Larcan FM-250, Техническое руководство

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FM-250 FM BROADCASTING EXCITER
Issue Date: 21 Jan 2003
2. OPERATION
With the electrical connections completed above the unit is now ready for operation.
a) SWITCH ON SEQUENCE
Adjust the RF power control on the front panel, fully acw. then set the power on/off
switch to ON.
b) FRONT PANEL LED's:
RF ENABLE (green led)
ON
PLL LOCK (green led) ON
PRE EMPHASIS (yellow led) ON
REMOTE PLL (yellow led) OFF
RF FAULT (red led) ON
VSWR FAULT (red led) OFF
TEMP FAULT (red led) OFF
A/C SUPPLY (green led) ON
EXT. DC (green led) ON
OVER VOLTAGE (red led) OFF
PSU FAULT (red led) OFF
RF PSU FAULT (red led) OFF
c) ALC METER
All the Leds on the ALC meter should be OFF when PWR ADJ is set to minimum.
d) MULTIMETER
Select the four functions in turn and check the meter readings:
•
TEMPERATURE Room ambient.
•
PA CURRENT 0 Amps (no Leds on).
•
FORWARD POWER 0 Watts (no Leds on).
•
REFLECTED POWER 0 Watts (no Leds on).
e) DECODED MPX (VU Meters).
The Left and Right, VU meters will be indicating the incoming program levels and should be
operating in the green zone of the meters with occasional peaks switching the 0dB yellow
led on. The program peaks should not be operating in the red zone of the meters. If the
meter is operating below the 0dB level (yellow), the internal sensitivity setting may have to
be increased on the Stereo coder module to suit the incoming program levels. See
calibration section for information.