Installation Instructions

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2.5.1 Mechanical alignment..................................................................................21
2.5.2 Final electrical position adjustment.............................................................. 21
2.6 DC-Loop adjustment and testing........................................................................21
2.6.1 DC-LOOP adjustment..................................................................................21
2.6.2 Antenna fault condition testing.....................................................................21
3 NM 3524 12 Elements antenna system adjustments - LLZ (Dual frequency).....23
3.1 Mechanical alignment of antenna array .............................................................23
3.1.1 Right angle points with reference to runway centre line .............................. 23
3.1.2 Spacing distance between LPDA’s..............................................................23
3.1.3 Vertical alignment of LPDA support masts ..................................................23
3.1.4 Azimuth alignment of LPDA’s ......................................................................23
3.2 Electrical measurements.................................................................................... 23
3.2.1 CSB and SBO cables ..................................................................................23
3.2.2 CSB/SBO phasing .......................................................................................24
3.2.3 Antenna cable lengths (Electrical phase equality).......................................24
3.2.4 Antenna pair phasing...................................................................................25
3.2.5 Phase and amplitude transfer measurement...............................................26
3.2.6 Antenna return loss......................................................................................27
3.3 Course sector width adjustment......................................................................... 27
3.3.1 DDM check of ADU O/P ..............................................................................28
3.3.2 Clearance SBO power................................................................................. 29
3.3.3 DDM field check...........................................................................................29
3.4 Monitor combining unit (MCU) adjustments .......................................................29
3.4.1 Course Line .................................................................................................29
3.4.2 Course Sector.............................................................................................. 29
3.4.3 Clearance ....................................................................................................29
3.5 Near field monitor adjustments...........................................................................29
3.5.1 Mechanical alignment..................................................................................30
3.5.2 Final electrical position adjustment.............................................................. 30
3.6 DC-Loop adjustment and testing........................................................................30
3.6.1 DC-LOOP adjustment..................................................................................30
3.6.2 Antenna fault condition testing.....................................................................30
4 NM 3525 24 Elements antenna system adjustments - LLZ...................................31
4.1 Mechanical alignments of antenna array............................................................31
4.1.1 Right angle points with reference to runway centre line .............................. 31
4.1.2 Spacing distance between LPDA’s..............................................................31
4.1.3 Vertical alignment of LPDA support masts ..................................................31
4.1.4 Azimuth alignment of LPDA’s ......................................................................31
4.2 Electrical measurements.................................................................................... 31
4.2.1 CSB and SBO cables ..................................................................................31
4.2.2 CSB/SBO phasing .......................................................................................32
4.2.3 Antenna cable lengths (Electrical phase equality).......................................32
4.2.4 Antenna pair phasing...................................................................................33
4.2.5 Phase and amplitude transfer measurement...............................................34
4.2.6 Antenna return loss......................................................................................35
4.3 Course sector width adjustments .......................................................................35
4.3.1 DDM check of ADU O/P ..............................................................................35
4.3.2 Clearance SBO power................................................................................. 37
4.3.3 DDM field check...........................................................................................37
4.4 Monitor combining unit (MCU) adjustments .......................................................37
4.4.1 Course Line .................................................................................................37
4.4.2 Course Sector.............................................................................................. 37