Solidyne 462dsp, Руководство пользователя

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SOLIDYNE 462
dsp - broadcast digital processor Page 33
Chapter 7 Measurrements
7.1 MEASURREMENT PR OTOC OL
Next instructions offer to make diverse
measurements in case that it is required to state
the engineering specifications of the equipment.
7.1.1 Checking the INPUT LEVELS
Input:
Audio generator at 1 KHZ on both input
channels (the amplitude is varied throughout the
test).
Output:
Oscilloscope on XLR audio output.
Procedure:
a)
Select the program Nº 28.
b)
Adjust the input level of the processor at
+8dBm and check that for this input level both
input VUmeters be exactly a 1 pixel from the
maximum.
c)
Check that increasing the input level until
+10dbm the VUmeters at full scale. At this
value the warning “OVL” must appear under
the Vumeters. In the oscilloscope you must
observe a perfect sinus wave.
d)
Increase the input signal in step of 1dB until
+18dbm. At this value the signal at the output
must be seen distorted, clipped by the input
stage.
e)
Check that previous distortion happens just at
+18dbm at the other channel.
7.1.2 Checking the OUTPUT LEVELS
Input:
Audio generator at 1KHz on both input
channels, adjust the
AGC
so it compress 15db.
Output:
Connect a dB meter on left audio output
(XLR).
Procedure:
a)
Select the program Nº 26.
b)
Under this conditions, the audio output Hill
must be +4dbm.
c)
Repeat for the other channel.
7.1.3 FREQUENCY RESPONSE
Input:
Audio generator at 1 KHz on both input
channels the amplitude is varied throughout the
test).
Output:
Connect a dB meter to the left audio
output (XLR).
Procedure:
a)
Select the el program Nº 27.
b)
Enter with a sine wave and adjust its amplitude
so that the AGC compress exactly 30 dB;
waiting around 10 second to the AGC
stabilized.
c)
Disconnect abruptly the source of signal
(HOLD Hill appears on screen) Verify
throughout this test that this legend do not
disappear at any moment.
d)
Make a frequency sweep with an amplitude 25
dB under the final amplitude used in the point
b). Under these conditions the HOLD indication
must be always on screen.
Realizar el barrido de respuesta frecuencia con
una amplitud de 25dB por debajo de la
amplitud final utilizada en el punto b. Bajo
estas circunstancias la leyenda HOLD deberá
permanecer siempre encendida. Whereas no
of the 4 bands must enter compression (does
matter the input frequency of the oscillator).
e)
At the audio output of the processor you must
verify a response from 20 to 15.000 Hz with a
variation of +/- 0.7 dB.
f)
Repeat for the other channel.
7.1.4 S/N
Input:
Audio generator at 1KHz on both input
channels, adjust the
AGC
so it compress 15db.
Output:
Connect a dB meter on left audio output
(XLR).
Procedure:
a)
Select the program Nº 26.
b)
Take this output level as reference of
maximum output level.