HF Maritime Radiotelephone Channels


What frequency do you mean?

 

The frequency listed or displayed for a radio station can differ, depending upon the radio receiver, the type of modulation used and how you are demodulating (or modulating) the signal, and the person listing the frequency.  This is especially true for high frequency (HF)  radios.  To help avoid confusion, three terms are used to describe these radio frequencies: assigned, carrier, and window.

Assigned Frequency

The assigned frequency is defined by the International Telecommunications Union Radio Regulations as "the centre of a frequency band assigned to a station".  In fact, it is the actual radio frequency of the signal being transmitted and received.  This is the most commonly used frequency designation.

Carrier Frequency

The carrier frequency is the frequency of the carrier, or the suppressed carrier of a signal.  For many, perhaps most radio signals, the carrier frequency and the assigned frequency are identical.  They are identical for AM (dual sideband) signals.  They are different for single sideband radios.  For maritime HF single sideband transmissions, which are always upper sideband, the assigned frequency is always 1.4 kHz greater than the carrier frequency. 

The carrier frequency designation, not the assigned frequency designation, is normally used in referring to single sideband transmissions.  History partially explains the reason for this.  Marine radiotelephony was originally AM (dual sideband), and the carrier and assigned frequencies were the same.  Certain frequencies, such as the distress and calling frequency 2182 kHz, were internationally recognized and known by any mariner using a marine radiotelephone.  When marine spectrum became scarce, the International Telecommunications Union moved all marine radiotelephony transmissions from dual sideband to the more efficient single sideband.   At first, the carrier signal was left untouched, so old AM radios could still receive the new single sideband transmissions.  In time however, the old carrier signal was eliminated.  The old marine frequencies such as 2182 kHz, commonly known and used, were retained and still displayed by marine radios.  Although no signal was actually transmitted on these carrier frequencies any longer, receivers still had to be tuned to those frequencies so that the voice signal could be properly demodulated and understood. 

Maritime digital signals, such as narrow band direct printing (NBDP or sitor) or digital selective calling (DSC), are transmitted on an assigned frequency 1.7 kHz above the (suppressed) carrier frequency.  Marine weatherfax signals are transmitted on an assigned frequency 1.9 kHz above the carrier frequency.  NBDP, DSC and weatherfax radios normally display the assigned frequency.  However, if a single sideband radio with a separate decoder unit is used to receive a sitor, DSC or weatherfax signal, it's likely that receiver would have to be tuned to the carrier frequency for the decoder to work properly.

The ITU assigned channel numbers to many single sideband and NBDP frequencies to help avoid this confusion.  However, DSC frequencies, and most simplex single sideband, NBDP and weatherfax frequencies do not have channel numbers.

Window Frequency

The window frequency is simply the frequency displayed (on the front panel numeric display "window") by a particular radio receiver or transmitter.   Depending on the equipment, the window frequency could be either the carrier or the assigned frequency.  Since the window frequency is dependent upon the equipment used, the term is not generally used by the USCG.

Is the frequency listed assigned or carrier?  What frequency do I tune my radio to?

The USCG tries to use standard convention in its listing of radio frequencies: Single sideband frequencies are generally carrier frequencies; all others are generally assigned frequencies.  When the carrier and assigned frequencies differ, we generally list both.

Read your radio's instruction manual, or talk to your marine electronics dealer, to learn whether your radio should be tuned to the assigned or the carrier frequency. 

 


 

2 MHz Marine Radiotelephone Frequencies

 

Intership Safety and Operational Communications.

Carrier Frequency (kHz)

Geographic Area

2003.0

Great Lakes only

2782.0

Mississippi River System working frequency

2082.5

All Areas.  Also, Intership non-commercial fishing.

2086.0

Mississippi River System working frequency

2093.0

All Areas.

2142.0

Pacific Coast, daily, south of 42 deg. N

2182.0

Distress, safety and calling

2203.0

Gulf of Mexico.  Also, Intership non-commercial fishing.

2214.0

All Areas.

2635.0

ITU Regions 2-3 (ITU RR 4193).  Not in FCC rules.

2638.0

All Areas.

2670.0

U.S. Coast Guard Liaison and Maritime Safety Broadcasts, Also Intership Safety and Operational Communications in all areas.

2738.0

All Areas, except Great Lakes. Shared with aircraft.

2830.0

Gulf of Mexico only. Shared with aircraft.

 

Business and Operational Frequencies

Carrier Frequency (kHz)

Geographic Area

2065.0

All Areas. 

2079.0

All Areas.

2096.5

All Areas.

3023.0

Government shore, ship and aircraft stations for search and rescue coordination.

Reference: FCC Regulations, 47 CFR 80.373(b) and (c), except as noted.  Assignments are required before these frequencies can be used by land stations.  Duplex channels are not available in this band.

 


HF Single Sideband Maritime Radiotelephone Channels

Commandant (G-SCT-2)
U.S. Coast Guard                        27 Aug 1999
Washington DC 20593


HF Single Sideband Maritime Radiotelephone Channels

4 MHz Duplex Channels

ITU Channel No.     Coast Transmit      Ship Transmit

     401            4357 kHz            4065 kHz
     402            4360                4068
     403            4363                4071
     404            4366                4074
     405            4369                4077
     
     406            4372                4080
     407            4375                4083
     408            4378                4086
     409            4381                4089
     410            4384                4092

     411            4387                4095
     412            4390                4098
     413            4393                4101
     414            4396                4104
     415            4399                4107

     416            4402                4110
     417            4405                4113
     418            4408                4116
     419            4411                4119
     420            4414                4122

     421            4417                4125 (Calling; distress 
                                              & safety working on
                                              4125 kHz simplex) 
     422            4420                4128
     423            4423                4131
     424            4426                4134 (USCG Calling)
     425            4429                4137

     426            4432                4140
     427            4435                4143
     428            4351              (varies)
     429            4354              (varies)
     
6 MHz Duplex Channels

ITU Channel No.     Coast Transmit      Ship Transmit

     601            6501 (kHz)          6200 (kHz)(USCG Calling)
     602            6504                6203
     603            6507                6206
     604            6510                6209
     605            6513                6212

     606            6516                6215 (Calling; distress 
                                              & safety working on
                                              6215 kHz simplex)
     607            6519                6218
     608            6522                6221
8 MHz Duplex Channels

ITU Channel No.     Coast Transmit      Ship Transmit

     801            8719 (kHz)          8195 (kHz)
     802            8722                8198
     803            8725                8201
     804            8728                8204
     805            8731                8207

     806            8734                8210
     807            8737                8213
     808            8740                8216
     809            8743                8219
     810            8746                8222

     811            8749                8225
     812            8752                8228
     813            8755                8231
     814            8758                8234
     815            8761                8237

     816            8764                8240 (USCG Calling)
     817            8767                8243
     818            8770                8246
     819            8773                8249
     820            8776                8252

     821            8779                8255 (Calling)
     822            8782                8258
     823            8785                8261
     824            8788                8264
     825            8791                8267

     826            8794                8270
     827            8797                8273
     828            8800                8276
     829            8803                8279
     830            8806                8282

     831            8809                8285
     832            8812                8288
     833            8291                8291
     834            8707              (varies)
     835            8710              (varies)

     836            8713              (varies)
     837            8716              (varies)12 MHz Duplex Channels

ITU Channel No.     Coast Transmit      Ship Transmit

     1201           13,077 kHz          12,230 kHz
     1202           13,080              12,233
     1203           13,083              12,236
     1204           13,086              12,239
     1205           13,089              12,242 (USCG Calling)

     1206           13,092              12,245
     1207           13,095              12,248
     1208           13,098              12,251
     1209           13,101              12,254
     1210           13,104              12,257

     1211           13,107              12,260
     1212           13,110              12,263
     1213           13,113              12,266
     1214           13,116              12,269
     1215           13,119              12,272

     1216           13,122              12,275
     1217           13,125              12,278
     1218           13,128              12,281
     1219           13,131              12,284
     1220           13,134              12,287

     1221           13,137              12,290 (Calling)
     1222           13,140              12,293
     1223           13,143              12,296
     1224           13,146              12,299
     1225           13,149              12,302

     1226           13,152              12,305
     1227           13,155              12,308
     1228           13,158              12,311
     1229           13,161              12,314
     1230           13,164              12,317

     1231           13,167              12,320
     1232           13,170              12,323
     1233           13,173              12,326
     1234           13,176              12,329
     1235           13,179              12,332

     1236           13,182              12,335
     1237           13,185              12,338
     1238           13,188              12,341
     1239           13,191              12,344
     1240           13,194              12,347

     1241           13,197              12,35016 MHz Duplex Channels

ITU Channel No.     Coast Transmit      Ship Transmit

     1601           17,242 kHz          16,360 kHz
     1602           17,245              16,363
     1603           17,248              16,366
     1604           17,251              16,369
     1605           17,254              16,372

     1606           17,257              16,375
     1607           17,260              16,378
     1608           17,263              16,381
     1609           17,266              16,384
     1610           17,269              16,387

     1611           17,272              16,390
     1612           17,275              16,393
     1613           17,278              16,396
     1614           17,281              16,399
     1615           17,284              16,402

     1616           17,287              16,405
     1617           17,290              16,408
     1618           17,293              16,411
     1619           17,296              16,414
     1620           17,299              16,417

     1621           17,302              16,420 (Calling)
     1622           17,305              16,423
     1623           17,308              16,426
     1624           17,311              16,429
     1625           17,314              16,432 (USCG Calling)

     1626           17,317              16,435
     1627           17,320              16,438
     1628           17,323              16,441
     1629           17,326              16,444
     1630           17,329              16,447

     1631           17,332              16,450
     1632           17,335              16,453
     1633           17,338              16,456
     1634           17,341              16,459
     1635           17,344              16,462

     1636           17,347              16,465
     1637           17,350              16,468
     1638           17,353              16,471
     1639           17,356              16,474
     1640           17,359              16,477

     1641           17,362              16,480
     1642           17,365              16,483
     1643           17,368              16,486
     1644           17,371              16,489
     1645           17,374              16,492

     1646           17,377              16,495
     1647           17,380              16,498
     1648           17,383              16,501
     1649           17,386              16,504
     1650           17,389              16,507

     1651           17,392              16,510
     1652           17,395              16,513
     1653           17,398              16,516
     1654           17,401              16,519
     1655           17,404              16,522

     1656           17,407              16,52518/19 MHz Duplex Channels

ITU Channel No.     Coast Transmit      Ship Transmit

     1801           19,755 kHz          18,780 kHz
     1802           19,758              18,783
     1803           19,761              18,786
     1804           19,764              18,789
     1805           19,767              18,792

     1806           19,770              18,795 (Calling)
     1807           19,773              18,798
     1808           19,776              18,801
     1809           19,779              18,804
     1810           19,782              18,807

     1811           19,785              18,810
     1812           19,788              18,813
     1813           19,791              18,816
     1814           19,794              18,819
     1815           19,797              18,822

22 MHz Duplex Channels

ITU Channel No.     Coast Transmit      Ship Transmit

     2201           22,696 kHz          22,000 kHz
     2202           22,699              22,003
     2203           22,702              22,006
     2204           22,705              22,009
     2205           22,708              22,012

     2206           22,711              22,015
     2207           22,714              22,018
     2208           22,717              22,021
     2209           22,720              22,024
     2210           22,723              22,027

     2211           22,726              22,030
     2212           22,729              22,033
     2213           22,732              22,036
     2214           22,735              22,039
     2215           22,738              22,042

     2216           22,741              22,045
     2217           22,744              22,048
     2218           22,747              22,051
     2219           22,750              22,054
     2220           22,753              22,057

     2221           22,756              22,060 (Calling)
     2222           22,759              22,063
     2223           22,762              22,066
     2224           22,765              22,069
     2225           22,768              22,072

     2226           22,771              22,075
     2227           22,774              22,078
     2228           22,777              22,081
     2229           22,780              22,084
     2230           22,783              22,087

     2231           22,786              22,090
     2232           22,789              22,093
     2233           22,792              22,096
     2234           22,795              22,099
     2235           22,798              22,102

     2236           22,801              22,105
     2237           22,804              22,108
     2238           22,807              22,111
     2239           22,810              22,114
     2240           22,813              22,117

     2241           22,816              22,120
     2242           22,819              22,123
     2243           22,822              22,126
     2244           22,825              22,129
     2245           22,828              22,132

     2246           22,831              22,135
     2247           22,834              22,138
     2248           22,837              22,141
     2249           22,840              22,144
     2250           22,843              22,147

     2251           22,846              22,150
     2252           22,849              22,153
     2253           22,852              22,156  25/26 MHz Duplex Channels

ITU Channel No.     Coast Transmit      Ship Transmit

     2501           26,145 kHz          25,070 kHz
     2502           26,148              25,073
     2503           26,151              25,076
     2504           26,154              25,079
     2505           26,157              25,082

     2506           26,160              25,085
     2507           26,163              25,088
     2508           26,166              25,091
     2509           26,169              25,094
     2510           26,172              25,097 (Calling) HF Single Sideband Maritime Radiotelephone Channels

Simplex Channels

These frequencies are shared and are not available for the
exclusive use of any station. 

4 MHz Band     6 MHz Band     8 MHz Band     12 MHz Band

4146 kHz       6224 kHz       8294 kHz       12,353 kHz
4149           6227           8297           12,356
               6230                          12,359
                                             12,362
                                             12,365



16 MHz         18/19 MHz Band 22 MHz Band    25/26 MHz Band

16,528 kHz     18,825 kHz     22,159 kHz     25,100 kHz
16,531         18,828         22,162         25,103
16,534         18,831         22,165         25,106
16,537         18,834         22,168         25,109
16,540         18,837         22,171         25,112

16,543         18,840         22,174         25,115
16,546         18,843         22,177         25,118


Maritime Channels Shared with the Fixed Service

The following channels in the band 4000-4063 kHz and 8100-8195 kHz may be used:

 - for supplementing ship-to-shore channels for duplex operation;
 - for intership simplex (single-frequency) and cross-band operation;
 - for cross-band working with coast stations;
 - for duplex operation with coast stations working in the band 4438-4650 kHz or 
   with Channels 834, 835, 836 and 837;
 - for ship-to-shore or shore-to-ship simplex operations (8100-8195 kHz only).


	       		  4 MHz Carrier	   8 MHz Carrier 
   Channel No.            Frequency kHz	   Frequency kHz

	 1			4000		8101	
	 2			4003		8104
	 3			4006		8107
	 4			4009		8110
	 5			4012		8113
	 6			4015		8116
	 7			4018		8119
	 8			4021		8122
	 9			4024		8125
	10			4027		8128
	11			4030		8131
	12			4033		8134
	13			4036		8137
	14			4039		8140
	15			4042		8143
	16			4045		8146
	17			4048		8149
	18			4051		8152
	19			4054		8155
	20			4057		8158
	21			4060		8161
	22			 --		8164
	23			 --		8167
	24			 --		8170
	25			 --		8173
	26			 --		8176
	27			 --		8179
	28			 --		8182
	29			 --		8185
	30			 --		8188
	31			 --		8191

Global Maritime Distress & Safety System Radiotelephone Channels

These simplex frequencies are used for distress and safety
communications, and (except for 2182 kHz) are not normally
guarded.

          2182 kHz       8291 kHz
          4125           12,290
          6215           16,420