Technical Handbook
Table Of Contents
- 1 General Information
- 1.1 Introduction
- 1.2 Product Type Numbers
- 1.3 Abbreviations
- 2 Physical Organization
- 2.1 Module and Assembly Location
- 2.2 Service Kit Assembly
- 2.3 Power Supply
- 3 System description
- 3.1 Overview
- 3.2 Physical Description
- 3.3 Monitors
- 3.4 Transmitters / Modulators
- 3.5 TX Control
- 3.6 Remote Monitoring (RMS) Unit
- 3.7 Remote Control Unit
- 3.8 Remote Slave Panel
- 3.9 Remote Maintenance Monitoring (RMM)
- 4 Technical Specifications
- 4.1 Signal Minimum Performance GP
- 4.2 Environmental Characteristics
- 4.3 EMC Characteristics
- 4.4 Mechanical Characteristics
- 4.5 Power Supply
- 5 Mechanical Installation
- 5.1 Mounting Kit MK1343A
- 5.2 Moving RF Connectors
- 6 Electrical Installation
- 6.1 Connection Overview
- 6.2 Power and Battery
- 6.3 RF Inputs
- 6.4 RF Outputs
- 6.5 DC Loop (Localizer only)
- 6.6 Remote Control
- 6.7 PC and Modem
- 6.8 DME (localizer only)
- 6.9 For the Fernau 2020 DME the following connection is recommended
- 6.10 Analog Inputs
- 6.11 Digital Inputs and Outputs
- 6.12 Battery Warning
- 6.13 Remote control connections
- 6.14 Automatic shutdown of GP
- 6.15 Remote slave connection
- 6.16 Interlock switch connection
- 7 Tests and Adjustments
- 7.1 Configuration Settings
- 7.2 Technical note - Leased Line Setup for Remote Control (Westermo)
- 7.3 Transmitter Alignments and Calibration
- 7.3.1 RF Phase Feedback Adjustment
- 7.3.2 RF Power
- 7.3.3 LF Phase Adjustment
- 7.3.3.1 One-frequency system
- 7.3.3.2 Two-frequency system
- 7.3.4 RF Power Balance Adjustment
- 7.3.5 RF Phase at Combiner I/P
- 7.3.6 SDM Calibration
- 7.3.7 DDM Calibration
- 7.3.7.1 Test DDM Setting
- 7.3.8 Ident Tone Modulation Depth
- 7.3.8.1 Method 1
- 7.3.8.2 Method 2
- 7.3.9 RF Frequency Adjustment
- 7.4 Antenna System Adjustments
- 7.5 Monitor Alignment and Calibration.
- 7.6 Monitor Alarm Setting Procedure
- 7.7 Maintenance Limit Adjustments
- 7.8 Adjustment points
- 8 Functional Description
- 8.1 Introduction
- 8.2 Transmitter
- 8.3 Monitor
- 8.4 Transmitter Control
- 8.5 Remote control system
- 8.6 Remote Monitoring System (RMS)
- 8.7 Power Supply
- 9 Detailed description
- 9.1 Main Cabinet
- 9.1.1 MF1219A Glidepath Monitor Frontend
- 9.1.2 MO1212A Monitor
- 9.1.2.1 NMP101A Monitor Digital Frontend
- 9.1.2.2 NMP102A / NMP103A Comparator
- 9.1.3 TCA1218A Transmitter Control Assembly
- 9.1.3.1 NMP104A Station Control Monitor Data Detector
- 9.1.3.2 NMP105A Station Control Event Detection
- 9.1.3.3 NMP106A Station Control State Machine Control
- 9.1.3.4 NMP107A Terminator
- 9.1.3.5 NMP109A Remote Control Interface
- 9.1.4 LF1223A Low Frequency Generator
- 9.1.4.1 NMP110A Low Frequency Generator Control
- 9.1.5 OS1221B RF Oscillator
- 9.1.6 GPA1231A Glidepath Course Power Amplifier Assembly
- 9.1.7 GPA1232A Glidepath Clearance Power Amplifier Assembly
- 9.1.7.1 PA1234A Power Amplifier
- 9.1.7.2 AC1226A Amplitude control
- 9.1.7.3 PC1225B Phase Control
- 9.1.7.4 FD1236A Feedback Detector
- 9.1.7.5 FD1224A Feedback detector
- 9.1.7.6 CD1238A Combiner Detector
- 9.1.8 COA1207C Change-Over Assembly
- 9.1.9 PS1227A Power Supply
- 9.1.10 RMA1215A RMS Assembly
- 9.1.11 CI1210A External Connection Interface
- 9.1.12 MB1203A Monitor Section Motherboard
- 9.2 Tower Equipment
- 10 Parts Lists
- 10.1 Introduction
- 10.2 Parts Lists
- 10.3 Usable on code index
- 10.4 Figures
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See transmitter block diagram.
Block Description:
The PC1225B Phase Control receives the RF signal from the oscillator OS1221B. The RF sig-
nal is fed into the 90Hz branch and further through buffers and amplifiers. The 150Hz branch
is inactive.
The PA1234A Power Amplifier modulates the incoming RF signal from PC1225B with a CBS
LF signal to obtain an AM-signal and amplifies it.
The AC1226B Amplitude Control generates the required CSB LF modulation signal to the
power amplifier, to keep the output RF level and amplitude modulation constant.
The FD1224A Feedback Detector provides a feedback signal for amplitude correction of the
CSB modulated RF signal.
9.1.7.1 PA1234A Power Amplifier
General Description :
Power amplifier PA1234A is a three stage single-ended amplifier.
The first stage works as an AM-modulator. The modulation tone (90Hz or 150Hz) is fed to the
collector of a bipolar transistor. This modulation stage is operating in class C and has imped-
ance matching network at both input and output. Nominal RF input level is approximate
20dBm.
Second stage consists of a 5W MOSFET-transistor operating in class B. The input impedance
network is matched to 50
Ω
, while the output impedance network is matched to the complex
conjugated impedance of the third stage transistor. This stage has a collector-to-gate feed-
back and a input shunt loading resistor at the transistor gate, to prevent unwanted oscillations
and keep the transistor unconditionally stable.
Third stage is a 30W MOSFET-transistor operating in class AB. Its output impedance network
consists of microstrip transmission lines and a variable capacitor to achieve maximum power
and efficiency. This stage has also feedback and shunt resistors to prevent unwanted oscilla-
tions. As gain control, both the second and third stage have potentiometers to set the operat-
ing point. A positive voltage regulator is used to keep a fixed input voltage to these gain
control circuits.
The lowpass filter at the output is a 7th order filter, giving better than 50dB attenuation of all
harmonics and forward loss is less than 0.5dB. Filter input and output impedance are 50
Ω
.
9.1.7.2 AC1226A Amplitude control
General Description :
The main purpose of the AC1226A is to maintain a constant modulation and RF level for the
output signals from the PA 1234A power amplifiers. The RF level and modulation depths are
derived from three reference input signals coming from LF 1233A. A DC reference level sets
the RF level for both power amplifiers and one 90Hz and one 150Hz AC reference signal
determines the modulation depths of the 90Hz and 150Hz power amplifiers respectively. The
AC1226A also contains measurement circuits for the RMS.
ADJUSTMENTS:
The levels of the reference DC signal and the two reference AC signals are separately adjust-