Nautel XL12, Technical Instructions

Page: 41 / 238

12 000 WATT AM BROADCAST TRANSMITTER
XL12
Page 2-17
01 January 2002
WARNING
(b) At the circuit breaker enclosure end, route the
AC power wiring through the selected cable
entry hole.
- install the voltage carrying conductors on the
circuit breaker's
LOAD terminals.
- install the ground wire in the ground
terminal.
NOTE
Final selection of the power transformer's
primary winding taps is completed during the
technical pre-commissioning procedures
(paragraph 2.3.1.1).
2.2.8 INSTALLATION OF RF FEED
CABLE:
Connect the RF feed cable to the
transmitter's RF output connection point, noting the
transmitter end must contain the appropriate
termination (1 5/8 inch EIA flange connector unless
otherwise specified in contract documents). The RF
feed cable's connection point is on top of the RF
output filter and it is accessible from the top of the
cabinet (see figure MD-28 for location/ dimensional
information).
Hazardous static and RF voltages which may
cause serious personal injury or even death can
be applied thru the RF feed cable if it is
connected directly to an antenna system. Ensure
the centre conductor is properly grounded/
disconnected from the antenna before touching it
or any of the exposed conductors in the RF output
filter.
NOTE
The RF output should be applied to a dummy load
during commissioning procedure's initial turn-on.
If the RF feed cable is not connected to a
switching circuit that permits antenna/dummy
load selection, ensure the dummy load's RF feed
cable is connected to the RF output connection
until otherwise specified during the
commissioning procedures.
The following instructions assume the RF feed
cable's terminating device is a 1 5/8 inch EIA
flange connector. If any other termination is
used, the user is responsible for proper
connection.
(a) Verify the RF feed cable has been cut to the
required length and has been terminated by a 1
5/8 inch EIA flange connector which contains
a male inner connector (bullet).
(b) Remove the M6 nuts/washers from the four 1
5/8 inch EIA flange mounting studs on the top
of RF output filter (see figure MD-14).
(c) Install the RF feed cable's 1 5/8 inch EIA
flange connector on the RF output filter's
flange mounting studs and secure using the M6
nuts/washers removed in step (b). Ensure nuts
are firmly tightened.
(d) Gain access to the interior of the RF output
filter, from the rear of the transmitter.
(e) Locate the RF output filter's female inner (cup)
connector (J1) noting it terminates a twisted
pair of teflon wires which originate at the top
of capacitor C3 (see figure MD-15).
(f) Install the RF output filter's female inner (cup)
connector on the RF feed cable's male inner
connector (bullet) ensuring it is firmly and fully
mated.
2.2.9 INSTALLATION OF EXTERNAL
WIRING:
Connect wiring from the modulating
audio source, remote control/monitoring devices, and
when used, the external RF drive source; to
terminating points in the transmitter:
NOTE
Chassis punch pilot holes are provided at both
front corners of the cabinet's top, front cover to
accommodate cable entry. If their location is not
satisfactory, any suitable point may be selected.
The installer must drill/punch an appropriate size
cable entry hole at the selected entry point. It is
recommended the wiring be installed in a metal
conduit which is rigidly attached at both ends.
(a) Route all external wiring through the selected
cable entry hole to the vicinity of the remote
interface PWB on the rear of the
control/monitor panel. Ensure all wiring passes
through the panel's ferrite toroid. Refer to
figure MD-1 to locate the control/ monitor
panel, to figure MD-3 to locate the remote
interface PWB and to figure MD-5 for the
remote interface PWB's assembly detail.