SSB marine radio is the bluewater sailors' favourite method of long-range communication. Once you've got the equipment installed - sadly not an inconsequential investment - all calls are free.
SSB (Single Sideband) radio has a much greater range than a VHF (Very High Frequency) radio's typical 35 to 50 nautical miles.
Medium Frequency (MF) SSB radio has a range of around 400 nautical miles, but High Frequency (HF) will reach out for several thousand.
Clearly the power required to achieve this range is considerably more than for a VHF radio; SSB marine radio sets typically draw a peak current of around 25A when transmitting.
The SSB Marine Radio Installation
The component parts of an SSB radio installation are:~
An MF/HF SSB transceiver - Some SSB radios can transmit and receive on all of the HAM radio frequencies as well as the marine channels. If you have, or intend getting, a HAM Radio License then the additional cost of one of these sets may well represent excellent value for money.
An antenna - Most sailboats use an insulated section of the backstay as an antenna, although some twin-masted vessels use the triatic stay if they have one. Alternatively, a fibreglass whip antenna can be used - and most usually is on catamarans that have no backstays. But whatever antenna set-up is used, without a good ground plane, radio signal and reception will be dismal.
A ground plane - Bronze thru-hulls, bonded together with copper strapping, can be used successfully to form a ground plane but this method may promote electrolysis problems. An easier approach, avoiding any electrolysis issues, is to use a sintered bronze grounding shoe to the outside of the hull, below the waterline. Of course the best ground plane of all is provided by a steel hull.
An automatic antenna tuner - SSB radios transmit on a wide range of frequencies which affects the impedance of the fixed-length antenna, which in turn affects the performance of the transmitter. An automatic antenna tuner, sometimes referred to as a coupler, matches the antenna to the output from the SSB. Manual tuners are available, and are cheaper too, but require constant readjustment with frequency changes, making the radio much more difficult to operate as a result.
As with all modern VHF radios, top of the range SSB radio sets have DSC functionality built in, but if you want to use it together with the capability of being able to transmit on all marine MF/HF/VHF frequencies from a yacht then you need a GMDSS Long Range Certificate.
Such an SSB set, interfaced with a GPS (for DSC capability) and a laptop computer provides further functionality - access to weather fax, and email communication.
Weatherfax via an SSB Marine Radio
There are around ninety weather stations around the world which regularly broadcast meteorological maps on HF SSB frequencies.
With one of the weatherfax software programmes - Mscan Meteo or ICS Weather Fax6 for example - loaded into your computer, a weather map specific to your area of interest can be downloaded, often together with an associated forecast.
It can then be viewed on screen, or sent to a printer if you have one, for detailed analysis.
Email via an SSB Marine Radio
Just one more electronic gizmo - a radio modem - to install and then, once you've enlisted with an SSB email service provider, you can send and receive emails wherever you are.
Most SSB email service providers charge an annual subscription, so there are no line-time or by-the-bit (minutes used) charges as with mobile phone or satellite systems.
There are limits on usage though. For example, subscribers to www.sailmail.com, one of the most popular SSB ESP's are required to limit their use of the SailMail stations to a running average of 90 minutes per week.
File attachments can't be sent with outgoing emails and only certain attachments - such as weather data in .grib file format - can be received.
Licensed HAM Radio Operators can sign-up to the Winlink 2000 system which is completely free to use, but unlike sailmail, does not allow business transactions to be carried out over their network.