PARTY-LINE INTERCOM SYSTEM INSTALLATION MANUAL
Clear-Com System Installation Manual TABLE OF CONTENTS Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . The Clear-Com Concept . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Power Distribution and Short Circuit Protection . . . . . . . . . . . . . . . . . . . Installing an Intercom System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1 2 3 Single-Channel System . . . . . .
Clear-Com System Installation Manual INTRODUCTION Congratulations on choosing Clear-Com products. Clear-Com was established in 1968 and remains the market leader in providing intercom for entertainment, educational, broadcast and industrial applications. The ruggedness and high build-quality of Clear-Com products is the industry standard. In fact, many of our original beltpacks and Main Stations are still in daily use around the world.
Clear-Com System Installation Manual POWER DISTRIBUTION AND SHORT CIRCUIT PROTECTION A Main Station or Power Supply is the heart of an intercom system. It has special features which are not found in traditional designs. It must supply low-noise 30 Volt DC current to multiple intercom lines. It must continue to operate in adverse conditions such as low AC line voltage, momentary shorts on the DC power lines to the stations, and excessive peak loads during power-on conditions.
Clear-Com System Installation Manual INSTALLING AN INTERCOM SYSTEM When considering how to install and wire an intercom system, several factors must be taken into account. These include the number of stations, the length of the cable runs and whether single or multiple channels are required. If multi-channel stations are connected with multi-pair cables, then crosstalk becomes an important issue.
Clear-Com System Installation Manual Multi-Channel System In a multi-channel system where each channel is run on its own cable and connected only to single channel Remote Stations as in the following diagram, there are no crosstalk issues because the channels do not share a common ground. Consult the table in the next section for cable recommendations.
Clear-Com System Installation Manual When multiple channels are fed to Remote Stations, the amount of crosstalk between channels is proportional to the DC resistance of the ground return path back to the channel terminations. To minimize this crosstalk between channels when running more than one channel in a multi-pair cable, keep the DC resistance of the ground return as low as possible. Ideally, this should be less than 2 Ohms. This can be achieved as follows: Keep cable runs under 500 feet.
Clear-Com System Installation Manual Portable Installation Cable: Practical cable for portable system interconnections is flexible, twoconductor, shielded microphone cable. We suggest using BELDEN #8413 (24 Gauge). For runs longer than 500 feet use a 20 gauge cable or larger (BELDEN #8412). Permanent Installation Cable: Vinyl-jacketed shielded pair is the cable of choice for permanent installations. Placing the cable in conduit is recommended but not necessary.
Clear-Com System Installation Manual The wiring of the headset is to be as follows: Pin 1 Pin 2 Pin 3 Pin 4 --------- Mic common Mic hot Headphone common Headphone hot The mic and headphone wiring in the headset cord must be individually shielded. Do not connect Pins 1 and 3 together. Headset extension cords or headset "Y" cables are not recommended because they will increase crosstalk between channels.
Clear-Com System Installation Manual Ring --- Normally Closed Contact --- N/C Tip --- Common Contact --- C Sleeve --- Normally Open Contact --- N/O Program Input: A 3-pin XLR female connector on most Main Stations and Power Supplies provides the program input to the intercom system. The Program Input accepts a balanced or unbalanced line-level audio signal from -20 dBv to +10 dBv. There is an option to feed program audio to the Announce Output.
Clear-Com System Installation Manual KB-112 Speaker Station The KB-112 Speaker Station provides intercom communication capability in places where wearing a headset is not feasible. It can be optioned for several remote control functions. Refer to the KB-112 Instruction and Service Manual for details on setting its option switches. A Main or Remote Station can control the microphone on a KB-112 set to Remote Listen operating mode, allowing the KB-112 operator to talk "hands free.
Clear-Com System Installation Manual TYPICAL APPLICATIONS Cable or School Television Studio Video Director Assistant Director 2-Channel Main Station 3 3 3 Graphics 2-Channel Remote Station 3 3 3 3 3 Headset Station Headset Station 3 3 Program Input Channel A Channel B Cameras Beltpack Floor Managers Beltpack 3 3 Beltpack 3 3 Beltpack 3 3 3 3 Beltpack 3 Channel A Talent Announcer Talent Receiver Studio PA System Talent Receiver 3 Line Splitter 3 Studio Paging 3 3 3 = Male
Clear-Com System Installation Manual Headset Stations are wired to both channels A and B and are used by the video and graphics people. This allows them the flexibility of communicating on either Channel A or Channel B. Program feed audio is connected to the Remote Station so it can be heard by the Director as well as the Talent and Announcers. A Call signal can interrupt the program audio that feeds into the Remote Station. Talent and Announcers use Talent Receivers which are connected to Channel B.
Clear-Com System Installation Manual Theatre 1 Patch Panel Light Board Stage Manager 2-Channel Main Station Beltpack 3 3 Beltpack 3 3 3 3 Program Input 3 Channel A Curtain Operator Spot Operators 3 Beltpack Audio Mixing Console Beltpack 3 3 3 3 3 3 Beltpack 3 Channel A Stage Pickup Mic Green Room 3 = Male 3-Pin XLR 3 = Female 3-Pin XLR Beltpack Channel B Dressing Rooms Speaker Station Speaker Station Speaker Station In the preceding diagram of a typical Theatre installation,
Clear-Com System Installation Manual The Program Level control can be used to adjust the stage microphone audio level the Stage Manager hears. If or whenever the Stage Manager does not need to monitor this, the Program Level control can be turned fully counter-clockwise. Channel B is connected to Speaker Stations such as the Clear-Com KB-112 which are installed in the green room and in dressing rooms.
Clear-Com System Installation Manual Theatre 2 Props Scenery Stage Manager 2-Channel Main Station Beltpack 3 3 3 Beltpack 3 3 3 Program Input 3 Channel A 3 Audio Mixing Console Light Board Patch Panel Sound Beltpack Stage Pickup Mic Beltpack 3 3 3 3 Beltpack 3 3 Spot Operators Beltpack 3 Channel B Stage Announce Output Green Room Hallways Dressing Rooms Speaker Speaker Speaker 3 = Male 3-Pin XLR 3 = Female 3-Pin XLR Power Amplifier In this example of another typical Theatre
Clear-Com System Installation Manual To adjust the stage announce and program levels, use the following steps: 1 Press the Announce button and adjust the program audio power amplifier for the correct level from the speakers connected to it. The Stage Announce output will provide a 0 dBv signal to the stage announce amplifier. 2 With the Announce button released, adjust the Mixing Console so that the Program level is correct as heard through the speakers connected to the stage announce amplifier.
Clear-Com System Installation Manual ENG/EFP Truck Director Telephone Interface 2-Channel Main Station 3 3 3 3 2-Channel Remote Station 3 3 3 Channel B Studio Program Feed Telephone Central Office Line Engineer 3 3 Channel A Channel B Talent / Announcer Camera Operator Assistant Director / Floor Manager Talent Receiver Beltpack Beltpack Channel B 3 3 3 3 3 Channel A Intercom Interface 3 = Male 3-Pin XLR 3 3 = Female 3-Pin XLR Channel A 3 Other Intercom In the preceding diagram o
Clear-Com System Installation Manual SYSTEM CHECKOUT Before you turn on the power, perform the following tests: Check Termination There should be one and only one termination for each channel in the system. This termination is usually set to ON at the Main Station or Power Supply. To ascertain that only one termination is present on the channel, perform the following test: NOTE: The location of the termination switch varies with model.
Clear-Com System Installation Manual 4 If connected, check that Program Input, Announce Output and Hot Mic Output / IFB System jacks are functional. Verify the operation of the controls that affect the function of these inputs and outputs. Refer to the User Manual of the particular Main Station. TROUBLESHOOTING Problem: Cause 1: Solution 1: System does not operate. No power to Main Station or Power Supply.
Clear-Com System Installation Manual Solution 3: Set the Main Station or Power Supply termination switch for that channel to the ON position. Cause 4: Solution 4: A headset extension cord was used. Headset extension cords are not recommended. Problem: Cause 1: Solution 1: Excessive crosstalk High DC resistance in ground return. Use heavier cable; add additional conductor(s) to ground return. Cause 2: Solution 2: MULTI-CHANNEL cable pairs are not individually shielded.
Clear-Com System Installation Manual GLOSSARY Some of the terms used when discussing critical communications for television or theatre may be new to you as they are unique to intercom applications. Although many of the terms are common to other audio applications, to be certain you understand their meanings we offer the following definitions: All Call: Ability to push one button from the Main Station and talk to all channels at once on a multiple channel system.
Clear-Com System Installation Manual Master Station: A Remote Station which requires AC power to operate, and cannot power other stations Multi-Channel: More than one channel Party Line (P.L.): Intercom system where all people talking on the system can talk or listen to each other simultaneously. Also called conferencing. Point to Point: One path to one person. Program: Audio source that is fed into the intercom channels.
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