Telex MCE325 manual True Sidetone Adjust, Talk Button Test Point Potentiometer

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8Repeat for channels 2 through 4 by activating the TALK buttons, connecting to the test points and adjusting the potentiometers as indicated in Table 4.4.

True Sidetone Adjust

1Configure the DYN MIC HEADSET jack for stereo mode (See Section 3, “MONO”)

2Set all front panel buttons to off.

3Connect 51 ohm load resistors across the left headphone output (J2 pins 3 and 4) and right headphone output (J2 pins 3 and 5).

4Connect an AC voltmeter across the left headphone output.

5Remove the signal generator from the mic input, and connect it across intercom channel 1. Adjust the generator output to –1 dBu (0.69 VAC), 1 kHz.

6Activate the CH 1 TALK button, and adjust the CH 1-3 volume control (R1) until you measure 11.2 dBu (2.82 VAC) across the left headphone output.

7Disconnect the signal generator from intercom channel 1. Adjust the generator for minimum output, and reconnect it across the DYN MIC HEADSET jack mic input (J2 pins 1 & 2). Readjust the generator output level to –45 dBu, 1 kHz.

8Turn on the MIC ON button.

9Adjust R37 (sidetone) on the MCE325 main board to obtain 8.7 dBu (2.1 VAC) at the left headphone output.

Level and Frequency Response Check, Intercom Channel to Headphone

1Set all front panel buttons to off.

2Remove the signal generator from the mic input, and reconnect it across intercom channel 1.

3Adjust the signal generator output to –1 dBu, 1 kHz.

4Preset the CH 1-3 volume control to the 2 o’clock position.

5Activate the CH 1 TALK button. The left headphone output level should be 11.2 ±2 dBu (2.2 to 3.6 VAC).

6Adjust the CH 1-3 volume control to measure 11.2 dBu (2.8 VAC) at the left headphone output. Check for no distortion or clipping in the output.

7Adjust the signal generator output to –1 dBu, 100 Hz. The left headphone output should read

10.2dBu ±2 dBu (1.9 to 3.2 VAC)

8Adjust the signal generator output to –1 dBu, 10 kHz. The left headphone output should read

7.8dBu ±2 dBu (1.5 to 2.4 VAC).

9Repeat the test for channels 2 through 4. For channel 3, continue to use the CH 1-3 volume control and monitor the left headphone output. For channels 2 and 4, use the CH2-4 volume control and monitor the right headphone output.

Table 4.4 Channel 1-4 sidetone trimmer adjust.

TALK BUTTON

TEST POINT

POTENTIOMETER

 

 

 

CH 1

U5 pin 7

R57 (Sidetone 1)

 

 

 

CH 2

U5 pin 1

R73 (Sidetone 2)

 

 

 

CH 3

U7 pin 1

R88 (Sidetone 3)

 

 

 

CH 4

U7 pin 7

R104 (Sidetone 4)

 

 

 

4-6C S I - 2 0 0 U s e r I n s t r u c t i o n s

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Contents Model MCE325 Proprietary Notice Return Shipping Instructions End-User License Agreement for Telex Software Table of Contents Operation Diagrams Page General FeaturesDescription Front Panel Features Connections, Inputs and OutputsRear Panel Features Intercom LinesProgramming PowerMounting Configuration MCE325 Specifications Power and MechanicalMicrophone Preamplifier Headphone AmplifierMCS325 Specifications ConnectorsStandard four-channel, two-wire configuration Standard two-channel, four wire configuration Page 10M C E 3 2 5 U s e r I n s t r u c t i o n s 11 MCE325 button configurations 12M C E 3 2 5 U s e r I n s t r u c t i o n s Installation Internal Programming and AdjustmentsSwitch Number Switch Function Default Setting Jumper Number Jumper Function Default Setting Internal DIP switches, jumpers and level trimmers Front Panel Setup Mode Lock-out DS4 Remote Talk-off DS7Mechanical Installation Headphone Sidetone Trimmer Adjustment R37Speaker Dim Adjustment R157 Program Assignment IFB Option J4, J5, J16-J18Mounting configurations Intercom Lines J8, J9, and J10 Electrical InstallationAC Power and Fuse Auxiliary Connector, J22 Four-Wire Channel a and B InputProgram Inputs, J14 and J15 External Speaker, J27Remote Microphone Switch Key outputs Expanded IFB OptionISO Connection External HeadsetFront Panel Headset Connections Carbon-microphone headset connector LED Indicators GeneralOperating Instructions Momentary/Latching Button actionVolume Adjustment Front Panel Sidetone Nulling Trimmer AdjustmentPanel Mic/Headset Mic Selection Microphone On/OffFront Panel Programming Call Disable Latch DisableChannel ID Four-channel ListenReset Instant Mic6C S I 2 0 0 U s e r I n s t r u c t i o n s Preventive Maintenance Corrective MaintenanceAccess Factory Support InformationTest and Adjustment Procedures CleaningPower Supply Test Test EquipmentInitial Configuration Keying Output TestFour-Channel, Two-Wire Mode Frequency Response and Level Check, Mic to LineSidetone Null Test and Adjustment Two-Channel, Four-Wire ModeTrue Sidetone Adjust Talk Button Test Point PotentiometerProgram a to Left Headphone Program to Speaker IFB TestProgram B to Right Headphone Four-Wire a Input to Left Headphone Four-Wire B input to Right HeadphonePanel Mic to Channel Test Carbon Mic to Channel TestVOX Test Mic Kill Receive TestCall Receive Test Mic Kill Transmit TestCall Transmit Test Remote Mic Switch Test ISO TestProgram Lockout Test Noise ChecksPage 14C S I 2 0 0 U s e r I n s t r u c t i o n s Packaging Assembly Final Assembly, MCE325Front Panel Assembly Main PC Board Assembly Back Panel AssemblyHeatsink Assembly 4C S I 2 0 0 U s e r I n s t r u c t i o n s Reference 9027-6245-01 Drawing, Section CR1 FB1 #73 Shield Bead 8C S I 2 0 0 U s e r I n s t r u c t i o n s Reference 9027-6245-01 Drawing, Section 10C S I 2 0 0 U s e r I n s t r u c t i o n s RP2 Washer Flat PC Board Assembly, Front Panel DS1-DS814C S I 2 0 0 U s e r I n s t r u c t i o n s Diagrams 2C S I 2 0 0 U s e r I n s t r u c t i o n s Date 7/23/01 Title D\TEMP\AS624501D.cal Title D\TEMP\AS626101C.cal Title D\TEMP\AS626201C.cal Date 7/19/01 Title D\TEMP\AS646401G.dwg Title D\TEMP\BD646401A.cal Title D\TEMP\IS671801A.cal Title D\TEMP\OD635501A.cal Title D\TEMP\OD635502A.cal Title D\TEMP\OD635503A.cal Title D\TEMP\OD635504A.cal Title c\home\cms\benedil\view\9000-646401.CAL Telex Mother Board Mother Board MCE325 Title D\TEMP\SD624601A.cal

MCE325 specifications

The Telex MCE325 is a sophisticated communications headset designed primarily for professionals who demand clarity and reliability in their audio equipment. Renowned for its advanced features and high-quality construction, the MCE325 is a popular choice in various fields, including aviation, broadcast, and live event production.

One of the standout features of the Telex MCE325 is its superior noise-cancellation technology. This headset is engineered to effectively reduce ambient noise, allowing users to focus on important audio signals without distractions. The exceptional passive noise isolation works in tandem with the active noise-cancelling capabilities to ensure that you can communicate clearly, even in loud environments.

The MCE325 also incorporates a high-performance microphone that delivers crystal-clear sound transmission. The flexible boom design allows users to position the microphone for optimal voice pickup, making it suitable for both left- and right-handed users. The microphone’s windscreen further minimizes wind noise, providing an extra layer of clarity during outdoor use.

Comfort is a critical aspect of the MCE325. The headset features plush, padded ear cups that provide excellent comfort for extended use. The adjustable headband ensures a secure fit, catering to a wide range of head sizes and shapes. This ergonomic design minimizes fatigue, allowing users to maintain focus during long hours of operation.

Connectivity is another area where the Telex MCE325 excels. It is versatile enough to work with various devices, thanks to its dual 1/4” and XLR connectors. This flexibility makes it compatible with many audio interfaces and communication systems used in professional settings. The headset also includes a detachable cable, allowing for easy replacement if needed.

The construction of the Telex MCE325 reflects a commitment to durability and longevity. Built with high-quality materials, the headset can withstand the rigors of demanding professional environments. This robustness ensures that users can trust the MCE325 in the most challenging situations, whether it’s in a busy studio or a bustling airport.

In summary, the Telex MCE325 is a versatile and reliable headset designed to meet the needs of professionals across various industries. With its cutting-edge noise-cancellation technology, high-quality microphone, comfort-focused design, versatile connectivity options, and durable construction, it stands out as an ideal choice for anyone seeking superior audio performance and reliability. Whether in communications, aviation, or live broadcasting, the MCE325 delivers an exceptional audio experience.
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