AUSTRALIAN MONITOR AMIS250 Series, Руководство по обслуживанию

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4 AC Check:
4.1 Set signal generator to 1mV. Turn up Mic1 volume control to full. Watch for irregularities
in the output waveform.
4.2 Set output voltage to 35V using the master volume control. Check voltages across the Emitter resistors
(on the output power devices)
4.3 Voltage should be between 150mV – 200mV. Min. and Max. values should be between 33% of the
average value ( i.e. min/max = 0.5mV ).
4.4 Turn the master up to full. Check sensitivity of the microphone inputs. – MIC 1mV (+ 1mV) 32V in a
4
Ω
load.
4.5 Check the output level of the amplifier using each of the input channels.
4.6 Measure 25V line 70V LINE.
4.7 Check tape outputs (L and R) 300mV (+50mV) (Measure on RCA socket).
4.8 Check line outputs. Approx. (2.0V
±
25mV).
5. Function Checks :
5.1 check the position of header links.
a. Vox muting enabled.
b. VCA Con. Disabled.
5.2 Keep signal in CH1 insert ‘INSERT-PLUG’ having external signal of different frequency the out put
should cut off and switch over to applied insert signal, check signal on inset plugs ring terminal with
respective ground should be 300mV. Remove insert plug .
5.3 Check Phantom Switch for on/off operation. Measure Phantom voltage on an XLR inputs ( the
measurement should be 14.5VDC) (Reset the phantom switch)
5.4 Switch off the set connect battery (24V) check for rated out put power (out put signal will clip up
to 2% on battery power)
FINAL TESTING
Requirements for final testing
a. Load 40
Ω
.
b. Multimeter
c. Oscilloscope
d. Microphone
e. Variac
6 Check sensitivity of all channels.
6.2 Mic input (CH1-CH4) = 1mV out put =70V (
±
5V)
6.3 AUX input (CH1-CH5) = 150mV out put =70V (
±
5V)
6.4 AUX input (CH6) = 150mV out put = 32.5V (
±
1.5V)
6.5 Check the Power bandwidth of CH 1 MIC input. – (68Hz
±
5Hz – 15KHz
±
2KHz).
6.6 Check Bass control @ 100HZ = + 10dB (TOL. +1dB), MID C 10dB (TOL. +1dB) and treble @
10kHz = + 10dB (TOL.
±
1dB)
6.7 Check that input signal and output signal are in same phase by comparing CH 1 AUX Input and all
other Outputs ( 25V, 70v, 4
Ω
, 8
Ω
)