Manual

©1999 Navia Aviation AS 21464-5 System Description
USER MANUALNORMARC 7050
MARKER BEACON
3-3
audio signal in the Power Amplifier (PA). The PA is capable of delivering up to 4W power at
97% depth of modulation.
Unwanted frequencies are removed by a lowpass filter after the PA.
3.3 Monitors / Transmitter Control
The marker beacon has one or two MO1374 monitor modules depending on model (Table 3-
1).
The MO1374 is mainly a microprocessor based module. It contains the MB software and
forms the basis of the monitor, station control, system maintenance handling and RMS user
interface.
A detection of error in the transmitter signal causes change-over to the standby transmitter.
Failure of the standby transmitter leads to an alarm and optional shutdown of the standby
transmitter.
On a system with two monitor units, both must report error for alarm to be generated (2 of 2
voting). If the monitors disagree, the WARNING and DISAGR LEDs on the front panel is lit.
The MO1374 consists of two submodules:
The RF frontend
receives a RF signal from the antenna (or recombining network for dual
antenna system). It demodulates the signal into analogue values propotional to the RF
power, the modulation depth and the morse code envelope. These parameters are digitized
and monitored by the CPU section.
The CPU section
includes an 80CI88 CPU, memory, communication ports and an AD con-
verter system.
3.4 Power Systems
The marker beacon can have either one or two PS1375 power modules depending on model
(Table 3-1). The PS1375 is 100W with 120V or 230V AC input voltage and +28V/3.5 A, +20/
2.5A, ±12V/1.25A and 5V/6A DC output voltages. Outputs are short circuit protected. On the
NM7050 B/D the two modules operate in parallel.
The 28V output is temperature compensated to ensure optimum battery charging. It gives
26.4V at 50°C and linearly increase to 29.6V at -30°C.
The backup battery is an external 24V battery. The battery gives a backup time of 6 hours,
and have external charging possibilities for longer backup time. This battery is automatically
brought into circuit on mains power failure. The charging time is approximately eight hours
with one PS1375 and five hours with two PS1375.
3.5 Remote control system
The remote control unit is used in the tower or in the technical control room. It has indicators
for operating status as well as detailed warnings and an aural alarm device with reset. It can
control equipment on/off and change over, and has an Access Grant switch to allow/inhibit
remote control from the RMM system.