it comes to purchasing a marine MF/HF (SSB) transceiver the choice is
a little limited.
The reason for this is that marine equipment needs to meet the relevant type approval standards and marine radios (both VHF and HF) have to meet the GMDSS requirements.
Here in Europe marine radios being sold today must be compliant to the European Radio equipment and Telecommunications Terminal Equipment (R&TTE) directive, manufacturers like Icom, Furuno and Sailor produce marine transceivers that meet the R&TTE directive for SOLAS vessels which only operate on 24 volts and come with a very large price tag.
Currently no manufacturer produce a Class 'E' MF/HF (SSB) transceiver for the non-solas leisure market that meets the R&TTE directive.
It is a legal requirement for ALL ocean going ships to have MF/HF & VHF DSC and therefore all new marine MF/HF & VHF fixed transceivers have Digital Selective Calling (DSC).
DSC is a powerful way of attracting attention as it activates an alarm at the receiving station and the radio will automatically go to the working channel/frequency where an announcement will be made.
Therefore DSC calls should be made prior to any voice announcement.
of DSC calls are:
* Distress alert
* Distress relay
* Test calls
The Icom M801E, M802, M803 and GM800 all have the ability to make and receive DSC calls.
The advantage of DSC via HF SSB is that calls can be made over a far greater range than can be achieved using VHF DSC and therefore it is highly recommend that an ocean going yacht is fitted with an MF/HF (SSB) transceiver with DSC capabilities.
Marine MF/HF (SSB) radios have been around for a while and can be picked up on the second-hand market.
If buying a second-hand yacht with an SSB it is worth checking which SSB is fitted.
Amateur radio MF/HF (SSB) transceivers are fitted on some yachts, because they are a lower price and usually lower specification to marine MF/HF transceivers.
Amateur radio is a hobby for radio enthusiast and the radios are designed for the hobby amateur radio market by a number of manufacturers such as Icom, Yaesu and Kenwood.
Popular Icom amateur radios are: IC-706, IC-718, IC-736, IC-7200, IC-7300 to just name a few.
Amateur radio transceivers do not have DSC, you will only find DSC on marine transceivers.
Below you will find information on Icom marine MF/HF transceivers.
The ICOM M801E is designed for the marine environment and suitable for installation on non-SOLAS vessels (leisure craft) and is one of the best marine MF/HF (SSB) transceivers, ideal for installation on a small vessel.
Housed in a robust diecast housing that acts as a heat sink, therefore the M801E has no holes or fans and with heavy duty connectors, the M801E is ideal for the marine environment.
The M801E has a built in DC to DC isolated convertor which reduces the issue on galvanic electrolysis. There are both 12 volt and 24 volt versions of the M801E.
The M801E is no longer available but can be found on the second-hand market.
Although the M801E and M802 control head look similar in operation, the M802 is a lower cost radio to the M801E. The ICOM M802 is housed in a non-water resistant housing using a cooling fan to keep cool, blowing air across circuit boards and other components and therefore over time may suffer from corrosion.
The M802 is powered directly from 12 volt DC power supply.
ICOM M801 v M802
Although the M801E and M802 look the same that is where the difference finishes.
The M801 is housed in a more robust housing with heavy duty connectors, ideal for the marine environment.
The M801 as an internal DC to DC converter which allows for better voltage stability and reduces the possibility of Galvanic corrosion .
By using the latest DSP technology, the M801E has better receiver performance.
The M801E is a fully compliant class 'E' DSC unit offering a full range of DSC features compared with the M802 limited range of DSC functions.
Launched in 2020, the Icom M803 is the latest marine MF/HF (SSB) transceiver from Icom, with a new improved control head and easier to use interface.
The control head is water-resistant but the main unit is not!
The main until looks similar to the M802 with one or two minor changes.
The M803 does meet the latest DSC requirements and has a built in GPS and is powered directly from a 12 volt DC supply.
The Icom M710 is an old marine MF/HF (SSB) transceiver manufactured by Icom back in the 1990s and does not include built-in DSC, although an external DSC control could be attached to the GMDSS version of the M710.
There were several versions of the M710 manufactured. The 2 most popular were the GMDSS version which was mainly sold in Europe and has the capability to have a DSC controller attached to it and the RT version which was sold in the US and other parts of the world.
The Icom M710 was a very popular transceiver for use with a Pactor modem for SSB email.
The M710 is no longer available.
Icom’s first MF/HF SSB marine transceiver was the M600, this was followed by the M700 and even an M800 (M800 not to be confused with the later GM800).
There are several versions on the M700. The latest being the M700pro which has the capability of fitting an external modem, so they could be used for SSB Email
These are all very old radios with no DSC capability.