Harris DX 25U, Техническое руководство

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c. With the POWER switch in the FORWARD position, the
Power meter should indicate zero power. Supply voltage and
supply current meters should both indicate zero readings.
3.6
Transmitter Operations
The following is intended to make the operator aware of some
basic operational characteristics of the transmitter.
3.6.1
Routine Meter Readings
A sample log sheet is provided in Section II, Installation/Initial
Turn On. Copies can be made of the log sheet for station records.
Readings should be taken monthly, at a minimum. However,
more frequent logs can be an important tool in assisting mainte-
nance personnel.
3.6.2
Fault Conditions
The following describes normal transmitter actions for certain
possible fault conditions. It is very important that operators log all
abnormal operation, such as incorrect meter readings, overloads,
fault indications, and transmitter shut-downs. A log or record of
abnormal operating conditions will be useful to technical personnel
in locating and correcting transmitter or other system problems.
3.6.2.1
Transmitter Shuts Off
The operator should first check for overload or fault indications
that are RED and log any fault indications that are found. Press
the RESET button on the ColorStat™ panel to clear fault indica-
tions. ColorStat™ panel indicators should change from RED to
GREEN.
If any LEDs are still RED, contact qualified maintenance per-
sonnel.
When the fault indicators are GREEN, follow the normal turn-on
procedure.
If the transmitter shuts OFF again, and the same overload or fault
indication comes on, try turning the transmitter ON by using the
LOW power button. Under some conditions, a transmitter may
operate satisfactorily at reduced power. If it will not come on at
LOW power, contact qualified maintenance personal.
3.6.2.2
AC Power Failure
If Battery Backup has been installed in the transmitter, no opera-
tor action is required for AC power failures less than approxi-
mately 96 hours. The transmitter will automatically return to an
on-air condition, at the same power level as before the power
failure.
If Battery Backup has not been installed in the transmitter, no
operator action is required for AC power failures less than
approximately 2 hours. The backup capacitor will hold transmit-
ter memory for this time and the transmitter will automatically
return to an on-air condition, at the same power level as before
the power failure.
If AC power failures greater than approximately 2 hours occur
and no Battery Backup has been installed, the transmitter will
remain OFF after AC power returns, and operator action will be
required to turn the transmitter ON and to reset power levels on
the LOW, MEDIUM and HIGH positions.
3.6.2.3
Power Supply Current Fault
During a Current Fault condition the transmitter will shut off and
the indicator will change to RED. The transmitter will attempt to
restart once by itself. If the fault is no longer present, the
transmitter will remain ON. If the fault is still present when the
transmitter attempts to restart, the transmitter will turn OFF and
operator action will be required to restart the transmitter and
possibly correct the problem.
a. If the transmitter turns back on and stays on, check pro-
gram modulation level. If overmodulating on positive
peaks, reduce audio level to reduce modulation.
b. If the transmitter shuts off again and no longer automat-
ically restarts. Log or record the fault, RESET the fault
indicator, and try turning the transmitter on.
c. If the fault occurs again, try operating at LOW power. If
the transmitter will operate at LOW power, operation may
continue on a temporary, emergency basis.
3.6.2.4 Power Reduction
The transmitter will reduce the power output during certain fault
conditions.
If the power output has been reduced, the transmitter has re-
sponded to one of the following faults.
3.6.2.5 VSWR Faults
If the BANDPASS VSWR, ANTENNA VSWR, OR VSWR
TEST indicators are RED, the following may be the cause:
a. This may be a normal occurrence during a thunderstorm,
rain storm, blowing sand, or under conditions of ice on the
antenna and will stop when the weather conditions im-
prove.
b. The indicators may flash RED when overmodulation oc-
curs. Reducing modulation to normal levels may correct
the condition.
c. If the indicators remain RED and weather conditions or
overmodulation are not the cause, transmitter and/or an-
tenna problems are indicated.
3.6.2.6
Temperature Faults
If the TEMP FAULT LED on the Driver Encoder/Temp Sense
Board, inside the Driver Compartment door, is RED, the follow-
ing may be the cause:
a. Failure of the building cooling system (high ambient tem-
peratures).
b. Possible transmitter mistuning
3.6.2.7 Air Flow Faults
If the AIR FLOW indicator on the ColorStat™ panel is AMBER,
the following may be the cause:
a. Obstruction of air flow at the air intake on the transmitter
rear doors or at the air outlet on the transmitter top.
b. Dirty or clogged air filters.
DX-25U
3-2 888-2297-002
WARNING: Disconnect primary power prior to servicing.