em-trak B952 vs B954: separate AIS antenna or built-in splitter?

Choose B952 when the plan uses a suitable dedicated AIS antenna; investigate B954 when sharing the main VHF antenna is the better installation. Do not buy the splitter version simply because its model number is higher. The antenna arrangement is the decision that separates these two candidates.

#What changes between them?

Shaded rows contain different values. On a small screen, scroll the table; model names stay visible within it.

Sources: em-trak's model features, electrical specifications and antenna instructions. The average figures do not size a circuit's fuse or cable; follow the installation manual for peak demand and protection.

#Example: a yacht with a good masthead antenna

Imagine a yacht with a recently inspected masthead VHF antenna and limited practical sites for a second antenna. B954 merits a quote if the existing antenna and cable meet the manufacturer's shared VHF/AIS requirements. Ask the installer to inspect the whole path rather than assuming an antenna that works for voice is automatically a suitable AIS installation.

Alternatively, a boat with a properly planned separate AIS antenna may favour B952. This can keep the voice-radio antenna and AIS antenna physically separate, but its practical value depends on location, cable loss and the wider power plan. Two antennas installed badly are not an improvement over one installed correctly.

#Sharing is a design choice

Draw the two alternatives. On the shared arrangement, mark the masthead antenna and coax as common dependencies. On the dedicated arrangement, mark the separate cable, mounting position and any obstructions. Then decide which failures the owner actually wants to tolerate.

Do the same for displays. A plotter and tablet showing the same AIS data provide two viewing options, but they still rely on the same transceiver. If the tablet connection fails, a wired display may remain useful; if the AIS unit loses power, changing screens will not restore its reports. This is an installation exercise, not a claim that either model is inherently more reliable.

#Before accepting the installation

Confirm vessel identity, position input and the supported display connection. Use the manufacturer's diagnostic procedure and arrange a suitable independent check that the boat's transmitted identity is received correctly. An internet vessel-tracking site alone is not an acceptance test because coverage and delays can obscure a working installation.

Request itemised local quotes including antenna work, data wiring and commissioning. We have not verified Australian installed totals. Choose B952 or B954 on the resulting antenna design, then practise recognising loss of data and silent mode. Our AIS ranking explains how these options sit beside a tablet-oriented installation.

#The antenna decision is also a failure decision

The B952 route invites a dedicated AIS antenna installation; the B954 adds an integrated splitter for a supported shared-antenna arrangement. A dedicated antenna needs a suitable location, separation and cable route. A shared installation needs the manufacturer-approved connections and preserves dependence on the shared antenna and its cable. Neither is inherently the right answer for every yacht.

Imagine a monohull whose masthead VHF antenna and coax are in good condition but whose stern space is crowded. A supported splitter arrangement may simplify the layout. On a boat with a well-sited dedicated AIS antenna already fitted, retaining that path may be sensible. Inspect both installations rather than assuming that a second antenna guarantees better coverage or that sharing has no tradeoff.

#Understand what “independent” means in the quote

If the AIS and VHF share one antenna, loss of that antenna can affect both functions. If they use separate antennas but the same failed power distribution, separation alone will not keep them running. Trace the entire path: device power, antenna, GPS arrangement, wired output, display and any wireless client.

Shaded rows contain different values. On a small screen, scroll the table; model names stay visible within it.

The average power numbers in the comparison help with an energy estimate, but circuit protection and wire sizing still require the manual’s installation requirements. Do not size a fuse from average consumption alone. Include the receiving display’s consumption when estimating the energy needed for a useful complete AIS view.

#Acceptance needs evidence of your own transmission

Receiving nearby targets proves only part of the installation. Have a competent installer verify configuration, diagnostics and the vessel’s own transmission using an appropriate independent check. Do not treat the absence of the vessel on a public tracking website as a definitive installation test: shore reception and third-party processing are separate dependencies.

Record the vessel identity, software, antenna path and test result. Make sure the crew knows what the status indications mean and that AIS does not reveal every nearby craft or object. For a budget system, spend first on the correct antenna arrangement and commissioning. For a premium system, use the failure-path drawing to justify any additional independence instead of buying duplicate screens that share the same weakness.