MAIN/STANDBY 125 WATT RADIOBEACON TRANSMITTERS WITH CRCU and NDDS/T
(USER SUPPLIED ENCLOSURE/CABINET)
IS02007 (Page 5)
15 February 2002
energized when the
main
transmitter is shut
down and applying a positive DC voltag as the
changeover alarm
.
(c) It determines the energized/de-energized state
of '
A
'/'
B
' relay K3. K3 will be energized when
transmitter '
A
' is selected as the
main
transmitter and it will be de-energized when
transmitter '
B
' is selected as the
main
transmitter.
4.4.2
Changeover Alarm Status:
The status
of the
changeover alarm
output at 3TB1-10 (
CHG OV
ALM
) is determined by the energized/ de-energized
state of
main tx status
relay K5, which in turn is
determined by the on/off status of the selected
main
transmitter [see step (b) of paragraph 4.4.1]. It will
be a positive DC voltage when relay K5 is energized
(
main
transmitter operational) or a ground potential
when relay K5 is de-energized (
main
transmitter shut
down).
4.5 REMOTE AUDIO SOURCE:
The
source of the audio which is provided for remote
monitoring is determined by the energized/de-
energized states of
main tx status
relay K5 [see step
(b) of paragraph 4.4.1] and '
A
'/'
B
' relay K3 [see step
(c) of paragraph 4.4.1].
4.5.1
The remote audio being applied to 3TB1-
6 from the '
A
' transmitter is routed to 3TB1-9 (
RMT
AUD
) as the system
remote audio
output when:
(a) Relays K3 and K5 are both energized
(transmitter '
A
' is selected as the
main
transmitter and it is operational).
(b) Relays K3 and K5 are both de-energized
(transmitter '
B
' is selected as the
main
transmitter but it has failed and a changeover to
the
standby
transmitter has occurred and the '
A
'
transmitter is operational.
4.5.2
The remote audio being applied to 3TB1-
8 from the '
B
' transmitter is routed to 3TB1-9 (
RMT
AUD
) as the system
remote audio
output when:
(a) Relay K3 is energized and relay K5 is de-
energized (transmitter '
B
' is selected as the
main
transmitter and it is operational).
(b) Relay K3 is de-energized and relay K5 is
energized (transmitter '
A
' is selected as the
main
transmitter but it has failed, a changeover
to the
standby
transmitter has occurred and the
'
B
' transmitter is operational.
INSTALLATION INFORMATION
5.
Complete or verify the following
requirements are completed during installation of the
main/standby transmitter system.
5.1 UNPACKING:
The transmitters and
CRCU/remote control interface and NDDS/T Dual
Direct Digital Synthesizer are packed in individual
crates for shipping. Remove them from their crates
and perform a visual inspection in preparation for
system assembly.
5.1.1
It is recommended the main and standby
transmitters, associated remote interfacing
assemblies (including CRCU) and NDDS/T Dual
Direct Digital Synthesizer be installed in an
enclosure that will permit access to their assemblies
during maintenance and trouble shooting procedures.
Install the transmitters as described in the ND500II
instruction manual using figures 1 and SD-1 of this
document as a guide to complete the internal
electrical interconnection between transmitters (units
1 and 2), remote control interface assembly (unit 3),
computer remote control unit (unit 4) and NDDS/T
Digital Direct Digital Synthesizer (unit 5)
5.2
POSITIVE IDENTIFICATION:
If the
identification tag has been removed from the front
handle of a transmitter, the following will provide a
positive identification.
5.2.1
The transmitter that must be installed as
the ‘A’ (xmtr 1) transmitter contains a main/ standby
relay and two type 'N' coaxial connectors in/on its
harmonic filter. The transmitter which has a '
1
' as the
first digit of the first group of three numbers
(ND500-
1
xx-xxx) of its identifier number must be
installed as the '
A
' transmitter. This identifier is
stamped on the variation nameplate, which is located
on the transmitter's upper, front, right-hand side.
