Page 5-12
Vector-LP Radio Beacon Transmitter Technical Instruction Manual
Issue 1.1
Section 5 Maintenance and Troubleshooting
(l) Reinstall the device on its cleaned
heat sink using the hardware removed
in step (j). Replace the Belleville
(cupped) washer with a new washer
(Nautel Part # HZ48, located in
ancillary kit). Apply a thin, even coat
of thermal compound to both sides of
the insulator (if replaced). Refer to the
assembly’s detail drawing in Section
10 to verify the hardware orientation
for the device being replaced.
(m) Using a torque screwdriver, tighten
the mounting hardware to the value
(typically 3 to 4 inch-pounds) specified
on the assembly’s detail drawing in
Section 10, ensuring that the pins of
the device are aligned with their
corresponding solder terminals.
Solder the pins to their associated
terminals.
5.8 EXCITER PANEL PWB
REPLACEMENT
Replace defective printed wiring boards
(PWBs) on the exciter panel and perform
necessary adjustments as follows:
NOTE
The exciter panel is located directly
behind the transmitter’s front panel (see
Figure 2-2). It contains all the PWBs
referenced in the following replacement
procedures.
(a) Press the
Control - RF OFF
switch.
Switch off the ac power and disconnect
the dc supply, if applicable.
(b) Gain access to the exciter panel by
opening the hinged front panel.
(c) Replace the appropriate assembly or
PWB (see 5.8.1, 5.8.2 or 5.8.3).
5.8.1 Exciter Interface PWB and
Interconnecting PWB Replacement
See 5.8 first. The exciter interface PWB
(A2) physically interconnects with the RF
synthesizer PWBs (A5 and A8) and the
interphase PDM driver PWBs (A6 and A9).
Removing the exciter interface PWB
involves removing its interconnecting
PWBs first. Complete the instructions in the
sub-paragraphs (5.8.1.1, 5.8.1.2, and/or
5.8.1.3) to replace the appropriate PWB.
Complete all three paragraphs if replacing
the exciter interface PWB.
5.8.1.1 RF SYNTHESIZER PWB
REMOVAL/REPLACEMENT
(See 5.8 and 5.8.1 first)
(a) Remove six sets of mounting hardware
from the RF synthesizer PWB being
replaced (A5 or A8). If the exciter
interface PWB is to be removed (see
5.8.1.3), remove both RF synthesizer
PWBs, if applicable, and go to 5.8.1.2.
(b) Pull the PWB(s) away from the exciter
interface PWB (A2A2). It may be
helpful to gently pry the connector
loose with a screwdriver.
(c) Install the new RF synthesizer PWB by
reversing the steps above.
(d) Install all shorting jumpers on the
replacement PWB in the same position
as the replaced PWB.
(e) Verify the carrier frequency is set using
BCD switches S1 through S5. Each
switch represents one of the five most
significant digits in the carrier
frequency expressed in kHz:
- S1 is thousands digit (
x1000
)
- S2 is hundreds digit (
x100
)
- S3 is tens digit (
x10
)
- S4 is units digit (
x1
)
- S5 is the tenths digit (
x0.1
)
