Telex MCE325 manual Frequency Response and Level Check, Mic to Line, Four-Channel, Two-Wire Mode

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2Set the MIC ON button to on. Set all other front panel buttons to off.

3Check for 13 VDC minimum at the key 1 output.

4Turn CH 1 TALK on and check for less than 2 VDC at the key 1 output.

5Repeat steps 3 and 4 for the other channels:

CH2 TALK: key 2 out (J22 pin 19)

CH3 TALK: key 3 out (J22 pin 7)

CH4 TALK: key 4 out (J22 pin 20)

6Remove the 47 kohm pull-up resistors when finished.

USMB (Un-Switched Microphone Balanced) Frequency Response and Level Check

1Set all front panel buttons to off.

2Connect a signal generator to the DYN MIC HEADSET jack mic input (J2 pins 1 & 2).

3Connect a 600 ohm resistor across the USMB output (J22, pins 1 and 14).

4Connect an AC voltmeter across the 600 ohm resistor.

5Verify the output levels for the input frequencies and levels in Table 4.2.

6Remove the 600 ohm resistor across the USMB output.

Frequency Response and Level Check, Mic to Line

Four-Channel, Two-Wire Mode

1Activate the MIC ON button. (All other front panel buttons should be off.)

2Connect an AC voltmeter across the channel 1 output. The signal generator should still be connected to the dynamic mic input.

3Activate the CH 1 TALK button.

4Verify the output levels for the input frequencies and levels in Table 4.3.

5Repeat for channels 2 through 4 by connecting the AC voltmeter across the appropriate output, activating the appropriate TALK button, and measuring the output level:

Table 4.1 Talk button vs. output.

TALK BUTTON

OUTPUT

 

 

CH 2

J8, pins 1 and 3

 

 

CH 3

J10, pins 1 and 2

 

 

CH 4

J10, pins 1 and 3

 

 

Table 4.2 USMB frequency response and level check.

INPUT

 

 

 

FREQUENCY

INPUT LEVEL

OUTPUT LEVEL

 

 

 

1 kHz

-55 dBu (1.4 mV)

-1 ±3 dBu (0.49 – 0.98 VAC)

 

–45 dBu (4.35 mV)

2.5 ±2 dBu (0.83

– 1.32 VAC)

 

–25 dBu (43.5 mV)

2 ±2 dBu (0.75 – 1.2 VAC)

 

 

 

100 Hz

-55 dBu (1.4 mV)

-0.5 ±3 dBu (0.51 – 1.03 VAC)

 

–45 dBu (4.35 mV)

4.2 ±2 dBu (0.98 – 1.55 VAC)

 

–25 dBu (43.5 mV)

4.2 ±2 dBu (0.98 – 1.55 VAC)

 

 

 

 

4-4C 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 Features DescriptionGeneral Front Panel Features Connections, Inputs and OutputsRear Panel Features Intercom LinesPower Mounting ConfigurationProgramming Microphone Preamplifier MCE325 SpecificationsPower and Mechanical 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 DS7Speaker Dim Adjustment R157 Mechanical InstallationHeadphone Sidetone Trimmer Adjustment R37 Program Assignment IFB Option J4, J5, J16-J18Mounting configurations Electrical Installation AC Power and FuseIntercom Lines J8, J9, and J10 Program Inputs, J14 and J15 Auxiliary Connector, J22Four-Wire Channel a and B Input External Speaker, J27ISO Connection Remote Microphone SwitchKey outputs Expanded IFB Option External HeadsetFront Panel Headset Connections Carbon-microphone headset connector Operating Instructions LED IndicatorsGeneral Momentary/Latching Button actionPanel Mic/Headset Mic Selection Volume AdjustmentFront Panel Sidetone Nulling Trimmer Adjustment Microphone On/OffFront Panel Programming Channel ID Call DisableLatch Disable 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 Access Preventive MaintenanceCorrective Maintenance Factory Support InformationPower Supply Test Test and Adjustment ProceduresCleaning 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 IFB Test Program B to Right HeadphoneProgram to Speaker Four-Wire a Input to Left Headphone Four-Wire B input to Right HeadphoneVOX Test Panel Mic to Channel TestCarbon Mic to Channel Test Mic Kill Receive TestMic Kill Transmit Test Call Transmit TestCall Receive Test Program Lockout Test Remote Mic Switch TestISO 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 Back Panel Assembly Heatsink AssemblyMain PC Board 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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