NARB14 Dual ND500II (IP66) – IS03013
Page 1
Information Sheet
Issue 1.0
IS03013 NARB14 Dual ND500II (IP66)
Information Sheet
1. INTRODUCTION
This document identifies the information
specific to a dual (main/standby) ND500II
radiobeacon transmitter system installed in
an NARB14 cabinet. It also provides an
electrical parts list and point-to-point wiring
information for the cabinet. Information
provided includes cabinet description, theory
of operation, installation, start-up and
calibration/testing procedures, parts list,
wiring list, electrical schematics and
mechanical drawings (including dimensions).
2. CABINET DESCRIPTION
The NARB14 cabinet meets IP66
requirements. It houses two ND500II
radiobeacon transmitters. The upper
transmitter is designated as transmitter A
(unit 1), while the lower transmitter is
designated as transmitter B (unit 2). The
uncrated cabinet (with transmitters) weighs
approximately 75kg (165 lbs). The cabinet
also contains:
-
a type 'N' RF coaxial connector (J1),
which is used as the RF output
connection point for the RF feed cable
-
an AC power duplex receptacle (J2)
-
a dual transmitter interface assembly
(unit 3)
-
a computer remote control unit (unit 4,
optional)
- interconnecting
wiring
Refer to figures 2 and 3 for electrical
schematics of the dual transmitter system.
Refer to figures 4 through 6 for assembly
detail and dimensional information of the
NARB14 cabinet.
3. THEORY OF OPERATION
The theory of operation presented in the
ND500II instruction manual describes the
operation of both transmitters A (ND500II-
11x-x20) and B (ND500II-01x-x20). The
following provides a brief description for
transmitters that are connected in a
main/standby dual installation. See figure
2A or 2B for interconnecting detail. See
figure 3 for the electrical schematic of the
dual transmitter interface PWB (3A1).
3.1 Normal Operation:
When the ‘main’
transmitter, selected by
MAIN XMTR A/B
switch 3S2, is turned on and producing a
satisfactory RF output, the following will
occur:
(a)
15V will be applied from the main
transmitter (1A11J4-13 or 2A11J4-13),
through the dual transmitter interface
PWB (3A1J4-11 or 3A1J5-19) to the
standby transmitter (1A11J4-20 or
2A11J4-20), as the 'standby off'
control signal.
(b)
If transmitter A is selected as the
'main' transmitter, the main/standby
relay in transmitter A's harmonic filter
will be energized and will connect
transmitter A’s output to J1
(
RF OUT
)
as
the RF output to the antenna system.
(c)
If transmitter B is selected as the
'main' transmitter, the main/standby
relay in transmitter A's harmonic filter
will be de-energized and transmitter
B’s output will be connected to J1
(
RF
OUT
)
as the output to the antenna
system.
(d)
The selected 'main' transmitter will
provide 15V and the manually
controlled slewing commands
(
ATU
CONT
)
for the antenna system's
antenna tuning unit via the dual
transmitter interface assembly (unit 3).
(e)
The selected 'main' transmitter will be
providing the 'audio out'
(
RMT AUD
)
sample via the dual transmitter
interface assembly (unit 3).
(f)
If transmitter A is selected as the
'main' transmitter, an open collector
SHTDN ALM
(
B
)
signal will be applied to
3A1J5-23 from A11J4-17 ('shutdown')
of transmitter B.
Summary of Contents for ND500II
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