500 WATT RADIOBEACON TRANSMITTER
ND2000A-02x-xx0
Page 6-2
15 October 2004
6.3.10 BATTERY CONTROL PANEL
ASSEMBLY WIRING
:
Table 8-11 provides a
tabular wiring list for battery control panel assembly
A11.
6.3.11 INTERFACE PANEL ASSEMBLY
WIRING:
Table 8-12 provides a tabular wiring list
for the interface panel assembly.
MECHANICAL DRAWINGS
6.4
Mechanical drawings, shown in figures
MD-1 through MD-38, are illustrations that depict the
assembly detail for and show the location of most
electrical components. The illustrations are presented
in their order on the reference designation hierarchy.
SCHEDULED MAINTENANCE
6.5
Scheduled maintenance is restricted to
performing a visual inspection and a functional test/
calibration procedure (see paragraph 5.3) at scheduled
intervals. The recommended time between scheduled
maintenance visits is three months. Local operating
and environmental conditions may dictate more
frequent visits and in the case of remote sites, less
frequent visits may be acceptable. Experience and
system reliability will determine the most practical
schedule for a specific installation.
CORRECTIVE MAINTENANCE
6.6
Corrective maintenance procedures
comprise identifying and correcting defects or
deficiencies that arise during operation and/or testing
of the transmitter. The transmitter will switch to the
standby side and/or shut down automatically if the
carrier level or modulation depth fall below preset
thresholds or if the identification code keying is lost.
A functional test and where appropriate an attempted
calibration procedure should be the first step in taking
corrective action. Figure 6-1 through 6-15 provides
waveform indications for use in fault isolation.
ISOLATION OF DEFECTIVE POWER
MOSFETs
6.7
Isolate defective power MOSFET devices
using a digital multimeter that can measure a diode's
forward/reverse resistance, as follows:
Power MOSFET transistors are susceptible to
damage from static electricity. Observe static
protection procedures when handling the devices
and the assemblies containing devices. As a
minimum grounded conductive, bench mats and
wrists straps should be used.
NOTE
The following procedures require the power MOSFET
under test to be turned on by the application of a DC
voltage (minimum of 4.0 V dc to a maximum of 9.0 V
dc) between its gate and source. Some digital
multimeters have sufficient dc voltage on their test
leads when they are set to diode or resistance test
positions.
If the digital multimeter to be used falls in this
category, it may be used as the voltage source. If it
does not, a dc voltage source that is between 4.0 and
9.0 V dc must be obtained.
6.7.1
ISOLATION OF DEFECTIVE POWER
MOSFET's IN A POWER AMPLIFIER:
Isolate
defective power MOSFETs in a power amplifier
assembly as follows:
NOTE
Previously recorded alarm/status indications
(
PA
VOLTS
1 through 4 lamps) will indicate which power
amplifier assembly is suspected of having a defective
power MOSFET(s). Refer to figure SD-4.
(a) Locate the power amplifier assembly that is
suspected of having defective power MOSFETs
(Refer to figure MD-7 to identify a specific
power amplifier assembly and to figure MD-11
for its assembly detail).
(b) Remove suspect power amplifier assembly as
follows:
-
Disconnect coaxial cable connector from J1
(BNC) of power amplifier assembly.
