RADIOBEACON TRANSMITTER
ND500II (125 WATTS) DOUBLE SIDEBAND - NO VOICE
Page 3-2
15 September 2003
3.3.6
CONTROL/MONITOR CABLING
:
Control and monitoring connections are made to
terminal block TB1 on the remote interface PWB
(A11) at the rear of the transmitter. Connections can
also be made to a 25-socket ‘D’ connector (J4),
which is also located on the remote interface PWB.
Refer to figures MD-5 and MD-17 for information to
assist in determining cable length.
3.3.7
19-INCH MOUNTING RACK
: The
transmitter is designed to be mounted in a standard
'G' size opening (12 7/32 inches) of a 19-inch
mounting rack cabinet. The depth of the cabinet
must be not less than 22.0 inches. The transmitter
can be fitted with drawer slides for ease of access
during maintenance procedures. The rack mounted
portion of the slides must be securely installed during
installation. The mounting rack must be securely
fastened or counter-balanced to ensure the 25
kilogram (55 pound) weight of the transmitter does
not cause the mounting rack to topple when the
transmitter is fully extended on its drawer slides.
3.3.8
EXTERNAL ALARM/STATUS
MONITORING FEATURES
: The transmitter
provides outputs to monitor critical alarm/status
parameters from a remote location. The circuit for
each parameter contains a switching transistor that
provides a current sink to ground or an open collector
as its alarm/status output. Diodes are connected
between the collector of each switching transistor and
ground to protect the internal circuitry from voltage
transients that enter the transmitter on the external
cabling. The external monitoring circuits must
operate from a positive DC voltage power source.
+15V from TB1-24 may be used as the voltage
source or an external DC power supply may be used.
If an external DC power supply is used, the negative
(DC return) output should be connected to TB1-5.
Current flow through the switching transistor should
not exceed 50 milliamperes. The following provides
additional information for each output.
3.3.8.1
Shutdown Alarm
: A 'remote
shutdown
alarm
' output is available at TB1-17 or J4-17 of
remote interface PWB A11. When the transmitter is
not shut down, a current sink to ground is provided.
When a fault is sensed and the transmitter is shut
down, an open collector is provided.
3.3.8.2
High SWR Alarm
: A '
remote SWR
alarm
' output is available at TB1-18 or J4-18 of
remote interface PWB A11. When the SWR is
satisfactory, an open collector is provided. When the
SWR is excessive, a current sink to ground is
provided.
3.3.8.3
Battery Status:
A '
remote battery status
'
output is available at TB1-19 or J4-19 of remote
interface PWB A11. When AC power is being used
as the transmitter’s power source, an open collector
is provided. When the AC power fails or it is
removed and the battery is connected as the
transmitter's power source, a current sink to ground
is provided.
3.3.9
VENTILATION
: The interior of the
transmitter enclosure must contain a ventilation
system that will ensure the inside temperature does
not exceed 55
°
C.
3.3.10
HEATING
: The interior of the transmitter
enclosure must contain a heating system that will
ensure the inside temperature does not go below -
10
°
C.
3.3.11
WORK AREA
: It is recommended that a
suitable work area be provided adjacent to the
transmitter to permit bench inspection/repair of
removable assemblies.
UNPACKING
3.4
The transmitter is packed fully assembled
in a wooden crate that is 55 cm (25 inches) x 53 cm
(24 inches) x 42 cm (19 inches). Shipping weight is
approximately 49 kilograms (108 pounds). Open the
crate and remove the transmitter as follows:
Crates should be inspected for transit damage prior
to shipment acceptance and/or uncrating.
(a)
Locate the crate in an upright position, as
marked on the crate, in a clear area that will
permit extraction of the transmitter without risk
of damage to the unit or injury to personnel.
(b)
Remove the panel identified as the top from the
crate by carefully prying it open using a small
pry bar or other suitable tool.
