Telex MCE325 - Manual (Page 42)

4-4 C S I - 2 0 0 U s e r I n s t r u c t i o n s
2 Set the MIC ON button to on. Set all other front panel buttons to off.
3 Check for 13 VDC minimum at the key 1 output.
4 Turn CH 1 TALK on and check for less than 2 VDC at the key 1 output.
5 Repeat 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)
6 Remove the 47 kohm pull-up resistors when finished.
USMB (Un-Switched Microphone Balanced) Frequency Response
and Level Check
1 Set all front panel buttons to off.
2 Connect a signal generator to the DYN MIC HEADSET jack mic input (J2 pins 1 & 2).
3 Connect a 600 ohm resistor across the USMB output (J22, pins 1 and 14).
4 Connect an AC voltmeter across the 600 ohm resistor.
5 Verify the output levels for the input frequencies and levels in Table 4.2.
6 Remove the 600 ohm resistor across the USMB output.
Frequency Response and Level Check, Mic to Line
Four-Channel, Two-Wire Mode
1 Activate the MIC ON button. (All other front panel buttons should be off.)
2 Connect an AC voltmeter across the channel 1 output. The signal generator should still be
connected to the dynamic mic input.
3 Activate the CH 1 TALK button.
4 Verify the output levels for the input frequencies and levels in Table 4.3.
5 Repeat 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)
–45 dBu (4.35 mV)
–25 dBu (43.5 mV) -1 ±3 dBu (0.49 – 0.98 VAC)
2.5 ±2 dBu (0.83 – 1.32 VAC)
2 ±2 dBu (0.75 – 1.2 VAC)
100 Hz -55 dBu (1.4 mV)
–45 dBu (4.35 mV)
–25 dBu (43.5 mV) -0.5 ±3 dBu (0.51 – 1.03 VAC)
4.2 ±2 dBu (0.98 – 1.55 VAC)
4.2 ±2 dBu (0.98 – 1.55 VAC)