SSB / HF marine radio
Communication
Marine single-sideband (SSB) radio uses medium and high frequencies to reach hundreds or thousands of miles, mainly for offshore cruisers. It also receives high-seas weather and weather-fax charts. It needs an FCC licence, a tuned antenna and a good ground.
How it works
Marine MF/HF radios work roughly between 2 and 26 MHz using single sideband. An antenna tuner matches the radio to a long antenna, and the system needs a proper radio-frequency ground. Newer HF radios have DSC, which the Coast Guard monitors for distress. Since February 7, 2022 the Coast Guard no longer keeps a voice watch on HF distress frequencies, except 4125 kHz at Kodiak and Guam.
Using it
- For distress, use the radio's DSC distress function; the Coast Guard watches HF DSC frequencies, not HF voice.
- Program your MMSI into an HF DSC radio just as with VHF. Test DSC with a test call to a Coast Guard station; test calls on 4207.5 kHz are acknowledged automatically.
- Keep live DSC test calls with coast stations to no more than once a week, as the International Maritime Organization recommends.
- Use HF to receive the National Weather Service's high-seas forecasts and radiofax charts broadcast from Coast Guard stations.
- In a real emergency you may use any means to get help, including amateur (ham) frequencies, according to NAVCEN.
- Ship station licence (FCC, 47 CFR 80.13(c)): licence-by-rule covers only VHF, AIS, EPIRB and radar, so an MF/HF SSB radio needs an FCC ship station licence even on a recreational boat in US waters (also stated by USCG NAVCEN).
- Operator permit (FCC): using MF/HF SSB also requires an FCC Restricted Radiotelephone Operator Permit; no test, valid for life.
- Amateur (ham) radio is a separate service (47 CFR Part 97); transmitting on ham bands requires an FCC amateur licence earned by exam.
Looking after it
- Check the antenna tuner, antenna insulators and ground connections for corrosion; an antenna maker notes SSB antennas, unlike VHF, must be properly grounded.
- Keep your FCC licence and MMSI details current.
Troubleshooting
Tuner won't tune, or transmissions are weak
- Check the ground connections.
- Check the antenna, its insulators and connections.
- Check the cable between radio and tuner, then have a technician test the system.
No reply from the Coast Guard on HF voice
- The Coast Guard has stopped listening on HF voice distress frequencies except 4125 kHz at Kodiak and Guam; use HF DSC instead.
Buying a boat that has one
- You'll need your own FCC ship station licence and operator permit; the seller's don't transfer with the radio.
- Check whether it has DSC and an MMSI programmed.
- Inspect the tuner, antenna and ground system, which often cause more trouble than the radio.
Sources (8)
navcen.uscg.gov · navcen.uscg.gov · weather.gov · navcen.uscg.gov · fcc.gov · ecfr.gov · fcc.gov · shakespeare-marine.com
General guidance for recreational boaters, researched from the sources listed and written in our own words. Your equipment manuals, local knowledge, the Navigation Rules and a qualified instructor come first.