User's Manual

MODEL 2130 MARKER BEACON
Rev. A April, 2005 2-1
This document contains proprietary information and such information may not be disclosed to others for any
purposes without written permission from SELEX Sistemi Integrati Inc.
2. TECHNICAL DESCRIPTION
2.1 Introduction
The Marker Beacon is comprised of a Local Control Unit, RMS Processor, one Amplifier/ Monitor Assembly for single
equipment or two Amplifier/Monitor Assemblies for dual equipment. In addition the power panel assembly contains the
Battery Charging Power Supply (BCPS) with one power supply for single equipment and two power supplies for dual
equipment. The Marker Beacon is provided with battery backup capability through the BCPS function.
The Amplifier/ Monitor Assembly provides frequency synthesizer for signal generation, an RF amplifier and monitor
functions.
2.2 Antenna Operation
The required coverage pattern of each Marker Beacon is elliptically shaped as defined in Table 2-1, with the minor axis
oriented along the course centerline.
The Marker Beacon transmitter power is capable of being adjusted to provide the required signal (1700 microvolts) within
the bounds of the minimum and maximum dimensions of the axes.
The vertical coverage of the Marker Beacon is such that the received signal rises to 3000 microvolts/meter near the center
of the ellipse.
Table 2-1 Marker Beacon Coverage Pattern
Measured distance along course
Centerline (Minor axis)
Measured distance along 75 uA lines (Major
axis)
Marker Beacon
Type
Minimum (ft) Maximum (ft) Minimum (ft) Maximum (ft)
Inner 340 660 Not Measured Not Measured
Middle 675 1325 350 1325
Outer 1350 4000 700 4000
The field strength within the coverage area meets the following requirements:
a. Provides an elliptical radiation pattern with its minor axis parallel to the course line when cut by a horizontal plane
with a minimum major-to-minor axis ratio of 1.5 to 1.0. Coverage is measured along the Localizer course line while
descending along the commissioned glide path. With the Marker Beacon power adjusted for the desired coverage
pattern, signal strength sufficient to provide an indication on the Marker Beacon receiver extends at least 3000 feet
above the station.
b. The major axis width is sufficient to provide sufficient signal strength to a standard Marker Beacon receiver at the 75
microampere edge-of-course line at the altitude established by the instrument approach procedure established for the
runway.
2.3 Marker Beacon Transmitter Theory of Operation
2.3.1 Marker Beacon Amplifier/ Monitor Theory of Operation
The Marker Beacon Amplifier/Monitor CCA performs the RF signal generation and monitoring for the Marker Beacon
transmitter cabinet. There is one Amplifier/ Monitor for single equipment and two provided for dual equipment
configuration. The Amplifier/Monitor CCA is located on the inside left wall of the Marker Beacon cabinet. For a single
configuration the transmitter output cable and Integral monitor cable connect directly to the exterior interface box. For a
dual transmitter configuration the transmitter output connects to the LCU CCA.