INTRODUCTION
Congratulations on choosing this Clear-Com product. Clear-Com was established in 1968 and remainsthe market leader in providing intercom for entertainment, educational, broadcast and industrial appli-cations. 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 heartof a Clear-Com system. We recommend that you read through this manual completely to better under-stand the functions of the MS-232. If you encounter a situation or have a question that this manualdoes not address, contact your dealer or call Clear-Com directly at the factory. Our applications sup-port and service people are standing by to assist you. Thank you for selecting Clear-Com for yourcommunications needs.
Description
The Clear-Com PL-ProTM MS-232 is a two-channel, one rack space main station ideal for ENG and EFPtrucks, production studio consoles, theatre, live performances, and small TV facilities. It features ex-cellent speech intelligibility in all noise levels and can be tailored to your needs through its programma-ble options.
Selectable two-channel talking and/or listening allows the operator to communicate on either of the in-tercom channels separately or on both at once. The illuminated dual-action talk buttons are electronicmomentary or latching. Monitoring can be done through the headset, the integral speaker, or both atonce. The MS-232 offers both visual and audible call signaling to attract the attention of operators whohave removed their headsets or turned off their speakers. The Remote Mic Kill (RMK) feature providesthe ability to turn off all open mics on Series 500 beltpacks.
The MS-232 can control a paging speaker for studio announcements. A front panel button activatesthis function and an associated relay. A balanced program input allows monitoring external audio usingthe headset or speaker.
This main station accepts dynamic headsets, such as the Clear-Com PL-ProTM Series. Individual side-tone controls for each intercom channel allow the operator to vary the level of his/her own voice asheard 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 speakerdipping circuit will lower the level of the speaker when the announce button, talk buttons or program in-terrupt are activated. This feature helps minimize feedback.
The MS-232 also incorporates a dual-channel program interrupt system (IFB). When activated, one ormore stations can interrupt the program audio to another intercom station or a talent wearing Clear-Com's wired or wireless talent receivers. Clear-Com's stand-alone IFB system can also be connectedto this station.
The MS-232 provides 30-Volt DC power to operate Clear-Com beltpacks and remote stations. Thispower is distributed between the two channels, and will support up to 60 headset stations or 20 speakerstations. Clear-Com's new fail-safe design automatically shuts down the power to a channel when ashort circuit or electronic overload is sensed on that channel. The other channel will continue to oper-ate 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. TheMS-232 installs in a standard 19" equipment rack, using only one rack space. The unitized aluminumchassis and extra-thick front panel with integral rack ears result in reduced size and a lighter weightpackage that maintains legendary Clear-Com ruggedness. Three 3-pin XLR connectors are providedfor connection to each intercom channel.
The MS-232 is compatible with all Clear-Com Party-Line intercoms.
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QUICK START
1 Unpack the unit and inspect for any damage that may have occurred in shipping. Connect theproper AC Mains cable.
2 Install the MS-232. (For additional information, refer to the Clear-Com PL-ProTM System Installa-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 beOFF.
7 Set Listen Levels and Sidetones. (Refer to the Listen Level and Sidetone setting topics in theOperation section of this manual.)
8 The intercom system should now be operating properly.
Read the rest of this manual for further information.
OPERATION
Normal operation of the MS-232 Main Station only requires access to the front panel controls. Thecontrols located elsewhere on the unit are intended to be set-and-forget in nature. For intercom opera-tion, set the Listen level controls for each channel to the desired level and press the Talk buttons whentalking. If a headset is used, set the Sidetone control for each channel for the desired amount of side-tone in the earphone. If the Panel Mic and Speaker are being used, set the sidetone controls for mini-mum 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 followingfigure 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 microphonefeed to that channel. Each Talk button has a dual action (momentary or latching) dependingupon how the button is pressed. If desired, the latching function for each channel can be de-feated using the option switches on the rear panel. The following describes the various func-tions of these multi-purpose buttons.
MOMENTARY: Press and hold the Talk button while you are speaking. Release it whenyou are finished.
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LATCHING: Press the button quickly to latch the Talk function. Press the button again toturn off the Talk function.
TALK INDICATION: The Talk button will illuminate dimly whenever the Talk function isactivated.
CALL INDICATION: The Talk button will flash brightly when a Call signal is received onthat channel.
CALL ON TALK: Each channel can optionally be set to send a Call signal whenever youpress the Talk button. This function is used to activate program interrupts or any otherCall-activated function available on other stations. Option switches on the rear panel willenable this function.
SPEAKER MUTE: If the front panel speaker is turned on, pressing either Talk button willreduce the speaker output level to avoid feedback.
The Talk buttons can be labeled to indicate their function. To label the Talk buttons, use thefollowing 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 itup with the square white diffuser and press the cap onto the body of the button. Press thebutton back into the front panel.
2 Call Buttons: Each channel has its own Call button. Pressing a Call button will send a Callsignal on that channel. All the call lights on that channel will flash. Call signals can also besent while talking if required. The Talk button will flash while the Call button is pressed, indi-cating 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 oneither channel. This can be useful when the operator's attention has been drawn away fromthe MS-232 indicator panel. Press the Tone Alert button to alternately enable or disable theaudible tone alert. The green indicator next to this button is lit when the audible Tone Alert isenabled. When enabled, the Tone Alert will sound when a Call button on a beltpack or stationis 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 counter-clockwise to silence a channel.
6 Sidetone Controls: Each channel has a Sidetone Null control. Sidetone is the level of yourown voice that you hear while talking on the intercom. Setting a comfortable level of sidetonewill ensure that the intercom line sounds alive and also helps you modulate your voice relativeto other voices on the line.
Typically, different Sidetone Null settings are needed depending upon whether you are usingthe gooseneck panel microphone along with the speaker or not. Use one the following proce-dures 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 ChannelA to a comfortable level.
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3 Press the Channel A Talk button and speak into the microphone while turning the SidetoneNull control for Channel A slowly back and forth. There should be a point where yourvoice (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 ChannelA 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 SidetoneNull control for Channel A slowly back and forth until you hear your voice at a comfortablelevel 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 tomanually or automatically control program audio feed into the intercom lines. The settings areas follows:
ON: The channel will receive program audio when the switch is set to ON. The audio levelfor each channel can be adjusted with the Program Level trimpots as described in thefollowing 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 toINTRPT.
8 Program Level Controls: Adjust the Program Level controls to set the program audio levelheard on the intercom. There are three Program Level controls. The Program Level knob tothe left of the Speaker On-Off switch adjusts the level of program heard in the headset orpanel speaker.
The program levels heard on each intercom channel line can be individually adjusted, but thisis intended to be a one time setting made when the MS-232 is set up. This is done using thescrewdriver level adjustment trimpots adjacent to the Program ON-OFF-INTRPT switches onChannels A and B. Set the Sidetone Null controls and the Program Level knob fully counter-clockwise when adjusting the individual channel Program Level trimpots. After the ProgramLevel trimpots are properly adjusted, use the procedure listed in the Sidetone Controls sec-tion on this page to set the sidetone level.
NOTE: Do not force the trimpots past their stop points. This will damage them.
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 posi-tion, the green lamp directly above the switch will light, and all of the stations on the B channelwill be moved onto the A intercom line. This will allow communication between everyone onboth channels at once.
In this mode, the Channel B controls and switches will be inactive. Since the wiring for the Bchannel has been now added to the A channel, the Sidetone Null control for Channel A mayrequire some readjustment.
10 Speaker ON/OFF Switch: The Speaker ON/OFF Switch turns the front panel speaker on oroff. This switch does not affect whether the Tone Alert is heard through the speaker. Thespeaker volume will automatically dip whenever the panel or headset microphone is on.
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11 Remote Mic Kill Switch: The Remote Mic Kill (RMK) switch will turn off the Talk function ofevery beltpack on channels A and B. If the Talk functions of a large number of beltpacks haveinadvertently been left activated, incidental noise and talking can make it difficult or impossi-ble to communicate on the party line intercom. The Remote Mic Kill switch can be pressed toquiet the line in this situation. Those needing to communicate can then set their Talk functionsON as needed.
NOTE: The Remote Mic Kill switch can only function if the MS-232 Main Station ispowering all of the stations in the system. The switch momentarily interrupts powerto the other beltpacks and stations in the system. If there are other power supplies ormain stations in the system, then the Remote Mic Kill switch cannot interrupt powerand therefore cannot work.
12 Mic Select Switch: Set the Mic Select switch to select whether the panel microphone or theheadset microphone is active.
13 Panel Mic Gain: This control is located on the underside of the MS-232 chassis. It may beused to increase or decrease the sensitivity of the panel microphone. It has no effect on thesensitivity of the headset microphone. Use a small screwdriver to turn the control clockwise toincrease 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 panelconnector and activates the Announce Relay. Simultaneously, if the program audio feed tothe Announce Output is enabled, it is interrupted by the announcement. Program audio feedto the Announce Output is selected by setting jumper JP2 on the Main board to the ON posi-tion. Optionally, pressing the Announce button can also disconnect the selected headset orpanel microphone audio from the intercom line(s). This option is controlled by the InterruptAnnounce option switch.
19 Headset Connector: The headset connector is located on the front panel. All Clear-Comheadsets are recommended for use with the MS-232. The following is a description of thecharacteristics of a suitable headset:
Mic Type --- Dynamic; 150 to 250 ohms impedance; -55 dB output levelHeadphone --- Dynamic; 50 to 2000 ohms impedance
The wiring of the headset is to be as follows:
Pin 1 --- Mic commonPin 2 --- Mic hotPin 3 --- Headphone commonPin 4 --- Headphone hot
The mic and headphone wiring in the headset cord must be individually shielded. Do notconnect Pins 1 and 3 together. Headset extension cords or headset "Y" cables are not rec-ommended 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 withthe 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 thethreads 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 inplace.
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26 Party Line Link (A+B) LED: This green LED is lit when the Party Line Link (A+B) switch isON, 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 Alertis an audible indication that a Call signal is active. Toggle the Tone Alert function ON or OFFusing the Tone Alert button.
28 Power LED: This green LED lights when the MS-232 is receiving AC power and the powerswitch 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 lightwhen the MS-232 senses a short or overload on the associated channel. When the fault is re-moved, 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 andbriefly 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. Thisis normally adjusted when the system is set up and there should be no need to adjust it in nor-mal operation.
15 Option Switches: Eight Option switches are provided on the rear panel. They should beconfigured when the system is set up, but are not changed in normal operation. The defaultposition 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 thelatching function of the Channel A Talk button. In this mode, the Talk button must alwaysbe 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 thelatching function of the Channel B Talk button. In this mode, the Talk button must alwaysbe 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 willbe placed on Channel A whenever the Talk function is activated. This can be used to acti-vate 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 willbe placed on Channel B whenever the Talk function is activated. This can be used to acti-vate any Call activated functions available on other stations.
5 INTRPT ANNC: If the Interrupt Announce switch is set to the ON position, pressing theAnnounce button will disconnect the microphone from the intercom line(s). This will allowannouncements 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 andthe Interrupt External IFB switch is set to the ON position, pressing a key on the IFB
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System will disconnect the selected headset or panel microphone from the intercomline(s). This allows the MS-232 microphone to be used to cue talent without affecting in-tercom line communication.
7 LONG LINE A: If a long cable run on Channel A is unavoidable and approaches 1,000feet or more, set the Long Line A option switch to the ON position. The ability to set asidetone 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 1,000feet or more, set the Long Line B option switch to the ON position. The ability to set asidetone null on Channel B depends upon properly setting this switch.
16 Termination Switches: These switches provide switchable terminations for channels A andB. In most systems, both terminations on the MS-232 should be in the ON position (defaultsetting). The fundamental concept of Clear-Com Party-Line intercom is that all channels areterminated in one location, preferably at a main station or power supply. The terminationswitches on the MS-232 rear panel should be set to the OFF position only if the channel is ter-minated by another main station or power supply in the system. If there are no other mainstations, power supplies, or other terminations on the line, set the rear panel switcheslabeled TERM A and TERM B to the ON position.
NOTE: All intercom lines must be terminated only once, whether they are used or not.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 switchesto set power line voltage or frequency.
21 Intercom Line Connection: The MS-232 contains three 3-pin male XLR connectors for eachintercom line. These connectors are wired in parallel. Any single-channel station or channelof 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 isto assign specific people to the correct group, i.e. the other people they need to be in contactwith the most. This is particularly important when the party line users are on a single-channelbeltpack or station; less so if they are on multi-channel stations. The pinout of the intercomconnectors 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 inter-com channels. The level to the speaker or headphone is controlled by the Program Levelcontrol. The Program ON-OFF-INTRPT switches control whether each intercom channel re-ceives program audio. The program audio levels on each intercom channel can be adjustedusing the individual Program Level trimpots. The Program Input accepts a balanced or unbal-anced line-level audio signal from -20 dBv to +10 dBv. An option is to feed program audio tothe Announce Output. This is selected by setting jumper JP2 on the Main board to the ON po-sition. When this option is selected, a 0 dBv signal on the Program Input will produce a 0dBvsignal on the Announce Output.
The pinout of the Program Input connector is as follows:
Pin 1 --- Ground (Shield)Pin 2 --- + SignalPin 3 --- - Signal
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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 headsetor panel microphone on the Annc Out rear panel connector. Optionally, pressing the An-nounce button can also disconnect the selected headset or panel microphone from the inter-com 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 interruptedby the announcement. Program audio feed to the Announce Output is selected by settingjumper JP2 on the Main board to the ON position. The pinout of the Announce Out connectoris as follows:
Pin 1 --- Ground (Shield)Pin 2 --- - SignalPin 3 --- + Signal
The audio output is balanced and transformer isolated. It has a 600 ohm impedance and anominal output level of 0 dBV. A shielded twisted pair cable should be used in the cable wiredto this connector.
24 Relay Out: A dry set of relay contacts is provided through a 1/4 inch jack to activate externalswitching as needed when the Announce button is pressed. These contacts can be used tocontrol an external device such as a PA amplifier to another room. The contacts are rated for2.0 Amps at 24 VDC. The contacts are wired as follows:
Ring --- Normally Closed ContactTip --- Common ContactSleeve --- Normally Open Contact
25 Hot Mic Out / IFB System: This connection is a 1/4 inch phone jack. It provides a 0 dBVoutput signal from the selected headset or panel microphone. This output is intended inter-face with the External Line In jack on Clear-Com's IFB System. The jack is wired as follows:
Ring --- Ext. IFB Control Signal InputTip --- Hot Mic Audio OutputSleeve --- Ground (Shield)
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MS-232 Block Diagram
The following is a block diagram of the MS-232:
Figure 3 - MS-232 Block Diagram
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 andpower will come back up within several seconds. Check for shorts between pins 1and 2 or improper cable wiring.
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E Q /L I M
E Q /L I M Headset
Select
HeadsetMic
Panel Mic
Hot MicOut
AnnounceAnnounce
Output
Talk
Int. On/Off
ProgramLevel A
Sidetone
CallLightCall
Send
Channel AListen
Talk
Int. On/Off
ProgramLevel B
Sidetone
CallLightCall
Send
Channel BListen
Green
AlertVolume
ToneAlert
SpeakerDip/Mute
SpeakerOn/Off
ProgramFeed on
AnnounceOpt ion
BalancedProgram
Input
AnnounceRelay
Switching PowerSupply
Short Circuit Protection
Ch. A Ch. B
R e dShort
GreenO K
RemoteMic Kill
ProgramLevel
Term.Sw.
Term.Sw.
A+BLink
Ch. AOutput
Ch. BOutput
Speaker
HeadsetOutput
StationPower
Control Logic
InterruptAnnc. IFB
Call onTalk
TalkMomentary
LongLine
A B A B A B
Option Switches
PowerOn/Off
Problem: Red SHORT LED illuminatedCause 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 1and 2 or improper cable wiring. Once the short is removed, the MS-232 will resetautomatically 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 illuminatedCause 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 systemCause 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 thatwas "HOT" with respect to the power supply earth ground. Carefully check the system groundand AC distribution in the area.
WARNING: THIS IS A POTENTIALLY DANGEROUS SITUATION. A SHOCK HAZARDMAY 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 crosstalkCause 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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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 equipmentmust be connected to the intercom line, please contact Clear-Com application orservice 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
CapacitorsValue Type Volts Tol. Part # Designator.1 uF Monolithic 50V 10% 150035 C301
ResistorsValue Power Type Tol. Part # Designator4.7K OHM 1/4 Carbon Film 5% 410013 R30010K OHM 1/4 Carbon Film 5% 410016 R312 R31336K OHM 1/4 Carbon Film 5% 410163 R303
Diodes and TransistorsDevice Description Part # DesignatorLED RED, ROUND, FLAT TOP LED 390044 LED301 LED303LED GREEN, ROUND, FLAT TOP LED 390045 LED302 LED300 LED304Diode 1N4148 SIGNAL 10MA 75PIV 480000 D301
MiscellaneousDevice Description Part # DesignatorButton FLAT TOP GREY KEYCAP 240064 S300 S301Button ROUND MINIATURE 240081 S304 S305 S311Button RECT. MINIATURE 240082 S306 S307Knob GREY INSERT 6X4.5MM HOLE .45DIA 240089 R306 R307 R308Assembly 65 W 30 V SWITCHING POWER SUP. 400013Relay SPDT 24V MINI PC RELAY 450004 K301Pot 50K TRIM POT H MTG. 470018 R309 R310Pot 5K TRIMPOT H MTG. 470063 R304 R305Pot 50K 25MM FLATTED SHAFT 470070 R306 R307 R308Switch DPDT SLIDE SWITCH 510090 S302 S303 S308Switch PUSH BUTTON SWITCH W/32V LAMP 510104 S300 S301
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Miscellaneous (Continued)Device Description Part # DesignatorSwitch DPDT MINIATURE 510107 S304 S305 S306 S307 C311Switch POWER SWITCH, SPST SNAP-IN 510119Switch SPDT ON-OFF-ON 510120 S309 S310Cord IEC POWER CORD 610022Cable POWER ENTRY HARNESS 740063Cable DC POWER CABLE, MS-232 & PS-464 740064Cable ASSY, CABLE, HEADSET, MS-232 740065Cable ASSY, CABLE, PLUG-IN MIC, MS-232 740066Speaker SPEAKER ASSY, MS-232 740067Cable RIBBON, 3 CONN 770021 J16 J18Cable RIBBON, 16-PIN 770023
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Parts List for MS-232 Audio / Logic PCBs
CapacitorsValue Type Volts Tol. Part # Designator1 uF Aluminum NP 50V 10% 150002 C1 C62 C68 C69 C79 C83 C84 C85
C109 C11422 uF Aluminum 16V 150010 C14 C136 C137.01 uF Ceramic Disc 30V 20% 150012 C4 C5 C6 C21 C23 C46 C47 C95
C96 C107 C108470 pF Ceramic Disc 50V 10% 150014 C57 C74 C75 C78 C92 C93 C12339 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 C82C97 C101 C102 C103 C106 C116C124 C125 C126 C127 C128 C129C130 C131 C132 C133 C134 C135
220 uF Aluminum 50V 150037 C12247 pF Ceramic Disc 50V 10% 150041 C54 C58 C72 C110.0022 uF Mylar 100V 5% 150045 C115200 pF Ceramic Disc 100V 5% 150063 C87 C8610 uF Aluminum 50V 150064 C35 C119 C1202.2 uF Aluminum NP 50V 150065 C19 C20 C9947 uF Aluminum 35V 150081 C56 C734.7 uF Aluminum NP 50V 150087 C50 C521000 uF Aluminum 35V 150092 C1722 pF Ceramic Disc 50V 10% 150098 C117820 pF Monolithic 50V 5% 150101 C112 C118.0047 uF Mylar 50V 5% 150114 C67 C70 C71 C94 C10O C1041 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
C105100 uF Aluminum 35V 150136 C7 C8 C90 C91 C121.47 uF Aluminum NP 50V 150151 C24 C25
ResistorsValue Power Type Tol. Part # Designator10 OHM 1/4 Carbon Film 5% 410002 R12722 OHM 1/4 Carbon Film 5% 410004 R107 R116 R199220 OHM 1/4 Carbon Film 5% 410007 R75 R146 R159 R194 R19639 OHM 1/4 Carbon Film 5% 410008 R72 R74 R137 R1381K OHM 1/4 Carbon Film 5% 410010 R6 R7 R10 R11 R22 R174 R1984.7K OHM 1/4 Carbon Film 5% 410013 R18 R32 R35 R58 R125 R128 R186
R195 R1972K OHM 1/4 Carbon Film 5% 410014 R39 R46 R98 R130 R180 R2273.3K OHM 1/4 Carbon Film 5% 410015 R19 R148 R153 R16410K OHM 1/4 Carbon Film 5% 410016 R24 R93 R94 R102 R118 R147 R151
R152 R158 R170 R17715K OHM 1/4 Carbon Film 5% 410017 R14433K OHM 1/4 Carbon Film 5% 410020 R2 R3 R4 R168 R169 R188100K OHM 1/4 Carbon Film 5% 410024 R47 R48 R49 R50 R51 R52 R97
R103 R108 R122 R124 R132 R22668K OHM 1/4 Carbon Film 5% 410025 R68 R69 R87220K OHM 1/4 Carbon Film 5% 410028 R57 R59 R84470K OHM 1/4 Carbon Film 5% 410030 R41 R44 R45 R91 R109 R133 R134
R149 R154 R155 R1566.8K OHM 1/4 Carbon Film 5% 410036 R145 R165 R171 R217 R218680 OHM 1/4 Carbon Film 5% 410044 R1505 OHM 5 Wirewound 10% 410051 R5
Clear-Com MS-232 Two-Channel Main Station
14
Resistors (Continued)Value Power Type Tol. Part # Designator120 OHM 1/4 Carbon Film 5% 410053 R105 R1061M OHM 1/4 Carbon Film 5% 410058 R9 R16 R83 R85 R1632.2K OHM 1/2 Carbon Film 5% 410068 R20 R21820K OHM 1/4 Carbon Film 5% 410070 R23.39 OHM 2 Carbon Film 5% 410073 R28120K OHM 1/4 Carbon Film 5% 410079 R135 R13643K 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 R202R205 R206 R207 R208 R212 R213R215 R216
820 OHM 1/4 Carbon Film 5% 410096 R1239.1K OHM 1/4 Carbon Film 5% 410100 R14 R15 R17 R119 R141 R142 R22447.5K OHM 1/8 Metal Film 1% 410105 R99 R100 R126 R166 R167 R209
R210 R211 R214430 OHM 1/4 Carbon Film 5% 410106 R1 R115 R131 R1602.2 OHM 1/4 Carbon Film 5% 410113 R191 R173 R2256.2K OHM 1/4 Carbon Film 5% 410137 R96 R10160.4K OHM 1/4 Metal Film 1% 410164 R71 R731.5 OHM 1/4 Carbon Film 5% 410208 R225100K OHM X 9 SIP BUSSED 415002 RP1 RP2220K OHM X 4 SIP ISOLATED 415007 RP3
Diodes and TransistorsDevice Description Part # DesignatorDiode 1N4148 SIGNAL 10MA 75PIV 480000 D1 D3 D7 D8 D9 D11 D16 D19 D20
D21 D22 D26 D27 D33 D34 D43 D45D46 D48
Transistor MPS-A13 NPN 30V DARL 480004 Q11 Q14 Q15 Q16 Q17 Q18 Q19Diode 1N5401 RECT 3A 100PIV 480005 D5 D6Transistor MPS-A63 PNP 30V DARL 480008 Q12 Q13Diode 1N957B ZENER 6.8V .4W 5% 480026 D12 D14Transistor MPS-A55 PNP 60V 480050 Q2 Q3 Q4 Q5 Q6Transistor MPS-A05 NPN 60V 480052 Q8 Q23Diode 1N4003 RECT 1A 200PIV 480058 D2 D4 D10 D13 D15 D47Transistor 2N5639 JFET NCHAN 8V VGS 480069 Q25Transistor J174 JFET PCHAN 8V VGS 480079 Q21 Q22Transistor TIP41 NPN 40V 6A TO-220 POWER 480099 Q24Transistor TIP35C NPN 100V 25A TO-218 480228 Q9 Q10
Integrated CircuitsDevice Description Part # DesignatorIC LM384 POWER 4W AMP 480012 IC14IC 555 TIMER 480017 IC1IC LM340-15 POS 15V REGULATOR 480024 IC8IC RC4559NB DUAL OP AMP 480056 IC16 IC17 IC20 IC23IC 4071 CMOS QUAD 2 IN OR GATE 480081 IC7IC 4584B CMOS HEX SCMITT TRIG 480090 IC2 IC9IC 4040 CMOS 12 STAGE CONVERTER 480108 IC12IC 4011 CMOS QUAD 2 IN NAND GATE 480111 IC5IC 4001 CMOS QUAD 2 IN NOR GATE 480112 IC4IC 4013 CMOS DUAL D TYPE FLIP FLOP 480171 IC3 IC13IC LM833N DUAL OP AMP 480175 IC15 IC18 IC19IC DG444 QUAD ANALOG SWITCH 480212 IC21 IC22 IC24IC 4556 CMOS DUAL 1 OF 4 DECODER 480236 IC10
Clear-Com MS-232 Two-Channel Main Station
15
MiscellaneousDevice Description Part # DesignatorInductor 100UH 2A 180010 L1Connector 1/4 IN STEREO JACK 210135 P11 J20Connector HEADER MULTI-PIN 210217 J3(6) P1 P3(3) P4(3) P7(3) P8(3)Connector JUMP JACK .1IN 210226 JP1 JP2Connector HEADER .156IN PIN 210234 J2(3)Connector 3 PIN MALE 210245 P5 P6 P10 P12 P13 P14 P15Connector 3 PIN FEMALE 210246 P9Connector SINGLE ROW RT ANG HEADER 210253 JP1(3) JP2(3)Connector DUAL ROW HEADER 8 POS. .230IN 210276 P17Connector DUAL ROW HEADER 17 POS. .230IN 210279 P16 P22Connector DUAL ROW HEADER 7 POS. .320IN 210282 J25Connector 7 POS DUAL ROW SOCKET .635 TALL 210349 J26Relay SPDT 24V MINI PC RELAY 450004 K2Pot 2K TRIMPOT H MTG. 470029 R161Pot 50K TRIMPOT 470059 R193Switch DIP SWITCH PIANO 8 POS. 510110 S1Switch DPDT R/A SLIDE SWITCH 510121 S12 S13Transformer 600CT/600CT 560018 T1Cable 34 PIN FLAT, 2 CONN. 770018 J23
Clear-Com MS-232 Two-Channel Main Station
16
CLEAR-COMINTERCOM SYSTEMS
R
PROGRAM INPUT
OUTPUT
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
,10,1
1,
12,1
3
PANELMICGAIN
HOT MIC
DIP EN
*CALL B*CALL A*PRG INT B*PRG INT A
ALERT TONEALT TONE EN
ANN RELAY
LINK B OUTLINK B LN DRVLINK A LN DRV
SPK MUTE
To J23 onLogic Board
CHL A POWERCHL B POWER
KILL RLY CONTKILL RLY COIL
CHL ATERMINATION
CHL BTERMINATION
ONOFFONOFF
ALERT TONELEVEL
CW
CW
HEADSET
PANELMIC
SPEAKER
INTERCOMCHANNEL A
INTERCOMCHANNEL B
ANNOUNCEOUTPUT
ANNOUNCE OUT +ANNOUNCE OUT -
PROGRAM IN +
PROGRAM IN -
ANNOUNCERELAY
Spares:
2
1
13
15
5
7
PROGRAMVOLUME
CW
2
P17/J17
J17/P17
J17/P17
J17/P17
P17/J17
J17/P17
5
7
13
15
CW
SIDETONE A
P17/J17
J17/P17
1
2 2
CW
SIDETONE B
J17/P17
4 4
P17/J17
6 6
8 8
10 10
12 12
P17/J17
J17/P17
J17/P17CW
CW
LISTENLEVEL B
LISTENLEVEL A
P17/J17
14 14
PRGM FEEDA LEVEL
PRGM FEEDB LEVEL
LONG LINE A
LONG LINE B
99
J23/P22J16/P16
4 22
P22/J23
P22/J23
P16/J16
P16/J16
10 10 23 5
11 11 24 6
PARTY LINELINK A+B
16 16
FRONT PANEL PCA
GROUND PLANE
J18/P16 J23/P22
3 3 1 1
SPK ON-OFF(CLOSE ON)
PANEL SELHEADSET SELIFB MUTEANNOUNCETALK SEL BTALK SEL A
REMOTEMIC KILL
J18/P16 J23/P22
5 5 25 25
J16/P16
J18/P16
J23/P22
J23/P22
2828
27271
16 16
19
CH AFAULT(RED)
CH BFAULT(RED)
HEADSET CABLE ASS'YP/N 740065
PANEL MIC CABLE ASS'YP/N 740066
PANELSPEAKER ASS'Y
P/N 740067
65W SWITCHINGPOWER SUPPLY
POWER ON-OFF
POWER ENTRYHARNESS ASS'Y
P/N 740063
DC POWERCABLE ASS'YP/N 740064
2. ALL CAPACITORS ARE LISTED IN MICROFARADS
TEST
MS-232 2-Channel Main Intercom Station SchematicSHEET 1 OF 2
IFB INPUT
X0459.DSN
PROGRAM FEED ONANNOUNCE OPTION
Clear-Com MS-232 Two-Channel Main Station
17
+30V
+30V
BIAS
+30V
+30V
+30V
+30V
+30V
+30V
+30V
VDD
VDD
+30V
BIAS
BIAS
BIAS
BIAS
BIAS
VDD
+30V
+30V
+30V
VDD
VDD
+30V
VDD
+30V+30V
+30V
BIAS
+30V
+30V
BIAS
BIAS
BIAS
BIAS
BIAS
BIAS
BIAS
BIAS
BIAS
VSS
BIAS
BIAS
BIAS
BIAS
BIAS
VSS
VSS
VSS
VSS
BIAS
BIAS
BIAS
BIAS BIAS
BIAS
BIAS
BIAS
VSSVSS
VSS
VSS
VSS
+30V
VDD
C831uF NP
C124.1uF
IC21CDG444
11
9
10
R2410K
R1631M
P15XLR-3M
1
3
2
4
R131430
R324.7K
P5XLR-3M
1
3
2
4
C841uF NP
+ C91100uF
+C1422uF
R12647.5K*
P13XLR-3M
1
3
2
4
C71.0047uF
IC19B
LM8335
67
P14XLR-3M
1
3
2
4
C93
470pF
C851uF NP
C65.047uF
R13920K*
C691uF
C4.01uF
C76.1uF
C681uF
IC15ALM833
3
21
84
C4939pF
T11 6
5
3 4
2
R12710
Q8MPSA05
3
2
1
C92
470pF
R132100K
C81.01uF 1.4KV
R202
20K*
R15210K
R14020K*
IC17A4559
3
21
84
R193.3K
D7
R9947.5K*
IC20A4559
3
21
84
IC24BDG444
6
8
7
R1429.1K
R18
4.7K
R208
20K*
D26
P10XLR-3M
1
3
2
4
R10047.5K*
Q252N5639
3
2 1
R966.2K
C524.7uF
IC15BLM833
5
67
J3
1 2 3 4 5 6
C82.1uF
R207
20K*
R224
9.1K
P9XLR3-F
1
3
2
4
R115430
C86200pF
R206
20K*
R15110K
R17
9.1K
R226
100K
R135120K
R20120K*
R205
20K*
C100.0047uF
+
C631uF
C64
.047uF
R209
47.5K*
C132.1uF
D8
R227
2K
R146220
R1802K
R210
47.5K*
C130.1uF
D1
C131.1uF
R216
20K*
IC16B4559
5
67
C128.1uF
IC24DDG444
14
16
15
R212
20K*
R11810K
R214
47.5K*
C129.1uF
C66.047uF
R80
R130
2K
R21
2.2K 1/2W
R213
20K*
R1864.7K
C78470pF
R20
2.2K 1/2W
R215
20K*
R211
47.5K*
R11
1K
R187
20K*
Q10TIP35
2
1
3
+
C5647uF
C105.047
R12
20K
Q9TIP35
2
1
3
IC21ADG444
3
1
2134
5 12
R10
1K
R105120
C108.01uF
J20
R2176.8K
R13
20K
S12SW SPDT
R149.1K
C104.0047uF
R2186.8K
R144
15K
S13SW SPDT
R159.1K
R145
6.8K
IC22ADG444
3
1
2134
5 12
R61K
Q19MPSA13
3
2
1
IC22DDG444
14
16
15
R2251.5
C67.0047uF
R71K
R18833K
IC24CDG444
11
9
10
IC19ALM833
3
21
84
P22
123456789
10111213141516171819202122232425262728293031323334
R1716.8K
R28.39 2W
+C121100uF
C77.1uF
C2.1uF
C57470pF
C3.1uF
Q2
MPSA55
1
2
3
IC21DDG444
14
16
15
Q3
MPSA55
1
2
3
Q6MPSA55
1
2
3
Q5MPSA55
1
2
3
R133470K
Q21J174
2
31
D41N4003
R134470K
P8
123
R13739
D21N4003
JP2
R13839
C118820pF
C6.01uF
C5.01uF
R14710K
R194220
Q4MPSA55
1
2
3
R196220
+ C8100uF
R1974.7K
+
C13622uF
R1284.7K
R1954.7K
C112 820pF
+ C7100uF
IC16A4559
3
21
84
C106.1uF
R12920K*
C791uF NP
R1199.1K
R125
4.7K R10210K
R12020K*
R30850KPOT
+ C11910uF
C5447pF
C1091uF NP
+ C12010uF
R30336K
D10
1N4003
P7
123
+
C90100uF
R12120K*
L1
100uH
R433K
C55
.1uF
R11720K*
R333K
R3045K
POT
R31050KPOT
C107
.01uF
R233K
P3
123
R30950KPOT
Q24TIP41
2
1
3
D51N5401
+
C13722uF
R1912.2
D61N5401
C80
.22uF
IC23B4559
5
67
R16647.5K*
C116
.1uF
P4
123
R1732.2
R123820
C621uF NP
R174
1K
K2
RELAY SPDT
R106
120
R3055K
POT
R30750KPOT
C301.1uF
R30650KPOT
D471N4003
C101
.1uF
C5139pF
IC24ADG444
3
1
2134
5 12
IC23A4559
3
21
84
D151N4003
IC20B4559
5
67
R1016.2K
C87200pF
R136120K
RP1100K SIP
1 2 3 4 5 6 7 8 9 10
C88
.047uF
R165
6.8K
C11722pF
R122100K
IC22BDG444
6
8
7
R1483.3K
U22CDG444
11
9
10
XLR-4M
1
2
4
5
3
C115.0022uF
S1-7OPTION
C89.22uF
S1-8OPTION
P11
470pF1KV
R103100K
R1533.3K
470pF1KV
S303
R109470K
R168
33K
C61
.047uF
D45
K301RELAY SPDT
R169
33K
R17010K
Q23
MPSA053
2
1
S308SW DPDT
D43
LED304
C70.0047uF
R149
470K
R18220K*
C97.1uF
D3011N4003
C95.01uF
R154
470K
R19350K POT
R313
10K
8 OHM
R97100K
C96.01uF
R150
680
12
C7247pF
R11622
C1141uF NP
C103.1uF
123
R10722
R159
220
+
C7347uF
Q22J174
2
31
IEC 320 MALE
C102.1uF
R1430
C53
.1uF
R16747.5K*
R982K
J2
123
R158
10K
C11047pF
-
+
IC14LM384
6
2
8
7 3
1 14
+ C171000uF
R164
3.3K
C59
.1uF
C74470pF
C98.01Uf
R155470K
R108100K
R124100K
R1419.1K
+C122220uF
R156470K
IC17B4559
5
67
C5847pF
C75470pFR161
2K
IC18ALM833
3
21
84
R55 5W
C60
.1uF
IC18BLM833
5
67
R160430
IC1555
2
5
3
7
6
4
TR
CV
Q
DIS
THR
R
C123
470pF
D46
C992.2uF
S301
R2543K
R199
22
D26
P12XLR-3M
1
3
2
4
R23820K
C504.7uF
R198
1K
IC21BDG444
6
8
7
R221K
D7
P6XLR-3M
1
3
2
4
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
CHL A POWER
CHL B POWER
SPK MUTEPANEL SELHEADSET SEL
ANNOUNCETALK SEL BTALK SEL ADIP EN
IFB MUTE
ANN RELAYCALL BCALL APRG INT BPRG INT A
ALERT TONEALERT TONE EN
CHL A POWERCHL B POWER
LINK A LN DRV
LINK B LN DRVLINK B OUT
LINK B OUTLINK B LN DRVLINK A LN DRV
KILL RLY COILKILL RLY CONT
CHL B POWER
CHL A POWER
CALL ASENSE
CALL BSENSE
CALL BSEND
SEND
CLEAR-COMINTERCOM SYSTEMS
CALL A
+15V VDD SOURCE
ANNOUNCE RELAY
ALERT TONEALT TONE EN
LINK B OUTLINK B LN DRVLINK A LN DRV
CALL BCALL A
DIP ENABLE
TALK SEL BTALK SEL A
PRG INT BPRG INT A
SPK MUTEPANEL SEL
HEADSET SELIBF MUTE
ANNOUNCE
+30VVDD
+30VVDD
VSS
VSS
POWER ONRESET
CHL A POWERCHL B POWER
J16/P16
J18/P16
11 29
11 11
J25/P26
J25/P26
4 4
6 6
P26/J25
P26/J25
3 3
5 5
J25/P26 P26/J25
1 1 9 9
2 2 10 10
MOMENTARYONLY CH A
P26/J25
P26/J25
7 7
8 8
INTRPT ANNC
INTRPT EXT IFB
J25/P26 P26/J25
MOMENTARYONLY CH B
CALL ON TALK A
CALL ON TALK B
CALL A
CALL B
J16/P16
J16/P16
9 27
7 25
TALK A
TALK B
TONE ALERTJ18/P16
9 9
PANEL MIC / HEADSET(CLOSE-PANEL)
J16/P16
10 28
P16/J18
77
TONE ALERT(GREEN)
TALK A(IN TALK A SW)
TALK B(IN TALK B SW)
P16/J16
P16/J18
1230
10 10
J16/P16
J16/P16
J18/P16
J18/P16
13
14
31
32
13
12
13
12
PROGRAMFEED AENABLE
PROGRAMFEED BENABLE
PROGRAMINTERRUPTA ENABLE
PROGRAMINTERRUPTB ENABLE
PROGRAM ASELECT
PROGRAM BSELECT
1 1
J16/P16
8 26
ANNOUNCE
J18/P16
J18/P16
P16/J16
P16/J16
3
14
21
14
15 33
FRONTPANEL
PCA
SHOWN ONSHEET 1
SHOWN ONSHEET 1
ALERT TONE DELAYNONE (OPEN) - 2 SEC (CLOSED)
RMK SW
MS-232 2-Channel Main Intercom Station SchematicSHEET 2 OF 2
X0460.DSN
R
18
Clear-Com MS-232 Two-Channel Main Station
+30V
+30V
VDD
VDD
VDD
+30V
VCC
+30V
VDD
VDD
VDD
VDD
VDD
VDD
VDD
VDD
VDD
VDD
VDD
VDD
VDD
VDD
+30V
+30V
VDD
VDD+30V
VDD
VSS
VSS
VSS
VSS
VSS
VSS
VSS
VSSVSS
VSS
VSS
VSS VSS
VSS VSS VSS
VSS VSS VSS
VSS
VSSVSS
VSS
VSS
VSS
VSS
VSS
VSS
VSS
VSS
VSS
VSS
VSS
+ C3510uF
R91470K
C41.1uF
(IC9)
S300
R41470K
S301
IC8LM340-15
VI
GN
D
VO
IC5D
4011
12
1311
C126.1uF
(IC10)
RP2-7100K SIP
S305
C27.1uF(IC1)
RP2-5100K SIP
C28.1uF(IC2)
C29.1uF(IC3)
IC4D4001
12
1311
C30.1uF(IC4)
RP2-4100K SIP
C31.1uF(IC5)
RP2-6100K SIP
C32.1uF(IC7)
RP2-3100K SIP
IC13A4013
5
3
1
2
64
D
CLK
Q
Q
SR
R45470K
IC4C4001
8
910
IC13B4013
9
11
13
12
810
D
CLK
Q
Q
SR
S302
IC2B
45843 4
IC2C
45845 6
Q18MPSA13
3
2
1
RP2-2100K SIP
IC2A
45841 2
Q15MPSA13
3
2
1
S1-1
OPTION
LED300
IC2D
4584
9 8
Q14MPSA13
3
2
1
S1-6
OPTION
R3004.7K
R44470k
D27
Q11MPSA13
3
2
1
S1-5
OPTION
IC4B
4001 5
64
Q16MPSA13
3
2
1
S1-2
OPTION
IC4A
4001 1
23
C46.01uF
Q17MPSA13
3
2
1
S1-4
OPTION
S304
S1-3
OPTION
IC10A4556
23
1
4567
AB
E
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1413
15
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R9310K
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64
R161M
C134
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C23.01uF
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D16
IC124040
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11
9765324131214151
CLK
RST
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Q10Q11Q12
R7439
R7360.4K*
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R9410K
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C38.22uF
C133.1uF(IC13)
C125.1uF
RP3C220K SIP5 6
C192.2uF
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12
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34
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R354.7K
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11
13
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64
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1
23
J23
12345678910111213141516171819202122232425262728293031323334
R49100K
R75
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R50
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D19
D20
R584.7K
D21
D22
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IC9B
45843 4
D11
IC9C
45845 6
C39.047uF
IC9D
45849 8
IC9E
458411 10
D126.8V ZD
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R59220K
R47100K
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13 12
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1
2
3
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R6968K
R52100K
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C135
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IC5C
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8
910
S309
D131N4003
S310
CALL A
CALL B
TALK SEL A
TALK SEL B
IFB MUTE
TALK SEL BTALK SEL A
SPK MUTE
HEADSET SEL
PANEL SEL
PANEL SELHEADSET SEL
ANNOUNCE RELAY
ANNOUNCE
ANNOUNCE
ANNOUNCE RELAY
ANNOUNCE
IFB MUTE
IFB MUTE
DIP ENABLE
DIP ENABLE
CALL SENSE A
CALL SENSE B
CALL SENSE A
CALL SENSE B
PRG INT B
PRG INT A
ALERT TONE
ALERT TONEALT TONE EN
ALT TONE EN
CALL ACALL B
PRG INT APRG INT B
ANNOUNCE
TALK SET A
TALK SET B
TALK SET A
TALK SET B
CLEAR-COM LIMITED WARRANTY
The Clear-Com warranty does not cover any defect, malfunction or failure caused beyond the control ofClear-Com, including unreasonable or negligent operation, abuse, accident, failure to follow instructionsin the manual, defective or improper associated equipment, attempts at modification and repair notauthorized by Clear-Com, and shipping damage. Products with their serial numbers removed or de-faced are not covered by this warranty.
This warranty is the sole and exclusive express warranty given with respect to Clear-Com products. It isthe responsibility of the user to determine before purchase that this product is suitable for the user's in-tended purpose.
Any and all implied warranties, including the implied warranty of merchantability are limited to the dura-tion of this express limited warranty. Neither Clear-Com nor the dealer who sells Clear-Com productsis 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 ReturnAuthorization Number.
Send equipment to be repaired to:
Customer Service DepartmentClear-Com Intercom Systems4065 Hollis St. Emeryville, CA 94608-3505Telephone: (510) 496-6666Telefax: (510) 496-6699
Warranty Repairs - If in warranty, no charge will be made for the repairs. Equipment being returned forwarranty 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 re-quested, an estimate of repair costs will be issued prior to service. Once your approval for repair, andrepair of equipment is completed, the equipment will be shipped freight collect from the factory to thecustomer.
Clear-Com MS-232 Two-Channel Main Station
19
TECHNICAL SPECIFICATIONS
HEADSET MICROPHONE PRE-AMP
Input Type: DynamicImpedance: 1KΩInput Level: -55 dBV nominal; -10 dBV max.Gain from headset mic to intercom line: +41 dB
PANEL MICROPHONE PRE-AMP
Input Type: ElectretInput Level: -45 dBV nominalGain from panel mic to intercom line: +31 dB
PRE-AMP RESPONSE CURVE
Frequency Response: 250 Hz - 12 KHz, contoured for intelligibilityLimiter Range: 20 dB
HEADPHONE/SPEAKER AMPLIFIER
Load Impedance Range: 50 - 2 KΩ ΩOutput Level: at least +20 dBV across 600ΩDistortion: < 0.2% THD @ 1 KHzFrequency Response: 200 Hz - 18 KHz, 2 dB±Gain from intercom line: +37 dBPower Output: 110 dB SPL
PROGRAM AMPLIFIER
(Transformerless, balanced differential input)Input Level: -20 dBVInput Impedance: > 100 KΩFrequency Response: 150 Hz - 18 KHz, 2 dB±
TERMINATION IMPEDANCE
Impedance: 200 , switchableΩ
POWER SUPPLY
Type: Switching, with overcurrent limiting and reset circuitryOutput Voltage: 30 volts DCOutput Current: 2 amps peak, 1.75 amps max, distributed over both channelsShort 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
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-3FHot Mic / IFB Interface: (1) 1/4" Phone JackAC Power: IEC 320 Connector
REAR PANEL CONTROLS
(2) Termination On-Off switches; (8) Option switches; (1) Power switch; (1) Tone Alert Volume control
Clear-Com MS-232 Two-Channel Main Station
20
FRONT PANEL CONNECTORS
Panel Mic: (1) 1/4" panel mounting jackHeadset: (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) Talkbuttons; (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 - 122o 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 prod-uct manuals, that information is subject to change without notice. Performance specifications includedin this manual are design-center specifications and are included for customer guidance and to facilitatesystem installation. Actual operating performance may vary.
MS-232 Manual P/N 810212(C) 1998 Clear-Com SystemsAll Rights Reserved
Clear-Com MS-232 Two-Channel Main Station
21