The Fathom Systems current loop microphone, or diver's hot mic, 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.