Broadcast Electronics PNP 1000, Руководство пользователя, Страница: 11 / 52

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ADJUSTMENT WITHOUT MODULATION MONITOR –
NOTE
NOTE
WITHOUT A MODULATION MONITOR, THE FOLLOWING AD-
JUSTMENT WILL NOT ENSURE A 100% MODULATION LEVEL
FROM THE TRANSMITTER.
1. Operate the front–panel breaker to ON.
2. Depress the front–panel ON switch/indicator to illuminate the switch/indicator.
3. Operate the audio source with normal program music.
4. Ensure pilot indicator DS1 is illuminated. If the indicator is not illuminated, the composite
signal is not present at the transmitter.
5. Adjust the composite source output level control until the front–panel COMPRESSION indicator blinks at a
rate of approximately once per second. This will provide a modulation level of less than 100%. However,
the audio input will be adjusted to a level preventing audio input overload and clipping. Ensure the level does
not exceed 3.5 volts peak–to–peak.
SCA.
The SCA input audio level is adjusted by using the output level control on the audio source. To adjust the level to
obtain the desired modulation, proceed as follows:
1. Connect an SCA decoder to the modulation monitor.
2. Operate the front–panel breaker to ON.
3. Depress the front–panel ON switch/indicator to illuminate the switch/indicator.
4. Operate the audio source to output a 400 Hz tone.
5. Adjust the audio source output level for approximately 15% modulation on the SCA decoder. Indicator D8
on the DSP circuit board illuminates to indicate the overload of the SCA input. If D8 illuminates decrease
the audio level until D8 extinguishes.
MOUNTING.
The PNP 1000 transmitter requires 21 inches (53.3 cm) of a 19 inch (48.3 cm) rack cabinet. Do not mount the trans-
mitter directly above or below heat generating equipment. Once a rack location is determined, mount the chassis in
the rack using 4 screws.