31
PC9500N/PC4800N
1.2.8 Channel separation
Feed the sine wave as specified below to the input terminal of one channel and measure the output voltage. Also, measure the
output voltage at the other channel grounded via a 600
Ω
resistance and check that the voltage measured here is less than -
70dB as compared with the above measured voltage (0dB).
1.2.9 Output noise level
With the input attenuator set at MAX, the input terminal grounded via a 600
Ω
resistance, measure the noise level occurring at
the output terminal and check that it is -65dB or lower. Next, measure the noise level again with the input attenuator set at MIN.
It should be -70dB or lower.
1.2.10 Stability
Feed 10kHz, -10dB rectangular wave, connect 10pF to 0.47
µ
F capacity in parallel with a 4
Ω
load resistance and check that the
following conditions are satisfied.
Next, connect a resistance of only net capacity of 10pF to 0.47
µ
F and check that the following conditions are satisfied.
Vp/Vo 2.5
Ringing should converge within 7 waves and cause no oscillation, etc. to occur
1.2.11 Protection circuit
Feed 10Hz, +10.0dB sine wave and have the output waveform clipped, and check that the protection circuit functions then to
prevent the relay from opening. Next, feed 1Hz, 5.0dB sine wave and check that the protection circuit functions within 2 seconds
to shut off the output and the PROTECTION LED lights in red.
After that, turn off the input signal, turn on the POWER switch again and check that the PROTECTION LED lights in red and the
POWER LED lights in green. Also, check that the muting function is cancelled about 9 seconds after that.
1.2.12 Efficiency
q
Feed 1kHz, 0dB sine wave to the input terminal, measure the primarypower and check that the measured value is within the
range given in the table below.
w
Ground the input terminal via 600
Ω
resistance, measure the primary power and check that the measured value is within the
range given in the table below.
1.2.13 PC limiter and compressor
Feed 1kHz, 0dB sine wave to the input terminal, connect 1
Ω
(
±
5%) resistance to the output terminal, and check that the output
obtained then is as specified in the table below and that the clip indicator is lit at that time.
Make sure to finish this check within 30 seconds.
1.2.14Level meter (no load)
Feed 1kHz sine wave to the input terminal and set the input signal so that the voltage obtained at the output terminal is as
specified in the table below.
Adjust VR702 so that “3” of the A ch level meter lights up. And then, adjust VR704 so that “3” of the B ch level meter lights up.
After that, lower the input voltage by 1dB and check that “3” turns off.
PC9500N
PC4800N
450
±
30W
435
±
30W
PC9500N
PC4800N
29.5
±
1.5dB
26
±
1dB
PC9500N
PC4800N
63.3V
44.7V
60
±
10W
45
±
10W
PC9500N
PC4800N
PC9500N
PC4800N
1KHz 6dB
1KHz 3dB
Vo
Vp
Overshoot:
Vp/Vo 1.8
Ringing:
Within 5 waves
