235:
153:
effective radiated power to have a decided advantage in being heard by long-distance receiving stations. With very high transmitting antennas or large vertically polarized arrays and full legal power, reliable worldwide communications occurs over nighttime paths. Good receiving antennas have far more modest requirements to reliably get signals from worldwide sources.
216:: Since short antennas have very low radiation resistance, the lion's share of their fed power is lost to heat, and their efficiency is typically below 10%, with roughly 90% of the power input lost to wire and ground resistance. Additionally, the large inductance of the loading coil creates an antenna system with an extremely narrow bandwidth (very high
104:) and goes up to 4.0 MHz (74.9 m wavelength). The upper part of the band, mostly used for voice, is often referred to as 75 meters, since in Region 2, the wavelengths in that section are between 80–75 meters (adjacent to or overlapping a shortwave broadcast band called by the same name: "75 m").
568:
voice ("phone"), to occupy frequencies on the low end of 80 meters. Most intrusions of this type are from fishing vessels and their marker buoys; although most of those vessels are from SE Asia and South
American ports, some band intrusions are committed by fishing vessels based in ports in
148:
significantly affects the 80 meter band by absorbing signals. During the daylight hours, a station in middle or high latitudes using 100 watts and a simple dipole antenna can expect a maximum communication range of 200 miles (320 km), extending to a few thousand miles or more at night.
112:
80 meters can be plagued with noise: The same ionospheric refraction that makes long-distance shortwave propagation possible also traps terrestrial noise under the ionosphere, preventing it from dissipating into space, which quiets down radio bands at higher frequencies, above ~20 MHz. The
83:
from the late afternoon through the night time hours. At night, 80 m is usually reliable for short- to medium-distance contacts, with average distances ranging from local contacts within 200 miles / 300 km out to a distance of 1,000 miles / 1,600 km or more at night – even
301:
sometimes appears on the band during nighttime hours in midwinter, which can be as much as 300 miles / 500 km, rendering communication with closer stations impossible. This is not generally a problem at middle or equatorial latitudes, or for large parts of the year anywhere, but it does
348:
to amateurs in the
Americas, and 3.5–3.8 MHz or 3.5–3.9 MHz to amateurs in other parts of the world. However, amateurs outside the Americas must share this useful piece of spectrum with other users, usually on a joint primary basis. As a result, authorities in the affected parts of the
642:
transmitted at a nominal 3.999 MHz will certainly modulate across the 4.0 MHz band edge and are against licensing regulations, a few very narrow-band data modes – like CW – can be used, as long as the power of the emissions beyond the band edge that get past the transmitting system's
187:
of that height, which is still a formidable construction project for an amateur. Erecting such large antennas and ensuring the antennas radiate significant power at low angles are two of the challenges facing amateurs wishing to communicate over long distances. Amateurs interested in regional
152:
Global coverage can be routinely achieved at high latitudes during the late fall and winter, by stations using modest power and common antennas. The higher background noise on 80 meters, especially when combined with higher ionospheric absorption, causes transmitting stations with higher
604:
power-level meters have better dynamic range, hence more acute signal detection, than all but the best spectrum analyzers, and are excellent for detecting out-of-band emissions when used properly. While some operators reporting out-of-band emissions might have used a wide receiver bandwidth,
203:
Mobile radio operation with portable antennas is still possible, but the relatively short length of practical mobile antennas compared to a quarter-wave antenna – usually under 10 feet (3.0 meters) vs. around 65 feet (20 meters) tall – results in the need to compensate with a large
629:
generally are not useful for measuring bandwidth, either on-air or off-air. Wide detection bandwidth, slow sweep rates, and common, loud, local ambient noise all mask the presumably weak emissions that survive a transmitter's internal filtering. Although voice ("phone") modes like
117:
and cumulative regional sources of human-made static. The urban and suburban 80 m noise floor is typically set by the amount of noise generated locally, from electrical machinery and household electronics, and is generally 10–20 dB stronger than typical rural noise.
161:
Antennas for 3.5 MHz are large: For example, a quarter-wave vertical sized to resonate at 3.6 MHz is approximately 65 feet (20 meters) high; for reasonable antenna efficiency, even a reduced-size antenna needs to be a large fraction
78:
persists until nightfall, 80 meters is usually only good for local communications during the day, and hardly ever good for communications over intercontinental distances during daylight hours. But it is the most popular band for regional
613:
bandwidth, so the perceived bandwidth seems wider than it actually is: Any measurement of out-of-band emissions using a receiver should be made with it set to a significantly narrower bandwidth than the transmitter's – for example, a narrow
309:
During spring and summer (year-round in the tropics), lightning from distant storms creates significantly higher background noise levels, often becoming an insurmountable obstacle to maintaining normal communications. Nearby
265:
The 80 meter band was made available to amateurs in the United States by the Third
National Radio Convention in 1924. The band was allocated on a worldwide basis by the International Radiotelegraph Convention in 1927.
589:
transceivers have third- and fifth-order products of significant level, typically only 30–35 dB below PEP for third order intermodulation. This means any operation above 3.998 MHz even
786:. International Radiotelegraph Convention (in French and English). Washington, DC: London, UK: His Majesty's Stationery Office (published 1928). 4 October – 27 November 1927. Archived from
196:
on this band. Horizontally polarized antennas closer than a quarter-wave to earth produce predominantly high-angle radiation, which is useful for short-distance propagation modes, such as
585:. But depending on quality and condition of radio, audio characteristics, and proper adjustments the bulk of emissions on lower sideband will typically occupy 3.9970–3.9997 MHz. All
596:
It is a common misconception that operating a transmitter set at 3.9997 MHz is not legal, since emissions extend beyond the 4.000 MHz band edge; this is true for some forms of
137:
between amateurs within a range of 500 miles / 800 km. During contests the band is filled with activity beginning before sunset and continuing all through the night.
208:
to bring the antenna to resonance. However a large coil looses power through resistive heating of its wire, and that wire resistance is always high enough to compete for
121:
On 80 meters, nearly all areas of the world are subject to weather-induced noise from regionally local thunderstorms, and combined distant lightning strikes from
1663:
All allocations are subject to variation by country. For simplicity, only common allocations found internationally are listed. See a band's article for specifics.
314:
activity during the summer months can make the band completely unusable, even for local communications. In the winter months during the peak years of the
659:. When it is night on both ends of the transmission path some broadcasters in Asia and Europe can be heard in North America between 3.9–4.0
222:), which can be good for reducing received noise, but makes changing frequency a challenge, since one must retune the loading coil's inductance.
778:
812:
1063:
998:
968:
200:. Nonetheless, occasional favorable propagation conditions make substantial distances still possible with modest-height antennas.
1676:
1666:
851:
337:
577:
For
Canadian and U.S. Amateurs with infeasibly perfect transmitters, the highest usable frequency in the 80 m band for
719:
In
Australia the upper 3.776–3.800 MHz band segment is a DX window, only allowed for amateurs with advanced licenses.
1072:
331:
710:, a few nations allocate different sub-bands of 3.5–3.8 MHz, 3.5–3.9 MHz, or 3.5–4.0 MHz for amateur use.
1041:
1710:
884:
855:
40:
880:
600:, but not all, and is challenging to measure accurately. In general, high quality receivers or frequency-selective
291:
1056:
197:
564:) primarily used for long-distance communications. It is common for illegal marine operations, generally using
55: 3). The upper portion of the band, which is usually used for phone (voice), is sometimes referred to as
910:
1733:
548:
As is common for many other wide amateur bands, the lower edge of 80 meters is predominantly used for
134:
1018:
760:
1646:
1639:
994:
964:
938:
1049:
917:
686:
signal is strong enough, its noise may mask weak amateur signals. Most DRM signals occupy 9 or 10
667:
receiver this produces a tone in the received audio when the station is broadcasting with conventional
652:
631:
578:
80:
823:
787:
246:
1556:
819:
290:
paths must be largely, although not entirely, in darkness. At times, there is pronounced dark-side
275:
1706:
934:
683:
672:
990:
282:
anywhere on the planet, the main propagation barrier to long-distance communication is heavy
1480:
1404:
676:
668:
639:
635:
213:
960:
8:
1598:
1543:
1316:
549:
1071:
1467:
1453:
1433:
1410:
113:
80 m rural noise floor is mostly determined by noise produced by distant tropical
125:
thunderstorms that perpetually supply world-wide a continuous source of radio static.
1626:
1612:
1576:
1562:
1529:
1505:
1486:
682:
can blank out the carrier tone, but the audio signal often can still be heard. If a
294:, which is most useful on polar routes, away from equatorial thunderstorm activity.
1127:
615:
311:
287:
1683:, but many individual administrations have commonly adopted this allocation under
1385:
1114:
780:
International
Radiotelegraph Convention and General and Supplementary Regulations
741:
664:
601:
590:
586:
553:
349:
world restrict amateur allocations between 3.7 MHz and the top of the band.
303:
209:
60:
1165:
1147:
1133:
622:
565:
189:
51: 1); and 3.5–3.9 MHz in south and east Asia and the eastern Pacific (
1727:
1654:
Some administrations have authorized spectrum for amateur use in this region;
1303:
1275:
1261:
1247:
1233:
1209:
1195:
1108:
315:
32:
1685:
1366:
1346:
1322:
679:
656:
593:(LSB) comes with some risk of illegal emissions, even with good equipment.
205:
193:
114:
47: 2); generally 3.5–3.8 MHz in Europe, Africa, and northern Asia (
302:
occasionally limit local wintertime traffic on the band in areas such as
888:
234:
1289:
1101:
1096:
1091:
707:
626:
597:
141:
101:
67:
52:
48:
44:
63:
between 3.9–4.0 MHz used by a number of national radio services.
1670:
655:
band overlaps the upper edge of the 80 m ham band allocation in
298:
28:
728:
In Korea the 3.520–3.525 MHz sub-band is for digital messaging.
1026:
217:
122:
767:. Third National Radio Conference. 6–10 October 1924. p. 15.
283:
145:
84:
worldwide – depending on atmospheric and ionospheric conditions.
75:
59:; however, in Europe, "75 m" is used to name an overlapping
1656:
others have declined to regulate frequencies above 300 GHz.
319:
322:
effects can also render the band useless for hours at a time.
675:(DRM). Setting an SSB receiver to the exact frequency of the
1699:. These allocations may only apply to a group of countries.
920:(JARL). 25 September 2023 – via jarl.org / jarl.or.jp.
188:
communication can use low wire antennas, such as horizontal
278:
for long-distance communication seldom dips below 3.5
687:
660:
582:
561:
557:
386:
345:
341:
279:
97:
71:
36:
306:, the northern tier of the United States and Canada.
875:
873:
846:
844:
1073:International amateur radio frequency allocations
1725:
671:, or white noise if the station is transmitting
953:
929:
927:
870:
841:
107:
1057:
983:
286:absorption during the daytime, ensuring that
212:power against the antenna's meager effective
1359:
924:
156:
128:
1064:
1050:
805:
646:
903:
753:
325:
96:"80 meter" band begins at 3.5
887:Region 3 (IARU-R3). Archived from
771:
765:Recommendations for Regulation of Radio
133:The 80 meter band is favoured for
1726:
643:filtering remain insignificantly low.
1667:World Administrative Radio Conference
1045:
971:from the original on 7 September 2005
338:International Telecommunication Union
761:"Frequency or wave band allocations"
581:voice ("phone") would be 3.999
229:
822:(RAC). 11 July 2008. Archived from
332:Amateur radio frequency allocations
13:
1665:HF allocation created at the 1979
1001:from the original on 3 August 2005
572:
543:
297:At higher latitudes, a noticeable
192:, inverted vee dipole antennas or
14:
1745:
1691:This includes a currently active
1669:. These are commonly called the "
885:International Amateur Radio Union
856:International Amateur Radio Union
352:Some allocations are as follows:
1446:
1438:
1398:
1390:
916:(Report). Toshima-ku Tokyo, JP:
621:Inexpensive spectrum analyzers,
233:
1009:– via ARRLWeb (arrl.org).
979:– via ARRLWeb (arrl.org).
722:
609:bandwidth expands the measured
198:near vertical incidence skywave
66:Because high absorption in the
1697:Table of Frequency Allocations
1681:Table of Frequency Allocations
713:
700:
269:
1:
1675:This is not mentioned in the
881:"IARU Region 3 Bandplan"
837:– via RAC Web (rac.ca).
747:
340:allocated the whole 500
693:
108:Natural and human-made noise
39:in North and South America (
16:Amateur radio frequency band
7:
995:American Radio Relay League
965:American Radio Relay League
939:Korean Amateur Radio League
852:IARU Region 1 Bandplan
735:
525:United States
87:
10:
1750:
918:Japan Amateur Radio League
556:), with the lower 10
329:
225:
1704:
1661:
1652:
1631:
1617:
1603:
1589:
1567:
1555:
1548:
1534:
1496:
1479:
1472:
1458:
1420:
1403:
1376:
1336:
1315:
1308:
1294:
1280:
1266:
1252:
1238:
1200:
1164:
1157:
1138:
1126:
1119:
1079:
993:(Report). Newington, CT:
963:(Report). Newington, CT:
492:3.500–3.550, 3.790–3.800
479:3.745–3.770, 3.791–3.805
477:3.662–3.687, 3.702–3.716,
475:3.500–3.580, 3.599–3.612,
462:3.500–3.700, 3.890–3.900
423:3.500–3.700, 3.776–3.800
408:3.500–3.750, 3.790–3.800
157:Cumbersome large antennas
129:Daytime and nighttime use
1711:Electromagnetic spectrum
899:– via iaru-r3.org.
866:– via iaru-r1.org.
820:Radio Amateurs of Canada
276:maximum usable frequency
61:shortwave broadcast band
27:band is a span of radio
1695:mentioned in the ITU's
949:– via karl.or.kr.
858:Region 1 (IARU-R1)
813:"RAC MF / HF Band Plan"
651:The European 75 m
81:communications networks
35:use, from 3.5–4.0
673:Digital Radio Mondiale
647:Broadcast interference
206:inductive loading coil
1426:(420.000–450.000 MHz)
937:(Report). Seoul, KR:
326:Frequency allocations
292:gray-line propagation
1029:on 24 September 2005
669:amplitude modulation
640:frequency modulation
569:the USA and Canada.
214:radiation resistance
1734:Amateur radio bands
1693:footnote allocation
1633:241.000–250.000 GHz
1619:134.000–141.000 GHz
1605:122.250–123.000 GHz
1443:902.000–928.000 MHz
1422:430.000–440.000 MHz
1417:430.000–440.000 MHz
1395:220.000–225.000 MHz
1378:144.000–148.000 MHz
1373:144.000–146.000 MHz
1333:(50.000–54.000 MHz)
829:on 27 November 2010
653:shortwave broadcast
1686:"Article 4.4"
344:from 3.5–4.0
312:convective weather
245:. You can help by
1721:
1720:
1716:
1715:
1591:76.000–81.500 GHz
1569:47.000–47.200 GHz
1550:24.000–24.250 GHz
1536:10.000–10.500 GHz
1355:70.000–70.500 MHz
1338:50.000–54.000 MHz
1329:50.000–52.000 MHz
1310:28.000–29.700 MHz
1296:24.890–24.990 MHz
1282:21.000–21.450 MHz
1268:18.068–18.168 MHz
1254:14.000–14.350 MHz
1240:10.100–10.150 MHz
1202:5.3515–5.3665 MHz
537:
536:
263:
262:
1741:
1689:
1634:
1620:
1606:
1592:
1587:
1570:
1551:
1537:
1523:
1518:
1513:
1499:
1494:
1475:
1461:
1444:
1427:
1423:
1418:
1396:
1379:
1374:
1356:
1339:
1334:
1330:
1311:
1297:
1283:
1269:
1255:
1241:
1227:
1222:
1217:
1203:
1189:
1184:
1179:
1160:
1155:
1141:
1122:
1082:
1081:
1066:
1059:
1052:
1043:
1042:
1038:
1036:
1034:
1025:. Archived from
1011:
1010:
1008:
1006:
987:
981:
980:
978:
976:
961:US Amateur Bands
957:
951:
950:
948:
946:
931:
922:
921:
915:
907:
901:
900:
898:
896:
877:
868:
867:
865:
863:
848:
839:
838:
836:
834:
828:
817:
809:
803:
802:
800:
798:
792:
785:
775:
769:
768:
757:
729:
726:
720:
717:
711:
704:
550:radio telegraphy
359:
358:
258:
255:
237:
230:
220:
186:
184:
183:
182:
180:
179:
176:
173:
1749:
1748:
1744:
1743:
1742:
1740:
1739:
1738:
1724:
1723:
1722:
1717:
1690:
1684:
1674:
1664:
1655:
1632:
1618:
1604:
1590:
1582:
1568:
1549:
1535:
1522:5.650–5.850 GHz
1521:
1517:5.650–5.925 GHz
1516:
1512:5.650–5.850 GHz
1511:
1498:3.300–3.500 GHz
1497:
1493:3.400–3.475 GHz
1492:
1474:2.300–2.450 GHz
1473:
1460:1.240–1.300 GHz
1459:
1442:
1425:
1424:
1421:
1416:
1394:
1377:
1372:
1354:
1337:
1332:
1331:
1328:
1309:
1295:
1281:
1267:
1253:
1239:
1226:7.000–7.200 MHz
1225:
1221:7.000–7.300 MHz
1220:
1216:7.000–7.200 MHz
1215:
1201:
1188:3.500–3.900 MHz
1187:
1183:3.500–4.000 MHz
1182:
1178:3.500–3.800 MHz
1177:
1159:1.800–2.000 MHz
1158:
1154:1.810–1.850 MHz
1153:
1139:
1121:135.7–137.8 kHz
1120:
1075:
1070:
1040:
1032:
1030:
1019:"Ham Radio QRP"
1017:
1014:
1004:
1002:
991:ARRL Band Plans
989:
988:
984:
974:
972:
959:
958:
954:
944:
942:
933:
932:
925:
913:
909:
908:
904:
894:
892:
891:on 22 July 2011
879:
878:
871:
861:
859:
850:
849:
842:
832:
830:
826:
815:
811:
810:
806:
796:
794:
793:on 8 March 2014
790:
783:
777:
776:
772:
759:
758:
754:
750:
742:Shortwave bands
738:
733:
732:
727:
723:
718:
714:
705:
701:
696:
649:
632:upper side band
623:spectrum scopes
579:lower side band
575:
573:Upper band edge
560:(3.5–3.51
546:
544:Lower band edge
478:
476:
417:
402:
384:
375:
365:
334:
328:
304:Northern Europe
272:
259:
253:
250:
243:needs expansion
228:
218:
177:
174:
171:
170:
168:
167:
165:
163:
159:
131:
110:
90:
17:
12:
11:
5:
1747:
1737:
1736:
1719:
1718:
1714:
1713:
1707:Radio spectrum
1702:
1701:
1659:
1658:
1651:
1642:
1636:
1635:
1630:
1622:
1621:
1616:
1608:
1607:
1602:
1594:
1593:
1588:
1580:
1572:
1571:
1566:
1559:
1553:
1552:
1547:
1539:
1538:
1533:
1525:
1524:
1519:
1514:
1509:
1501:
1500:
1495:
1490:
1483:
1477:
1476:
1471:
1463:
1462:
1457:
1449:
1448:
1445:
1440:
1437:
1429:
1428:
1419:
1414:
1407:
1401:
1400:
1397:
1392:
1389:
1381:
1380:
1375:
1370:
1362:
1361:
1358:
1351:
1341:
1340:
1335:
1326:
1319:
1313:
1312:
1307:
1299:
1298:
1293:
1285:
1284:
1279:
1271:
1270:
1265:
1257:
1256:
1251:
1243:
1242:
1237:
1229:
1228:
1223:
1218:
1213:
1205:
1204:
1199:
1191:
1190:
1185:
1180:
1175:
1168:
1162:
1161:
1156:
1151:
1143:
1142:
1137:
1130:
1124:
1123:
1118:
1111:
1105:
1104:
1099:
1094:
1089:
1086:
1080:
1077:
1076:
1069:
1068:
1061:
1054:
1046:
1015:
1013:
1012:
982:
952:
923:
911:JARL Band Plan
902:
869:
840:
818:. Ottawa, ON:
804:
770:
751:
749:
746:
745:
744:
737:
734:
731:
730:
721:
712:
698:
697:
695:
692:
690:of bandwidth.
648:
645:
591:lower sideband
574:
571:
545:
542:
541:
540:
539:
538:
535:
534:
532:
529:
526:
522:
521:
519:
516:
513:
509:
508:
506:
503:
500:
496:
495:
493:
490:
487:
483:
482:
480:
473:
470:
466:
465:
463:
460:
457:
453:
452:
450:
447:
444:
440:
439:
437:
434:
431:
427:
426:
424:
421:
418:
413:
412:
409:
406:
403:
398:
397:
390:
379:
370:
327:
324:
271:
268:
261:
260:
240:
238:
227:
224:
158:
155:
130:
127:
109:
106:
89:
86:
57:75 meters
31:allocated for
15:
9:
6:
4:
3:
2:
1746:
1735:
1732:
1731:
1729:
1712:
1708:
1703:
1700:
1698:
1694:
1687:
1682:
1678:
1672:
1668:
1660:
1657:
1650:
1649:
1648:
1643:
1641:
1638:
1637:
1629:
1628:
1624:
1623:
1615:
1614:
1610:
1609:
1601:
1600:
1596:
1595:
1585:
1581:
1579:
1578:
1574:
1573:
1565:
1564:
1560:
1558:
1554:
1546:
1545:
1541:
1540:
1532:
1531:
1527:
1526:
1520:
1515:
1510:
1508:
1507:
1503:
1502:
1491:
1489:
1488:
1484:
1482:
1478:
1470:
1469:
1465:
1464:
1456:
1455:
1451:
1450:
1441:
1436:
1435:
1431:
1430:
1415:
1413:
1412:
1408:
1406:
1402:
1393:
1388:
1387:
1383:
1382:
1371:
1369:
1368:
1364:
1363:
1357:
1352:
1350:
1349:
1348:
1343:
1342:
1327:
1325:
1324:
1320:
1318:
1314:
1306:
1305:
1301:
1300:
1292:
1291:
1287:
1286:
1278:
1277:
1273:
1272:
1264:
1263:
1259:
1258:
1250:
1249:
1245:
1244:
1236:
1235:
1231:
1230:
1224:
1219:
1214:
1212:
1211:
1207:
1206:
1198:
1197:
1193:
1192:
1186:
1181:
1176:
1174:
1173:
1169:
1167:
1163:
1152:
1150:
1149:
1145:
1144:
1136:
1135:
1131:
1129:
1125:
1117:
1116:
1112:
1110:
1107:
1106:
1103:
1100:
1098:
1095:
1093:
1090:
1087:
1084:
1083:
1078:
1074:
1067:
1062:
1060:
1055:
1053:
1048:
1047:
1044:
1039:
1028:
1024:
1020:
1000:
996:
992:
986:
970:
966:
962:
956:
940:
936:
935:KARL Bandplan
930:
928:
919:
912:
906:
890:
886:
882:
876:
874:
857:
853:
847:
845:
825:
821:
814:
808:
789:
782:
781:
774:
766:
762:
756:
752:
743:
740:
739:
725:
716:
709:
703:
699:
691:
689:
685:
681:
678:
674:
670:
666:
662:
658:
654:
644:
641:
637:
633:
628:
624:
619:
617:
612:
608:
603:
599:
594:
592:
588:
584:
580:
570:
567:
563:
559:
555:
551:
533:
530:
527:
524:
523:
520:
517:
514:
511:
510:
507:
504:
501:
498:
497:
494:
491:
488:
485:
484:
481:
474:
471:
468:
467:
464:
461:
458:
455:
454:
451:
448:
445:
442:
441:
438:
435:
432:
429:
428:
425:
422:
419:
415:
414:
410:
407:
404:
400:
399:
396:
395:
391:
388:
383:
380:
378:
374:
371:
369:
364:
361:
360:
357:
356:
355:
354:
353:
350:
347:
343:
339:
333:
323:
321:
317:
316:sunspot cycle
313:
307:
305:
300:
295:
293:
289:
285:
281:
277:
267:
257:
248:
244:
241:This section
239:
236:
232:
231:
223:
221:
215:
211:
207:
201:
199:
195:
194:loop antennas
191:
154:
150:
147:
143:
138:
136:
126:
124:
119:
116:
115:thunderstorms
105:
103:
100:(85.7 m
99:
95:
85:
82:
77:
73:
69:
64:
62:
58:
54:
50:
46:
42:
38:
34:
30:
26:
22:
21:80 meter
1696:
1692:
1680:
1662:
1653:
1645:
1644:
1625:
1611:
1597:
1586:– 81.500 GHz
1583:
1575:
1561:
1542:
1528:
1504:
1485:
1466:
1452:
1432:
1409:
1384:
1365:
1353:
1345:
1344:
1321:
1302:
1288:
1274:
1260:
1246:
1232:
1208:
1194:
1171:
1170:
1146:
1132:
1113:
1102:ITU Region 3
1097:ITU Region 2
1092:ITU Region 1
1031:. Retrieved
1027:the original
1022:
1016:
1003:. Retrieved
985:
973:. Retrieved
955:
943:. Retrieved
905:
893:. Retrieved
889:the original
860:. Retrieved
831:. Retrieved
824:the original
807:
795:. Retrieved
788:the original
779:
773:
764:
755:
724:
715:
702:
657:the Americas
650:
620:
610:
606:
595:
576:
547:
531:3.500–4.000
518:3.500–3.800
505:3.500–3.900
499:New Zealand
449:3.500–3.800
436:3.500–4.000
393:
392:
381:
376:
372:
367:
362:
351:
335:
308:
296:
273:
264:
254:January 2012
251:
247:adding to it
242:
202:
160:
151:
146:D layer
139:
132:
120:
111:
93:
91:
76:D layer
65:
56:
25:3.5 MHz
24:
20:
18:
1140:472–479 kHz
797:25 December
627:panadaptors
611:transmitter
270:Propagation
74:-activated
29:frequencies
1705:See also:
1671:WARC bands
1584:75.500 GHz
945:January 5,
862:January 5,
854:(Report).
748:References
708:ITU Region
598:modulation
382:Allocation
330:See also:
142:ionosphere
102:wavelength
68:ionosphere
45:ITU Region
1172:80 / 75 m
975:August 3,
895:5 January
833:1 October
694:Footnotes
636:amplitude
416:Australia
401:Argentina
299:skip zone
1728:Category
1033:3 August
1023:ac6v.com
1005:3 August
999:Archived
969:Archived
736:See also
706:In each
663:. On an
607:receiver
552:(called
135:ragchews
123:tropical
88:Overview
680:carrier
512:Russia
443:Europe
430:Canada
363:Country
320:auroral
284:D-layer
274:As the
226:History
190:dipoles
181:
169:
94:nominal
33:amateur
1647:Sub-mm
1599:2.5 mm
1544:1.2 cm
1386:1.25 m
1115:2200 m
1085:Range
941:(KARL)
625:, and
618:mode.
486:Korea
469:Japan
456:India
377:Region
53:Region
49:Region
1468:13 cm
1454:23 cm
1434:33 cm
1411:70 cm
1148:160 m
1134:630 m
1088:Band
914:(PDF)
827:(PDF)
816:(PDF)
791:(PDF)
784:(PDF)
638:, or
1627:1 mm
1613:2 mm
1577:4 mm
1563:6 mm
1530:3 cm
1506:5 cm
1487:9 cm
1304:10 m
1290:12 m
1276:15 m
1262:17 m
1248:20 m
1234:30 m
1210:40 m
1196:60 m
1035:2005
1007:2005
977:2005
947:2017
897:2010
864:2010
835:2010
799:2023
616:"CW"
554:"CW"
394:Refs
385:(in
368:Area
336:The
140:The
92:The
43:and
41:IARU
19:The
1679:'s
1677:ITU
1640:THF
1557:EHF
1481:SHF
1405:UHF
1367:2 m
1347:4 m
1323:6 m
1317:VHF
688:kHz
684:DRM
665:SSB
661:MHz
587:SSB
583:MHz
566:USB
562:MHz
558:kHz
387:MHz
373:ITU
366:or
346:MHz
342:kHz
280:MHz
249:.
144:'s
98:MHz
72:Sun
70:'s
37:MHz
23:or
1730::
1709:,
1673:".
1447:—
1439:—
1399:—
1391:—
1360:—
1166:HF
1128:MF
1109:LF
1021:.
997:.
967:.
926:^
883:.
872:^
843:^
763:.
677:AM
634:,
602:RF
528:2
515:1
502:3
489:3
472:3
459:3
446:1
433:2
420:3
411:—
405:2
318:,
288:DX
210:RF
178:3
172:2
166:≳
1688:.
1065:e
1058:t
1051:v
1037:.
801:.
389:)
256:)
252:(
219:Q
185:)
175:/
164:(
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