Question: We have a problem integrating our Clear-com unit to our JVC CCU. We found that the CCUs are creating termination which builds with each successive CCU we turn on. If we have the Clear-com Master station terminated then the audio to camera is low. Take termination off and intercom is good with only one CCU on. As soon as we start turning more CCUs on the audio drops in step with each CCU. We have everything hooked up like shown in clear-com and JVC manuals to no avail.
The CCU is a JVC RM-HP790du
The Clearcom unit is MS-702
Pin 1 is going to G on CCU
Pin 3 is going to H on CCU
Pin 2 is Not connected
CCU is switched to unbalanced
Termination ONLY on MS-702
When we have termination OFF and only one CCU on the system works. If we turn termination on the MS-702 audio drops significantly. As we turn more CCUs on (5) the audio keeps dropping like we are adding. We have worked hours on this. Please help
Answer: If the JVC camera CCU were equipped with a 4-wire option it should be used and connected back to the Clear-Com MS-702 via a IF4W4 interface. As the CCU for the JVC RM-HP790du only accepts an unbalanced 2-wire IC connection the problem is the audio line impedance of this 2-wire camera system, the camera circuits usually load the line with a low loading impedance. Thus, each camera added to the line, usually in parallel, reduces the line impedance. The system is then totally dependent upon the number of headsets in use, as well as the volume control settings at each individual camera.
The best solution in this case would be to simply bypass the CCU intercom connections and use a Clear-Com series RS-600 beltpack for each camera operator, either a RS-601 single channel beltpack with headset or a RS-602 dual channel beltpack with headset tied into the existing Clear-Com party-line.