Instruction Manual - DECA | Diving Equipment Company of America

INSTALLATION & OPERATION
SIMULCOM - WHAT WHY AND HOW (continued) 6.12
DOESN’T THE SAME THING HAPPEN WITH ROUND ROBIN? NO!
With Round Robin you split the microphone and earphones, but also stack all the microphones
together. The microphones load each other and you are right back where you started. Also, you
have another problem - the headset used by the tender usually has 85-ohm earphones and a 150-
ohm microphone. With two diver's microphones we have an impedance of 4 ohms, which really
loads the tender microphone, and the 85-ohm earphones tend to be rather low so you end up with
a volume imbalance as well as low signal levels from the diver & tender microphones.
So it sounds as though it might be worth trying; how do you go about doing it?
Okay - step by step:
1. First you must have an AMCOM III series unit.
2. You must have 4 wires in your communication cable.
3. You must have 4 wires to your hat/helmet, (i.e., Marsh Marine connector or such).
With those three things we can begin:
1. Install male marsh-marine 4-pin connector in hat/helmet. Attach black and white wires to
binding post and both speakers. Attach red and green wires to leads from microphone. It
doesn’t matter which color goes to which lead. Use 8-32 x 1/4 SS screw and nuts, cover
each with tape or shrink tubing. You are now finished with the diving hat/helmet.
2. Install 4-pin female marsh-marine connector on diver's end of communication cable. Red
and green wires to the pair of comm-cable wires; black and white wires to the other pair of
comm-cable wires. You are now finished with this step.
3. For communicator model 2830A (Binding Post Connectors) - Install black dual banana
plug to microphone pair of wires on tender end of diver commo-cable and attach red dual
banana plug to speaker pair of wires. If you don’t have red dual banana plugs, red tape
will serve to identify that pair as the microphone circuit.
For communicator model 2830A-MS (MS Connectors, 5 PIN) – Solder umbilical wires to
mating MS connector, Pin A&B to microphone pair of wires on tender end of diver commcable,
Pin C&D to speaker pair of wires.
YOU ARE FINISHED!
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