Level and Frequency Response Check, Intercom Channel to Speaker

1Set all front panel buttons to off. Set all volume controls to minimum.

2Connect an 8 ohm load across the speaker output (J27, tip and ring)

3Connect an AC voltmeter and an oscilloscope across the speaker output.

4Connect the signal generator to intercom channel 1, and adjust the generator output to –1 dBu, 1 kHz.

5Set the SPKR ON and CH 1 TALK buttons to on.

6Rotate the CH 1-3 volume control (R1), and check that the speaker output level reaches +18 dBu (17.4 Vp-p) before clipping.

7Set the CH 1-3 volume control to get +15 dBu (4.4 VAC) at the speaker output. The volume control should be approximately at the 2 o’clock position.

8Activate speaker muting by grounding J22 pin 25 to pin 10. The speaker output level should drop to 5 mV or less, and the SPKR LED should turn off. Remove the ground connection.

9Activate speaker dim by grounding U15 pin 9.

10Adjust R157 to the maximum clockwise position. The speaker output should be –5.5dB ±1 dB below the level set in step 7.

11Adjust R157 to the maximum counter-clockwise position. The speaker output should be –39.5 dB ±2 dB below the reference level set in step 7.

12Reset R157 to the maximum clockwise position, and remove the speaker dim ground (U15 pin 9).

13Set the signal generator to –1 dBu, 100 Hz. The speaker output should be 10.8 dBu ±2 dBu.

14Set the signal generator to –1 dBu, 10 kHz. The speaker output should be 17.5 dBu ±2 dBu.

Level and Frequency Response, Program to Headphones and Speaker

Program A to Left Headphone

1Set all front panel buttons to off. Set all volume controls to minimum.

2Set program jumpers J16, J17 and J18 to assign PROGRAM A and PROGRAM B inputs to the headphones and speaker (pins 1 & 2 shorted on all three jumpers).

3Remove the signal generator from channel 1, and reconnect it to the PROGRAM A input (J14 tip and ring).

4Set the signal generator to 0 dBu, 1 kHz.

5Set the PGM VOL control to maximum.

6Measure the level at the left headphone output. It should be 1.3 dBu ±2 dBu.

7Set the signal generator to 0 dBu, 100 Hz. The left headphone output should be 0.8 dBu ±2 dBu.

8Set the signal generator to 0 dBu, 10 kHz. The left headphone output should be –3.8 dBu ±2 dBu.

9Reset the generator to 0 dBu, 1 kHz.

10Remove jumper J16 (program not assigned to left headphone). Verify that the signal level drops at least 35 dB from the reference level in step 9.

4-7

Page 44 Page 46
Page 45
Image 45
Telex MCE325 manual Program a to Left Headphone
Page 44 Page 46

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.
Top Page Image Contents