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

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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.

™

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

™

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

Rev. A

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.)

™

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.

Rev. A

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.

Rev. A

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.

Rev. A

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

Rev. A

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.

Rev. A

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

1413

Rev. A

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).

Rev. A

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

Pin 1

KB-211 Intercom

Connector

FIGURE 3: One-Channel Cable Wiring

Pin 1

KB-211 Intercom

Connector

FIGURE 4: Two-Channel Cable Wiring

17—Program Input

XLR

Connector

1 2

XLR

Connectors

Channel A

Channel B

A three-terminal, plug-on connector provides the program input to the station. Program is fed to the headset and speaker. The level to the speaker or headset is controlled by the Program Level control. The Program Input accepts a balanced or unbalanced line-level audio signal from -20 dBv to +10 dBv. If this input is connected to the stage announce (SA) output of a Main Station it can be used as a paging input. Since the level of this input is independently adjustable from the intercom audio volume, it can be used to override the intercom audio. The pinout of this connector is as follows:

• Pin 1— Ground (Shield)

• Pin 2— + Signal

• Pin 3— - Signal.

Rev. A

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

Program Input

Cable Wiring:

Pin 1

KB-211 Program

Input Connector

FIGURE 5: Program-Input Cable Wiring

XLR

Connector

18—Option Board Jumpers

The three jumper plugs P1, P2, and P3 must be installed when optional modules are not used. When the optional EB-4W or EB-TW modules are used, both P1 and P3 must be removed. In the KB-211GM, P2 is replaced by the VOX module. Save these jumper plugs for possible future use.

Note:

The KB-211 will not operate without either these jumper plugs or the

optional modules ins tal le d.

Rev. A

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

Headset

Mic

Talk

RMK

EQ/ LIM

Mic

Mute

Microprocessor

Latch

Disable

Talk

Power

TW Option

Sidetone

Null

Long Line

Call Alert

Tone Level

Call

Call Send &

Receive

Speaker

Dip

Call

Light

Intercom

Program

Channel

Switch

Volume

Level

Single Chan.

Program

Mute

Speaker

On/Off

Speaker

Headset

Output

Balanced

Program

Input

Common +30 VDC

Ch. B

Ch. A

Ground

16 VA C

4-Wire Option

Rectifier

Power

2-Wire / 4-Wire

Select

FIGURE 6: KB-211 Block Diagram

Ch. B

Ch. A

Ch. B

Ch. A

4-Wire

Input

4-Wire

Output

Rev. A

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

Headset

Mic

Panel

Mic

Mic Select

Talk

RMK

EQ/ LIM

Mic Dip /

Mute

Microprocessor

Talk/ VOX

Red /

Green

Latch

Disable

VOX

Power

TW Option

Sidetone

Null

Long Line

Call Alert

Tone Level Call

Call Send &

Receive

Speaker

Dip

Call

Light

Intercom

Program

Channel

Switch

Volume

Level

Single Chan.

Program

Mute

Speaker

On/Off

Speaker

Headset

Output

Balanced

Program

Input

Common +30 VDC

Ch. B

Ch. A

Ground

16 VA C

4-Wire Option

Rectifier

Troubleshooting

System does not operate. Talk Light does not come on when Talk

•

button is pressed

Scenario 1

The KB-211 doesn’t have an intercom connection. If the EB-4W 4-Wire Option Module is connected, the KB-211 may not be receiving AC power.

Solution: Check connections and cable.

Power

2-Wire / 4-Wire

Select

FIGURE 7: KB-211GM Block Diagram

Ch. B

Ch. A

Ch. B

Ch. A

4-Wire

Input

4-Wire

Output

Rev. A

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

Scenario 2

The KB-211 has an internal failure. Solution: Unit requires servicing.

Speaker does not operate, but the Talk Light comes on when Talk

•

button is pressed

Scenario 1

The Speaker switch is turned off, the volume knob is turned all the way down, or the channel switch is set to the unused channel.

Solution: Adjust controls appropriately.

Scenario 2

The speaker plug or wiring has come loose. Solution 2: Make sure speaker is connected internally.

Scenario 3

Plug P3 is missing on circuit board. Solution: Plug P3 must be installed in J3 jack if the EB-TW or EB-4W options

are not used.

• Hum or buzz in the system.

Scenario 1

Inductive pickup caused by close proximity of this speaker station or connected stations to power lines or transformers.

Solution: Relocate the offending unit or wiring. If the cable run is exceptionally long, consider adding and using the EB-4W 4-Wire Option Module. (Requires an additional 4-wire interface at the opposite end of the “long run.”)

• System feedback (Acoustical). Scenario 1

Intercom Level control at this station or another station is set too high. Solution: Adjust.

Scenario 2

The Sidetone control at this station or another station is not correctly adjusted. Solution: Adjust. Refer to “5—Sidetone Control” on page 4.

Scenario 3

Channel not terminated. Solution: Set the Main Station or Power Supply termination switch for that

channel to the ON position.

Scenario 4

The Channel switch set to an unconnected channel.

Rev. A

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

Solution: If only one intercom line is connected, set Option Switch 1 to the ON or CLOSED position to link both channel switch positions to the same intercom line.

Scenario 5

A headset extension cord was used. Solution: Headset extension cords are not recommended.

• VOX problems (KB-211GM only) Scenario 1

VOX stays tripped (red light on) or the sensitivity is set too high. Solution: Turn VOX sensitivity control in a counter-clockwise direction.

Scenario 2

VOX will not trip with voice (green light on) or the sensitivity is set too low. Solution: Turn VOX sensitivity control in a clockwise direction.

Note:

VOX is intended for close-in operation.

• Excessive crosstalk Scenario 1

High DC resistance has a ground return. Solution: Use heavier cable to add additional conductor(s) to the ground

return. If the cable run is exceptionally long, consider adding and using the EB-4W 4-Wire Option Module.

Scenario 2

The multi-channel cable pairs are not individually shielded. Solution: Replace the cable with individually shielded pairs.

Scenario 3

Headset cables are not wired or shielded properly. Solution: Correct the wiring and use headsets with properly shielded wiring

(see “10—Headset Connector” on page 5).

• Program signal sounds distorted. Scenario 1

The Program Level control is set too high. Solution: Turn the Program Level control counter-clockwise.

Scenario 2

Overload of Program Input circuit. Solution: Reduce the gain of the program signal at the source, such as an

audio mixer.

Rev. A

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

• The call signal does not function. Scenario 1

Excessive DC loading of intercom line. Solution: Remove any audio transformers or other equipment that may be

connected across the intercom line. If equipment other than Clear-Com intercom equipment must be connected to the intercom line, please contact Clear-Com application or service personnel for information or recommendations.

Scenario 2

Far too many terminations on the intercom line. Solution: Check all main stations and power supplies to make sure each

intercom channel is terminated at only one point.

Scenario 3

Plug P1 is missing on circuit board. Solution: Plug P1 must be installed in the J1 jack if the EB-4W or EB-TW

options are not used.

Rev. A

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

Parts Lists

Parts List fo r the KB-211 / KB-211GM Main PCB and Chassis

Capacitors

Value Type Voltage Tol. Part # Designator

220 uF Aluminum 35V 150021 C8 C47 .01 uF Ceramic Disc 1.4KV 20% 150029 C1 22 uF Tantalum 16V 150032 C28

4.7 uF Tantalum 35V 150044 C6

4.7 uF Aluminum NP 50V 150087 C11 .047 uF Mylar 100V 5% 150131 C24 100 uF Aluminum 35V 150136 C17 C41 22 pF Ceramic Disc SMD 50V 5% 151116 C14 47 pF Ceramic Disc SMD 50V 5% 151120 C5 C19 C27 C30 220 pF Ceramic Disc SMD 50V 5% 151128 C26 470 pF Ceramic Disc SMD 50V 5% 151132 C7 C46 .0022 uF Ceramic Disc SMD 50V 10% 151152 C16 .0047 uF Ceramic Disc SMD 50V 10% 151156 C9 C20 C22 .01 uF Ceramic Disc SMD 50V 10% 151160 C13 C37 C38 C40C31

C29 .047 uF Ceramic Disc SMD 50V 10% 151168 C18 C35 .1 uF Ceramic Disc SMD 50V 10% 151172 C10 C25 C32 C33 C34

C36 C45 .22 uF Ceramic Disc SMD 50V 10% 151176 C15 C21 C23 .47 uF Tantalum SMD 35V 10% 151184 C44 C39 1 uF Tantalum SMD 16V 10% 151185 C2 C4 C12 C43 10 uF Tantalum SMD 25V 10% 151192 C42

Resistors

Value Power Type Tol. Part # Designator

10 OHM 1/4 Carbon Film 5% 410002 R15 R53 390 OHM 1/4 Carbon Film 5% 410005 R46

1.3K OHM 1/2 Carbon Film 5% 410075 R44

2.2 OHM 1/10 SMD 5% 411181 R27

39.2 OHM 1/10 SMD 1% 411254 R25 100 OHM 1/10 SMD 1% 411293 R45 R35 221 OHM 1/10 SMD 1% 411326 R13 301 OHM 1/10 SMD 1% 411339 R47 R51 432 OHM 1/10 SMD 1% 411354 R20 825 OHM 1/10 SMD 1% 411381 R22

1.00K OHM 1/10 SMD 1% 411389 R14 R33

1.50K OHM 1/10 SMD 1% 411406 R43

2.00K OHM 1/10 SMD 1% 411418 R18 R21 R42

2.74K OHM 1/10 SMD 1% 411431 R48

6.19K OHM 1/10 SMD 1% 411465 R28

6.81K OHM 1/10 SMD 1% 411469 R17

Rev. A

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

8.25K OHM 1/10 SMD 1% 411477 R52

12.1K OHM 1/10 SMD 1% 411493 R19 R38

15.0K OHM 1/10 SMD 1% 411502 R16

20.0K OHM 1/10 SMD 1% 411514 R24 R30 R31 R34 R39

56.2K OHM 1/10 SMD 1% 411557 R37 R41 100K OHM 1/10 S MD 1% 411581 R6 R12 R49 R50 121K OHM 1/10 S MD 1% 411589 R32 475K OHM 1/10 S MD 1% 411646 R26

1.0M OHM 1/10 S MD 5% 411677 R54 10K OHM X4 SMD DIP Isolated 1% 416016 R8 R9 R10 R11 47K OHM X4 SMD DIP Isolated 1% 416018 R2 R3 100K OHM X4 SMD DIP Isolated 1% 416019 R1 220K OHM X4 SMD DIP Isolated 1% 416020 R7 470K OHM X4 SMD DIP Isolated 1% 416021 R4 Pot 10K TRIMPOT 470058 R36 Pot 5K TRIMPOT 470063 R40 R23 Pot 5K POT 470081 R29

Diodes and Transistors

Device Description Part # Designator

LED BI-COLOR RED/GREEN 3 LEAD 390032 D8 LED LED, YELLOW, ULTRA BRIGHT T1 3/4 390057 D14 IC LM384 POWER 4W OP AMP 14 PIN 480012 IC5 IC 7805L POS 5V REGULATOR TO-92 PKG 480088 IC11 Diode BAV70 DUAL DIODE COM CATHODE SMD 481019 D9 D12 D15 D16 IC 833 DUAL OPAMP... SMD 481023 IC1 IC2 IC8 Transistor 2907A PNP 60V 600MA... SMD 481027 Q2 Diode BAV99 DUAL DIODE... SMD 481033 D1 D2 D3 D4 D5 D6

D11 D13 Transistor MPSA14 DNPN 30V 300MA... SMD 481038 Q5 IC DG444 QUAD CMOS ANALOG SW SMD 481050 IC9 Transistor J175 P-CHANNEL JFET... SMD 481056 Q1 Q3 Diode 5.1V 5% ZENER 1/4W... SMD 481061 D7 D10 Transistor MPSA64 DPNP 30V 500MA SMD 481075 Q4 IC MICROPROCESSOR, KB/MR SERIES 710508 IC10

Miscellaneous

Device Description Part # Designator

Connector 5 POS, SCREW TERM. PLUG-IN 5MM 210085 P4 XLR 4 PIN M FLUSH MOUNT W/SOLDER CUPS 210286 Connector 3 POS, SCREW TERM. PLUG-IN 5MM 210370 P10 Pot SHAFT FOR PIHER POT, GREY 240043 R36 Pot PIHER TRIM POT SHAFT, GREY 240057 R23 R40 Pot KNOB GREY INSERT .45 DIA POINT TO RD 240077 R29 Button ROUND MINIATURE BUTTON, BLACK 240081 S5 Button RECT. MINIATURE BUTTON, BLACK 240082 S4 Lens LENS, YELLOW, ROUND FOR T1 3/4 240099 D14 Speaker 2 1/2 IN. SPKR 16 OHM 3.5W 500139

Rev. A

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

Switch DPDT P.B. MINIATURE W/LONG PLUNGER 510107 S4 S5 Switch DPDT ROCKER PC MOUNT W/BRACKET 510111 S2 Switch DIP SWITCH PIANO 3 POS 510114 S3 Switch SPDT ROCKER, PC MNT W/BR AC K ET 510125 S1 Wire 4 CONNDUCTOR FLAT CABLE 770017 W1

Parts List f or the KB-211GM VOX PCB

Capacitors

Value Type Voltage Tol. Part # Designator

1 uF Aluminum NP 50V 10% 150002 C13 470 pF Ceramic Disc 50V 10% 150014 C10

4.7 uF Tantalum 16V 150030 C8 C12 .1 uF Monolithic 50V 10% 150035 C1 C2 C3 680 pF Ceramic Disc 50V 10% 150061 C5 .022 uF Monolithic 50V 10% 150082 C4 .01 uF Monolithic 50V 20% 150109 C6 C9 220 uF Aluminum 16V 20% 150146 C11 22 uF Tantalum 10V 10% 150158 C14

Resistors

Value Power Type Tol. Part # Designator

4.7K OHM 1/4 Carbon Film 5% 410013 R1 R12 R16 R17 R13

6.8K OHM 1/4 Carbon Film 5% 410036 R2

1.5K OHM 1/4 Carbon Film 5% 410055 R6 1M OHM 1/4 Carbon Film 5% 410058 R4 R8 100K OHM 1/4 Metal Film 1% 410148 R11 R15 20K OHM 1/4 Carbon Film 5% 410151 R14 10K OHM X5 SIP ISOLATED 415003 R3 R10 100K OHM X4 SIP ISOLATED 415014 R9 Pot 50K TRIMPOT 470038 R5

Diodes and Transistors

Device Description Part # Designator

Diode 1N4148 SIGNAL 10MA 75PIV 480000 D3 D4 D5 D6 D7 D8 Transistor PN2222A NPN 30V 480006 Q1 Q2 IC LF353 BIFET OP AMP 480010 IC1 IC2 Diode 1N5231B ZENER 5.1V .5W 5% 480038 D1 D2 Diode 1N4740A ZENER 10V 0.5W 5% 480162 D9

Miscellaneous

Device Description Part # Designator

Panel Mic Jack PHONE JACK 210050 Pot SHAF T FOR PIHER POT BLACK 240069 R5 Switch DPDT TOGGLE, PC MNT W/BRACKET 510126 S1

Rev. A

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

FIGURE 8: Main PCB Component Layout

Rev. A

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

This page is a place holder.

Rev. A

FIGURE 9: KB-211 Schematic

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

Rev. A

This page is a place holder.

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

FIGURE 10: VOX PCB Component Layout

Rev. A

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

Rev. A

FIGURE 11: VOX Schematic

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

Technical Specifications

Headset Microphone Pre-Amp

Input Type: Dynamic Impedance: 1k ohm Input Level: -55 dBV nominal; -10 dBV max. Gain from headset mic to intercom line: +41 dB

Panel Microphone Pre-Amp (KB-211GM only)

Input Type: Electret Input Level: -45 dBV nominal Gain from panel mic to intercom line: +31 dB VOX not tripped/+41 dB VOX tripped

Pre-Amp Response Curve

Frequency Response: 250 Hz to 12 kHz, contoured for intelligibility Limiter Range 20 dB

Headphone Amplifier

Load Impedance Range: 50 ohm to 2k ohm Output Level: at least +20 dBV across 600 ohm Distortion: < 0.5% THD at 1 kHz Frequency Response: 200 Hz to 15 kHz, ±3 dB Gain from intercom line: +37 dB Power Output: 110 dB SPL

Speaker Amplifier

Speaker Type: 2.5 in. round, 16 ohm Power Output: 2 W into 16 ohms Frequency Response: 200 Hz to 15 kHz, ±3 dB Signal-to-Noise: 75 dB Gain from intercom line: +37 dB Distortion: < 0.5% THD at 1 kHz Speaker Level: 98 dB SPL at 3 ft.

Program Amplifier

(Transformerless, balanced differential input) Input Level: -20 dBV Input Impedance: > 100k ohm Frequency Response: 150 Hz to 15 kHz, ± 3 dB

Rev. A

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

Power Requirements

Voltage: 30-VDC standard unit;

16 to 18 VAC with 4-Wire Option Module

Current: 100 mA average

Internal Connectors

Intercom: five-position, plug-on screw terminals Program: three-position, plug-on screw terminals AC Power (4-Wire Option Module): two-position, plug-on screw terminals

Internal Controls

(1) Call Signal jumper; (3) Option switches; (1) Tone Alert Volume control

Front P anel Connectors

Panel Mic: (1) 1/4-in. panel mounting jack (KB-211GM only) Headset: (1) XLR-4M

Front P anel Controls & Indicators

(1) Panel/Headset Mic switch (KB-211GM only); (1) Program Level control; (1) Intercom volume control; (1) Sidetone control; (1) Talk button; (1) Call button; (1) VOX control (KB211GM only); (1) Channel selector; (1) Speaker On-Off switch; (1) Talk LED; (1) Call LED

Environmental

32 to 122 F (0 to 50 C)

Dimensions

8.25 in. W x 4.5 in. H x 1.75 in. D (210 mm x 114 mm x 44 mm)

Weight

1.22 lbs. (0.56 kg)

Notice About Specifications

While Clear-Com makes every attempt to maintain the accuracy of the information contained in its product manuals, that information is subject to change without notice. Performance specifications included in this manual are design-center specifications and are included for customer guidance and to facilitate system installation. Actual operating performance may vary.

Rev. A

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

Clear-Com Limited Warranty

The Clear-Com warranty does not cover any defect, malfunction, or failure caused beyond the control of Clear-Com, including unreasonable or negligent operation, abuse, accident, failure to follow instructions in the manual, defective or improper associated equipment, attempts at modification and repair not authorized by Clear-Com, and shipping damage. Products with their serial numbers removed or defaced are not covered by this warranty.

This warranty is the sole and exclusive express warranty given with respect to Clear-Com products. It is the responsibility of the user to determine before purchase that this product is suitable for the user's intended purpose.

Any and all implied warranties, including the implied warranty of merchantability are limited to the duration of this express limited warranty. Neither Clear-Com nor the dealer who sells Clear-Com products is liable for incidental or consequential damages of any kind.

For your own records fill in the information below: Model No Serial No. Date Purchased Purchased from (dealer) Address City State ZIP

Factory Service

All equipment returned for repair must be accompanied by documentation stating the return address, telephone number, date of purchase, and a description of the problem.

Note:

Do not return any equipment to the factory without first obtaining a

Return Authorization Number. Send equipment to be repaired to:

Customer Service Department Clear-Com Intercom Systems 4065 Hollis Street Emeryville, CA 94608-3505 Telephone: (510) 496-6666 Fax: (510) 496-6601

Warranty Repairs

If in warranty, no charge will be made for the repairs. Equipment being returned for warranty repair must be sent prepaid and will be returned prepaid.

Rev. A

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

Non-Warranty Repair

Equipment that is not under warranty must be sent prepaid to Clear-Com. If requested, an estimate of repair costs will be issued prior to service. Once repair is approved and repair of equipment is completed, the equipment will be shipped freight collect from the factory.

Rev. A

4065 Hollis Street, Emeryville, CA 94608

(510) 496-6666 Fax (510) 496-6601 Manual Part Number 810253 Rev. A

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

Specifications and Main Features

Frequently Asked Questions

User Manual