Clear-Com MS-232 User Manual

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Clear-Com MS-232 Two-Channel Main Station

INTRODUCTION

Congratulations on choosing this Clear-Com product. 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.

The MS-232 Two-Channel Main Station is a powerful, yet user friendly unit that can serve as the heart of a Clear-Com system. We recommend that you read through this manual completely to better understand the functions of the MS-232. If you encounter a situation or have a question that this manual does not address, contact your dealer or call Clear-Com directly at the factory. Our applications support and service people are standing by to assist you. Thank you for selecting Clear-Com for your communications needs.

Description

The Clear-Com PL-Pro trucks, production studio consoles, theatre, live performances, and small TV facilities. It features excellent speech intelligibility in all noise levels and can be tailored to your needs through its programmable options.

Selectable two-channel talking and/or listening allows the operator to communicate on either of the intercom channels separately or on both at once. The illuminated dual-action talk buttons are electronic momentary or latching. Monitoring can be done through the headset, the integral speaker, or both at once. The MS-232 offers both visual and audible call signaling to attract the attention of operators who have removed their headsets or turned off their speakers. The Remote Mic Kill (RMK) feature provides the ability to turn off all open mics on Series 500 beltpacks.

MS-232 is a two-channel, one rack space main station ideal for ENG and EFP

The MS-232 can control a paging speaker for studio announcements. A front panel button activates this function and an associated relay. A balanced program input allows monitoring external audio using the headset or speaker.

This main station accepts dynamic headsets, such as the Clear-Com PL-Pro

Series. Individual sidetone controls for each intercom channel allow the operator to vary the level of his/her own voice as heard in the headset and speaker. It also accepts Clear-Com gooseneck panel microphones.

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 when the announce button, talk buttons or program interrupt are activated. This feature helps minimize feedback.

The MS-232 also incorporates a dual-channel program interrupt system (IFB). When activated, one or more stations can interrupt the program audio to another intercom station or a talent wearing ClearCom's wired or wireless talent receivers. Clear-Com's stand-alone IFB system can also be connected to this station.

The MS-232 provides 30-Volt DC power to operate Clear-Com beltpacks and remote stations. This power is distributed between the two channels, and will support up to 60 headset stations or 20 speaker stations. Clear-Com's new fail-safe design automatically shuts down the power to a channel when a short circuit or electronic overload is sensed on that channel. The other channel will continue to operate normally. Once the fault condition is removed, the MS-232's fail-safe circuit will restore power, even under full load conditions. LED indicators signal a short or overload on either channel.

The MS-232 will operate from any AC line voltage between 90 and 240 Volts AC at 50 or 60 Hz. The MS-232 installs in a standard 19" equipment rack, using only one rack space. The unitized aluminum chassis and extra-thick front panel with integral rack ears result in reduced size and a lighter weight package that maintains legendary Clear-Com ruggedness. Three 3-pin XLR connectors are provided for connection to each intercom channel.

The MS-232 is compatible with all Clear-Com Party-Line intercoms.

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Clear-Com MS-232 Two-Channel Main Station

QUICK START

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

proper AC Mains cable.

2 Install the MS-232. (For additional information, refer to the Clear-Com PL-Pro

tion Manual.) 3 Connect the AC to the Mains circuit. Connect the intercom lines. 4 Set the two termination switches on the rear panel to ON. 5 Set the Option switches to the default (up) position. 6 Switch POWER ON. The green power light should be ON and the two red short lights should be

OFF. 7 Set Listen Levels and Sidetones. (Refer to the Listen Level and Sidetone setting topics in the

Operation section of this manual.) 8 The intercom system should now be operating properly.

Read the rest of this manual for further information.

System Installa-

OPERATION

Normal operation of the MS-232 Main Station only requires access to 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 controls for each channel to the desired level and press the Talk buttons when talking. If a headset is used, set the Sidetone control for each channel for the desired amount of sidetone in the earphone. If the Panel Mic and Speaker are being used, set the sidetone controls for minimum feed-through to the speaker to prevent feedback.

Front Panel

The controls, indicators, and connectors found on the MS-232 front panel are shown in the following figure and are described by the following text. The numbers in the left column refer to Figure 1.

Figure 1 - Front Panel

1 Talk Buttons: Each channel has an illuminated Talk button for activating the microphone

feed to that channel. Each Talk button has a dual action (momentary or latching) depending upon how the button is pressed. If desired, the latching function for each channel can be defeated using the option switches on the rear panel. The following describes the various functions of these multi-purpose buttons.

MOMENTARY: Press and hold the Talk button while you are speaking. Release it when you are finished.

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Clear-Com MS-232 Two-Channel Main Station

LATCHING: Press the button quickly to latch the Talk function. Press the button again to turn off the Talk function.

TALK INDICATION: The Talk button will illuminate dimly whenever the Talk function is activated.

CALL INDICATION: The Talk button will flash brightly when a Call signal is received on that channel.

CALL ON TALK: Each channel can optionally be set to send a Call signal whenever you press the Talk button. This function is used to activate program interrupts or any other Call-activated function available on other stations. Option switches on the rear panel will enable this function.

SPEAKER MUTE: If the front panel speaker is turned on, pressing either Talk button will reduce the speaker output level to avoid feedback.

The Talk buttons can be labeled to indicate their function. To label the Talk buttons, use the following procedure:

1 Pull the Talk button straight off. 2 Insert a small flat blade screwdriver into the slot between the cap and the body of the but-

ton and gently twist. This will remove the cap.

3 Remove the square white diffuser from the cap. 4 Insert a 1/2" X 1/2" square of thin paper with the needed description into the cap. Follow it

up with the square white diffuser and press the cap onto the body of the button. Press the button back into the front panel.

2 Call Buttons: Each channel has its own Call button. Pressing a Call button will send a Call

signal on that channel. All the call lights on that channel will flash. Call signals can also be sent while talking if required. The Talk button will flash while the Call button is pressed, indicating the presence of a Call signal on the line.

3 Tone Alert: An audible tone alert can be enabled to sound when a Call signal is received on

either channel. This can be useful when the operator's attention has been drawn away from the MS-232 indicator panel. Press the Tone Alert button to alternately enable or disable the audible tone alert. The green indicator next to this button is lit when the audible Tone Alert is enabled. When enabled, the Tone Alert will sound when a Call button on a beltpack or station is pressed. The Tone Alert will not sound if a Call signal is originated at the MS-232 station. The level can be adjusted by the control on the rear panel (4).

5 Listen Level Controls: Each channel has a separate Listen level control. Turn these con-

trols to set the listen level you need on each channel. Turn the control completely counterclockwise to silence a channel.

6 Sidetone Controls: Each channel has a Sidetone Null control. Sidetone is the level of your

own voice that you hear while talking on the intercom. Setting a comfortable level of sidetone will ensure that the intercom line sounds alive and also helps you modulate your voice relative to other voices on the line.

Typically, different Sidetone Null settings are needed depending upon whether you are using the gooseneck panel microphone along with the speaker or not. Use one the following procedures to correctly set the Sidetone level controls.

Sidetone Adjustment Procedure for Gooseneck Microphone with Speaker turned on:

1 Turn off the Party Line Link (A+B) switch. 2 Turn the Level control for Channel B all the way down. Set the Level control for Channel

A to a comfortable level.

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Clear-Com MS-232 Two-Channel Main Station

3 Press the Channel A Talk button and speak into the microphone while turning the Sidetone

Null control for Channel A slowly back and forth. There should be a point where your voice (and any accompanying acoustic feedback) disappears. This is the null point.

4 Repeat this procedure for Channel B by turning the Channel A Level control down and ad-

justing the Channel B controls.

Sidetone Adjustment Procedure for Headset:

1 Turn off the Party Line Link (A+B) switch. 2 Turn the Level control for Channel B all the way down. Set the Level control for Channel

A to a comfortable level by having someone talk to you from another station.

3 Press the Channel A Talk button and speak into the microphone while turning the Sidetone

Null control for Channel A slowly back and forth until you hear your voice at a comfortable level in the headset.

4 Repeat this procedure for Channel B by turning the Channel A Level control down and ad-

justing the Channel B controls.

7 Program ON-OFF-INTRPT Switches: The Program ON-OFF-INTRPT switches are used to

manually or automatically control program audio feed into the intercom lines. The settings are as follows:

ON: The channel will receive program audio when the switch is set to ON. The audio level for each channel can be adjusted with the Program Level trimpots as described in the following paragraph.

OFF: The channel will not receive program audio when the switch is set to OFF. INTRPT: Pressing the Talk button will interrupt the program when this switch is set to

INTRPT.

8 Program Level Controls: Adjust the Program Level controls to set the program audio level

heard on the intercom. There are three Program Level controls. The Program Level knob to the left of the Speaker On-Off switch adjusts the level of program heard in the headset or panel speaker.

The program levels heard on each intercom channel line can be individually adjusted, but this is intended to be a one time setting made when the MS-232 is set up. This is done using the screwdriver level adjustment trimpots adjacent to the Program ON-OFF-INTRPT switches on Channels A and B. Set the Sidetone Null controls and the Program Level knob fully counterclockwise when adjusting the individual channel Program Level trimpots. After the Program Level trimpots are properly adjusted, use the procedure listed in the Sidetone Controls section on this page to set the sidetone level.

: Do not force the trimpots past their stop points. This will damage them.

NOTE

9 Party Line Link (A+B) Switch: The Party Line Link (A+B) switch is used to combine both in-

tercom channels into one, for example, for rehearsals. When this switch is set to the ON position, the green lamp directly above the switch will light, and all of the stations on the B channel will be moved onto the A intercom line. This will allow communication between everyone on both channels at once.

In this mode, the Channel B controls and switches will be inactive. Since the wiring for the B channel has been now added to the A channel, the Sidetone Null control for Channel A may require some readjustment.

10 Speaker ON/OFF Switch: The Speaker ON/OFF Switch turns the front panel speaker on or

off. This switch does not affect whether the Tone Alert is heard through the speaker. The speaker volume will automatically dip whenever the panel or headset microphone is on.

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Clear-Com MS-232 Two-Channel Main Station

11 Remote Mic Kill Switch: The Remote Mic Kill (RMK) switch will turn off the Talk function of

every beltpack on channels A and B. If the Talk functions of a large number of beltpacks have inadvertently been left activated, incidental noise and talking can make it difficult or impossible to communicate on the party line intercom. The Remote Mic Kill switch can be pressed to quiet the line in this situation. Those needing to communicate can then set their Talk functions ON as needed.

: The Remote Mic Kill switch can only function if the MS-232 Main Station is

NOTE powering all of the stations in the system. The switch momentarily interrupts power to the other beltpacks and stations in the system. If there are other power supplies or main stations in the system, then the Remote Mic Kill switch cannot interrupt power and therefore cannot work.

12 Mic Select Switch: Set the Mic Select switch to select whether the panel microphone or the

headset microphone is active.

13 Panel Mic Gain: This control is located on the underside of the MS-232 chassis. It may be

used to increase or decrease the sensitivity of the panel microphone. It has no effect on the sensitivity of the headset microphone. Use a small screwdriver to turn the control clockwise to increase sensitivity or counterclockwise to decrease sensitivity.

14 Announce: Press the Announce button to make stage or PA system announcements. It di-

rects the audio from the selected headset or panel microphone to the Annc Out rear panel connector and activates the Announce Relay. Simultaneously, if the program audio feed to the Announce Output is enabled, it is interrupted by the announcement. Program audio feed to the Announce Output is selected by setting jumper JP2 on the Main board to the ON position. Optionally, pressing the Announce button can also disconnect the selected headset or panel microphone audio from the intercom line(s). This option is controlled by the Interrupt Announce option switch.

19 Headset Connector: The headset connector is located on the front panel. All Clear-Com

headsets are recommended for use with the MS-232. The following is a description of the characteristics of a suitable headset:

Mic Type --- Dynamic; 150 to 250 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 --- Mic common Pin 2 --- Mic hot Pin 3 --- Headphone common Pin 4 --- 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.

18 Panel Mic Connector: Clear-Com recommends the GM-9 and GM-18 plug-in panel micro-

phones for use with the MS-232. The GM-9 is 9 inches long and the GM-18 is 18 inches long. The microphone is an electret type. The 1/4 inch phone jack on the microphone mates with the Panel Mic receptacle on the front panel of the MS-232.

To install a GM-9 or GM-18 microphone, use the following steps: 1 Check and unscrew the set screw in the mic mounting flange to make sure it is clear of the

threads in the bushing.

2 Screw the microphone into the bushing hand tight. 3 Turn the set screw on top of the mic mounting flange clockwise to lock the microphone in

place.

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Clear-Com MS-232 Two-Channel Main Station

26 Party Line Link (A+B) LED: This green LED is lit when the Party Line Link (A+B) switch is

ON, to provide a visual indication that party line Channels A and B are linked together.

27 Tone Alert LED: This green LED lights when the Tone Alert function is enabled. Tone Alert

is an audible indication that a Call signal is active. Toggle the Tone Alert function ON or OFF using the Tone Alert button.

28 Power LED: This green LED lights when the MS-232 is receiving AC power and the power

switch on the rear panel is turned on.

29 Short LEDs: There is one red LED for Channel A and one for Channel B. These LEDs light

when the MS-232 senses a short or overload on the associated channel. When the fault is removed, the MS-232 will automatically reset and the LED will go out.

Rear Panel

The controls and connectors found on the MS-232 rear panel are shown in the following figure and briefly described by the following text. The numbers in the left column refer to Figure 2.

Figure 2 - Rear Panel

4 Tone Alert Volume Control: This control adjusts the volume of the Tone Alert sound. This

is normally adjusted when the system is set up and there should be no need to adjust it in normal operation.

15 Option Switches: Eight Option switches are provided on the rear panel. They should be

configured when the system is set up, but are not changed in normal operation. The default position of the switches is in the OFF (up) position. The function of each switch is as follows:

1 MOM TALK A: Setting the Momentary Talk A switch to the ON position will disable the

latching function of the Channel A Talk button. In this mode, the Talk button must always be held in continuously while the operator is talking on Channel A.

2 MOM TALK B: Setting the Momentary Talk B switch to the ON position will disable the

latching function of the Channel B Talk button. In this mode, the Talk button must always be held in continuously while the operator is talking on Channel B.

3 CALL ON TALK A: If the Call On Talk A switch is set to the ON position, a Call signal will

be placed on Channel A whenever the Talk function is activated. This can be used to activate any Call activated functions available on other stations.

4 CALL ON TALK B: If the Call On Talk B switch is set to the ON position, a Call signal will

be placed on Channel B whenever the Talk function is activated. This can be used to activate any Call activated functions available on other stations.

5 INTRPT ANNC: If the Interrupt Announce switch is set to the ON position, pressing the

Announce button will disconnect the microphone from the intercom line(s). This will allow announcements to be made without being heard over the intercom channels.

6 INTRPT EXT IFB: When the Hot Mic output is connected to Clear-Com's IFB System and

the Interrupt External IFB switch is set to the ON position, pressing a key on the IFB

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Clear-Com MS-232 Two-Channel Main Station

System will disconnect the selected headset or panel microphone from the intercom line(s). This allows the MS-232 microphone to be used to cue talent without affecting intercom line communication.

7 LONG LINE A: If a long cable run on Channel A is unavoidable and approaches 1,000

feet or more, set the Long Line A option switch to the ON position. The ability to set a sidetone null on Channel A depends upon properly setting this switch.

8 LONG LINE B: If a long cable run on Channel B is unavoidable and approaches 1,000

feet or more, set the Long Line B option switch to the ON position. The ability to set a sidetone null on Channel B depends upon properly setting this switch.

16 Termination Switches: These switches provide switchable terminations for channels A and

B. In most systems, both terminations on the MS-232 should be in the ON position (default setting). The fundamental concept of Clear-Com Party-Line intercom is that all channels are terminated in one location, preferably at a main station or power supply. The termination switches on the MS-232 rear panel should be set to the OFF position only if the channel is terminated by another main station or power supply in the system. If there are no other main

stations, power supplies, or other terminations on the line, set the rear panel switches labeled TERM A and TERM B to the ON position.

: All intercom lines must be terminated only once, whether they are used or not.

NOTE Never "double-terminate" a line.

17 Power Switch: The power switch can be used to turn AC power to the MS-232 on and off.

When in the ON position, the Power LED on the front panel will be illuminated.

20 AC Power Connection: An IEC type 320 connector is provided to interface to the appropri-

ate AC power cord to be used. Voltages from 90 to 240 VAC at 50 or 60 Hz are acceptable. The MS-232 will automatically adjust for the power applied, so there are no manual switches to set power line voltage or frequency.

21 Intercom Line Connection: The MS-232 contains three 3-pin male XLR connectors for each

intercom line. These connectors are wired in parallel. Any single-channel station or channel of a multi-channel station connected on a line plugged into Channel A of the MS-232 will be "party-lined" with all the other stations on that channel. In a multi-channel system, the goal is to assign specific people to the correct group, i.e. the other people they need to be in contact with the most. This is particularly important when the party line users are on a single-channel beltpack or station; less so if they are on multi-channel stations. The pinout of the intercom connectors is as follows:

Pin 1 --- Ground (Shield) Pin 2 --- Power (+30 VDC) Pin 3 --- Audio

22 Program Input: A 3-pin XLR female connector provides the main program input to the sta-

tion. Program can be fed to the headphone or speaker as well as to either or both of the intercom channels. The level to the speaker or headphone is controlled by the Program Level control. The Program ON-OFF-INTRPT switches control whether each intercom channel receives program audio. The program audio levels on each intercom channel can be adjusted using the individual Program Level trimpots. The Program Input accepts a balanced or unbalanced line-level audio signal from -20 dBv to +10 dBv. An option is to feed program audio to the Announce Output. This is selected by setting jumper JP2 on the Main board to the ON position. When this option is selected, a 0 dBv signal on the Program Input will produce a 0dBv signal on the Announce Output.

The pinout of the Program Input connector is as follows:

Pin 1 --- Ground (Shield) Pin 2 --- + Signal Pin 3 --- - Signal

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Clear-Com MS-232 Two-Channel Main Station

23 Announce Out: A 3-pin XLR male connector is provided as a feed to a studio PA amplifier.

Pressing the Announce button on the front panel places the audio from the selected headset or panel microphone on the Annc Out rear panel connector. Optionally, pressing the Announce button can also disconnect the selected headset or panel microphone from the intercom line(s). This option is controlled by the Interrupt Announce option switch. Simultaneously, if the program audio feed to the Announce Output is enabled, it is interrupted by the announcement. Program audio feed to the Announce Output is selected by setting jumper JP2 on the Main board to the ON position. The pinout of the Announce Out connector is as follows:

Pin 1 --- Ground (Shield) Pin 2 --- - Signal Pin 3 --- + Signal

The audio output is balanced and transformer isolated. It has a 600 ohm impedance and a nominal output level of 0 dBV. A shielded twisted pair cable should be used in the cable wired to this connector.

24 Relay Out: A dry set of relay contacts is provided through a 1/4 inch jack to activate external

switching as needed when the Announce button is pressed. These contacts can be used to control an external device such as a PA amplifier to another room. The contacts are rated for

2.0 Amps at 24 VDC. The contacts are wired as follows: Ring --- Normally Closed Contact

Tip --- Common Contact Sleeve --- Normally Open Contact

25 Hot Mic Out / IFB System: This connection is a 1/4 inch phone jack. It provides a 0 dBV

output signal from the selected headset or panel microphone. This output is intended interface with the External Line In jack on Clear-Com's IFB System. The jack is wired as follows:

Ring --- Ext. IFB Control Signal Input Tip --- Hot Mic Audio Output Sleeve --- Ground (Shield)

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Clear-Com MS-232 Two-Channel Main Station

MS-232 Block Diagram

The following is a block diagram of the MS-232:

Figure 3 - MS-232 Block Diagram

Headset

Mic

Panel Mic

Tone Alert

Balanced

Program

Input

Interrupt

Annc. IFB

EQ/ LIM

Green

Alert

Volume

Option Switches

Call on

Talk

Momentary

A B A B A B

Control Logic

Program Feed on

Announce

Option

Long Line

Headset

Select

Program

Level A

Program

Level

Program

Level B

Announce

Power On/Off

Talk

Int. On/Off

Talk

Int. On/Off

Switching Power

Supply

Hot Mic

Out

Call

Light

Call

Send

Call

Light

Call

Send

Sidetone

Announce

Output

Remote

Mic Kill

Channel A

Listen

Channel B

Listen

Announce

Relay

Ch. A Ch. B

Red

Short

Short Circuit Protection

Term.

Sw.

Speaker Dip/Mute

Speaker

On/Off

A+B Link

Term.

Sw.

Station Power

Green

Headset

Output

Speaker

Ch. A

Output

Ch. B

Output

TROUBLESHOOTING

Problem: System does not operate. Green POWER LED is not illuminated and no

SHORT LED's are illuminated

Cause 1: No AC power to the MS-232. Solution 1: Make sure the power switch on the rear panel is turned ON. Check the AC connec-

tion and cable. Plug into a dependable AC source.

Cause 2: The MS-232 has an internal power supply failure. Solution 2: Unit requires servicing.

Problem: System does not operate when power switch is turned on. Green POWER

LED and red SHORT LED wink

Cause: Direct short on the intercom channel indicated by the red Short LED. Solution: Remove the intercom line cables one at a time from that channel until the faulty

line is located. Once the short is removed, the MS-232 will reset automatically and power will come back up within several seconds. Check for shorts between pins 1 and 2 or improper cable wiring.

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Clear-Com MS-232 Two-Channel Main Station

Problem: Red SHORT LED illuminated

Cause 1: Short or overload on that channel due to a shorted or miswired cable. Solution 1: Remove the intercom line cables one at a time from the system until the faulty line

is located. (The red Short LED will then turn off.) Check for shorts between pins 1 and 2 or improper cable wiring. Once the short is removed, the MS-232 will reset automatically and power will come back up within several seconds.

Cause 2: Defective remote station. Solution 2: Check the remote station and replace if necessary.

Problem: Both red SHORT LEDs are illuminated Cause 1: System is overloaded. Solution 1: Remove the intercom line cables one at a time from the system to help determine

where the excess current requirements lie. Re-evaluate the system current needs.

Cause 2: Short in multipair cable. Solution 2: Remove the intercom line cables one at a time from system until the faulty line is

located. Check for shorts between pins 1 and 2 or improper cable wiring.

Problem: Hum or buzz in system

Cause 1: Inductive pickup caused by close proximity of this main station or connected re-

mote stations to power lines or transformers.

Solution 1: Relocate the offending unit. Cause 2: 10 Ohm chassis ground resistor is open.

Solution 2: Check the DC resistance for 10 Ohms between the chassis and pin 1 of any inter-

com connector.

If this condition occurs, it is because the system ground came into contact with something that was "HOT" with respect to the power supply earth ground. Carefully check the system ground and AC distribution in the area.

WARNING

: THIS IS A POTENTIALLY DANGEROUS SITUATION. A SHOCK HAZARD

MAY EXIST BETWEEN A REMOTE STATION HEADSET AND GROUND.

Problem: System feedback (Acoustical)

Cause 1: Listen Level control at this station or a remote station is set too high. Solution 1: Adjust.

Cause 2: Sidetone Null control at this station or a remote station is not adjusted correctly. Solution 2: Adjust. Refer to the procedure in the Front Panel section of this manual.

Cause 3: Channel unterminated. Solution 3: Set the MS-232 termination switch for that channel to the ON position.

Cause 4: A headset extension cord was used. Solution 4: Headset extension cords are not recommended.

Problem: Excessive crosstalk

Cause 1: High DC resistance in ground return. Solution 1: Use heavier cable; add additional conductor(s) to ground return.

Cause 2: MULTI-CHANNEL cable pairs are not individually shielded. Solution 2: Replace cable with individually shield pairs.

Cause 3: Headset cables are not wired properly or shielded properly. Solution 3: Correct wiring. Use headsets with properly shielded wiring.

Problem: Program signal sounds distorted. Cause: Overload of Program Input circuit. Solution: Reduce Program Input level or reduce the gain of the program signal at the source,

such as an audio mixer.

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Clear-Com MS-232 Two-Channel Main Station

Problem: Call signals do not function.

Cause 1: Excessive DC loading of intercom line. Solution 1: Remove any audio transformers or other equipment which 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 advice.

Cause 2: Far too many terminations on the intercom line. Solution 2: Check all Main Stations and Power Supplies to make sure each intercom channel

is terminated at only one point.

PARTS LISTS

Front Panel PCB Layout

Parts List for MS-232 Front Panel PCB and Chassis Capacitors

Value Type Volts Tol. Part # Designator

.1 uF Monolithic 50V 10% 150035 C301

Resistors Value Power Type Tol. Part # Designator

4.7K OHM 1/4 Carbon Film 5% 410013 R300 10K OHM 1/4 Carbon Film 5% 410016 R312 R313 36K OHM 1/4 Carbon Film 5% 410163 R303

Diodes and Transistors Device Description Part # Designator

LED RED, ROUND, FLAT TOP LED 390044 LED301 LED303 LED GREEN, ROUND, FLAT TOP LED 390045 LED302 LED300 LED304 Diode 1N4148 SIGNAL 10MA 75PIV 480000 D301

Miscellaneous Device Description Part # Designator

Button FLAT TOP GREY KEYCAP 240064 S300 S301 Button ROUND MINIATURE 240081 S304 S305 S311 Button RECT. MINIATURE 240082 S306 S307 Knob GREY INSERT 6X4.5MM HOLE .45DIA 240089 R306 R307 R308 Assembly 65 W 30 V SWITCHING POWER SUP. 400013 Relay SPDT 24V MINI PC RELAY 450004 K301 Pot 50K TRIM POT H MTG. 470018 R309 R310 Pot 5K TRIMPOT H MTG. 470063 R304 R305 Pot 50K 25MM FLATTED SHAFT 470070 R306 R307 R308 Switch DPDT SLIDE SWITCH 510090 S302 S303 S308 Switch PUSH BUTTON SWITCH W/32V LAMP 510104 S300 S301

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Clear-Com MS-232 Two-Channel Main Station

Miscellaneous (Continued) Device Description Part # Designator

Switch DPDT MINIATURE 510107 S304 S305 S306 S307 C311 Switch POWER SWITCH, SPST SNAP-IN 510119 Switch SPDT ON-OFF-ON 510120 S309 S310 Cord IEC POWER CORD 610022 Cable POWER ENTRY HARNESS 740063 Cable DC POWER CABLE, MS-232 & PS-464 740064 Cable ASSY, CABLE, HEADSET, MS-232 740065 Cable ASSY, CABLE, PLUG-IN MIC, MS-232 740066 Speaker SPEAKER ASSY, MS-232 740067 Cable RIBBON, 3 CONN 770021 J16 J18 Cable RIBBON, 16-PIN 770023

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Clear-Com MS-232 Two-Channel Main Station

Parts List for MS-232 Audio / Logic PCBs Capacitors

Value Type Volts Tol. Part # Designator

1 uF Aluminum NP 50V 10% 150002 C1 C62 C68 C69 C79 C83 C84 C85

C109 C114 22 uF Aluminum 16V 150010 C14 C136 C137 .01 uF Ceramic Disc 30V 20% 150012 C4 C5 C6 C21 C23 C46 C47 C95

C96 C107 C108 470 pF Ceramic Disc 50V 10% 150014 C57 C74 C75 C78 C92 C93 C123 39 pF Ceramic Disc 50V 5% 150026 C51 C49 .01 uF Ceramic Disc 1.4KV 20% 150029 C81 .22 uF Monolithic 50V 10% 150034 C38 C48 C80 C89 .1 uF Monolithic 50V 10% 150035 C2 C3 C27 C28 C29 C30 C31 C32

C41 C53 C55 C59 C60 C76 C77 C82

C97 C101 C102 C103 C106 C116

C124 C125 C126 C127 C128 C129

C130 C131 C132 C133 C134 C135 220 uF Aluminum 50V 150037 C122 47 pF Ceramic Disc 50V 10% 150041 C54 C58 C72 C110 .0022 uF Mylar 100V 5% 150045 C115 200 pF Ceramic Disc 100V 5% 150063 C87 C86 10 uF Aluminum 50V 150064 C35 C119 C120

2.2 uF Aluminum NP 50V 150065 C19 C20 C99 47 uF Aluminum 35V 150081 C56 C73

4.7 uF Aluminum NP 50V 150087 C50 C52 1000 uF Aluminum 35V 150092 C17 22 pF Ceramic Disc 50V 10% 150098 C117 820 pF Monolithic 50V 5% 150101 C112 C118 .0047 uF Mylar 50V 5% 150114 C67 C70 C71 C94 C10O C104 1 uF Tantalum 35V 20% 150116 C63 .01 uF Metal Film 100V 2% 150122 C98 .047 uF Mylar 100V 5% 150131 C22 C39 C61 C64 C65 C66 C88

C105 100 uF Aluminum 35V 150136 C7 C8 C90 C91 C121 .47 uF Aluminum NP 50V 150151 C24 C25

Resistors

Value Power Type Tol. Part # Designator

10 OHM 1/4 Carbon Film 5% 410002 R127 22 OHM 1/4 Carbon Film 5% 410004 R107 R116 R199 220 OHM 1/4 Carbon Film 5% 410007 R75 R146 R159 R194 R196 39 OHM 1/4 Carbon Film 5% 410008 R72 R74 R137 R138 1K OHM 1/4 Carbon Film 5% 410010 R6 R7 R10 R11 R22 R174 R198

4.7K OHM 1/4 Carbon Film 5% 410013 R18 R32 R35 R58 R125 R128 R186

R195 R197 2K OHM 1/4 Carbon Film 5% 410014 R39 R46 R98 R130 R180 R227

3.3K OHM 1/4 Carbon Film 5% 410015 R19 R148 R153 R164 10K OHM 1/4 Carbon Film 5% 410016 R24 R93 R94 R102 R118 R147 R151

R152 R158 R170 R177 15K OHM 1/4 Carbon Film 5% 410017 R144 33K OHM 1/4 Carbon Film 5% 410020 R2 R3 R4 R168 R169 R188 100K OHM 1/4 Carbon Film 5% 410024 R47 R48 R49 R50 R51 R52 R97

R103 R108 R122 R124 R132 R226 68K OHM 1/4 Carbon Film 5% 410025 R68 R69 R87 220K OHM 1/4 Carbon Film 5% 410028 R57 R59 R84 470K OHM 1/4 Carbon Film 5% 410030 R41 R44 R45 R91 R109 R133 R134

R149 R154 R155 R156

6.8K OHM 1/4 Carbon Film 5% 410036 R145 R165 R171 R217 R218 680 OHM 1/4 Carbon Film 5% 410044 R150 5 OHM 5 Wirewound 10% 410051 R5

Page 15

Clear-Com MS-232 Two-Channel Main Station

Resistors (Continued)

Value Power Type Tol. Part # Designator

120 OHM 1/4 Carbon Film 5% 410053 R105 R106 1M OHM 1/4 Carbon Film 5% 410058 R9 R16 R83 R85 R163

2.2K OHM 1/2 Carbon Film 5% 410068 R20 R21 820K OHM 1/4 Carbon Film 5% 410070 R23 .39 OHM 2 Carbon Film 5% 410073 R28 120K OHM 1/4 Carbon Film 5% 410079 R135 R136 43K OHM 1/4 Carbon Film 5% 410084 R25

20.0K OHM 1/4 Carbon Film 1% 410086 R12 R13 R117 R120 R121 R129

R139 R140 R182 R187 R201 R202

R205 R206 R207 R208 R212 R213

R215 R216 820 OHM 1/4 Carbon Film 5% 410096 R123

9.1K OHM 1/4 Carbon Film 5% 410100 R14 R15 R17 R119 R141 R142 R224

47.5K OHM 1/8 Metal Film 1% 410105 R99 R100 R126 R166 R167 R209

R210 R211 R214 430 OHM 1/4 Carbon Film 5% 410106 R1 R115 R131 R160

2.2 OHM 1/4 Carbon Film 5% 410113 R191 R173 R225

6.2K OHM 1/4 Carbon Film 5% 410137 R96 R101

60.4K OHM 1/4 Metal Film 1% 410164 R71 R73

1.5 OHM 1/4 Carbon Film 5% 410208 R225 100K OHM X 9 SIP BUSSED 415002 RP1 RP2 220K OHM X 4 SIP ISOLATED 415007 RP3

Diodes and Transistors

Device Description Part # Designator

Diode 1N4148 SIGNAL 10MA 75PIV 480000 D1 D3 D7 D8 D9 D11 D16 D19 D20

D21 D22 D26 D27 D33 D34 D43 D45

D46 D48 Transistor MPS-A13 NPN 30V DARL 480004 Q11 Q14 Q15 Q16 Q17 Q18 Q19 Diode 1N5401 RECT 3A 100PIV 480005 D5 D6 Transistor MPS-A63 PNP 30V DARL 480008 Q12 Q13 Diode 1N957B ZENER 6.8V .4W 5% 480026 D12 D14 Transistor MPS-A55 PNP 60V 480050 Q2 Q3 Q4 Q5 Q6 Transistor MPS-A05 NPN 60V 480052 Q8 Q23 Diode 1N4003 RECT 1A 200PIV 480058 D2 D4 D10 D13 D15 D47 Transistor 2N5639 JFET NCHAN 8V VGS 480069 Q25 Transistor J174 JFET PCHAN 8V VGS 480079 Q21 Q22 Transistor TIP41 NPN 40V 6A TO-220 POWER 480099 Q24 Transistor TIP35C NPN 100V 25A TO-218 480228 Q9 Q10

Integrated Circuits

Device Description Part # Designator

IC LM384 POWER 4W AMP 480012 IC14 IC 555 TIMER 480017 IC1 IC LM340-15 POS 15V REGULATOR 480024 IC8 IC RC4559NB DUAL OP AMP 480056 IC16 IC17 IC20 IC23 IC 4071 CMOS QUAD 2 IN OR GATE 480081 IC7 IC 4584B CMOS HEX SCMITT TRIG 480090 IC2 IC9 IC 4040 CMOS 12 STAGE CONVERTER 480108 IC12 IC 4011 CMOS QUAD 2 IN NAND GATE 480111 IC5 IC 4001 CMOS QUAD 2 IN NOR GATE 480112 IC4 IC 4013 CMOS DUAL D TYPE FLIP FLOP 480171 IC3 IC13 IC LM833N DUAL OP AMP 480175 IC15 IC18 IC19 IC DG444 QUAD ANALOG SWITCH 480212 IC21 IC22 IC24 IC 4556 CMOS DUAL 1 OF 4 DECODER 480236 IC10

Page 16

Clear-Com MS-232 Two-Channel Main Station

Miscellaneous

Device Description Part # Designator

Inductor 100UH 2A 180010 L1 Connector 1/4 IN STEREO JACK 210135 P11 J20 Connector HEADER MULTI-PIN 210217 J3(6) P1 P3(3) P4(3) P7(3) P8(3) Connector JUMP JACK .1IN 210226 JP1 JP2 Connector HEADER .156IN PIN 210234 J2(3) Connector 3 PIN MALE 210245 P5 P6 P10 P12 P13 P14 P15 Connector 3 PIN FEMALE 210246 P9 Connector SINGLE ROW RT ANG HEADER 210253 JP1(3) JP2(3) Connector DUAL ROW HEADER 8 POS. .230IN 210276 P17 Connector DUAL ROW HEADER 17 POS. .230IN 210279 P16 P22 Connector DUAL ROW HEADER 7 POS. .320IN 210282 J25 Connector 7 POS DUAL ROW SOCKET .635 TALL 210349 J26 Relay SPDT 24V MINI PC RELAY 450004 K2 Pot 2K TRIMPOT H MTG. 470029 R161 Pot 50K TRIMPOT 470059 R193 Switch DIP SWITCH PIANO 8 POS. 510110 S1 Switch DPDT R/A SLIDE SWITCH 510121 S12 S13 Transformer 600CT/600CT 560018 T1 Cable 34 PIN FLAT, 2 CONN. 770018 J23

Page 17

CLEAR-COM

INTERCOM SYSTEMS

PROGRAM

INPUT

OUTPUT

ANNOUNCE

NOTES: (UNLESS OTHERWISE SPECIFIED)

1. ALL RESISTORS ARE 1/4W 5% LISTED IN OHMS

3. ALL DIODES ARE 1N4148

DIP LEVEL

4,5,

10,11,

12,13

PANEL MIC GAIN

HOT MIC

DIP EN

*CALL B *CALL A *PRG INT B *PRG INT A

ALERT TONE ALT TONE EN

ANN RELAY

LINK B OUT LINK B LN DRV LINK A LN DRV

SPK MUTE

To J23 on

Logic Board

CHL A POWER CHL B POWER

KILL RLY CONT

KILL RLY COIL

CHL A

TERMINATION

CHL B

TERMINATION

ONOFFONOFF

ALERT TONE

LEVEL

HEADSET

PANEL

MIC

SPEAKER

INTERCOM CHANNEL A

INTERCOM CHANNEL B

ANNOUNCE

OUTPUT

ANNOUNCE OUT + ANNOUNCE OUT -

PROGRAM IN +

PROGRAM IN -

ANNOUNCE

RELAY

Spares:

PROGRAM VOLUME

P17/J17

J17/P17

P17/J17

J17/P17

SIDETONE A

P17/J17

J17/P17

SIDETONE B

J17/P17

P17/J17

10 10

12 12

P17/J17

J17/P17

J17/P17CW

LISTEN LEVEL B

LISTEN LEVEL A

P17/J17 14 14

PRGM FEED

A LEVEL

PRGM FEED

B LEVEL

LONG LINE A

LONG LINE B

J23/P22J16/P16

422

P22/J23

P16/J16

10 10 23 5

11 11 24 6

PARTY LINE LINK A+B

16 16

FRONT PANEL PCA

GROUND PLANE

J18/P16 J23/P22

33 11

SPK ON-OFF (CLOSE ON)

PANEL SEL HEADSET SEL IFB MUTE ANNOUNCE TALK SEL B TALK SEL A

REMOTE

MIC KILL

J18/P16 J23/P22

5 5 25 25

J16/P16

J18/P16

J23/P22

2828

27271

16 16

CH A FAULT (RED)

CH B FAULT (RED)

HEADSET CABLE ASS'Y

P/N 740065

PANEL MIC CABLE ASS'Y

P/N 740066

PANEL

SPEAKER ASS'Y

P/N 740067

65W SWITCHING POWER SUPPLY

POWER ON-OFF

POWER ENTRY HARNESS ASS'Y

P/N 740063

DC POWER CABLE ASS'Y P/N 740064

2. ALL CAPACITORS ARE LISTED IN MICROFARADS

TEST

MS-232 2-Channel Main Intercom Station Schematic

SHEET 1 OF 2

IFB INPUT

X0459.DSN

PROGRAM FEED ON ANNOUNCE OPTION

Clear-Com MS-232 Two-Channel Main Station

+30V

BIAS

+30V

VDD

+30V

BIAS

VDD

+30V

VDD

+30V

VDD

+30V+30V

+30V

BIAS

+30V

BIAS

VSS

BIAS

VSS

BIAS

BIAS BIAS

BIAS

VSSVSS

VSS

+30V

VDD

C83

1uF NP

C124 .1uF

IC21C

DG444

11910

R24 10K

R163 1M

P15

XLR-3M

132

R131

430

R32

4.7K

XLR-3M

132

C84

1uF NP

C91

100uF

C14 22uF

R126

47.5K*

P13

XLR-3M

132

C71

.0047uF

IC19B

LM833

P14

XLR-3M

132

C93

470pF

C85

1uF NP

C65

.047uF

R139 20K*

C69

1uF

.01uF

C76 .1uF

C68

1uF

IC15A

LM833

C49 39pF

1 6

3 4

R127 10

Q8 MPSA05

C92

470pF

R132 100K

C81

.01uF 1.4KV

R202

20K*

R152

10K

R140

20K*

IC17A 4559

R19

3.3K

R99

47.5K*

IC20A 4559

IC24B DG444

687

R142

9.1K

R18

4.7K

R208

20K*

D26

P10

XLR-3M

132

R100

47.5K*

Q25

2N5639

2 1

R96

6.2K

C52

4.7uF

IC15B

LM833

12345

C82

.1uF

R207

20K*

R224

9.1K

XLR3-F

132

R115

430

C86

200pF

R206

20K*

R151 10K

R17

9.1K

R226

100K

R135

120K

R201 20K*

R205 20K*

C100

.0047uF

C63

1uF

C64

.047uF

R209

47.5K*

C132 .1uF

R227

R146

220

R180 2K

R210

47.5K*

C130 .1uF

C131 .1uF

R216

20K*

IC16B 4559

C128 .1uF

IC24D DG444

141615

R212

20K*

R118

10K

R214

47.5K*

C129 .1uF

C66

.047uF

R8 0

R130

R21

2.2K 1/2W

R213

20K*

R186

4.7K

C78

470pF

R20

2.2K 1/2W

R215

20K*

R211

47.5K*

R11

R187

20K*

Q10

TIP35

213

C56

47uF

C105

.047

R12

20K

Q9 TIP35

213

IC21A DG444

312

13 4

R10

R105

120

C108 .01uF

J20

R217

6.8K

R13

20K

S12 SW SPDT

R14

9.1K

C104

.0047uF

R218

6.8K

R144

15K

S13 SW SPDT

R15

9.1K

R145

6.8K

IC22A DG444

312

13 4

R6 1K

Q19 MPSA13

IC22D DG444

141615

R225

1.5

C67

.0047uF

R7 1K

R188

33K

IC24C DG444

11910

IC19A LM833

P22

1 2 3 4 5 6 7 8

9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34

R171

6.8K

R28

.39 2W

C121 100uF

C77 .1uF

C2 .1uF

C57

470pF

C3 .1uF

MPSA55

IC21D DG444

141615

MPSA55

Q6 MPSA55

123

Q5 MPSA55

123

R133 470K

Q21

J174

D4 1N4003

R134 470K

1 2 3

R137 39

D2 1N4003

JP2

R138 39

C118

820pF

.01uF

C5 .01uF

R147 10K

R194 220

Q4 MPSA55

R196 220

C8 100uF

R197

4.7K

C136 22uF

R128

4.7K

R195

4.7K

C112

820pF

C7 100uF

IC16A

4559

C106

.1uF

R129 20K*

C79

1uF NP

R119

9.1K

R125

4.7K

R102 10K

R120 20K*

R308

50K

POT

C119 10uF

C54 47pF

C109 1uF NP

C120 10uF

R303 36K

D10

1N4003

1 2 3

C90

100uF

R121 20K*

100uH

R4 33K

C55

.1uF

R117 20K*

R3 33K

R304

POT

R310 50K

POT

C107

.01uF

R2 33K

R309

50K

POT

Q24 TIP41

1N5401

C137 22uF

R191

2.2

D6 1N5401

C80

.22uF

IC23B

4559

R166

47.5K*

C116 .1uF

R173

2.2

R123

820

C62

1uF NP

R174

RELAY SPDT

R106 120

R305

POT

R307

50K

POT

C301 .1uF

R306

50K

POT

D47

1N4003

C101 .1uF

C51

39pF

IC24A DG444

312

13 4

IC23A 4559

D15

1N4003

IC20B 4559

R101

6.2K

C87

200pF

R136 120K

RP1 100K SIP

123456789

C88

.047uF

R165

6.8K

C117 22pF

R122 100K

IC22B DG444

687

R148

3.3K

U22C DG444

11910

XLR-4M

124

C115

.0022uF

S1-7 OPTION

C89 .22uF

S1-8 OPTION

P11

470pF

1KV

R103

100K

R153

3.3K

470pF

1KV

S303

R109 470K

R168

33K

C61

.047uF

D45

K301 RELAY SPDT

R169

33K

R170 10K

Q23

MPSA05

S308 SW DPDT

D43

LED304

C70

.0047uF

R149

470K

R182 20K*

C97

.1uF

D301 1N4003

C95

.01uF

R154

470K

R193

50K POT

R313

10K

8 OHM

R97 100K

C96 .01uF

R150 680

1 2

C72 47pF

R116 22

C114 1uF NP

C103 .1uF

1 2 3

R107 22

R159

220

C73

47uF

Q22

J174

IEC 320 MALE

C102 .1uF

R1 430

C53

.1uF

R167

47.5K*

R98

1 2 3

R158

10K

C110

47pF

IC14 LM384

C17 1000uF

R164

3.3K

C59

.1uF

C74 470pF

C98

.01Uf

R155 470K

R108 100K

R124

100K

R141

9.1K

C122 220uF

R156 470K

IC17B

4559

C58

47pF

C75 470pF

R161 2K

IC18A LM833

R5 5 5W

C60

.1uF

IC18B

LM833

R160 430

IC1 555

253

7 6

TRCVQ

DIS

THR

C123

470pF

D46

C99

2.2uF

S301

R25 43K

R199

D26

P12

XLR-3M

132

R23 820K

C50

4.7uF

R198

IC21B DG444

687

R22 1K

XLR-3M

132

IFB MUTE

SPK MUTE

DIP EN

ALERT TONE

ALERT TONE EN

PRG INT A

HEADSET SEL

PANEL SEL

TALK SEL A

TALK SEL B

PRG INT B

CALL A

CALL B

ANNOUNCE

ANN RELAY

CHL A POWER CHL B POWER

SPK MUTE PANEL SEL HEADSET SEL

ANNOUNCE TALK SEL B TALK SEL A DIP EN

IFB MUTE

ANN RELAY CALL B CALL A PRG INT B PRG INT A

ALERT TONE ALERT TONE EN

CHL A POWER CHL B POWER

LINK A LN DRV LINK B LN DRV

LINK B OUT

LINK B OUT LINK B LN DRV LINK A LN DRV

KILL RLY COIL KILL RLY CONT

CHL B POWER

CHL A POWER

Page 18

CALL A

SENSE

CALL B SENSE

CALL B

SEND

CLEAR-COM

INTERCOM SYSTEMS

CALL A

+15V VDD SOURCE

ANNOUNCE RELAY

ALERT TONE ALT TONE EN

LINK B OUT LINK B LN DRV LINK A LN DRV

CALL B

CALL A

DIP ENABLE

TALK SEL B

TALK SEL A

PRG INT B PRG INT A

SPK MUTE PANEL SEL

HEADSET SEL

IBF MUTE

ANNOUNCE

+30V VDD

VSS

POWER ON

RESET

CHL A POWER CHL B POWER

J16/P16

J18/P16

11 29

11 11

J25/P26

P26/J25

J25/P26 P26/J25

11 99

2 2 10 10

MOMENTARY ONLY CH A

P26/J25

INTRPT ANNC

INTRPT EXT IFB

J25/P26 P26/J25

MOMENTARY ONLY CH B

CALL ON TALK A

CALL ON TALK B

CALL A

CALL B

J16/P16

927

725

TALK A

TALK B

TONE ALERT

J18/P16

PANEL MIC / HEADSET

(CLOSE-PANEL)

J16/P16 10 28

P16/J18

TONE ALERT

(GREEN)

TALK A

(IN TALK A SW)

TALK B

(IN TALK B SW)

P16/J16

P16/J18

1230

10 10

J16/P16

J18/P16

131431

131213

PROGRAM FEED A ENABLE

PROGRAM FEED B ENABLE

PROGRAM INTERRUPT A ENABLE

PROGRAM INTERRUPT B ENABLE

PROGRAM A

SELECT

PROGRAM B

SELECT

J16/P16

826

ANNOUNCE

J18/P16

P16/J16

31421

15 33

FRONT PANEL

PCA

SHOWN ON

SHEET 1

SHOWN ON

SHEET 1

ALERT TONE DELAY

NONE (OPEN) - 2 SEC (CLOSED)

RMK SW

MS-232 2-Channel Main Intercom Station Schematic

SHEET 2 OF 2

X0460.DSN

Clear-Com MS-232 Two-Channel Main Station

+30V

VDD

+30V

VCC

+30V

VDD

+30V

VDD

+30V

VDD

VSS

VSS VSS

VSS VSS VSS

VSS

C35 10uF

R91 470K

C41 .1uF

(IC9)

S300

R41 470K

S301

IC8 LM340-15

GND

IC5D

4011

C126 .1uF

(IC10)

RP2-7 100K SIP

S305

C27 .1uF

(IC1)

RP2-5 100K SIP

C28 .1uF

(IC2)

C29 .1uF

(IC3)

IC4D 4001

12 13

C30

.1uF

(IC4)

RP2-4 100K SIP

C31 .1uF

(IC5)

RP2-6 100K SIP

C32 .1uF

(IC7)

RP2-3 100K SIP

IC13A 4013

531

D CLK

R45 470K

IC4C

4001

8 9

IC13B 4013

91113

810

D CLK

S302

IC2B

4584

3 4

IC2C

4584

5 6

Q18 MPSA13

RP2-2 100K SIP

IC2A

4584

1 2

Q15 MPSA13

S1-1

OPTION

LED300

IC2D

4584

9 8

Q14 MPSA13

S1-6

OPTION

R300

4.7K

R44 470k

D27

Q11 MPSA13

S1-5

OPTION

IC4B

4001

Q16

MPSA13

S1-2

OPTION

IC4A

4001

C46

.01uF

Q17

MPSA13

S1-4

OPTION

S304

S1-3

OPTION

IC10A

4556

2 3

4 5 6 7

A B

Q0 Q1 Q2 Q3

IC2E

4584

11 10

IC10B

4556

14 13

12 11 10 9

A B

Q0 Q1 Q2 Q3

RP2-10 100K SIP

R93 10K

IC2F

4584

13 12

IC7D

4071

LAMP301

C21

.01uF

IC7A 4071

1 2

LAMP302

IC7B 4071

5 6

R16 1M

C134

.1uF

C23 .01uF

IC7C

4071

D16

IC12 4040

10119

7 6 5 3 2 4 13 12 14 15 1

CLK RST

Q1 Q2 Q3 Q4 Q5 Q6 Q7 Q8 Q9 Q10 Q11 Q12

R74

R73

60.4K*

R9 1M

C127 .1uF

(IC12)

R94 10K

C1 1uF

C38 .22uF

C133 .1uF

(IC13)

C125 .1uF

RP3C 220K SIP

5 6

C19

2.2uF

RP3A

220K SIP

C20

2.2uF

R72 39

D3RP3B

220K SIP

C25

.47uF

RP3D 220K SIP

7 8

C24

.47uF

R35

4.7K

R84 220K

R83

R48 100K

JP1

R39 2K

C48

.22uF

RP2-9 100K SIP

R87 68K

RP2-8

100K SIP

C94

.0047

R85

IC3A 4013

531

D CLK

Q12

MPSA63

C47

.01uF

R177

10K

IC3B 4013

91113

810

D CLK

D33

S306IC5B

4011

5 6

D34

S307

IC5A

4011

J23

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34

R49

100K

R75

220

R50

100K

D19

D20

R58

4.7K

D21

D22

R51 100K

IC9A

4584

1 2

R68 68K

IC9B

4584

3 4

D11

IC9C

4584

5 6

C39 .047uF

IC9D

4584

9 8

IC9E

4584

11 10

D12

6.8V ZD

D48

R59 220K

R47 100K

R46 2K

D14

6.8V ZD

R57 220K

IC9F

4584

13 12

Q13

MPSA63

R71

60.4K*

R69 68K

R52 100K

C22 .047uF

C135

.1uF

IC5C

4011

S309

D13

1N4003

S310

CALL A

CALL B

TALK SEL A

TALK SEL B

IFB MUTE

TALK SEL B TALK SEL A

SPK MUTE

HEADSET SEL

PANEL SEL

HEADSET SEL

ANNOUNCE RELAY

ANNOUNCE

ANNOUNCE RELAY

ANNOUNCE

IFB MUTE

DIP ENABLE

CALL SENSE A CALL SENSE B

CALL SENSE A

CALL SENSE B

PRG INT B

PRG INT A

ALERT TONE

ALERT TONE ALT TONE EN

ALT TONE EN

CALL A CALL B

PRG INT A

PRG INT B

ANNOUNCE

TALK SET A

TALK SET B

TALK SET A

TALK SET B

Page 19

Clear-Com MS-232 Two-Channel Main Station

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 your return address, telephone number and date of purchase, along with 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 St. Emeryville, CA 94608-3505 Telephone: (510) 496-6666 Telefax: (510) 496-6699

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.

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 your approval for repair, and repair of equipment is completed, the equipment will be shipped freight collect from the factory to the customer.

Page 20

Clear-Com MS-232 Two-Channel Main Station

TECHNICAL SPECIFICATIONS

HEADSET MICROPHONE PRE-AMP

Input Type: Dynamic Impedance: 1K Input Level: -55 dBV nominal; -10 dBV max.

Gain from headset mic to intercom line: +41 dB

PANEL MICROPHONE PRE-AMP

Input Type: Electret Input Level: -45 dBV nominal Gain from panel mic to intercom line: +31 dB

PRE-AMP RESPONSE CURVE

Frequency Response: 250 Hz - 12 KHz, contoured for intelligibility Limiter Range: 20 dB

HEADPHONE/SPEAKER AMPLIFIER

Ω

Load Impedance Range: 50 - 2 K Output Level: at least +20 dBV across 600

Distortion: < 0.2% THD @ 1 KHz Frequency Response: 200 Hz - 18 KHz, 2 dB

Gain from intercom line: +37 dB Power Output: 110 dB SPL

PROGRAM AMPLIFIER

(Transformerless, balanced differential input) Input Level: -20 dBV

Input Impedance: > 100 K Frequency Response: 150 Hz - 18 KHz, 2 dB

TERMINATION IMPEDANCE

Impedance: 200 , switchable

POWER SUPPLY

Type: Switching, with overcurrent limiting and reset circuitry Output Voltage: 30 volts DC Output Current: 2 amps peak, 1.75 amps max, distributed over both channels Short Circuit Reset Time: < 15 sec. Hum & Noise: < -80 dBv

STATION CAPACITY

Capacity: Maximum of 60 headset stations or 20 speaker stations, distributed over both channels

Ω

Ω Ω

Ω

REAR PANEL CONNECTORS

Intercom: (6) XLR-3M (3 per channel) Announce Out: (1) XLR-3M (Audio) Announce Relay: (1) 1/4" Phone Jack (Relay) Program: (1) XLR-3F Hot Mic / IFB Interface: (1) 1/4" Phone Jack AC Power: IEC 320 Connector

REAR PANEL CONTROLS

(2) Termination On-Off switches; (8) Option switches; (1) Power switch; (1) Tone Alert Volume control

Page 21

Clear-Com MS-232 Two-Channel Main Station

FRONT PANEL CONNECTORS

Panel Mic: (1) 1/4" panel mounting jack Headset: (1) XLR-5F

FRONT PANEL CONTROLS & INDICATORS

(1) Panel / Headset Mic switch; (1) Announce button; (1) Party Line Link switch; (2) Program On-Off-

Interrupt switches; (3) Program Level controls; (2) Listen controls; (2) Sidetone Null controls; (2) Talk buttons; (2) Call buttons; (1) Tone Alert button; (1) RMK button; (1) Speaker On-Off switch

(2) Short LEDs; (1) Power on LED; (1) Party Line Link LED; (1) Tone Alert LED

POWER REQUIREMENTS

90 - 240 VAC, 50 - 60 Hz, 60 VA

ENVIRONMENTAL

32 - 122

F (0 - 50o C)

DIMENSIONS

19" W x 1.75" H x 6.5" D (483 mm x 44 mm x 165 mm)

WEIGHT

5.0 lbs. (2.75 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.

Clear-Com MS-232 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual