SP3965 Communication Mode Comparison
The SAILOR SP3965 UHF ATEX Portable Radio can be operated in two different modes.
- Direct Mode.
- CTCSS Mode.
In Direct Mode, all radios of an on-board firefighting party use the same radio channel and can therefore listen and talk to all radios used by the firefighting party. It is recommended to use different UHF radio channels for routine on-board operations and for firefighting operations, to avoid interference from radios not participating in the firefighting operations. However, this mode will lead to interference from other vessels if such vessels use the same UHF channel.
To minimize interference from other vessels using the same UHF channel it is recommended to use the SP3965 in CTCSS mode, also called Trunked Mode (not to be confused with Trunked Radio Systems). In CTCSS mode, radios from the firefighting party on board your vessel will only start receiving once another radio of the firefighting party of your vessel starts transmitting using the same CTCSS signalling protocol. Hence, unless your radio is already "open" in receiving mode, radios of other vessels on the same frequency will not be heard.
Nonetheless, in view of the number of vessels commonly berthed in busy ports, even CTCSS can not totally avoid interference on the limited number of UHF channels available if all radios of your own vessel and other vessels are transmitting simultaneously on the same radio channel. For this reason the SP3965 is capable of operating on 16 channels, which in combination with the use of CTCSS minimizes the likelihood of interference by increasing the chance of finding a free channel.
Below diagrams explain the different modes of operation.
SP3965 Direct Mode
Radios 1,2,3 (blue and black) are radios from other vessels in the vicinity.
SP3965 CTCSS Mode
SP3965 Firefighting Accessories
Regardless of whether the SP3965 is used in Direct Mode or CTCSS Mode, firefighting operations are commonly conducted by personnel using firefighting gear such as helmets, breathing apparatus and protective suits. Hence a range of accessories is available to be used in conjunction with or integrated into firefighting gear.
SP3965 SAVOX Accessories
SP3965 Peltor Accessories
SP3965 Extended Coverage
For large vessels sch as tankers and container vessels below-deck radio coverage may be limited due to distances and obstructions involved. Lambda Marine can offer various repeater systems and/or Distributed Antenna Systems to extend radio coverage in spaces such as the engine room, steering gear-room etc.
All images courtesy of Cobham.
