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Also, refer back to
TOTAL-MOD DISPLAY INTEGRATION SELEC-
TION
on Page 17 for the discussion of jumper options that will
effect this reading.
Peak Flasher
The 531N includes the usual ‘Peak Flasher,’ an alarm for carrier
deviations beyond an acceptable maximum value. There is a
front-panel
PEAK
indicator
(25)
, a rear-panel closure to ground
for a remote flasher or other alarm, and SMS/text and email no-
tifications through the Web interface.
The peak flasher follows the total modulation measurement,
which, by default, is the composite of positive and negative car-
rier deviations. This does mean that if the display has been
switched to monitor only positive or only negative excursions,
the peak flasher will respond accordingly.
Cycle
SELECT
button
(14)
to light the
PK-SET
indicator
(24)
.
The digital readout
(12)
now shows the flasher trip level directly
in modulation percentage. Using the up/down
ADJUST
buttons
(13)
set this trip point at any value between 95% and 120%.
The flasher may be programmed for a modulation level that
will give frequent indications of modulation peaks. For in-
stance, if the audio processor has been set for a maximum de-
viation of 100%, the flasher can be set at 99% to show that
modulation is consistently meeting a deviation goal. Using this
feature as the intended alarm, on the other hand, requires that
the trip level be set somewhat above the maximum modulation
point. Again, if the processor is set to hold peaks at precisely
100%, an alarm value of 102% might be selected. This would
represent a value that should never be attained in normal oper-
ation, one that would indicate a legitimate fault.
Pilot Injection
SELECT
button
(6)
also cycles the
CARRIER MODULATION
dis-
play
(2)
to read the injection level of the 19kHz stereo pilot.
When the
SUB/PILOT
indicator
(5)
lights, pilot injection is read
off the lower metering scale. Stereo pilot is typically set to 9%
injection.
Subcarrier
Measurements
The
CARRIER MODULATION
readout
(2)
is also used to display
the injection levels of analog and digital subcarriers. This
measurement mode is accessed with
SELECT
button
(14)
, over
on the right side of the 531N.
The 531N does not
demodulate
data or analog subcarriers, but
it does give a peak-based indication of the
injection level
with
good accuracy.
Cycle the
SELECT
button
(14)
to light the
SUB
indicator
(22)
.
The digital readout
(12)
now indicates the frequency, in kHz, of
the subcarrier being measured. The default frequency is the
57kHz RDS/RBDS RadioData subcarrier.
Use the
ADJUST
buttons
(13)
to bring up analog SCA subcarri-
ers at 67kHz and 92kHz, as well as the ‘residual’ of the 38kHz
suppressed stereo subcarrier (see next page).
Содержание 531N
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