MAIN/STANDBY 125 WATT RADIOBEACON WITH NDDS/T
(INSTALLED
IN NARB07 CABINET)
IS02001 (Page 7)
29 January 2002
(k) Connect wires #'s 1, 3, 5, 7, 9, 11, 12, 16, 19,
21, 23, 25, 27, 29, 31, 37, 38, 43 and 44 of the
cabinet's wiring harness, to the
A
(1) transmitter
as tabulated in table 2.
(l)
Connect wires #'s 2, 4, 6, 8, 10, 13, 14, 15, 17,
18, 20, 22, 24, 26, 28, 30, 32, 45 and 46 of the
cabinet's wiring harness, to the
B
(2) transmitter
as tabulated in table 2.
NOTE
Wire #35 and #36 are not the size recommended in
the installation instructions of the ND500II manual.
They are installed to ensure the transmitter chassis is
grounded in conformance with most electrical codes.
It is intended that all transient currents flowing in the
RF feed cable will be shunted to the station safety
ground by the conductor connected to the ground stud
which is adjacent to J1 on the top of the cabinet.
(m) Connect wire #35 to the
A
transmitter's
safety/ground stud, noting it is located
immediately below 1TB1.
(n) Connect wire #36 to the
B
transmitter's
safety/ground stud, noting it is located
immediately below 2TB1.
(o) Verify connector P4 (terminates one end of wire
#34) is installed on and fully mated with the
interior portion of the cabinets RF output
connector (J1).
(p) Install connector P3 (terminates one end of wire
#34) on the
A
transmitter's RF output connector
(1A7J2). Ensure it is fully mated.
(q) Install connector P2 (terminates one end of wire
#33) on the
A
transmitter's RF input connector
(1A7J3). Ensure it is fully mated.
(r)
Install connector P1 (terminates one end of wire
#33) on the
B
transmitter's RF output connector
(2A7J2). Ensure it is fully mated.
(s)
Verify connector P5 (terminates one end of wire
#47) is installed on the NDDS/T's RF Osc (A)
output connecter (3J1). Ensure it is fully mated.
(t)
Install connector P6 (terminates one end of wire
#47) on the
A
transmitter's Ext RF Drive input
connector (1J3). Ensure it is fully mated.
(u) Verify connector P7 (terminates one end of wire
#48) is installed on the NDDS/T's RF Osc (B)
output connector (3J2). Ensure it is fully mated.
(v) Install connector P8 (terminates one end of wire
#48) on the
B
transmitter's Ext RF Drive input
connector (2J3). Ensure it is fully mated.
(w) Connect an AC power cable (W1) between the
A
transmitter's AC power cable receptacle (1J2)
and one side of the cabinet's AC power duplex
receptacle (J2).
(x) Connect an AC power cable (W2) between the
B
transmitter's AC power cable receptacle (2J2)
and the other side of the cabinet's AC power
duplex receptacle (J2).
INITIAL START-UP PROCEDURES
6.
It is recommended both transmitters and the
NDDS/T unit be tested as individual stand-alone
assemblies prior to full interconnection and operation
as a main/standby transmitter system during initial
start-up. The procedures described in the instruction
manuals for ND500II 125 watt radiobeacon
transmitter and the NDDS/T unit should be used.
ADJUSTMENT AND TESTING
7
Test each transmitter individually, check
the operation of the NDDS/T unit and then verify the
main/standby function is operational (automatic
changeover to
standby
transmitter occurs when the
main
transmitter is not producing a satisfactory RF
output).
7.1 NO
ON-AIR
TRANSMITTER:
If one
transmitter is to be operated (tested/serviced) into a
precision dummy load and the other is not required to
be on-air, proceed as follows:
(a) Turn off both transmitters. Set their
POWER
switches to
OFF
.
(b) Connect a 250 Watt, precision, 50-ohm,
resistive, dummy load to the cabinet's RF output
