Orban OPTIMOD-FM 8600S, Operating Manual

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4-10
MAINTENANCE ORBAN MODEL 8600S
H) Repeat steps (C) through (G) for the right channel.
5. Check distortion performance of Analog I/O.
A) Verify 8600S software controls are set to their default settings. (Refer to page
4-7.)
B) Be sure you are still in
B
YPASS mode [see step (3.F)] and set the
B
YPASS
G
AIN to
+17.0 dB.
C) Set the
AO 100%
control to +20 dBu.
D) Connect a THD analyzer to the Left Analog Output XLR connector. Set the
THD analyzer's bandwidth to 22 kHz.
E) Connect the oscillator to the Left Analog Input XLR connector. Set its fre-
quency to 50 Hz and its output level to +10 dBu. This should produce a level
of approxi18 dBu at the 8600S’s output.
F) For each frequency used to measure THD, adjust the output level of the oscil-
lator to make the
C
OMP meter on the 8600S read
100
. You will have to reduce
the output level of the oscillator at higher frequencies to compensate for the
pre-emphasis boost in the 8600S. As the frequency increases, you will have to
reduce the output level of the generator to follow the 75

s deemphasis curve.
At 15 kHz, you should have to reduce the output of the generator to ap-
proximately –7 dBu.
G) Measure the THD+N at the frequency levels listed below.
Frequency THD+N Typical THD+N Maximum
50 Hz 0.015% 0.03%
100 Hz 0.015% 0.03%
400 Hz 0.015% 0.03%
1 kHz 0.015% 0.03%
2.5 kHz 0.015% 0.03%
5 kHz 0.015% 0.03%
7.5 kHz 0.015% 0.03%
10 kHz 0.015% 0.03%
15 kHz 0.015% 0.03%
H) Repeat the above measurements for the right channel. Connect the oscillator
to the right analog input and the distortion analyzer to the right analog out-
put.
I) Disconnect the oscillator and THD analyzer from the 8600S.
6. Test Digital Sample Rate Converter (Receiver).
A) Verify 8600S software controls are set to their default settings. (Refer to page
4-7.)
B) Be sure you are still in
B
YPASS mode [see step (3.F)].
C) Navigate to
Setup > I/O C
ALIB
> D
IG
I
N
C
ALIB
.