took two weeks to run) had chosen 79 stations to make the transfer to the expanded band.<ref>[https://www.americanradiohistory.com/Archive-BC/BC-1994/BC-1994-10-24.pdf#page=15 "AM Pioneers chosen for expansion band"] by Chris McConnell, ''Broadcasting'', October 24, 1994, page 15 (americanradiohistory.com)</ref> 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.<ref>[https://www.americanradiohistory.com/Archive-BC/BC-1995/BC-1995-09-11.pdf#page=13 "FCC refigures AM moves"] by Christopher Stern, ''Broadcasting'', September 11, 1995, pages 13-14 (americanradiohistory.com)</ref>

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 fulltime stations.<ref>[https://babel.hathitrust.org/cgi/pt?id=uc1.31210024926006;view=1up;seq=8 "Additions to Section 331 of the Communications Act of 1934"] (Approved December 20, 1991), ''Telephone Consumer Protection Act of 1991'', page 2402.</ref> The two authorized stations that met this standard became the first two to begin broadcasting on the new band: WJDM, 1660 kHz in Elizabeth City, New Jersey (now [[WWRU]] in Jersey City, New Jersey) in late 1995,<ref name="first"/> and KXBT (now [[KDIA]]), 1640 kHz in Vallejo, California in early 1996.<ref>[https://books.google.com/books?id=ZwgEAAAAMBAJ&pg=PA99&lpg=PA99#v=onepage&q&f=false "FCC Chooses 80 Stations For Wider AM Band"] by Eric Boehlert, ''Billboard'', December 3, 1994, page 99.</ref>

On March 22, 1996 the FCC announced a revised allocation table, consisting of 87 stations,<ref>[https://babel.hathitrust.org/cgi/pt?id=msu.31293015299617;view=1up;seq=15 "Mass Media Bureau Announces Revised Expanded AM Broadcast Band Improvement Factors and Allotment Plan"] (FCC DA 96-408), March 22, 1996.</ref> but this too was eventually withdrawn due to errors. A third, and final, allocation, now approving 88 stations, was announced on March 17, 1997.<ref name="five">[https://babel.hathitrust.org/cgi/pt?id=uva.x004848309;view=1up;seq=268 "Mass Media Bureau Announces Revised AM Expanded Band Allotment Plan and Filing Window for Eligible Stations"] (FCC DA 97-537), March 17, 1997.</ref>

A 2006 accounting by ''Radio World'' reported that, out of 4,758 licensed U.S. AM stations, 56 were now operating on the expanded band.<ref>[https://www.radioworld.com/news-and-business/life-on-expanded-band-is-pretty-good "Life on Expanded Band Is (Pretty) Good"] by Randy J. Stine, February 28, 2006 (radioworld.com)</ref> The FCC originally assumed that the expanded band stations would simulcast the programming of the original standard band stations, and be licensed to the same community. However, in most cases the expanded band stations have run separate programming, and in some cases have moved to other communities. One policy the FCC has generally enforced is that the two stations must remain under common ownership.<ref>[https://babel.hathitrust.org/cgi/pt?id=osu.32437121992750;view=1up;seq=258 "In re: WHLY(AM), South Bend, Indiana"] (FCC DA 13-600, released April 3, 2013)</ref>

Most of the stations have non-directional antennas, using ten kilowatts during the day and one kilowatt at night. A exception for stations that use antennas with higher than normal efficiency or those multiplexed with an existing station on a different frequency. One station ([[KVNS]] 1700&nbsp;kHz, licensed to Brownsville, Texas) operates at 12% less than the standard (8.8kW day and 880 watts at night) due to treaty obligations with Mexico.

Despite the initial requirement that one of the two paired stations had to cease broadcasting by the end of a five year period,<ref name="five"/> as of 2015 there were 25 cases where both the standard band and expanded band stations were still active, some of which were approaching 20 years of operation. However, at this time the FCC expressed its intention to eventually eliminate the practice, stating: "We therefore tentatively conclude that any licensee with dual standard/Expanded Band authorizations... should be required to surrender one of the two authorizations within one year of release of a future ''Report and Order'' in this proceeding adopting this proposal..." This report also noted that "A total of 88 Expanded Band channels were originally allotted. There were 67 applications filed for Expanded Band allotments, of which 66 construction permits were granted, with one application still pending. Licenses were granted to 54 stations that migrated from the standard AM band to the Expanded Band. Of those, 22 unconditionally surrendered their standard band licenses and remained in the Expanded Band; three conditionally surrendered their standard band licenses, and four standard band licenses were canceled by the Commission. The Commission also received one unconditional surrender of an Expanded Band authorization and one conditional surrender, and it canceled one Expanded Band license."<ref>[https://docs.fcc.gov/public/attachments/FCC-15-142A1.pdf#page=32 "E. Require Surrender of Licenses by Dual Expanded Band/Standard Band Licenses"] ''Federal Communications Commission: First Report and Order, Further Notice of Proposed Rule Making, and Notice of Inquiry'', MB Docket No. 13-249, Adopted October 21, 2015, Released October 23, 2015, footnote #198, pages 32-33 (Appendix F, pages 67-69, lists the 25 stations) (FCC.gov)</ref>

The expanded band frequencies have also become popular for use by hobbyist [[microbroadcasting]] transmissions (which don't require licenses) due to the relatively limited number of broadcasting stations compared to the more congested standard/legacy AM band. 

==ITU Region 3==

===Australia===
{{Main|List of radio stations in Australia}}
In [[Australian Broadcasting Authority|Australia]], a limited number of [[broadcast licence]]s have been authorised for the extended band, primarily in the larger cities, operating as "narrowcast" stations.

===Japan===
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 Station]]s 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.

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

==References==
{{reflist}}

==External links==
* [http://cbc.am/Letter_PM_AU-NZ_RA-RNZI.pdf "A new international international broadcasting strategy is needed by both Australia and New Zealand in Melanesia and Western Polynesia"] (cbc.am)

{{Audio broadcasting}}

[[Category:Bandplans]]
[[Category:Broadcast engineering]]