Sharing the 630m Amateur Band
With The Coast Guard

Toby Haynes VE7CNF
[email protected]
October, 2026

1 Introduction

In Canada, the Amateur 630m band (472-479 kHz) allocation is shared with the Maritime Mobile service. A few years ago, when Canada’s RBR-4 (ref 2) was updated, Canadian amateurs were limited to a 1 kHz signal bandwidth on the 630 m band. Other jurisdictions (USA, Australia) are allowed wider signal bandwidth to support SSB voice and faster data modes. The reason given for the 1 kHz limit was that radio amateurs might cause interference to Marine Mobile services. Here, I investigate what medium-frequency Marine services exist that might be interfered with. There are few, and I believe there’s little chance of interference.

1.1 Background

At Amphitrite Point, B.C. the Canadian Coast Guard has a radio site that holds licenses for CW telegraphy on 478 KHz and AM telegraphy on 500 kHz. These are unused legacy licenses, as ship-to-shore telegraphy has not been used for many years. I can, however, understand the nostalgic desire to maintain a couple of the last marine telegraphy licenses in the world. It would be fantastic to activate Amphitrite Point as an amateur special event CW station on 478 kHz.

Adoption of the international “Global Maritime Distress and Safety System” (GMDSS) on Feb 1, 1999 removed the requirement for ship-to-shore telegraphy (ref 5). Officially, on July 28, 1999, the Canadian Coast Guard stopped the watch on 500 KHz (ref 6), although some monitoring continued in the arctic for a couple more years.

Canada’s active marine radio services are listed in “Radio Aids to Marine Navigation 2026” (ref 4). The only current service listed below 2 MHz is NAVTEX (FSK teleprinter) broadcasts. This is on 518 kHz, with some Eastern Canadian stations on 490 kHz. West coast NAVTEX transmissions are on 518 kHz from near Prince Rupert, B.C. and at Amphitrite Point.

The GMDSS supports MF/HF radiotelephone channels, where MF in the marine context refers to the 2-4 MHz range and HF to the 4-30 MHz range (ref 5). All marine radiotelephone channels in Canada and the USA are above 2 MHz.

A new NAVDAT digital data service is in development, to become part of the GMDSS, that will use 495 to 505 kHz and frequencies above 2 MHz. In Canada there are frequency allocations but no active licenses for this service.

Radio Amateurs in Southwest BC did a test in March, 2026 and verified that their 630m CW signals can be heard near Amphitrite Point. This shows that there would be a potential for interference if any active Marine services did exist in the 472-479 kHz range.

1.2 Conclusion

There are no active marine services within the Amateur 630m band, so Canadian Amateurs can operate freely throughout the band. We are limited to a 1 kHz signal bandwidth, although the bandwidth of our signal should not be a concern as long as we limit intermodulation and other spurious transmitter outputs. It’s good practice to keep spurious outputs 43 dB or more below the mean transmitter power (ref 7). We should check our transmitted spectrum to guarantee we will not cause interference to marine services on 490, 500, and 518 kHz.

2 Amateur 630m Band in Canada

In Canada the Amateur 630m band covers 472-479 kHz with an allowed signal bandwidth of 1 kHz and power up to 5W EIRP (ref 2). It is open to operators with Basic with Morse Code, Basic with Honours, and Advanced qualifications.

The Amateur 472 – 479 kHz allocation is shared with the Maritime Mobile service. The following excerpts from the Canadian “Table of Frequency Allocations” (ref 1) show the Amateur allocation and adjacent maritime mobile MF allocations:

415 – 472 kHz MARITIME MOBILE 5.79
5.82

472 - 479                              MARITIME MOBILE 5.79 (radiotelegraphy and NAVDAT)
                                                Amateur 5.80A (5W EIRP maximum)
                                                5.82 (no harmful interference to 490 kHz)

479 - 495 MARITIME MOBILE 5.79 5.79A
5.82

495 - 505 MARITIME MOBILE 5.82C (NAVDAT)

505 - 510 MARITIME MOBILE 5.79

510 - 525 MARITIME MOBILEend 5.79A 5.84
AERONAUTICAL RADIONAVIGATION

A search of the ISED Spectrum Management System (ref 3) shows that the only Canadian license in the 472 – 479 KHz range is held by the Canadian Coast Guard for Amphitrite Point, BC.

3 Amphitrite Point Coast Guard Station

The Canadian Coast Guard holds licenses for telegraphy on 478 and 500 kHz at Amphitrite Point, B.C. These are probably some of the last such licenses in the world. The licenses, and the station itself, are a nostalgic reminder of the days of MF and HF marine telegraphy. Sadly, that era ended over 25 years ago.

Following is a summary of the MF and HF radio licenses for Amphitrite Point, B.C. as of August, 2026 (ref 3). All licenses listed below share this common information:

Callsign                                                 XLK835
Location                                               48.925N 125.54638889W (in the water W of Amphitrite Point)
Operating Range                              20 km
License In-Service Date                 2024-08-07
Operational Status                          nil
Licensee                                              Fisheries and Oceans Canada - Canadian Coast Guard
                                                                9860 West Saanich Road, IOS Room 2610,Sidney,BC,V8L 4B2
                                                                Account Number 013080000490

The Canadian “Radio Aids to Marine Navigation 2026” (ref 4) does not list any currently active services on 478 or 500 kHz. British Columbia Amateurs have not reported hearing Coast Guard activity on these frequencies. These appear to be inactive legacy licenses.

478 KHz CW Telegraphy License

Frequency                  478 KHz, record ID 1372587 (Rx) 1372588 (Tx)
Emission                      100 Hz bandwidth CW telegraphy for aural reception, 100HA1AAN
Tx Power                     1000W, ERP 543W 27.35 dBW
Antenna                      Gain 0.9984 dBi, vertical polarization, height 10m

500 KHz AM Telegraphy License

Frequency                  500 KHz, record ID 1372587 (Rx) 1372588 (Tx)
Emission                      2.1 KHz bandwidth AM telegraphy for aural reception, 2K10A2AAN
Tx Power                     4000W, ERP 2173W 33.37 dBW
Antenna                      Gain 0.9984 dBi, vertical polarization, height 10m

Active services are listed on 2.054, 2.182, and 4.125 MHz USB at Amphitrite Point (ref 4, tables 2-17 and 2-18). There are also licenses for other frequencies that may be inactive. The ISED license records below show the channel-center frequency. I have received the 2.054 MHz USB weather bulletin in Burnaby, B.C. at the published times.

2-4 MHz HF SSB Telephony Licenses

Frequency                  2.0554 MHz, record ID 1372575 (Rx), 1372574 (Tx) (active, ref 4)
                                        2.1049 MHZ, record ID 1372576 (Rx), 1372577 (Tx)
                                        2.1834 MHz, record ID 1372582 (Rx), 1372583 (Tx) (active, ref 4)
                                        2.3414 MHz, record ID 1372578 (Rx)
                                        2.4594 MHz, record ID 1372579 (Tx)
                                        4.1264 MHz, record ID 1372584 (Rx), 1372585 (Tx) (active, ref 4)
Emission                      2.8 kHz SSB Telephony suppressed carrier, 2K80J3EJN
Tx Power                     100W, ERP 61W 17.85 dBi
Antenna                      Gain 0.9984 dBi, vertical polarization, height 9m

There is a 518 kHz NAVTEX transmitter license for Amphitrite Point, with different antenna specifications from the 478 and 500 KHz licenses. The ISED records (ref 3) show the license status as “not granted,” but this may be old information. It is already listed as an active service (ref 4, table 2-18) and I have received the signal at the published times in Burnaby, B.C.

518 KHz NAVTEX License

Frequency                          518 KHz, record ID 2456260 (Tx)
Emission                              170 Hz bandwidth FSK TTY NAVTEX, 170HF1BCN
Tx Power                             1000W, ERP 316W 25 dBW
Antenna                              Gain 2.1484 dBi, vertical polarization, height 20m
Callsign                                 CFAPX
Location                               48.92505278N 125.54281111W
Operating Range              555 km
In-Service Date                 2026-04-01
Status                                   Not Granted (Aug 2026, maybe old information)

The Amphitrite Point station’s services are listed under Prince Rupert Marine Communications and Traffic Services (MCTS) (ref 4 table 2-17), so it is probably operated remotely from there.

Fisheries and Oceans Canada
Canadian Coast Guard
Officer-in-Charge – MCTS Operations
Prince Rupert MCTS Centre, Bag 4444, Prince Rupert, BC V8J 4K2
Telephone: 250-627-3070 (MCTS Operations/Supervisor)
Email: [email protected]

The ISED licensee is the Coast Guard’s Western Region Office (ref 4):

Regional Superintendent
Marine Communications and Traffic Services
Canadian Coast Guard
Institute of Ocean Sciences
9860 West Saanich Road, Sidney, BC V8L 5T5
Telephone: 250-363-8904 (Regional Administrative Assistant)
Email: [email protected]

3.1 Reception of Marine Broadcasts from Amphitrite Point

From my home near Vancouver, B.C., I can receive the marine broadcasts from Amphitrite Point on 518 and 2054 kHz. This is at a range of 197 km (122 mi).

Audio Link: 2054 kHz USB Voice Broadcast Oct 7, 2026

Audio link: 518 kHz NAVTEX Broadcast Oct 7, 2026

518 kHz NAXTEX Broadcast as decoded using the Frisnit NAXTEX decoder

3.2 Antennas at Amphitrite Point (March 2026)

Except for the NAXTEX license, the above licenses for Amphitrite Point list the antenna “model” as “long wire.” However, the antenna specifications (front/back ratio 0 dB, polarization vertical) don’t fit with my understanding of a “long wire” antenna.

Four guyed vertical antenna towers were observed at Amphitrite Point in March, 2026. Two have wire cages. These towers are visible from a local hiking trail. The locations of these are visible on Google Earth imagery.

Amphitrite Point, BC (48.923N 125.541W). A hiking trail passes near the antenna towers.

Tower 1.

Tower 2A.

Tower 2B.

Tower 3.
This may be the 518 KHz NAVTEX antenna, as the licensed location is very near this tower.

3.3 Amateur 630m Signal Reception near Amphitrite Point

Reception of Amateur 630m signals near Amphitrite Point was tested after dark, around 8 pm, in March, 2026. Received signals were strong enough to cause interference to Coast Guard operation, if any such operation existed in the 630m band. Receiver sensitivity was not calibrated, so results are qualitative.

Transmitting stations were VE7SL (Mayne Is), VE7CA (North Vancouver), and VA7MM (Port Coquitlam). Signals were CW telegraphy on 473 kHz.

The receiving location (48.9495N 125.5592W) was 3 km NNW of the Amphitrite Point antenna field, near the water and away from power lines and structures. The receiving antenna was a 128 cm long E-field whip on top of a vehicle, with an antenna preamplifier feeding a Yaesu FT817 receiver. Receiver gain was set to give an S1 noise level with receiver bandwidth set for SSB (approx 2.8 kHz).

CW signals were received from all transmitters as high as S5 level, with slow fading noted. Copy was solid and the SNR was easily sufficient for a QSO.

4 References

User-friendly online search tools for this database are available at:
https://tafl.mckie.ca/
https://tafl.jonathanmorgan.net/

Download SMS Data field descriptions at:
https://ised-isde.canada.ca/site/spectrum-management-system/sites/default/files/attachments/2022/tafl_description_ltaf.pdf

To decode the “emission class” field, refer to:
https://ised-isde.canada.ca/site/spectrum-management-telecommunications/en/devices-and-equipment/telecom-regulation-circulars-trc/trc-43-designation-emissions-class-station-and-nature-service

4.1.4 Reference (4) Radio Aids to Marine Navigation

Canadian Coast Guard. (2026). Radio Aids to Marine Navigation 2026.
https://publications.gc.ca/collections/collection_2026/mpo-dfo/Fs151-18-2026-eng.pdf

4.1.5 Reference (5) GMDSS

Canadian Coast Guard. (2025 Dec 19). Global Maritime Distress and Safety System.
https://www.canada.ca/en/canadian-coast-guard/services/search-rescue/global-maritime-distress-safety-system.html

“The international Global Maritime Distress and Safety System (GMDSS) uses improved terrestrial and satellite technology and onboard radio systems. It was implemented globally on February 1, 1999.”

4.1.6 Reference (6) LAST CW MESSAGE

MacFarlane J, Fullerton W, Roscoe S. (2010 Dec 7). THE LAST CW MESSAGE SENT BY THE CANADIAN COAST GUARD. Jerry Proc Reading Room (Radio Stories)
http://jproc.ca/radiostor/ccgmsg.html

“Officially, on July 28 1999, the Canadian Coast Guard stopped the watch on 500 KHz.”

“The Coast Guard continued the monitoring of 500 KHz and MF CW from two stations in the Arctic but only until such time that GMDSS was implemented world wide. Around 2000 or 2001 these CW services were terminated for good and without any fanfare or ceremony.”

4.1.7 Reference (7) Spurious Emissions

Recommendation ITU-R SM.329-13 (2024 Sept). Unwanted emissions in the spurious domain. ITU Radiocommunication Publications
https://www.itu.int/dms_pubrec/itu-r/rec/sm/R-REC-SM.329-13-202409-I!!PDF-E.pdf

Table 2 “Spurious domain emission limits – Category A” lists the spurious limit for Amateur services below 30 MHz.