The Fathom Systems current loop powered microphone has been developed to provide reliable and high quality operation in the harsh environment present inside the diver’s helmet.
The microphone uses a high quality moisture resistant noise-cancelling element which is covered with a GoreTex waterproof membrane which permits pressurisation and de-pressurisation associated with diving applications.
An integral circuit board in the microphone housing provides the electrical interface to the DDCS, and when the microphone is connected correctly and powered up, a small red LED on the circuit board is illuminated. This can be clearly seen through the clear encapsulation around the PCB.
There are only two wires needed to connect the microphone to the umbilical, and these wires are polarity insensitive (i.e. the microphone will work correctly when connected either way).
It is recommended that the microphones be connected to the internal wiring inside the diving helmet or band-mask with single-pin sealed gold-pin connectors. These connectors ensure that water is kept away from the electrical connections and therefore provide the best performance and reliability. For this reason, we recommend that ‘bullet crimps’ or similar connection methods are not used. Mating female single-pin gold plated connectors are available from Fathom Systems.
Wireless Belt Pack
Supervisors have appreciated the benefits of a wireless diver communications system for many years, though not always available in a practical or reliable form.
Fathom Systems have used the latest 2.4GHz wireless technology in the new digital communication system to provide a high quality wireless audio link in both directions. The supervisor uses a small hand-held or belt-worn unit which contains the wireless interface and a headphone and microphone interface.
There are five pushbuttons on the current MKII belt-pack:
- Headphone Volume adjust + and – buttons (on the side of the unit);
- Power on/off button (red – with power symbol);
- Mode button (M);
- Press to Talk button (T).
The Belt Pack should be used with the custom Sennheiser headsets supplied by Fathom Systems.
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