Clear-Com MR-202, MR-204 User Manual

MR-202/MR-204

TWO- AND FOUR-CHANNEL HEADSET STATIONS

USER MANUAL

Clear-Com Intercom Systems MR-202/MR-204 Two- and Four-Channel Headset Stations

Introduction

Congratulations and thank you for choosing this Clear-Com product. The MR-202 Two-Channel and MR-204 Four-Channel Headset Stations are

powerful, yet user-friendly units that can serve as versatile intercom stations. Please read this manual completely to better understand the functions of

these products. For questions not addressed in this manual, contact the dealer or Clear-Com directly. Clear-Com applications support and service people are ready to help.

Description

The Clear-Com PL-Pro™ MR-202 and MR-204 are headset stations ideal for use in theatres, live performances, industrial environments, and small television facilities. They feature speech intelligibility in all noise levels and can be customized through their programmable options.

Selectable, multi-channel talking and/or listening allows the operator to communicate on one of two (MR-202) or four (MR-204) intercom channels. The dual-action talk button operates in electronic momentary or latching mode. The MR-202 and MR-204 offer visual call signaling to attract the attention of operators. The Remote Mic Kill (RMK) feature on main stations will turn off any open microphones on these headset stations.

The MR-202 and MR-204 stations accept dynamic headsets, such as the Clear-Com PL-Pro

control allows the operator to vary the level of his voice heard in the headset. The MR-202 and MR-204 receive 30-V DC power from the Clear-Com

intercom line. They mount in a standard two-gang electrical outlet box. The extra-thick front panel and compact, surface-mount circuitry results in a small size and lighter weight package that maintains Clear-Com ruggedness. The intercom channels connect to a plug-on screw terminal strip.

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or the HS-6 T elephone Headset Series. A sidetone

The optional EB-TW daughter board module can be installed to provide an interface to two intercom channels on a single microphone cable. Also, the EB-TW 4-Wire daughter board module is available to allow long-distance connections using separate pairs of wire for send audio and receive audio. The EB-4W 4-Wire option supports two-channel operation and may only be used on the MR-202.

The MR-202 and MR-204 are compatible with all Clear-Com Party-Line intercoms.

Rev. B

MR-202/MR-204 Two- and Four-C hannel Headset Stations Clear-Com Intercom Systems

Quick Start

1. Unpack the unit and inspect for any damage that may have occurred during shipping.

2. Connect the intercom lines. If less than the maximum number of intercom lines are to be connected, link unused intercom inputs to a connected input with jumper wires.

3. Install the MR-202 or MR-204 into the two-gang outlet box. (For additional information, refer to the Clear-Com PL-Pro

Installation Manual.)

4. Connect the appropriate headset or handset.

5. Set Listen Levels and Sidetones. (Refer to “3—Intercom Level Control” on page 4 and “4—Sidetone Control” on page 4.)

6. The headset station should now be operating properly.

7. Read the rest of this manual for further information.

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System

Operation

Normal operation of the MR-202 or MR-204 Headset Station only requires the front-panel controls. The controls located elsewhere on the unit are intended to be set-and-forget in nature. For intercom operation, set the Listen level control to the desired level and press the Talk button when talking. Set the Sidetone control for the desired amount of sidetone in the earphone.

Rev. B

Clear-Com Intercom Systems MR-202/MR-204 Two- and Four-Channel Headset Stations

Front Panel

The controls, indicators, and connectors found on the MR-204 front panel are shown in Figure 1 on page 3 and are described by the following text. The MR202 front panel is identical except the channel switch has two positions.

3 5

Intercom Level

Call

Sidetone

Talk

A B C D

Channel Select

pro

MR-204

R e m o t e

S t a t i o n

1—Talk Button and Lamp

The Talk button activates the microphone feed to the selected intercom channel. The Talk button has a dual action (momentary or latching) depending upon how the button is pressed. If desired, the latching function can be defeated using an internal switch. The following describes the various functions of this button.

• Momentary—Press and hold the Talk button while speaking. Release it when finished.

• Latching—Press and release the button quickly to latch the Talk function. Press and release the button again to turn off the Talk function.

FIGURE 1: Front Panel

Rev. B

MR-202/MR-204 Two- and Four-C hannel Headset Stations Clear-Com Intercom Systems

• Talk Indication—The associated Talk lamp will illuminate green when the Talk function is activated.

2—Call Button and Lamp

Pressing the Call button will send a call signal on the selected channel. All the call lights on that channel will then flash. Call signals can also be sent while talking if required. The C all lamp will light while the Ca ll button is pressed, or whenever a call signal is present on the selected channel.

3—Intercom Level Control

Turn this control to set the listen level required on the headset.

4—Sidetone Control

Sidetone is the level of the operator’s voice that heard while talking on the intercom. Setting a comfortable level of sidetone will ensure that the intercom line sounds alive and also helps modul ate the oper at or’s voice relative to other voices on the line.

Use the following procedure to correctly set the Sidetone level control.

1. Set the Intercom Level control to a comfortable level by having

someone talk to the operator from another station.

2. Press the Talk button and speak into the microphone while

turning the Sidetone control slowly back and forth until you hear your voice at a comfortable level in the headset.

Note:

Do not force the trimpot past its stop points. This will damage it.

5—Channel Switch

This switch selects the intercom channel (A, B, C, or D) on which the headset station is active.

6—Headset Connector

The headset connector is located on the front panel. All Clear-Com headsets are recommended for use with the MR-202 or MR-204. The Clear-Com PT-4 Push-to-Talk Microphone or the HS-6 Telephone Handset will also plug into the headset connector. The following is a description of the characteristics of a suitable headset:

• Mic Type—Dynamic; 150 to 400 ohms impedance; -55 dB output level

• Headphone—Dynamic; 50 to 2000 ohms impedance.

The wiring of the headset is to be as follows:

• Pin 1—microphone ground (shield)

• Pin 2—microphone hot

• Pin 3—headphone ground

• Pin 4—headphone hot.

Rev. B

Clear-Com Intercom Systems MR-202/MR-204 Two- and Four-Channel Headset Stations

The microphone and headphone wiring in the headset cord must be individually shielded.

Note:

Do not connect Pins 1 and 3 together. Headset extension cords or headset “Y” cables are not recommended because they may increase crosstalk between channe ls .

Internal Adjustments and Connections

The controls and connectors found inside the MR-202 and MR-204 are shown in the following figure and described by the following text. The jumpers can be accessed without completely removing the panel from its wall box by removing the top two screws and loosening the bottom two screws a few turns. The panel can then be leaned out from the wall. The jumpers will be accessible as shown in the lower view of Figure 2 on page 5.

P3 Must be

installed if

no option

JB2

JB1

P1 Must be

installed if

no option

View from top

of MR-202

Front Panel

FIGURE 2: Internal Adjustments and Connections

Rev. B

MR-202/MR-204 Two- and Four-C hannel Headset Stations Clear-Com Intercom Systems

7—Option Jumpers

Two option jumpers, JB1 and JB2, are provided. They should be configured when the system is set up, but shouldn’t need to be changed during normal operation.

Note:

The default position of the jumpers is in the OPEN (only one pin

connected) position. The function of each jumper is as follows:

JB1—Long Line

If a long cable run is unavoidable and approaches 1,000 ft. or more, set the Long Line option jumper to the CLOSED (both pins connected) position. The ability to set a sidetone null depends upon properly setting this jumper.

JB2—Latch Disable

Setting the Latch Disable jumper to the CLOSED (both pins connected) position will disable the latching function of the Talk button. In this mode, the Talk button must be held in continuously while the operator is talking.

8—Intercom Line Connection

The MR-202 contains a five-terminal, plug-on connector for intercom line connection. The MR-204 contains a seven-terminal, plug-on connector for intercom line connection. This connector is intended to be unplugged from the circuit board when connecting the intercom line(s), and then plugged back on when the wiring is completed. If less than the maximum number of intercom lines are to be connected to the intercom connector, link unused intercom inputs to a connected input with jumper wires. The connections for each pin are visible on the circuit board when the connector is unplugged. The pinout of this connector is as follows:

• Pin 1—(NC)

Rev. B

• Pin 2—Channel A Audio

• Pin 3—Channel B Audio

• Pin 4—Power (+30 VDC)

• Pin 5—Ground (Shield)

• Pin 6—Channel C Audio (MR-204 only)

• Pin 7—Channel D Audio (MR-204 only).

+ 15 hidden pages

Clear-Com MR-202, MR-204 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual