“20-meter band”的意思、由来-开放百科全书

The 20-meter or 14-MHz amateur radio band is a portion of the shortwave radio spectrum, comprising frequencies stretching from 14.000 MHz to 14.350 MHz.^[1] The 20-meter band is widely considered among the best for long-distance communication (DXing), and is one of the most popular—and crowded—during contests.^[2] Several factors contribute to this, including the band's large size, the relatively small size of antennas tuned to it (especially as compared to antennas for the 40-meter band or the 80-meter band) and its good potential for daytime DX operation even in unfavorable propagation conditions.^[3]

History

The 20-meter band was first made available to amateurs in the United States by the Third National Radio Conference^[4] on October 10, 1924. The band was allocated on a worldwide basis by the International Radiotelegraph Conference^[5] in

Band plans

IARU Region 1

IARU Region 2

IARU Region 3

United States

Canada

Canada^[8] is part of region 2 and as such is subject to the IARU band plan. Radio Amateurs of Canada offers the bandplan below as a recommendation for use by radio amateurs in that country but it does not have the force of law and should only be considered a suggestion or guideline.

References

1. ^{{cite web |url=http://www.arrl.org/FandES/field/regulations/allocate.html |title=Frequency Allocations |publisher=Arrl.org |date=2012-03-05 |accessdate=2012-10-29 |deadurl=no |archiveurl=https://web.archive.org/web/20100314191057/http://www.arrl.org/FandES/field/regulations/allocate.html |archivedate=2010-03-14 |df= }}
2. ^Picking a band. The ARRL Operating Manual, 8th Edition (Steve Ford, Ed.):1-15.
3. ^{{cite book | title = The ARRL Handbook For Radio Communications | edition = 82nd | year = 2005 | publisher = American Radio Relay League | isbn = 0-87259-928-0 | page = 20.4 | chapter = Propagation of RF Signals}}
4. ^{{cite web |url=https://earlyradiohistory.us/1924conf.htm |title=Recommendations for Regulation of Radio: October 6-10, 1924 |publisher=Earlyradiohistory.us |date= |accessdate=2012-10-29 |deadurl=no |archiveurl=https://web.archive.org/web/20121013125509/http://earlyradiohistory.us/1924conf.htm |archivedate=2012-10-13 |df= }}
5. ^{{cite web |url=http://www.itu.int/dms_pub/itu-s/oth/02/01/S02010000144002PDFE.pdf |title=Archived copy |accessdate=2014-07-06 |deadurl=yes |archiveurl=https://web.archive.org/web/20140308211326/http://www.itu.int/dms_pub/itu-s/oth/02/01/S02010000144002PDFE.pdf |archivedate=2014-03-08 |df= }}
6. ^{{cite web |url=http://www.itu.int/dms_pub/itu-s/oth/02/01/S020100002B4002PDFE.pdf |title=Archived copy |accessdate=2014-07-06 |deadurl=yes |archiveurl=https://web.archive.org/web/20140715055049/http://www.itu.int/dms_pub/itu-s/oth/02/01/S020100002B4002PDFE.pdf |archivedate=2014-07-15 |df= }}
7. ^¹²{{cite web |title=IARU Regions |url=http://www.iaru.org/regions.html |work=www.iaru.org |publisher=International Amateur Radio Union (IARU) |accessdate=6 January 2014 |deadurl=no |archiveurl=https://web.archive.org/web/20131230025948/http://www.iaru.org/regions.html |archivedate=30 December 2013 |df= }}
8. ^{{cite web|url=http://www.rac.ca/en/rac/services/bandplans/hf/hfplan-20080711.pdf |title=Archived copy |accessdate=2008-07-08 |deadurl=yes |archiveurl=https://web.archive.org/web/20101127081357/http://rac.ca/en/rac/services/bandplans/hf/hfplan-20080711.pdf |archivedate=2010-11-27 |df= }}