Nautel V10, Руководство пользователя по установке и эксплуатации

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V10/V7.5/V5/V3.5 Installation and Operation Manual
Page 5-17
Section 5 System Level Troubleshooting Issue 3.5
•
Visually inspect the antenna system for
ice buildup.
•
If no ice is present, the problem is
likely the fault detection circuitry on the
control/display PWB (A43).
Possible Associated Faults:
- SWR Foldback
5.5.3.3 SWR Shutback/Cutback Level
An SWR Shutback alarm occurs when
the transmitter’s peak reflected power
exceeds the SWR shutback threshold (2:1
SWR) due to a transient SWR condition
(arc or lightning) within the output
transmission line or antenna system [
SWR
Shutback threshold is user definable, but is
defaulted to 1,200 W for V10, 900 W for
V7.5, 600 W for V5 or 450 W for V3.5, for
all modes]. To reset the latched condition
immediately (clear the cutback levels),
press the Reset soft key in the Status
screen. Troubleshoot an
SWR Shutback
alarm as follows:
NOTE
Under excessive reflected power, the
transmitter shuts back and recovers to a
series of cutback levels. Each level
represents a 1/8th reduction in forward
power from the preset power. The
transmitter sequentially attempts to
recover to the highest level that yields
acceptable reflected power. The level
depends on the extent of damage to the
output transmission line or antenna
system. The recovery time is dependent
upon the cutback level.
•
Inspect the output transmission line for
punctures and/or damage.
•
If no damage can be found with the
output network, the problem is likely
with the fault detection circuitry on the
control/display PWB (A43).
Possible Associated Faults:
- SWR Shutback
- Cutback Level 1 - 7
5.5.3.4 SWR Shutdown
An SWR Shutdown alarm occurs when
the transmitter tries to reduce the forward
power below 1630 W (V10)/1223 W
(V7.5)/815 W (V5)/612 W (V3.5) (
FM
mode), 1164 W (V10)/873 W (V7.5)/582 W
(V5)/437 W (V3.5) (
FM+HD mode), or
465 W (V10)/349 W (V7.5)/232 W (V5)/
174 W (V3.5) (
HD mode) due to repeated
SWR Foldback alarms. The transmitter
latches off. To reset, press the Reset soft
key in the Status screen. When
troubleshooting an SWR Shutdown
alarm, refer to the troubleshooting tips for
an
SWR Foldback alarm (see 5.5.3.2) or
check the control/display PWB (A43)
detection circuitry.
Possible Associated Faults:
- SWR Shutdown
5.5.3.5 High Forward Power and
Forward Power Limiting
A High Fwd Pwr alarm occurs when the
transmitter average forward power
exceeds the high threshold (
High Forward
Power threshold is 1.036 times the
maximum power setting for all modes; e.g.,
11,396 W for a V10 in
FM mode). See
Table 1-1 for maximum power capability.
This alarm only occurs if ALC is disabled
or cannot respond fast enough to
transmitter load changes. Troubleshoot a
High Fwd Pwr alarm as follows:
NOTE
Once this alarm is active, the transmitter
prepares to fold back the forward power if
the forward power limiting threshold is
exceeded. The forward power limiting
threshold is 1.063 times the maximum
analog power setting for FM mode (e.g.,
11,693 W for a V10, the max hybrid power
setting for FM+HD mode, and the max all-
digital power setting for HD mode.
•
Verify ALC is enabled.
•
If ALC is enabled, suspect the fault
detection circuitry on the control/
display PWB (A43).