Nautel FM10, Технические инструкции

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10 000 WATT FM BROADCAST TRANSMITTER
FM10
Page 6-11
15 November 1999
greater than 2.3 VDC. When the RF drive to an RF
power module drops below the acceptable threshold,
the associated intermediate RF level sample voltage
will drop below the 2.3 VDC threshold and cause the
associated
PDM Inhibit ( A thru F ) output to go high,
disabling the associated switching power supply. At
the same time, the ALC circuit is disabled, the local
MODULE RF DRIVE
indicator LED turns on and the
remote
PA/MODULE FAIL
alarm activates (current
sink). A module inhibit reset is required after the
fault condition has been removed/repaired.
6.5.2.14 PA Fail Alarm: See figures SD-9 and
SD-10. The PA Fail ( A thru F ) inputs (J6-7 thru J6-
12) from the RF power modules (A thru F) and the
PA Fail (IPA) input (J8-5) from the IPA module
indicate if a power amplifier has failed in one of the
RF power modules or the IPA module. When one or
more of these input signals switch from a low
(ground) to a high (15 VDC), the local
PA FAIL
indicator LED turns on and the remote
PA/MODULE
FAIL
alarm activates (current sink).
6.5.2.15 Low IPA Module Input: See figures SD-
9 and SD-10. The IPA RF Drive Level input (J8-7)
is a DC voltage proportional to the RF drive being
applied to the IPA module from the exciter thru the
IPA input power probe. When this level falls below
the acceptable threshold, the
PA Volts Control and
the IPA Volts Control outputs will be inhibited (0.0
VDC). This will inhibit the output of all switching
power supplies and hence the transmitter output. At
the same time, the ALC circuit is disabled, the local
IPA INPUT
indicator LED turns on and the remote
IPA
FAULT/RF FAIL
alarm activates (current sink).
6.5.2.16 High IPA Module Input: See figures
SD-9 and SD-10. When the detected IPA RF drive
level to the IPA module (J8-7) exceeds the acceptable
threshold, the
PA Volts Control output will be
inhibited (0.0 VDC). This will inhibit the output of
all switching power supplies and hence the output of
the transmitter. At the same time, the ALC circuit is
disabled, the local
IPA INPUT
indicator LED turns on
and the remote
IPA FAULT/RF FAIL
alarm activates
(current sink).
6.5.2.17 Low IPA Module Output: See figures
SD-9 and SD-10. The
IPA FWD PWR
input (J8-10) is
a DC voltage that is proportional to the IPA module's
forward power, as sensed at the input of the
intermediate RF drive splitter. When the detected
IPA fwd Pwr level falls below the low drive
threshold, the PA Volts Control output will be
inhibited (0.0 VDC). This will inhibit the output of
all switching power supplies and the output of the
transmitter. At the same time, the ALC circuit is
disabled, the local
IPA OUTPUT
indicator LED turns
on and the remote
IPA FAULT/RF FAIL
alarm activates
(current sink). The alarm threshold is adjustable so
the RF drive level needed at different frequencies can
be compensated for.
6.5.2.18 High IPA Module Output: See figures
SD-9 and SD-10. When the detected IPA forward
power level to the intermediate RF drive splitter
indicates that IPA output power has risen above 600
watts, the
PA Volts Control and IPA Volts Control
outputs will be inhibited (0.0 VDC). This will inhibit
the output of all switching power supplies and hence
the output of the transmitter. At the same time, the
ALC circuit is disabled, the local
IPA SWR
indicator
LED turns on and remote
IPA FAULT/RF FAIL
alarm
activates (current sink).
6.5.2.19 High IPA Reflected Power: See figures
SD-9 and SD-10. The IPA Refld Pwr input (J8-9) is
a DC voltage that is proportional to the IPA reflected
power sensed at the input to the intermediate RF
drive splitter. When the sensed IPA reflected power
level exceeds 160 watts, the
PA Volts Control and
the IPA Volts Control outputs will be inhibited
(0.0VDC). This will inhibit the output of all
switching power supplies and hence the output of the
transmitter. At the same time, the ALC circuit is
disabled, the local
IPA SWR
indicator LED turns on
and the remote
IPA FAULT/RF FAIL
alarm activates
(current sink).
6.5.2.20 Low Transmitter Forward Power: See
figures SD-9 and SD-10. The Fwd Pwr input (J9-1)
is a DC voltage that is proportional to the amount of
forward power sensed by the RF power probe at the
transmitter's RF output. This forward power sample
voltage is compared to a DC voltage proportional to
the PA voltage which supplies the transmitter's final
RF power stage. When the forward power sample
voltage falls below the PA volts sample voltage, a
low forward power fault has been detected. The
PA
Volts Control and the IPA Volts Control outputs will
be inhibited (0.0 VDC). At the same time, the ALC
circuit is disabled, the local
COMBINER MATCHING
indicator LED turns on and the remote
PA VDC/
COMBINER MATCHING
alarm activates (current
sink).