Knowledge

Shortwave bands

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1727: 485:(WPAS) in Ireland services in the 27.600 to 27.995 MHz portion, AM and FM mode, with two overlapping sets of 40 channels (27.60125 to 27.99125 MHz in 10 kHz steps, and 27.605 to 27.995 MHz in 10 kHz steps). These transmissions are usually rebroadcasts of church services and can sometimes be heard hundreds or even thousands of km (miles). Part of the 11 m/27 MHz band was also allocated in many countries for early-model 1737: 1716: 1747: 231:
1 and 3, the segment 7.1–7.2 MHz is reserved for amateur radio use and there are no new broadcasting allocations in this portion of the band. 7.35–7.4 MHz is newly allocated; in Regions 1 and 3, 7.4–7.45 MHz was also allocated effective March 29, 2009. In Region 2, 7.2–7.3 MHz is
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In the US and Canada, as well as the Americas (ITU Region 2) as a whole, there are no pre-designated HF allocations for military use. Similar rules exist in Europe, where it has become necessary for European amateurs to police the bands due to overcrowding. Most military HF band incursions into the
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specific military HF allocations have gradually disappeared from the HF bands, except for Africa and some parts of Asia. In Australia, the military shares the HF bands with civilian users; this is mainly due to low population density and relative under-use of the HF bands. The military in the
533:. The industrial use of the frequency suggested the use of the 11 m band for CB radio. About a dozen narrow ("sliver") allocations for ISM exist throughout the radio spectrum. These allocations are among the smallest in the HF band, with respect to national HF allocations. 392:(CB) allocation in most countries, is slightly higher in frequency than the broadcasting 11m band. There are reports of pirate CB radio users operating equipment on frequencies as low as 25.615 MHz. In the United States, this band is also shared with 440:
is a communications service, educational tool and hobby. It is particularly useful in providing emergency communication where standard telecommunications infrastructure is compromised or nonexistent, such as a disaster area or remote region of the globe.
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and most cordless-phone use is at UHF or higher. Some segments of the HF spectrum are allocated for fixed services, providing point-to-point communication between sites with no access to wired communications.
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Illegal "freeband" CB activity can be heard from 25 to 28 MHz, steps with operators generally using AM below 26.965 (US and European CB channel 1) and SSB above 27.405 (US and European CB channel 40).
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Designated bands in the shortwave spectrum are used for ships, aircraft, and land vehicles. Shortwave (HF radio) is used by transoceanic aircraft for communications with air-traffic control centers out of
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Erratic daytime reception, with very little night reception. Similar to 11 metres, but long-distance daytime broadcasting (best on north–south paths) keeps this band active in the Asia-Pacific region.
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Particularly in the United States and at frequencies under 10 MHz, shortwave broadcasters may operate in between those bands, with the 60-meter band extending as high as
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Reception varies by region—reasonably good night reception, but few transmitters in this band target North America. According to the WRC-03 Decisions on HF broadcasting, in
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These bands are used by powerful long range AM radio stations, many operated by governments, which broadcast to multiple countries. Most international broadcasters use
94:, allocates bands for various services in periodic conferences. The most recent WRC took place in 2012. At WRC-97 in 1997, the following bands were allocated for 148:
Mostly used locally in tropical regions, with limited long-distance reception at night. A notable example of a station using this band is Canadian time station
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Most heavily used band. Good year-round night band; seasonal during the day, with best reception in winter. Time stations are clustered around 10 MHz.
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Accessed 2011-10-20. (Archived by WebCite at https://www.webcitation.org/62aCbliW6?url=http://www.itu.int/ITU-R/terrestrial/broadcast/hf/wrc-03/index.html
454:. Most countries with HF citizens'-band allocations use 40 or 80 channels between approximately 26.5 MHz and 27.9 MHz, in 10 kHz steps. 589: 1699: 1671: 1666: 691: 228: 372:
Seldom used. Daytime reception is poor in the low solar cycle, but potentially excellent when the solar cycle (generally indicated by the
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in these frequency ranges can be used for very long distance (transcontinental) communication because they can reflect off layers of
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can be heard from 27.60125 to 27.99125 MHz in 10 kHz steps as well as the lower 26.965 to 27.405 MHz allocation.
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Due to antenna-length requirements and the band's long-distance propagation characteristics (undesirable in these cases), much
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Americas and Australia has tended to use the civilian fixed, maritime mobile and aeronautical mobile allocations on an
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propagation. DRM has proposed that this band be used for local digital shortwave broadcasts, testing the concept in
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Amateur radio operators in many countries are allocated several shortwave bands for private, non-commercial use.
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Mostly used locally in tropical regions, with time stations at 2.5 MHz. Although this is regarded as
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equipment uses 27.12 MHz to heat bulk materials or adhesives for the purpose of drying or improving
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for radio services such as maritime communications, international shortwave broadcasting and worldwide
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and possible communication distances vary depending on the time of day, the season and the level of
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after dark; not widely received in North and South America. Shared with the North American
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http://stakeholders.ofcom.org.uk/binaries/consultations/cads_scheme/statement/statement.pdf
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The UK and Ireland both operate Community Audio Distribution (CADS) in the UK or
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Substantially used in Eurasia. Similar to the 19 m band; best in summer.
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Day reception good; night reception varies seasonally, with summer best.
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Good year-round night band; daytime (long distance) reception poor
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Day reception good, night reception variable; best during summer.
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Above 10 MHz there are numerous frequencies set aside for
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HF ham bands occur in Europe or Africa. Since the end of the
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Industrial/Scientific/Medical (ISM) and other HF allocations
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eng075 - UK Norfolk 11 mtr digital station sstv packet rtty
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and return to Earth beyond the horizon, a mechanism called
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operated 90-meter stations at 3.185 and 3.195 MHz.
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Introduction on digital technology in the HFBC bands
634: 619: 86:or reduced carrier single sideband modulation. The 82:with 5 kHz steps between channels; a few use 50:or “skip” propagation. They are allocated by the 1763: 396:(RPUs), from 25.87 to 26.1 MHz in FM mode. 73: 58:. The bands are conventionally named by their 631:and the body responsible for the ARRL Handbook 445:Marine, air, land mobile and fixed allocations 685: 229:International Telecommunication Union regions 22:are frequency allocations for use within the 62:in metres, for example the ‘20 meter band’. 1700:Global telecommunications regulation bodies 90:(WRC), organized under the auspices of the 1736: 692: 678: 414:and the 31-meter band extending as low as 637:– Canada's National Amateur Radio Society 1764: 699: 649:– Radio spectrum allocations reference 627:– the United States lobbying body for 16:List of shortwave radio spectrum bands 673: 543:World Administrative Radio Conference 92:International Telecommunication Union 1746: 432:Amateur radio frequency allocations 425: 88:World Radiocommunication Conference 13: 492: 268:the period before and after sunset 14: 1783: 613: 266:Generally best during summer and 1745: 1735: 1726: 1725: 1714: 1335:Free-space optical communication 664:IARU Region 1 Monitoring System 410:, the 41-meter band as high as 338:Lightly utilized; may become a 598: 579: 555: 483:Wireless Public Address System 1: 548: 74:International broadcast bands 1721:Telecommunication portal 1502:Telecommunications equipment 659:US Amateur Radio Bands chart 563:"Short wave broadcast bands" 406:, the 49-meter band down to 7: 1238:Alexander Stepanovich Popov 625:American Radio Relay League 536: 10: 1788: 942:Telecommunications history 514: 507:(non-interference) basis. 429: 232:part of the amateur radio 96:international broadcasting 1709: 1651: 1588: 1550:Public Switched Telephone 1510: 1474: 1431: 1372: 1362:telecommunication circuit 1323:Fiber-optic communication 1306: 1068:Francis Blake (telephone) 1015: 863:Optical telecommunication 707: 1461:Orbital angular-momentum 898:Satellite communications 737:Communications satellite 635:Radio Amateurs of Canada 1340:Molecular communication 1163:Gardiner Greene Hubbard 992:Undersea telegraph line 727:Cable protection system 418:. As recently as 2020, 193:Mostly used locally in 1482:Communication protocol 1268:Charles Sumner Tainter 1083:Walter Houser Brattain 1028:Edwin Howard Armstrong 836:Information revolution 461:activity has moved to 340:Digital Radio Mondiale 107:Frequency range (MHz) 1456:Polarization-division 1188:Narinder Singh Kapany 1153:Erna Schneider Hoover 1073:Jagadish Chandra Bose 1053:Alexander Graham Bell 784:online video platform 647:UnwantedEmissions.com 342:(DRM) band in future 1298:Vladimir K. Zworykin 1258:Almon Brown Strowger 1228:Charles Grafton Page 883:Prepaid mobile phone 811:Electrical telegraph 80:amplitude modulation 30:band and all of the 26:spectrum (the upper 1248:Johann Philipp Reis 1007:Wireless revolution 969:The Telephone Cases 826:Hydraulic telegraph 567:MonitoringTimes.com 394:remote pickup units 167:Mostly used in the 1446:Frequency-division 1423:Telephone exchange 1293:Charles Wheatstone 1223:Jun-ichi Nishizawa 1198:Innocenzo Manzetti 1133:Reginald Fessenden 868:Optical telegraphy 701:Telecommunications 592:2008-04-15 at the 476:CB radio in the UK 374:number of sunspots 169:Eastern Hemisphere 152:on 3.33 MHz. 1759: 1758: 1497:Store and forward 1492:Data transmission 1406:Network switching 1357:Transmission line 1203:Guglielmo Marconi 1168:Internet pioneers 1033:Mohamed M. Atalla 1002:Whistled language 459:land-mobile radio 400: 399: 308:use 15 MHz. 64:Radio propagation 40:charged particles 1779: 1749: 1748: 1739: 1738: 1729: 1728: 1719: 1718: 1717: 1590:Notable networks 1580:Wireless network 1520:Cellular network 1512:Types of network 1487:Computer network 1374:Network topology 1288:Thomas A. Watson 1143:Oliver Heaviside 1128:Philo Farnsworth 1103:Daniel Davis Jr. 1078:Charles Bourseul 1038:John Logie Baird 747:Data compression 742:Computer network 694: 687: 680: 671: 670: 607: 602: 596: 583: 577: 576: 574: 573: 559: 426:Amateur HF bands 195:tropical regions 101: 100: 28:medium frequency 1787: 1786: 1782: 1781: 1780: 1778: 1777: 1776: 1762: 1761: 1760: 1755: 1715: 1713: 1705: 1647: 1584: 1506: 1470: 1427: 1376: 1368: 1309: 1302: 1208:Robert Metcalfe 1063:Tim Berners-Lee 1011: 831:Information Age 703: 698: 653:short-wave.info 616: 611: 610: 603: 599: 594:Wayback Machine 584: 580: 571: 569: 561: 560: 556: 551: 539: 523:radio astronomy 519: 513: 495: 493:Military HF use 487:cordless phones 452:VHF radio range 447: 434: 428: 369: 364: 354: 349: 335: 330: 320: 315: 297: 292: 282: 277: 263: 258: 248: 243: 224: 219: 209: 204: 190: 185: 164: 159: 145: 140: 122: 117: 84:single sideband 76: 24:shortwave radio 20:Shortwave bands 17: 12: 11: 5: 1785: 1775: 1774: 1757: 1756: 1754: 1753: 1743: 1733: 1723: 1710: 1707: 1706: 1704: 1703: 1696: 1691: 1686: 1681: 1676: 1675: 1674: 1669: 1661: 1655: 1653: 1649: 1648: 1646: 1645: 1640: 1635: 1630: 1625: 1620: 1615: 1610: 1605: 1600: 1594: 1592: 1586: 1585: 1583: 1582: 1577: 1572: 1567: 1562: 1557: 1552: 1547: 1542: 1537: 1532: 1527: 1522: 1516: 1514: 1508: 1507: 1505: 1504: 1499: 1494: 1489: 1484: 1478: 1476: 1472: 1471: 1469: 1468: 1463: 1458: 1453: 1448: 1443: 1441:Space-division 1437: 1435: 1429: 1428: 1426: 1425: 1420: 1419: 1418: 1413: 1403: 1402: 1401: 1391: 1386: 1380: 1378: 1370: 1369: 1367: 1366: 1365: 1364: 1354: 1353: 1352: 1342: 1337: 1332: 1331: 1330: 1320: 1314: 1312: 1304: 1303: 1301: 1300: 1295: 1290: 1285: 1280: 1278:Camille Tissot 1275: 1270: 1265: 1260: 1255: 1253:Claude Shannon 1250: 1245: 1243:Tivadar Puskás 1240: 1235: 1230: 1225: 1220: 1215: 1213:Antonio Meucci 1210: 1205: 1200: 1195: 1190: 1185: 1183:Charles K. Kao 1180: 1175: 1170: 1165: 1160: 1158:Harold Hopkins 1155: 1150: 1145: 1140: 1135: 1130: 1125: 1120: 1115: 1110: 1105: 1100: 1095: 1090: 1085: 1080: 1075: 1070: 1065: 1060: 1058:Emile Berliner 1055: 1050: 1045: 1040: 1035: 1030: 1025: 1019: 1017: 1013: 1012: 1010: 1009: 1004: 999: 997:Videotelephony 994: 989: 988: 987: 982: 972: 965: 960: 954: 949: 944: 939: 934: 933: 932: 927: 922: 912: 911: 910: 900: 895: 893:Radiotelephone 890: 885: 880: 875: 870: 865: 860: 859: 858: 848: 843: 838: 833: 828: 823: 818: 813: 808: 803: 798: 797: 796: 791: 786: 781: 779:Internet video 771: 770: 769: 764: 759: 754: 744: 739: 734: 729: 724: 719: 713: 711: 705: 704: 697: 696: 689: 682: 674: 668: 667: 661: 656: 650: 644: 638: 632: 622: 615: 614:External links 612: 609: 608: 597: 578: 553: 552: 550: 547: 546: 545: 538: 535: 517:ISM radio band 512: 509: 494: 491: 446: 443: 430:Main article: 427: 424: 416:9.265 MHz 398: 397: 370: 367: 365: 362: 359: 358: 355: 352: 350: 347: 344: 343: 336: 333: 331: 328: 325: 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1493: 1490: 1488: 1485: 1483: 1480: 1479: 1477: 1473: 1467: 1466:Code-division 1464: 1462: 1459: 1457: 1454: 1452: 1451:Time-division 1449: 1447: 1444: 1442: 1439: 1438: 1436: 1434: 1430: 1424: 1421: 1417: 1414: 1412: 1409: 1408: 1407: 1404: 1400: 1397: 1396: 1395: 1392: 1390: 1387: 1385: 1382: 1381: 1379: 1377:and switching 1375: 1371: 1363: 1360: 1359: 1358: 1355: 1351: 1348: 1347: 1346: 1343: 1341: 1338: 1336: 1333: 1329: 1328:optical fiber 1326: 1325: 1324: 1321: 1319: 1318:Coaxial cable 1316: 1315: 1313: 1311: 1305: 1299: 1296: 1294: 1291: 1289: 1286: 1284: 1281: 1279: 1276: 1274: 1271: 1269: 1266: 1264: 1261: 1259: 1256: 1254: 1251: 1249: 1246: 1244: 1241: 1239: 1236: 1234: 1233:Radia Perlman 1231: 1229: 1226: 1224: 1221: 1219: 1216: 1214: 1211: 1209: 1206: 1204: 1201: 1199: 1196: 1194: 1191: 1189: 1186: 1184: 1181: 1179: 1176: 1174: 1171: 1169: 1166: 1164: 1161: 1159: 1156: 1154: 1151: 1149: 1146: 1144: 1141: 1139: 1136: 1134: 1131: 1129: 1126: 1124: 1123:Lee de Forest 1121: 1119: 1118:Thomas Edison 1116: 1114: 1111: 1109: 1108:Donald Davies 1106: 1104: 1101: 1099: 1096: 1094: 1093:Claude Chappe 1091: 1089: 1086: 1084: 1081: 1079: 1076: 1074: 1071: 1069: 1066: 1064: 1061: 1059: 1056: 1054: 1051: 1049: 1046: 1044: 1041: 1039: 1036: 1034: 1031: 1029: 1026: 1024: 1021: 1020: 1018: 1014: 1008: 1005: 1003: 1000: 998: 995: 993: 990: 986: 983: 981: 978: 977: 976: 973: 971: 970: 966: 964: 961: 958: 955: 953: 950: 948: 945: 943: 940: 938: 937:Smoke signals 935: 931: 928: 926: 923: 921: 918: 917: 916: 915:Semiconductor 913: 909: 906: 905: 904: 901: 899: 896: 894: 891: 889: 886: 884: 881: 879: 876: 874: 871: 869: 866: 864: 861: 857: 854: 853: 852: 849: 847: 844: 842: 839: 837: 834: 832: 829: 827: 824: 822: 819: 817: 814: 812: 809: 807: 804: 802: 799: 795: 792: 790: 787: 785: 782: 780: 777: 776: 775: 774:Digital media 772: 768: 765: 763: 760: 758: 755: 753: 750: 749: 748: 745: 743: 740: 738: 735: 733: 730: 728: 725: 723: 720: 718: 715: 714: 712: 710: 706: 702: 695: 690: 688: 683: 681: 676: 675: 672: 665: 662: 660: 657: 654: 651: 648: 645: 642: 641:EiBi & DX 639: 636: 633: 630: 629:amateur radio 626: 623: 621: 618: 617: 606: 601: 595: 591: 588: 582: 568: 564: 558: 554: 544: 541: 540: 534: 532: 528: 524: 518: 508: 506: 501: 490: 488: 484: 479: 477: 471: 468: 464: 460: 455: 453: 442: 439: 438:Amateur radio 433: 423: 421: 417: 413: 412:7.78 MHz 409: 405: 404:5.13 MHz 395: 391: 390:Citizens band 387: 383: 379: 375: 371: 366: 361: 360: 356: 351: 346: 345: 341: 337: 332: 327: 326: 322: 317: 312: 311: 307: 303: 302:Time stations 299: 294: 289: 288: 284: 279: 274: 273: 269: 265: 260: 255: 254: 250: 245: 240: 239: 235: 230: 226: 221: 216: 215: 211: 206: 201: 200: 196: 192: 187: 182: 181: 177: 174: 173:amateur radio 170: 166: 161: 156: 155: 151: 147: 142: 137: 136: 132: 128: 124: 119: 114: 113: 109: 106: 103: 102: 99: 97: 93: 89: 85: 81: 71: 69: 65: 61: 57: 56:amateur radio 53: 49: 45: 41: 37: 33: 29: 25: 21: 1433:Multiplexing 1308:Transmission 1273:Nikola Tesla 1263:Henry Sutton 1218:Samuel Morse 1148:Robert Hooke 1113:Amos Dolbear 1048:John Bardeen 967: 947:Telautograph 851:Mobile phone 806:Edholm's law 789:social media 722:Broadcasting 600: 581: 570:. Retrieved 566: 557: 520: 504: 496: 480: 472: 456: 448: 435: 408:5.8 MHz 401: 77: 19: 18: 1633:NPL network 1345:Radio waves 1283:Alfred Vail 1193:Hedy Lamarr 1178:Dawon Kahng 1138:Elisha Gray 1098:Yogen Dalal 1023:Nasir Ahmed 957:Teleprinter 821:Heliographs 382:Mexico City 353:21.45–21.85 281:13.57–13.87 270:year-round 36:Radio waves 1679:Antarctica 1638:Toasternet 1560:Television 1043:Paul Baran 975:Television 959:(teletype) 952:Telegraphy 930:transistor 908:Phryctoria 878:Photophone 856:Smartphone 846:Mass media 572:2010-11-19 549:References 515:See also: 378:groundwave 368:25.67–26.1 334:18.9–19.02 319:17.48–17.9 296:15.1–15.83 189:4.75–4.995 129:, it is a 116:120 m 60:wavelength 44:ionosphere 1772:Bandplans 1663:Americas 1652:Locations 1623:Internet2 1384:Bandwidth 1088:Vint Cerf 985:streaming 963:Telephone 903:Semaphore 794:streaming 527:diathermy 363:11 m 348:13 m 329:15 m 314:16 m 291:19 m 276:22 m 262:11.6–12.1 257:25 m 242:31 m 218:41 m 203:49 m 184:60 m 158:75 m 139:90 m 127:shortwave 121:2.3–2.495 1766:Category 1731:Category 1618:Internet 1608:CYCLADES 1525:Ethernet 1475:Concepts 1399:terminal 1350:wireless 1173:Bob Kahn 1016:Pioneers 841:Internet 732:Cable TV 590:Archived 537:See also 500:Cold War 304:such as 223:7.2–7.45 110:Remarks 1751:Commons 1741:Outline 1694:Oceania 1613:FidoNet 1598:ARPANET 1411:circuit 980:digital 709:History 247:9.4–9.9 208:5.9–6.2 144:3.2–3.4 48:skywave 42:in the 34:band). 1689:Europe 1659:Africa 1643:Usenet 1603:BITNET 1540:Mobile 1416:packet 925:MOSFET 920:device 717:Beacon 531:curing 505:ad hoc 133:band. 1672:South 1667:North 1628:JANET 1565:Telex 1555:Radio 1394:Nodes 1389:Links 1310:media 888:Radio 873:Pager 801:Drums 767:video 762:image 752:audio 163:3.9–4 104:Band 1684:Asia 1570:UUCP 1530:ISDN 420:WWRB 386:2005 1575:WAN 1545:NGN 1535:LAN 816:Fax 757:DCT 467:UHF 465:or 463:VHF 384:in 306:WWV 150:CHU 52:ITU 1768:: 565:. 489:. 388:. 236:. 178:. 131:MF 98:: 70:. 1702:) 1698:( 693:e 686:t 679:v 575:.

Index

shortwave radio
medium frequency
high frequency
Radio waves
charged particles
ionosphere
skywave
ITU
amateur radio
wavelength
Radio propagation
solar activity
amplitude modulation
single sideband
World Radiocommunication Conference
International Telecommunication Union
international broadcasting
shortwave
MF
CHU
Eastern Hemisphere
amateur radio
80 m band
tropical regions
International Telecommunication Union regions
40 m band
the period before and after sunset
Time stations
WWV
Digital Radio Mondiale

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