Clear-Com KB-211, KB-211GM User Manual

KB-211/KB-211GM

TWO-CHANNEL SPEAKER STATIONS

USER MANUAL

Clear-Com Intercom Systems KB-211/KB-211GM Two-Channel Speaker Stations

Introduction

Congratulations and thank you for choosing this Clear-Com product. The KB-211 and KB-211GM Two-Channel Speaker Stations are powerful,

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™ KB-211 is a two-channel speaker station designed for use in theatres, live performances, industrial environments, and small television facilities. It features speech intelligibility, even in high noise levels, and can be customized through its programmable options.

In addition, the Clear-Com PL-Pro optional Clear-Com gooseneck panel microphone and a close-in, voiceoperated circuit (VOX). This circuit allows automatic, alternate dipping of the panel microphone and the speaker in response to conversation.

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KB-211GM also contains a jack for an

Selectable, two-channel talking and/or listening allows the operator to communicate on either of the intercom channels. The dual-action talk button operates in electronic momentary or latching mode. Monitoring can be done through the headset, the integral speaker, or both simultaneously . The KB-211 offers both visual and audible call signaling to attract the attention of operators. The Remote Mic Kill (RMK) feature on main stations will turn off any open microphones on the KB-211.

A balanced program input allows the monitoring of external audio using the headset or speaker. This program input can also be used as a paging function.

The KB-211 speaker station accepts dynamic headsets, such as the ClearCom PL-Pro

Microphone. A sidetone control allows the operator to vary the level of his voice heard through the headset and speaker.

The integral speaker can be turned on or off by a convenient front-panel switch. An automatic speaker dipping circuit will lower the level of the speaker whenever the talk button is activated. The KB-211GM’s close-in VOX dips the speaker or gooseneck microphone automatically as the station is used. These features help minimize acoustical feedback.

The KB-211 receives 30-VDC power from the Clear-Com intercom line. The unit mounts either in a standard four-gang electrical outlet box or in an optional Clear-Com V-Box. The extra-thick front panel and compact, surfacemount circuitry results in a reduced size and lighter weight package that maintains Clear-Com ruggedness. The two intercom channels connect to a

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Series HS-6 Telephone Handset or PT-4 Push-to-Talk Hand

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KB-211/KB-211GM Two-Channel Speaker Stations Clear-Com Intercom Systems

plug-on screw terminal strip. Male and female three-pin XLR connectors are provided on the V-Box for an in-line connection to one of the intercom channels.

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-4W 4-Wire daughter board module is available to allow long-distance connections using separate pairs of wires for send audio and receive audio. The EB-4W 4-Wire option supports two-channel operation.

The KB-211 and KB-211GM are compatible with all Clear-Com Party-Line intercoms.

Quick Start

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

2. Set the Option switches to the default (up) position.

3. Connect the intercom lines. If only one intercom line is to be connected, set Option Switch 1 to the ON or CLOSED position.

4. Install the KB-211 into the four-gang outlet box or V-Box. (For additional information, refer to the Clear-Com PL-Pro

Installation Manual.)

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

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System

Operation

Front Panel

6. The speaker station should now be operating properly.

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

Normal operation of the KB-21 1 Speaker Station only requires the front-panel controls. The controls located elsewhere on the unit are intended to be setand-forget in nature. For intercom operation, set the Listen level control to the desired level and press the Talk button when talking. If a headset or handset is used, set the Sidetone control for each channel for the desired amount of sidetone in the earphone. If the PT-4 hand-held, push-to-talk microphone is used, or if the panel microphone is used on the KB-211GM, set the sidetone controls for minimum feed-through to the speaker to prevent acoustic feedback.

The controls, indicators, and connectors on the KB-211 and KB-211GM front panels are shown on Figure 1 on page 3 and are described by the following text.

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Clear-Com Intercom Systems KB-211/KB-211GM Two-Channel Speaker Stations

1211 8

VOX

Panel Mic

Headset

Sidetone

5 67

Call

Talk

Channel Select

Intercom Level

Program Level

Off On

Speaker

FIGURE 1: Front Panel

pro

KB-211GM

S p e a k e r 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.

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

• VOX indication—On the KB-211GM, when the VOX feature is enabled, the Talk lamp will illuminate green when the Talk function is activated, but will turn red when the panel microphone is in use. This automatically dips the speaker volume.

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KB-211/KB-211GM Two-Channel Speaker Stations Clear-Com Intercom Systems

• Speaker Dip—If the front-panel speaker is turned on and the VOX feature is not used, pressing the Talk button will reduce the speaker output level to avoid feedback.

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 Call lamp will light while the Call button is pressed, or whenever a call signal is present on the selected cha nne l. An internal option jumper can be set to allow the Call lamp to light when a call signal is present on either channel.

3—Tone Alert

An audible tone alert can sound when a call signal is received on the selected channel or either channel. This can be useful when the operator’s attention has been drawn away from the KB-211 indicator panel. The audible tone alert level can be adjusted or turned off by an internal control. The Tone Alert will not sound if a call signal is originated at the KB-211 station or if the Speaker ON/OFF Switch is turned off. The Tone Alert plays through both the speaker and headset if the Speaker ON/OFF Switch is turned on.

4—Intercom Level Control

Turn this control to set the listen level required on the speaker or headset. This control does not affect the Tone Alert level or the Program Input level.

5—Sidetone Control

Sidetone is the level of the operator’s voice that is 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.

Typically , different Sidetone settings are needed depending upon whether the speaker is used. Use one of the following procedures to correctly set the Sidetone level control.

Sidetone Adjustment Procedure for Headset

Follow these steps to adjust a headset’s sidetone level.

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 the voice reaches a comfortable level in the headset.

Follow these steps to adjust the sidetone for gooseneck microphones on the KB-211GM or PT-4 hand-held, push-to-talk microphone with the Speaker turned on.

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Clear-Com Intercom Systems KB-211/KB-211GM Two-Channel Speaker Stations

1. Set the VOX control fully counterclockwise to disable this feature. (KB-211GM only)

2. Set the Intercom Level control to a comfortable level.

3. Press the Talk button and speak into the microphone while turning the Sidetone control slowly back and forth. There should be a point where the operator’s voice (and any accompanying acoustic feedback) disappears. This is the null point.

4. Readjust the VOX control. (Refer to “12—VOX Control (KB211GM only)” on page 6.)

6—Program Level Control

Adjust the Program Level control to set the program audio level heard in the headset or panel speaker.

Note:

Forcing the trimpots past their stop points will damage them.

7—Speaker ON/OFF Switch

The Speaker ON/OFF Switch turns the front-panel speaker on or off. This switch also controls whether the Tone Alert is heard through the speaker. The speaker volume will automatically dip when the talk function is set, unless the VOX function is enabled.

8—Mic Select Switch (KB-211GM only)

The Mic Select switch selects whether the panel microphone or the headset microphone is active. When the VOX feature is enabled, it is only operational when the panel microphone is active.

9—Channel Switch

This switch selects the intercom channel (A or B) on which the speaker station is active.

10—Headset Connector

The headset connector is located on the front panel. All Clear-Com headsets are recommended for use with the KB-211. 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

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KB-211/KB-211GM Two-Channel Speaker Stations Clear-Com Intercom Systems

• Pin 4—headphone hot. 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 .

11—Panel Mic Connector (KB-211GM only)

Clear-Com recommends the GM-9 (9 in. long) and GM-18 (18 in. long) plug-in panel microphones be used with the KB-211GM. Both are the electret type. The 1/4-in. phone jack on the microphone mates with the Panel Mic receptacle on the KB-211GM’s front panel.

To install a GM-9 or GM-18 microphone:

1. Remove the plastic plug from the jack, if present.

2. If a set screw is present in the microphone-mounting flange,

check and unscrew it to make sure it is clear of the threads in the bushing.

3. Screw the microphone into the bushing and tighten.

4. Optional: Replace the set screw supplied with the gooseneck

microphone on top of the microphone-mounting flange and turn it clockwise to lock the microphone in place.

12—VOX Control (KB-211GM only)

When the panel microphone is selected on the KB-211GM, the VOX control should be adjusted for proper operation. This control is located to the right of the panel microphone connector and is recessed slightly into the front panel. Use a narrow, flat-blade screwdriver such as a "greenie" or "tweaker" for this adjustment. When the adjustment is correctly set, the Talk lamp will be red when speaking into the panel microphone and will be green when hearing audio from the speaker. Turning the control clockwise makes the KB-211GM more sensitive. The VOX feature can be disabled by turning the VOX control fully counterclockwise.

Internal Adjustments and Connections

The controls and connectors inside the KB-211 are shown in the following figure and described by the following text. The controls can be accessed without completely removing the panel from its wall box or V-Box enclosure 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 to make the controls accessible as shown in the lower view of Figure 2 on page 7.

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Clear-Com Intercom Systems KB-211/KB-211GM Two-Channel Speaker Stations

P2 Must be

installed if

no option

View from top

of KB-211

P3 Must be

installed if no option

P1 Call

on Both

P1 Call on

Selected

15 16

1 2 3

FIGURE 2: Internal Adjustments and Connections

13—Call Alert Tone Level Control

This control adjusts the volume of the Call Alert Tone sound. This is normally adjusted when the system is set up and shouldn’t need to be adjusted during normal operation. This feature can be disabled by turning the control fully counterclockwise.

14—Option Switches

Three Option switches are provided. They should be configured when the system is set up and shouldn’t be changed in normal operation.

Note:

The ON position of each switch is toward the circuit board and the OFF position is toward the front panel. The default position of the switches is in the OFF position. The function of each switch is as follows:

Front Panel

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KB-211/KB-211GM Two-Channel Speaker Stations Clear-Com Intercom Systems

1—Single Channel

In some installations, the KB-211 is intended to be used only with one intercom channel. Setting the Single Channel switch to the ON position will connect the KB-211 to the one intercom channel regardless of the position of the front-panel Channel selector.

Note:

In two-channel installations, this switch must be set to the OFF position.

2—Long Line

If a long cable run is unavoidable and approaches 700 ft. or more, set the Long Line option switch to the ON position. The ability to set an effective sidetone depends upon properly setting this switch.

3—Latch Diable

Setting the Latch Disable switch to the ON 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.

15—Call Signal Jumper

In some installations it is important to receive a call signal from either channel, regardless of the setting of the Channel selector. The plug-on jumper P1 makes the Call lamp respond to either the selected channel or to both channels, depending upon its orientation. By default, the jumper is set to the selected channel position. When the TW or 4-Wire Option modules are installed, this jumper is not used. In TW operation, the call signal always originates on channel A. In 4-Wire operation, the call signal is not used.

16—Intercom Line Connection

The KB-211 contains a five-terminal, plug-on connector for intercom line connection. This connector is intended to be unplugged from the circuit board when connecting the intercom line, and then plugged back on when the wiring is completed. 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)

• Pin 2—Channel A Audio

• Pin 3—Channel B Audio

• Pin 4—Power (+30 VDC)

• Pin 5—Ground (Shield).

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+ 22 hidden pages

Clear-Com KB-211, KB-211GM User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual