Orban Optimod-FM 8300 Operating Manual page 202

4-12
MAINTENANCE
NOTE: The recommended Belar monitor is the only instrument we have
encountered that can accurately measure the performance of the 8300's
stereo encoder. With most older-technology monitors, you will be meas-
uring the performance of the monitor, not the 8300's encoder. (Of
course, we have not evaluated every monitor on the market.)
B) On the 8300, navigate to S
C) Set the M to T
ODE ONE
D) Set the test tone parameters as follows:
Tone Freq...........................................................................................400 Hz
Tone Lvl................................................................................................. 91%
Tone Chan .............................................................................................. L+R
Pilot .......................................................................................................... On
You will have to press the N
E) Navigate to S / S
ETUP
F) Set the C
1 L
OMP VL
lation.
G) Navigate to S
/ T
ETUP
H) Measure the L–R level on the stereo monitor at several frequencies, in units of
dB below 100% modulation. This is the main channel to subchannel crosstalk.
It should not exceed –70 dB, 50-15,000 Hz.
I) Set the T C
ONE HAN
this setting and then the P
Measure the L+R level on the stereo monitor at several frequencies, in units of
dB below 100% modulation. This is the subchannel to main channel crosstalk.
It should not exceed –70 dB, 50-15,000 Hz.
J) Set the T
C
ONE HAN
several frequencies, in units of dB below 100% modulation. This is left-into-
right stereo separation. It should not exceed –60 dB, 50-15,000 Hz.
K) Set the T C
ONE HAN
several frequencies, in units of dB below 100% modulation. This is right-into-
left stereo separation. It should not exceed –60 dB, 50-15,000 Hz.
L) Set the T C
ONE HAN
kHz subcarrier suppression on the stereo monitor. It should not exceed –60
dB.
M) Measure the Pilot Modulation on the stereo monitor. It should read 0%.
N) Set S
/ S
ETUP TEREO
noise at the left and right outputs of the stereo monitor. It should not exceed
–80 dB below 100% modulation.
O) Repeat steps (D) through (N) for the 8300's C
control instead of the C
C 2 L
OMP VL
/ T .
ETUP EST
.
button to access all of these parameters.
EXT
E .
TEREO NCODER
control to make the stereo monitor read 100% total modu-
to access the 8300's tone oscillator parameters.
EST
to L–R. (You will have to press the N
button to return to the T
REV
to L . Measure the Right level on the stereo monitor at
EFT
to R . Measure the Left level on the stereo monitor at
IGHT
to L–R and the T
ONE
to 0.0%. Measure the de-emphasized
E / C 1 L
NCODER OMP VL
1 L
OMP
ORBAN MODEL 8300
button to access
EXT
ONE
F to 5000.0 H . Measure the 38
REQ Z
O
OMPOSITE UTPUT
control.)
VL
F control.)
REQ
2. (Use the