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 NORMARC 7033

INSTRUMENT LANDING SYSTEM

TRANSMITTER DESCRIP-

TESTS AND ADJUSTMENTS

©1999 Navia Aviation AS

3-30

Set the Ident Control to CONTINUOUS from the RMM Program or the Local Display/Key-
board.

On the Field Test Set, press IDENT.

1020 Hz modulation depth can be adjusted from the RMM Program or the Local Display/Key-
board.

Adjust modulation depth to 10.0% +/-0.3%.

If VOICE modulation is implemented, the ident modulation depth should be set to 5.5% +/-
0.3% to avoid over modulation. Before this adjustment is done, follow the instructions in the 
appendix VOICE GENERATOR. Make sure VOICE is turned off from the RMM program or the 
Local Keyboard/Display when adjusting the modulation depth.

3.1.8.2 Method 2

An alternative method of checking 1020 Hz modulation depth to 10% is described below: 

Connect the oscilloscope to the BNC test Connector labelled CSB.

Switch off the 90 Hz modulation and the 1020 Hz modulation.

Note the peak-to-peak deflection of the remaining 150 Hz waveform.

Then switch off the 150 Hz modulation and switch the 1020 Hz modulation to CONTINUOUS.

The observed 1020 Hz peak-to-peak waveform amplitude should be 50% of the 150 Hz ampli-
tude providing the 1020 Hz modulation depth is 10% (or 1/2 of 150 Hz depth).

3.1.9

RF Frequency Adjustment

Fine-adjustment of the operating frequency can be carried out by adjusting C1 in the 
OS1221A/B RF Oscillator module.

Mount the Oscillator OS1221A/B on an extension board.

In order to monitor the frequency, connect the Frequency Counter to the BNC test connector 
labelled CSB. (Make sure the transmitter under test is routed to Antenna). If necessary for sta-
ble counting switch off modulation tones. 

Adjust until frequency is less than 1 kHz from operating frequency. Trimmer C1 adjusts course 
and clearance frequencies simultaneously.

3.2

Antenna System Adjustments

After the transmitters has been aligned correctly the antenna system must be aligned. This 
includes mechanical adjustments of the Antenna System, electrical adjustments (phasing) 
and adjustments of the ADU and MCU.

For details, refer to the adjustment procedure for each antenna system.

Summary of Contents for 7033

Page 1: ... 1999 Navia Aviation AS NORMARC 7033 INSTRUMENT LANDING SYSTEM TRANSMITTER DESCRIPTION ...

Page 2: ... 1999 Navia Aviation AS ...

Page 3: ... 2 PA1234A Power Amplifier 20 2 4 3 AC1226A Amplitude control 21 2 4 4 PC1225B Phase Control 21 2 4 5 FD1236A Feedback Detector 21 2 4 6 CD1238A Combiner Detector 23 2 5 COA1207C Change Over Assembly 23 3 TESTS AND ADJUSTMENTS 25 3 1 Transmitter Alignments and Calibration 25 3 1 1 RF Phase Feedback Adjustment 25 3 1 2 RF Power 25 3 1 3 LF Phase Adjustment 26 3 1 4 RF Power Balance Adjustment 27 3 ...

Page 4: ...OPERATING MANUAL iv NORMARC 7033 INSTRUMENT LANDING SYSTEM Table of contents 1999 Navia Aviation AS ...

Page 5: ...ock Diagram part 2 13 Figure 2 3 NMP110A block diagram 15 Figure 2 4 OS1221B block diagram 16 Figure 2 5 Physical organization of power amplifier assembly 18 Figure 2 6 Changeover system block diagram 24 Figure 3 1 LF phase CSB illustration 26 Figure 3 2 LF phase SBO illustration 26 Figure 3 3 Power balance SBO illustration 28 Figure 3 4 RF phase SBO illustration 28 Figure 3 5 Front side adjustmen...

Page 6: ...TRANSMITTER DESCRIPTION vi NORMARC 7033 INSTRUMENT LANDING SYSTEM List of Figures 1999 Navia Aviation AS ...

Page 7: ... 1999 Navia Aviation AS List of tables TRANSMITTER DESCRIPTION NORMARC 7033 INSTRUMENT LANDING SYSTEM vii LIST OF TABLES Table 3 1 Normal operating power level 26 ...

Page 8: ...TRANSMITTER DESCRIPTION viii NORMARC 7033 INSTRUMENT LANDING SYSTEM List of tables 1999 Navia Aviation AS ...

Page 9: ... separate outputs for Course and Clearance These two channels are offset by 10 kHz The LF Generator also has independent outputs for Course and Clearance Clearence transmitter is however not included in this single frequency equipment The GPA 1231A Glidepath Course Power Amplifier Assembly contains modules to modulate amplify and combine signals into the required CSB and SBO signals Amplitude and ...

Page 10: ... CSB COUPLER COAX CONTROL RF OSC TX2 RF OSC TX1 LF GEN TX1 LF GEN TX2 CHANGE OVER COU CHANGE OVER CLR CSB CSB POWER AMPLIFIER ASSEMBLY COU TX2 POWER AMPLIFIER ASSEMBLY COU TX1 POWER AMPLIFIER ASSEMBLY CLR TX1 POWER AMPLIFIER ASSEMBLY CLR TX2 AMPLITUDE FEEDBACK AM MOD HPA FEEDBACK CONTROL AMPLITUDE FEEDBACK AM MOD HPA FEEDBACK CONTROL AMPLITUDE RF PHASE FEEDBACK AM MOD HPA HPA HYBRID FEEDBACK CONTR...

Page 11: ...DETAILED DESCRIPTION NORMARC 7033 2 11 INSTRUMENT LANDING SYSTEM TRANSMITTER DESCRIPTION 1999 Navia Aviation AS 2 Detailed Description 2 1 Transmitter block diagrams ...

Page 12: ...DENT KEYER IDENT DC LEVEL MOD 90 LEVEL MOD 150 LEVEL DATA 7 0 CONTROL 90 Hz LOWPASS FILTER AGC AMPLIFIER 150 Hz LOWPASS FILTER AGC AMPLIFIER 90 Hz CLR 150 Hz CLR MOD_AMP2 AGC_AMP4 AGC_AMP3 LPF_1502 LPF_902 Vref Vref Vref Vref LF1223A 90 HZ COU COU CLR DAC DAC DAC UNREG 150 Hz UNREG 90 Hz UNREG 90 Hz UNREG 150 Hz RF BAL BUFFER AC1226A COMPA RATOR AMP_90 MODU LATION CURRENT DRIVER AMP_90 MODU LATION...

Page 13: ...IER MODU LATOR DRIVER LOWPASS FILTER PA1234A MODU LATOR DRIVER LOWPASS FILTER PA1234A 90 HYBRID RF PHASE ADJ FD1236A 90 HYBRID CSB COU SBO COU CD1238A OS1221B SYNTHE SIZER Tx ON OFF RF PHASE FEEDBACK RF PHASE FEEDBACK MODU LATOR DRIVER LOWPASS FILTER PA1234A CSB CLR PHASE FEEDB OFFSET ADJ PHASE OUT PC1225B RF PHASE REGULATOR RF PHASE REGULATOR AMPLIFIER AMPLIFIER PHASE OUT PHASE FEEDB OFFSET ADJ F...

Page 14: ...ase between the 90 and 150Hz signals is done manually with potentiometers The morse code is keyed in an analog multi plexer and can be synchronized with a DME RF level and ident DC_IDENT SDM and DDM 90 150Hz are generated in the MDAC chain Multiplication m in the MDACs are 0 m 1 The reference voltage is multiplied in the first MDAC to form the DC portion of DC_IDENT The keyed 1020Hz sine wave is m...

Page 15: ... the RMS interface address decoding configuration control and automatic refresh of the DACs and the other registers The refresh cycle is performed after a completed RMS access cycle 2 3 OS1221B RF Oscillator General Description The OS1221B module generates the RF signals used for the generation of the carrier signals in the transmitters ch 2 5 Configuration Storage Counter Ident Sequencer Refresh ...

Page 16: ...ol of the prescaler The total count and thereby the frequency is set by inserting shunts onto an array of pins The correct count for a desired frequency FRQ is found as follows CHANNEL SELECT COU PROGRAMABLE DIVIDER RF OSCILLATOR PHASE DETECTOR LOWPASS FILTER VCO LOCK DETECT WINDOW COMP BANDPASS FILTER 12 dB OSC_C 64 MODULUS 2 DIVIDER COU Tx ON OFF X TAL FREQ TEST POINT FREQUENCY ADJUST MODULUS SE...

Page 17: ...oop is locked and wide pulses of variable width when out of lock Therefore the transistor will be turned off when in lock and on when out of lock The output from the transistor goes to two Schmidt triggers one latching and one unlatching The latching Schmidt triggers turns the signal off if the loop goes out of lock and alarms the I2C bus It is reset by power on and or a low transition of the COU_...

Page 18: ...CRIPTION 1999 Navia Aviation AS 2 18 Physical Organization Figure 2 5 Physical organization of power amplifier assembly FD 1xxxx PA 123xx PC 1xxxx CD 123xx AC 1226x C1 C2 C3 C4 J16 J15 J1 J2 J3 J10 J11 J12 J13 J7 J6 J8 J14 J9 TP1 J17 HBK695 2 PA 123xx Not present in GP CLR ...

Page 19: ...om bining them into CBS and SBO signals The AC1226A Amplitude Control provides and controls the required LF modulation signals 90Hz and 150Hz for the PA 1234A power amplifiers that keeps the output RF level and amplitude modulation constant The PA1234A Power Amplifier modulates the incoming RF signal from PC1225B with a 90Hz or a 150Hz LF signal to obtain an AM signal and amplifies the modulated s...

Page 20: ...A 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...

Page 21: ...made on the LF1223A module via the RMS system FEEDBACK FUNCTION The 90 and 150 Hz LF signals from LF1233A are combined with the DC ident signal also coming from LF1233A to form the desired RF envelope for each of the PA1234A This enve lope is compared with the envelope detected by FD1236A and the resulting signal is fed to the PA1234A modulator This process eliminates any ground offset between the...

Page 22: ...f the 90 degree 3 dB hybrid the phase difference at the hybrid inputs must be zero Proper phasing initially is here obtained by the insertion of a delay line in the 150 Hz modulated path The main RF input signals applied to the couplers are already 90 degrees out of phase here with the 90 Hz modulated signal lagging Therefore the additional delay line between the 150 Hz coupler and the hybrid will...

Page 23: ...ier frequency resulting in twice the input power at the CSB port and no power at the SBO port However the sideband frequencies at the two inputs are not identical The power of each sideband frequency will therefore be split equally between the two outputs The resulting depth of modulation at the CSB output will be one half relative to the input value At the SBO output the two sidebands will be in ...

Page 24: ...ED DESCRIPTION 1999 Navia Aviation AS 2 24 Figure 2 6 Changeover system block diagram PHASER ATTENUATOR COAX RELAY COAX RELAY OUTPUT SBO OUTPUT CSB MONITOR CSB COUPLER COAX CONTROL 50 ohm 50 ohm PHASER ATTENUATOR COAX CONTROL CSB TX1 CSB TX2 SBO TX1 SBO TX2 HBK533 1 ...

Page 25: ...the functions parameters depart considerably from normal then repeat the steps in sequence once more except steps 3 1 7 1 3 1 9 3 1 1 RF Phase Feedback Adjustment Connect the oscilloscope to the BNC test connector labelled PHASE CORR located on the transmitter modules NOTE Set the scope s input mode to DC The waveform observed should take a continuous form without limiting segments or deep notches...

Page 26: ...tion 3 1 3 1 One frequency system Connect oscilloscope channel A to the BNC test connector labelled CSB located on LPA GPA Course 1 2 Set oscilloscope input mode to DC Adjust 150 Hz COU phase adj R3 on Low Frequency generator LF1223A Figure 3 5 observing oscilloscope channel A until the waveform equals left hand graph in Figure 7 2 LLZ Course 15W CSB LLZ Clearance 15W CSB GP Course 5W CSB GP Clear...

Page 27: ...Tx and Clearance Tx On Low Frequency generator LF1223A Tx1 Tx2 adjust 150 Hz COU phase adj R3 to phys ical centre position Adjust 150 Hz CLR phase adj R180 to track 150 Hz Course waveform in the same phase waveform overlap By means of the RMM turn on 90 Hz modulation for both Course Tx and Clearance Tx Adjust 90 Hz COU phase adj R1 LF1223A observing oscilloscope channel A until the waveform equals...

Page 28: ... on the back of the LPA GPA See Figure 3 6 Adjust until both halves fall on the same envelope waveform or the two larg est sets of peak waveforms fall on lines parallel to the baseline See Figure 3 3 3 1 5 RF Phase at Combiner I P Connect the oscilloscope to the BNC test connector labelled SBO located on the transmitter modules NOTE Set the scope s input mode to DC Set the oscilloscope in normal t...

Page 29: ...EST DDM with 90Hz or 150Hz dominance can be switched on and off from the RMM Pro gram or the Local Display Keyboard The DDM values inserted by TEST DDM are preset val ues which is set as described below 90Hz Dominance Preset Utilize the Field Test Set as in the previous test Set the TEST DDM in position 90 Hz domi nance from the RMM Program or the Local Display Keyboard Adjust the 90 Hz test DDM s...

Page 30: ...e remaining 150 Hz waveform Then switch off the 150 Hz modulation and switch the 1020 Hz modulation to CONTINUOUS The observed 1020 Hz peak to peak waveform amplitude should be 50 of the 150 Hz ampli tude providing the 1020 Hz modulation depth is 10 or 1 2 of 150 Hz depth 3 1 9 RF Frequency Adjustment Fine adjustment of the operating frequency can be carried out by adjusting C1 in the OS1221A B RF...

Page 31: ...L INTERLOCK OVERRIDE MAINT STBY OFF REMOTE LOCAL AUTO MANUAL OVER CHANGE TX1 ALARM SERVICE PARAM DISAGR BATT IDENT TX1 TX2 TX2 STAND BY Mon 1 Mon 2 Mon stby 90Hz COU phase adj R1 150Hz COU phase adj R3 90Hz CLR phase adj R179 150Hz CLR phase adj R180 TX1 TX2 NF SDM adj NF AGC time constant adj NF RF level adj CL SDM adj CL AGC time constant adj CL RF level adj CLR SDM adj CLR AGC time constant adj...

Page 32: ...ENTS 1999 Navia Aviation AS 3 32 Figure 3 6 Power Amplifier Assembly adjustment points rear view Ver S no Type PH OFFS G150Hz RF BAL G90Hz DC OSC SBO CSB FREMDRIFT RF PHASE Phase feedback offset adj DC offset adj RF balance adj 90Hz mod adj 150 Hz mod adj RF phase adj HBK696 1 ...

Page 33: ...straps in the J2 strap block The configured course frequency is the channel frequency 7 5 kHz Ch freq MHz A0 A1 A2 A3 A4 A5 N0 N1 N2 N3 N4 N5 N6 N7 N8 N9 329 15 X X X X X X X X 329 3 X X X X X X X X X 329 45 X X X X X X X X 329 6 X X X X X X X 329 75 X X X X X X X X X 329 9 X X X X X X X 330 05 X X X X X X X 330 2 X X X X 330 35 X X X X X X X X X X X 330 5 X X X X X X X X X X 330 65 X X X X X X X ...

Page 34: ...A4 A5 N0 N1 N2 N3 N4 N5 N6 N7 N8 N9 329 15 X X X X X X 329 3 X X X X X X X X X 329 45 X X X X X X X 329 6 X X X X X X X 329 75 X X X X X 329 9 X X X X X X X 330 05 X X X X X X 330 2 X X X X 330 35 X X X X X X X X X 330 5 X X X X X X X X X X 330 65 X X X X X X X X 330 8 X X X X X X X X X 330 95 X X X X X X X 331 1 X X X X X X X X 331 25 X X X X X X X X X 331 4 X X X X X X X X 331 55 X X X X X X X 3...

Page 35: ...YSTEM TRANSMITTER DESCRIPTION 1999 Navia Aviation AS Table 0 2 OS1221B Clearance frequency settings for 2 freq GP 334 1 X X X X X X X X X X 334 25 X X X X X X X X 334 4 X X X X X X X X 334 55 X X X X X X 334 7 X X X X X X X X 334 85 X X X X X X X 335 X X X X X X ...

Page 36: ...NORMARC 7033 INSTRUMENT LANDING SYSTEM TRANSMITTER DESCRIP TESTS AND ADJUSTMENTS 1999 Navia Aviation AS 3 36 ...

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