Thales ATM 435 Users Manual

Description, Installation, Operation, Maintenance

Reference: Vol. 1 Code 955 900 031C

GROUND BEACON

DME 415/435

Technical Manual

VOLUME 1

Equipment description, Installation, Operation, Maintenance and PC user

SECTION 1

GENERAL INFORMATION

Vers. D, September 2005

THALES Italia S.p.A.- Air Systems Division

	955 900 031C	DME 415/435 -Technical Manual
		Vol. 1-Section 1-General Information

1-II

THALES Italia S.p.A.- A. S. D.

Vers. D, September 2005

	DME 415/435 -Technical Manual	955 900 031C
	Vol. 1-Section 1-General Information

Paragraph	Table of CONTENTS	Page
SECTION 1	............................................................................................................................................	1-1
GENERAL INFORMATION....................................................................................................		1-1
1.1 ..............................................................................................................	INTRODUCTION	1-1
1.2 ..............................................................................................................	DME PRINCIPLE	1-1
1.2.1 ..........................................................................................................................	Coverage	1-2
1.2.2 .................................................................................................................	Traffic Capacity	1-2
1.2.3 ...........................................................................................................................	Accuracy	1-2
1.2.4 .....................................................	Nominal Reply Delay – Pair Pulse Code - Channeling	1-2
1.3 ................................................................	GENERAL FEATURES OF THE EQUIPMENT	1-13
1.3.1 ..........................................................................................................	Equipment Versions	1-13
1.3.2 ........................................................................................	Main Feature of the Equipment	1-13
1.3.2.1 .......................................................................................................................	Engineering	1-14
1.3.2.2 ................................................................................................................................	Safety	1-14
1.3.2.3 .........................................................................................................................	Installation	1-14
1.3.2.4 ..........................................................................................................................	Operation	1-14
1.4 ..........................................................	BEACON COMPOSITION AND IDENTIFICATION	1-16
1.5 .......................................................	PHYSICAL AND MECHANICAL general Description	1-19
1.6 ...................................................................	EQUIPMENT FUNCTIONAL DESCRIPTION	1-26
1.6.1 .............................................................................................................	General Overview	1-26
1.6.2 ..................................................................	DME 415/435 System Functional Description	1-27
1.6.3 ...............................................................................	I/O SYSTEM - Functional description	1-31
1.6.3.1 .....................................................................................................................	I/O Local site	1-31
1.6.3.2 ..................................................................	LOCAL CONTROL & STATUS UNIT (LCSU)	1-34
1.6.3.2.1 ....................	CONTROL AND STATUS BOARD - CSB module – Functional description	1-36
1.6.3.2.1.1 ...........................................................................................................	CPU and Memories	1-37
1.6.3.2.1.2 .......................................................................................................................	Serial Lines	1-40
1.6.3.2.1.3 .....................................................................................................................	Parallel ports	1-41
1.6.3.2.2 .................................................................................	LOCAL FRONT CONTROL PANEL	1-44
1.6.3.2.2.1 ............................	INDICATION AND CONTROLS - INC Module - functional description	1-45
1.6.3.3 ........................................................................................	REMOTE CONTROL SYSTEM	1-48
1.6.3.3.1 ................................................................	Remote Control & Status Indicator (RCSI 446)	1-50
1.6.3.3.2 ...............................................................	Remote Control and Status Equipment (RCSE)	1-51
1.6.3.3.3 ..................................................................................................................................	MCS	1-52
1.6.3.4 ......................................................................................................	Status Indicator SI 446	1-53
1.6.3.5 ...................................................................................................	Personal Computer - PC	1-54
1.6.4 .......................................................................	TRANSPONDER – Functional description	1-55
1.6.4.1 ...........................................................................................................	General Overviews	1-55
1.6.4.1.1 .........................................................................................................................	Pilot Pulse	1-55
1.6.4.1.2 ...........................................................................	Transponder Main Delay Measurement	1-55
1.6.4.2 ...................................................................................................	RECEIVER - RX module	1-60
1.6.4.2.1 ....................................................	UHF coupler (pilot pulse mixer) and 63 MHz Oscillator	1-61
1.6.4.2.2 ..................................................................	UHF Front End & 63 MHz linear amplification	1-61
1.6.4.2.3 .......................................................................................................................	Synthesizer	1-62
1.6.4.2.4 ...............................................................................................	Programmable attenuators	1-62
1.6.4.2.5 ........................................................................................................	Logarithmic Amplifier	1-63
1.6.4.2.6 ............................................................................................	On channel validation (OCV)	1-63
1.6.4.2.7 ..............................................................................................	RX reference power supply	1-63

1.6.4.2.8Digital circuitry and data bus,............................................................................................1-64

Vers. D, September 2005

THALES Italia S.p.A.- A. S. D.

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	955 900 031C		DME 415/435 -Technical Manual
		Vol. 1-Section 1-General Information
	Paragraph			Page
	1.6.4.3	SIGNAL PROCESSOR - DPR module ............................................................................		1-66
	1.6.4.3.1	Analog Input, TOA & Delay Compare .............................................................................		1-68
	1.6.4.3.2	On-channel validate .........................................................................................................		1-69
	1.6.4.3.3	Decoder and Dead Time ..................................................................................................		1-69
	1.6.4.3.4	Echo suppression.............................................................................................................		1-70
	1.6.4.3.5	Main Delay & Priority Circuit.............................................................................................		1-71
	1.6.4.3.6	Keyer and 1350 Hz Generator .........................................................................................		1-71
	1.6.4.3.7	Squitter Generator...........................................................................................................		1-72
	1.6.4.3.8	DPR reference power supply ...........................................................................................		1-72
	1.6.4.3.9	Digital Input circuitry and Data bus ..................................................................................		1-72
	1.6.4.4	MODULATOR – DMD module .........................................................................................		1-73
	1.6.4.4.1	Microprocessor and Peripherals ......................................................................................		1-75
	1.6.4.4.1.1	Watchdog and Power-On Reset ......................................................................................		1-75
	1.6.4.4.1.2	Serial Communication Controller .....................................................................................		1-75
	1.6.4.4.1.3	Internal Timers .................................................................................................................		1-75
	1.6.4.4.2	Coded Gaussian former & Pedestal Modulation Generators...........................................		1-75
	1.6.4.4.3	Coded Square Gates Modulation.....................................................................................		1-76
	1.6.4.4.4	Scan & Calibration Counters and reply delay Fine compensation..................................		1-76
	1.6.4.4.4.1	Overload Protection..........................................................................................................		1-77
	1.6.4.4.5	Acquisition Process ..........................................................................................................		1-77
	1.6.4.4.6	Modulation signals measurements...................................................................................		1-77
	1.6.4.4.7	DMD reference power supply...........................................................................................		1-77
	1.6.4.4.8	Digital Input and Data bus................................................................................................		1-78
	1.6.4.5	TRANSMITTER -TX 100 module .....................................................................................		1-79
	1.6.4.5.1	RF amplifiers chain circuits ..............................................................................................		1-79
	1.6.4.5.2	Video Modulation amplifiers .............................................................................................		1-79
	1.6.4.5.3	Detectors circuits..............................................................................................................		1-81
	1.6.4.5.4	Pulse Duration Protection circuits ....................................................................................		1-81
	1.6.4.5.5	Dedicated Power supply for RF amplifiers and TX100 ref. voltage power supply...........		1-82
	1.6.4.5.6	Circuits for measurement and diagnostic purpose...........................................................		1-83
	1.6.4.5.7	Digital signals and Data bus.............................................................................................		1-83
	1.6.4.6	1kWp RF POWER AMPLIFIER – TKW module (only DME 435).....................................		1-84
	1.6.4.6.1	RF amplifiers ....................................................................................................................		1-84
	1.6.4.6.2	Detectors circuits..............................................................................................................		1-87
	1.6.4.6.3	Pulse Duration Protection circuits ....................................................................................		1-87
	1.6.4.6.4	Dedicated 50V Power supply for RF amplif. and TKW ref. voltage power supply ...........		1-87
	1.6.4.6.5	Circuits for measurement and diagnostic purpose...........................................................		1-88
	1.6.4.6.6	Digital signals and Data bus.............................................................................................		1-88
	1.6.4.7	TRANSPONDER POWER SUPPLY (+5V & ±15V) – PWS module...............................		1-90
	1.6.5	RF PATH AND DUPLEXER – DPX module – Functional description .............................		1-91
	1.6.5.1.1	RF electronic switch circuitry............................................................................................		1-92
	1.6.5.1.2	Coupler detecting the pilot pulse and the coupler of the monitor-interrogator .................		1-92
	1.6.5.1.3	Video driver of RF switches commands...........................................................................		1-92
	1.6.5.1.4	DPX reference power supply............................................................................................		1-93
	1.6.5.1.5	Patch Panel ......................................................................................................................		1-94
	1.6.6	MONITOR SYSTEM.........................................................................................................		1-96
	1.6.6.1	Monitor Reply Delay measurement..................................................................................		1-97
	1.6.6.2	MONITOR - MON module – Functional description.........................................................		1-99
	1.6.6.3	RF Analog Group .............................................................................................................		1-99
	1.6.6.3.1	Frequency synthesizer .....................................................................................................		1-101
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	Paragraph			Page
	1.6.6.3.2	59MHz oscillator & Linear modulator................................................................................		1-102
	1.6.6.3.3	Digital Attenuator ..............................................................................................................		1-102
	1.6.6.3.4	Mixer FRX - Filter & UHF Amplifier.....................................................................................		1-103
	1.6.6.3.5	Input-Output selector ........................................................................................................		1-103
	1.6.6.3.6	Linear 63 MHz Detector....................................................................................................		1-106
	1.6.6.4	Analog/digital video section ..............................................................................................		1-107
	1.6.6.4.1	Acquisition ad Generation.................................................................................................		1-107
	1.6.6.5	Parallel line and serial line interface .................................................................................		1-110
	1.6.6.5.1	Status signals from Transponders ....................................................................................		1-111
	1.6.6.5.2	Commands to Transponders ............................................................................................		1-111
	1.6.6.5.3	Status signals from the Antenna - Dummy Load Switch (Duplexer)		................................1-111
	1.6.6.5.4	Commands to the Antenna - Dummy Load Switch (Duplexer).........................................		1-111
	1.6.6.5.5	Signals Exchanging with the other Monitor.......................................................................		1-111
	1.6.6.5.6	Other signals from/to Transponders .................................................................................		1-112
	1.6.6.6	CPU and Digital processor ...............................................................................................		1-112
	1.6.6.6.1	Serial connection with LCSU unit .....................................................................................		1-113
	1.6.6.6.2	Automatic cycle.................................................................................................................		1-113
	1.6.6.6.3	Monitor Reply Delay measurement ..................................................................................		1-114
	1.6.6.7	Morse code (MORCO) decoder........................................................................................		1-114
	1.6.6.7.1	Identification code .............................................................................................................		1-114
	1.6.6.7.2	Morse code detector .........................................................................................................		1-115
	1.6.6.8	MON reference power supply ...........................................................................................		1-115
	1.6.6.9	MONITOR SOFTWARE PROGRAM................................................................................		1-115
	1.6.6.9.1	Automatic Monitoring Operation .......................................................................................		1-115
	1.6.6.9.2	Automatic & Semi-Automatic Testing ...............................................................................		1-116
	1.6.7	INTERFACE SYSTEM – Functional description ..............................................................		1-117
	1.6.7.1	Associated Facility Interface - AFI module .......................................................................		1-117
	1.6.7.2	Modem (MDM) ..................................................................................................................		1-118
	1.6.7.2.1	Modem Level Adapter interface........................................................................................		1-118
	1.6.7.2.2	Switched and dedicated line Modem - LGM28,8..............................................................		1-118
	1.6.7.2.3	Dedicated Line Modem LGM1200MD – Party line ...........................................................		1-120
	1.6.8	COAXIAL RELAY – KCX module .....................................................................................		1-121
	1.6.8.1	TAI dummy – Interface module.........................................................................................		1-121
	1.6.9	POWER SUPPLY SYSTEM – Functional description ......................................................		1-121
	1.6.9.1	BCPS unit .........................................................................................................................		1-123
	1.6.9.2	Power supply with BCPS subrack Frako type (optional) .................................................		1-125
	1.6.9.2.1	AC/DC module – AC-DC converter (type Frako optional) ................................................		1-127
	1.6.9.2.2	Battery Supervisor module ...............................................................................................		1-128
	1.6.10	DME ANTENNA................................................................................................................		1-129

Vers. D, September 2005

THALES Italia S.p.A.- A. S. D.

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	955 900 031C	DME 415/435 -Technical Manual
		Vol. 1-Section 1-General Information

List of FIGURES

Figure			Page
Figure 1.1. DME - Principle of the RF signals path .............................................................................			1-1
Figure 1.2. DME - Theory of operation, simplified block diagram .......................................................			1-2
Figure 1.3. DME Channels Reply and Interrogation Frequencies.......................................................			1-3
Figure 1.4. DME 415 (same as DME 435) – Cabinet and PC, example of arrangement....................			1-15
Figure 1.5. DME 435 – Front view with anterior door opened – Full		Dual version.............................	1-21
Figure 1.6. DME 415 – Front view with anterior door opened – Full Dual version..............................			1-22
Figure 1.7. DME 435 Single version – Front view with anterior door opened .....................................			1-23
Figure 1.8. DME 435 – Rear side view of the cabinet .........................................................................			1-24
Figure 1.9. DME 415/435 – Top view ..................................................................................................			1-25
Figure 1.10. DME 415/435 – Simplified general block diagram ..........................................................			1-28
Figure 1.11. DME 415/435 – Main RF path signals - General simplified block diagram.....................			1-29
Figure 1.12. DME 415/435 – Local I/O system general block diagram ...............................................			1-30
Figure 1.13. DME 415/435 – AC/DC Power Supply system & Battery Charge - Block diagram.........			1-30
Figure 1.14. I/O Panel..........................................................................................................................			1-32
Figure 1.15. Local site set up – Typical configuration .........................................................................			1-33
Figure 1.16. LCSU - Simplified Block Diagram....................................................................................			1-34
Figure 1.17. CSB module – Simplified Block Diagram ........................................................................			1-35
Figure 1.18. CSB module – General Block Diagram ...........................................................................			1-37
Figure 1.19. CSB module – CPU and Memories: Block Diagram .......................................................			1-39
Figure 1.20. CSB module – Serial lines: Block Diagram .....................................................................			1-41
Figure 1.21. CSB module – I/O Parallel Ports: Block Diagram............................................................			1-43
Figure 1.22. Local Front Panel ............................................................................................................			1-45
Figure 1.23. INC module - simplified block diagram............................................................................			1-46
Figure 1.24. INC Module - Indication and Control: General Block Diagram........................................			1-46
Figure 1.25. INC Module - Indication and Control: Block Diagram......................................................			1-47
Figure 1.26. Possible connection between Remote RCSI/RCSE and Local site ................................			1-48
Figure 1.27. Example of single site connection with RCSI..................................................................			1-49
Figure 1.28. Example of multi site connection with RCSI....................................................................			1-49
Figure 1.29. Example of multi site connection with RCSE ..................................................................			1-50
Figure 1.30. RCSI-8 – Remote control ................................................................................................			1-51
Figure 1.31. RCSE 443 – Remote control	...........................................................................................		1-51
Figure 1.32. RCSE 443 – Remote control CTU & RunWay select......................................................			1-52
Figure 1.33. MCS – Remote control ....................................................................................................			1-52
Figure 1.34. SI446-2 and SI 446-8 - Front panel view.........................................................................			1-53
Figure 1.35. Example of connections between beacon and PC with RCSI/RCSE..............................			1-54
Figure 1.36. DME 415/435 TRANSPONDER– General block diagram of the main signals ...............			1-56
Figure 1.37. DME 415/435 TRANSPONDER– Main Delay Measurement and compensation ...........			1-57
Figure 1.38. DME 415/435 TRANSPONDER– General block diagram ..............................................			1-58
Figure 1.39. RX module – General block diagram ..............................................................................			1-59
Figure 1.40. RX - Layout location in the extrusion of the Analog RF ..................................................			1-60
Figure 1.41. RX - Receiver Coupler and 63 MHz oscillator block diagram .........................................			1-61
Figure 1.42. RX – Front End and 63 MHz linear amplif. - Block diagram............................................			1-61
Figure 1.43. RX – Frequency Synthesizer & RF Amplifier - Block diagram ........................................			1-62
Figure 1.44. RX – IF programmable digital Attenuator - Block diagram..............................................			1-63
Figure 1.45. RX – 63 MHz logarithmic amplifiers - Block diagram ......................................................			1-64
Figure 1.46. RX – Digital circuitry and data bus block diagram...........................................................			1-65
Figure 1.47. DPR module – General block diagram............................................................................			1-67
Figure 1.48. DPR – TOA & Delay-Compare – Block diagram.............................................................			1-68
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	DME 415/435 -Technical Manual			955 900 031C
	Vol. 1-Section 1-General Information
	Figure			Page
	Figure 1.49. DPR – Decoder & Dead Time – Simplified Block diagram ..............................................			1-70
	Figure 1.50. DPR – Main Delay, keyer & Priority Circuit – Simplified Block diagram ..........................			1-71
	Figure 1.51. DPR – Squitter generator – Simplified Block diagram .....................................................			1-72
	Figure 1.52. DPR – Digital circuitry and data bus - Block diagram ......................................................			1-72
	Figure 1.53. DMD module – General Block diagram ...........................................................................			1-74
	Figure 1.54. DMD – Bus system - Block diagram ................................................................................			1-78
	Figure 1.55. TX100 module – General block diagram .........................................................................			1-80
	Figure 1.56. TX100 – Layout location of main functional blocks..........................................................			1-81
	Figure 1.57. TX100 – Pulse duration protection circuits ......................................................................			1-82
	Figure 1.58. TX100 – Dedicated power supply ....................................................................................			1-82
	Figure 1.59. TX100 – Digital circuits – Block Diagram.........................................................................			1-83
	Figure 1.60. TKW – RF stages Matching Network – Block Diagram ...................................................			1-84
	Figure 1.61. TKW module – General block diagram ............................................................................			1-85
	Figure 1.62. TKW – Main Components Location .................................................................................			1-86
	Figure 1.63. TKW – Pulse Duration Protection circuits........................................................................			1-87
	Figure 1.64. TKW – Dedicated power supply.......................................................................................			1-88
	Figure 1.65. TKW – Digital circuits – Block Diagram ...........................................................................			1-89
	Figure 1.66. PWS module – General Block Diagram...........................................................................			1-90
	Figure 1.67. DPX module – Simplified Block Diagram.........................................................................			1-91
	Figure 1.68. DPX – RF circuits Block Diagram ....................................................................................			1-92
	Figure 1.69. DPX– Video circuits – Simplified Block diagram..............................................................			1-93
	Figure 1.70. DPX– Video circuits – Example of PIN diodes commands..............................................			1-93
	Figure 1.71. DPX Ref. Power Supply – Simplified Block diagram .......................................................			1-94
	Figure 1.72. DPX & Patch panel – Frontal view...................................................................................			1-94
	Figure 1.73. DPX & Patch Panel – Simplified Block diagram ..............................................................			1-95
	Figure 1.74. DME 415/435 - MONITOR system – Simplified block diagram .......................................			1-97
	Figure 1.75. DME 415/435 - MONITOR – Reply Delay Measurement ................................................			1-98
	Figure 1.76. MONITOR – Location of the RF stages on the casting ...................................................			1-99
	Figure 1.77. MONITOR – Analog RF group - Block diagram...............................................................			1-100
	Figure 1.78. MONITOR – Synthesizer – Simplified block schematic diagram.....................................			1-101
	Figure 1.79. MONITOR – Synthesizer – Block diagram ......................................................................			1-101
	Figure 1.80. MONITOR – 59 MHz oscillator & Linear modulator – Block diagram..............................			1-102
	Figure 1.81. MONITOR – Digital Attenuator – Block diagram .............................................................			1-102
	Figure 1.82. MONITOR – Mixer FRX - Filter & UHF Amplifier – Block diagram....................................			1-103
	Figure 1.83. MONITOR – Input-Output RF selector – General Block diagram....................................			1-104
	Figure 1.84. MONITOR – Input-Output RF selector – Detailed Block diagrams .................................			1-105
	Figure 1.85. MONITOR – Linear Detector - Block diagram .................................................................			1-106
	Figure 1.86. MONITOR – Acquisition and Generation - General Block diagram.................................			1-107
	Figure 1.87. MONITOR – Parallel line and serial line interface - General Block diagram ..................			1-110
	Figure 1.88. MONITOR – CPU and Digital processor - Block diagram ...............................................			1-112
	Figure 1.89. MONITOR – Morse code decoder - Block diagram .........................................................			1-114
	Figure 1.90. AFI module - Association Facility Interface – Simplified Block Diagram .........................			1-118
	Figure 1.91. Modem Level adapter - Block diagram ............................................................................			1-118
	Figure 1.92. LGM 28,8 MODEM – Simplified Block Diagram ..............................................................			1-119
	Figure 1.93. LGM1200MD Modem, block diagram ..............................................................................			1-120
	Figure 1.94. Transfer relay, block diagram ..........................................................................................			1-121
	Figure 1.95. EQUIPMENT POWER SUPPLY SYSTEM – General Block Diagram ............................			1-122
	Figure 1.96. BCPS unit	– Simplified Block Diagram ...........................................................................		1-123
	Figure 1.97. BCPS unit – AC/DC module - Schematic block diagram................................................			1-124
	Figure 1.98. BCPS unit – AC/DC module - Auxiliary voltage - Schematic block diagram ..................			1-124
	Vers. D, September 2005	THALES Italia S.p.A.- A. S. D.		1-e

	955 900 031C	DME 415/435 - Technical Manual
		Vol. 1 - Section 1 - General Information
	Figure	Page
	Figure 1.99. BCPS unit – AC/DC module - Sharing current circuitry - Schematic block diagram......	1-125
	Figure 1.100. Power Supply with BCPS Frako type – Simplified Block Diagram................................	1-125
	Figure 1.101. Power Supply with BCPS Frako type – Front and Rear view	1-126
	Figure 1.102. BCPS Frako type AC/DC module – General block diagram .........................................	1-127
	Figure 1.103. Battery Supervisor: Protection Circuit - Block Diagram.................................................	1-128
	Figure 1.104. DME ANTENNA ............................................................................................................	1-130

List of TABLES

Table	Page
Table 1-1. Frequencies for DME Channels ..........................................................................................	1-3
Table 1-2. Frequencies and Code Pulses for DME Channels (1 to 17) ...............................................	1-4
Table 1-2. Frequencies and Code Pulses for DME Channels (18 to 28) .............................................	1-5
Table 1-2. Frequencies and Code Pulses for DME Channels (29 to 40) .............................................	1-6
Table 1-2. Frequencies and Code Pulses for DME Channels (41 to 52) .............................................	1-7
Table 1-2. Frequencies and Code Pulses for DME Channels (53 to 68) .............................................	1-8
Table 1-2. Frequencies and Code Pulses for DME Channels (69 to 85) .............................................	1-9
Table 1-2. Frequencies and Code Pulses for DME Channels (86 to 99) .............................................	1-10
Table 1-2. Frequencies and Code Pulses for DME Channels (100 to 113) .........................................	1-11
Table 1-2. Frequencies and Code Pulses for DME Channels (114 to 126) .........................................	1-12
Table 1-3. Composition of the Equipment ............................................................................................	1-16
Table 1-4. User Interface Composition (option)....................................................................................	1-17
Table 1-5. Material Supplied.................................................................................................................	1-18
Table 1-6. RF Interrogation levels by monitors to Rx ...........................................................................	1-106

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THALES Italia S.p.A.- A. S. D.

Vers. D, September 2005

	DME 415/435 -Technical Manual	955 900 031C
	Vol. 1-Section 1-General Information

SECTION 1

GENERAL INFORMATION

1.1INTRODUCTION

DME (Distance Measuring Equipment) has been standardized by the ICAO as a radio aid for short and medium-distance navigation. It is a secondary type of radar, which allows several aircraft to simultaneously measure their distance from a ground reference (DME transponder). The distance is determined by measuring the propagation delay of a RF pulse, which is emitted by the aircraft transmitter and returned at a different frequency by the ground station after reception.

In conjunction with a VOR, the DME, which should preferably be installed at the same location as a VOR/DME, enables to determine the direction and the distance (rho-theta method).

Since the DME operates in the same frequency range (960 to 1215 MHz) and according to the same principle as the distance measuring section of the TACAN, combined VOR/TACAN systems (VORTAC) are installed in many countries, as well as VOR/DME systems.

1.2DME PRINCIPLE

Aircraft's equipped with DME transmit encoded interrogating RF pulse pairs on the beacon's receiving channel. The beacon, in turn, emits encoded reply pulse pairs on the receiving channel of the air-borne equipment, which is 63 MHz apart from the transmitter frequency former.

The time interval between interrogation emission and reply reception provides the aircraft with the real distance information from the ground station; this information may be read by the pilot or the navigator directly on the airborne indicator.

The ground transponder is able to answer up to about 200 interrogators at a time (i.e. 4800 pulse pairs/s). Generates random pulse pairs ("squitter") to maintain a minimum PRF of 800 to 2700 pulse pairs per second (programmable) whenever the number of decoded interrogations is lower than that.

This reply is received and decoded by the airborne receiver, where special timing circuits automatically measure the lapse between interrogation and reply and convert this measurement into electrical output signals. The beacon introduces a fixed delay, called reply delay, between the reception of each encoded interrogating pulse pair and the transmission of the corresponding reply ( see Figure 1.1).

Travel time (50µs+1µs/150m)

Interrogation Paire pulses transmitted by aircraft

One way time				Interrogation Paire pulses
	1µs/300m
				received by transponder
						Replay delay Paire pulses
				Replay Delay of the beacon
						transmitted by transponder
				(50µs)

		Replay Paire pulses
	One way time
		received by aircraft
	1µs/300m

Figure 1.1. DME - Principle of the RF signals path

The transponder periodically transmits special identification pulse groups, interleaved with the reply and squitter pulses that can be decoded by the aircraft as a Morse tone, keyed with the beacon code name.

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	955 900 031C	DME 415/435 -Technical Manual
		Vol. 1-Section 1-General Information

The airborne receiver is able to recognize the replies to its own interrogations, among the many other pulses transmitted by the beacon, by means of a stroboscopic procedure.

The DME theory of operation is summarized in a block diagram in Figure 1.2.

	AIRCRAFT'S	BEACON'S
	ANTENNA
		ANTENNA

TRANSMITS DISTANCE

INFORMATION

and IDENTIFICATION

SIGNAL

AUTOPILOT

RECEIVED

INTERROGATIONS

TRANSMITTER

RECEIVER

DISTANCE

CIRCUITS

DISTANCE INFORMATION

TRANSMITTER

RECEIVER

TO BOARD INDICATOR

DME

AIRBORNE CHANNEL SELECTOR

INTERROGATION

TRIGGERS

BEACON			REPLY TRIGGER TO
IDENTIFICATION TONE			INTERROGATIONS

DME GROUND BEACON

Figure 1.2. DME - Theory of operation, simplified block diagram

1.2.1Coverage

According to the frequency band used, the DME system coverage is limited to the optical range and depends on the aircraft flight altitude and on the type of ground.

The high frequency used and the use of special techniques have made the system much less sensitive to site errors than other types of omni-directional beacons now in use.

1.2.2Traffic Capacity

The aircraft handling capacity is adequate for a traffic peak of 200 aircrafts. When the traffic peak exceeds 200 aircrafts the transponder should be capable of handling that peak.

1.2.3Accuracy

As a result of the development and the applications of modern electronic technologies, the accuracy of the distance information provided by the DME system is improving all the time.

At present, the accuracy of a DME system can be considered within the maximum values specified below:

±0.12 NM +0.05% of the distance, from 0 to 65 nautical miles, and ± 0.17 NM +0.05% of the distance, above 65 nautical miles.

1.2.4Nominal Reply Delay – Pair Pulse Code - Channeling

Each beacon is identified by means of its channel frequency, its pulse coding and its identity signal.

The ground beacon introduces a fixed delay between the reception of interrogating pulses and the transmission of the corresponding reply pulses.

This fixed delay, called main delay or fundamental delay, is introduced. So that an aircraft which is flying very close to the beacon can complete transmission of the encoded interrogating pulse pair, and then deactivate its own transmitter, before its receiver begins receiving the corresponding beacon reply pulses.

To render the system as immune as possible to errors caused by interfering signals, the DME system transmits pulse pairs instead of single pulses; each pair includes two 3.5 µs pulses whose spacing depends on the channel mode selected.

The channel code, pulse code, reply delay and operating mode are shown on the following table (standard ICAO).

		Nominal	Transponder	Transponder
	Channel	Interrogation Pulse Code	Reply Pulse Code	Nominal Reply Delay
	Code	[µs]	[µs]	[µs]
	X	12	12.0 ± 0.1	50
	Y	36	30.0 ± 0.1	56
1-2		THALES Italia S.p.A.- A. S. D.		Vers. D, September 2005

	DME 415/435 -Technical Manual	955 900 031C
	Vol. 1-Section 1-General Information

Each operational channel in the DME system is defined by two frequencies (interrogation and reply frequencies), spaced 63 MHz apart, and by the pulse code for the assigned channel (X or Y channel).

The DME system transmits on a pre-selected channel among the 252 available ones. These channels are divided into 126 X channels and 126 Y channels providing a frequency ranging from 1025 to 1150 MHz for aircraft transmission (interrogation). Moreover, a 962 to 1213 MHz frequency for signal reception by the aircraft (ground beacon reply transmission). Interrogation and reply frequencies are assigned with one MHz spacing between channels.

The diagram shown in figure 1.3 gives the aircraft interrogation frequency associated to the beacon reply frequency for both channel types X, Y. The same information is also given in table 1-1 and table 1-2 for X and Y channels respectively, as per ICAO ANNEX 10.

Each beacon emits a Morse identity code signal that can be heard in the pilot headset; this code consists of pulse pairs transmitted at a frequency of 1350 Hz.

Each beacon is therefore identified by means of its channel frequency, its pulse coding and its identity signal.

			Table 1-1. Frequencies for DME Channels
		X Channels (n° 126)			Channel		Y Channels (n° 126)
		I = 1025 + (CH-1)					I = 1025 + (CH-1)
		R = I - 63			1 ≤ CH ≤ 63		R = I + 63
		R = I + 63			64 ≤ CH ≤ 126		R = I - 63
	I = INTERROGATION FREQUENCY (MHz)						CH = CHANNEL NUMBER
	R = REPLY FREQUENCY (MHz)
960 MHz								1215 MHz
962 MHz		1025 MHz			1088 MHz		1151 MHz	1213 MHz

1-63X		64-126X

1-63Y

64-126Y

		INTERROGATION FREQUENCIES				REPLY FREQUENCIES
		Figure 1.3. DME Channels Reply and Interrogation Frequencies
Vers. D, September 2005			THALES Italia S.p.A.- A. S. D.		1-3

	955 900 031C	DME 415/435 -Technical Manual
		Vol. 1-Section 1-General Information

Table 1-2. Frequencies and Code Pulses for DME Channels (1 to 17)

							DME PARAMETERS
	CHANNEL PAIRING				INTERROGATION					REPLY
						Pulse Codes
							DME/P
	VHF	MLS									Pulse
DME	FREQ.	FREQ.	MLS	Frequency	DME/N		IAM		FAM	Frequency	Codes
Channel	MHz	MHz	Channel	MHz	µs		µs		µs	MHz	µs
1X	−	−	−	1025	12		−		−	962	12
1Y	−	−	−	1025	36		−		−	1088	30
2X	−	−	−	1026	12		−		−	963	12
2Y	−	−	−	1026	36		−		−	1089	30
3X	−	−	−	1027	12		−		−	964	12
3Y	−	−	−	1027	36		−		−	1090	30
4X	−	−	−	1028	12		−		−	965	12
4Y	−	−	−	1028	36		−		−	1091	30
5X	−	−	−	1029	12		−		−	966	12
5Y	−	−	−	1029	36		−		−	1092	30
6X	−	−	−	1030	12		−		−	967	12
6Y	−	−	−	1030	36		−		−	1093	30
7X	−	−	−	1031	12		−		−	968	12
7Y	−	−	−	1031	36		−		−	1094	30
8X	−	−	−	1032	12		−		−	969	12
8Y	−	−	−	1032	36		−		−	1095	30
9X	−	−	−	1033	12		−		−	970	12
9Y	−	−	−	1033	36		−		−	1096	30
10X	−	−	−	1034	12		−		−	971	12
10Y	−	−	−	1034	36		−		−	1097	30
11X	−	−	−	1035	12		−		−	972	12
11Y	−	−	−	1035	36		−		−	1098	30
12X	−	−	−	1036	12		−		−	973	12
12Y	−	−	−	1036	36		−		−	1099	30
13X	−	−	−	1037	12		−		−	974	12
13Y	−	−	−	1037	36		−		−	1100	30
14X	−	−	−	1038	12		−		−	975	12
14Y	−	−	−	1038	36		−		−	1101	30
15X	−	−	−	1039	12		−		−	976	12
15Y	−	−	−	1039	36		−		−	1102	30
16X	−	−	−	1040	12		−		−	977	12
16Y	−	−	−	1040	36		−		−	1103	30
17X	108.00	−	−	1041	12		−		−	978	12
17Y	108.05	5043.0	540	1041	36		36		42	1104	30
17Z	−	5043.3	541	1041	−		21		27	1104	15

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Vers. D, September 2005

	DME 415/435 -Technical Manual	955 900 031C
	Vol. 1-Section 1-General Information

Table 1-2. Frequencies and Code Pulses for DME Channels (18 to 28)

							DME PARAMETERS
	CHANNEL PAIRING				INTERROGATION					REPLY
						Pulse Codes
							DME/P
	VHF	MLS									Pulse
DME	FREQ.	FREQ.	MLS	Frequency	DME/N		IAM		FAM	Frequency	Codes
Channel	MHz	MHz	Channel	MHz	µs		µs		µs	MHz	µs
18X	108.10	5031.0	500	1042	12		12		18	979	12
18W	−	5031.3	501	1042	−		24		30	979	24
18Y	108.15	5043.6	542	1042	36		36		42	1105	30
18Z	−	5043.9	543	1042	−		21		27	1105	15
19X	108.20	−	−	1043	12		−		−	980	12
19Y	108.25	5044.2	544	1043	36		36		42	1106	30
19Z	−	5044.5	545	1043	−		21		27	1106	15
20X	108.30	5031.6	502	1044	12		12		18	981	12
20W	−	5031.9	503	1044	−		24		30	981	24
20Y	108.35	5044.8	546	1044	36		36		42	1107	30
20Z	−	5045.1	547	1044	−		21		27	1107	15
21X	108.40	−	−	1045	12		−		−	982	12
21Y	108.45	5045.4	548	1045	36		36		42	1108	30
21Z	−	5045.7	549	1045	−		21		27	1108	15
22X	108.50	5032.2	504	1046	12		12		18	983	12
22W	−	5032.5	505	1046	−		24		30	983	24
22Y	108.55	5046.0	550	1046	36		36		42	1109	30
22Z	−	5046.3	551	1046	−		21		27	1109	15
23X	108.60	−	−	1047	12		−		−	984	12
23Y	108.65	5046.6	552	1047	36		36		42	1110	30
23Z	−	5046.9	553	1047	−		21		27	1110	15
24X	108.70	5032.8	506	1048	12		12		18	985	12
24W	−	5033.1	507	1048	−		24		30	985	24
24Y	108.75	5047.2	554	1048	36		36		42	1111	30
24Z	−	5047.5	555	1048	−		21		27	1111	15
25X	108.80	−	−	1049	12		−		−	986	12
25Y	108.85	5047.8	556	1049	36		36		42	1112	30
25Z	−	5048.1	557	1049	−		21		27	1112	15
26X	108.90	5033.4	508	1050	12		12		18	987	12
26W	−	5033.7	509	1050	−		24		30	987	24
26Y	108.95	5048.4	558	1050	36		36		42	1113	30
26Z	−	5048.7	559	1050	−		21		27	1113	15
27X	109.00	−	−	1051	12		−		−	988	12
27Y	109.05	5049.0	560	1051	36		36		42	1114	30
27Z	−	5049.3	561	1051	−		21		27	1114	15
28X	109.10	5034.0	510	1052	12		12		18	989	12
28W	−	5034.3	511	1052	−		24		30	989	24
28Y	109.15	5049.6	562	1052	36		36		42	1115	30
28Z	−	5049.9	563	1052	−		21		27	1115	15

Vers. D, September 2005

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1-5

	955 900 031C	DME 415/435 -Technical Manual
		Vol. 1-Section 1-General Information

Table 1-2. Frequencies and Code Pulses for DME Channels (29 to 40)

							DME PARAMETERS
	CHANNEL PAIRING				INTERROGATION					REPLY
						Pulse Codes
							DME/P
	VHF	MLS									Pulse
DME	FREQ.	FREQ.	MLS	Frequency	DME/N		IAM		FAM	Frequency	Codes
Channel	MHz	MHz	Channel	MHz	µs		µs		µs	MHz	µs
29X	109.20	−	−	1053	12		−		−	990	12
29Y	109.25	5050.2	564	1053	36		36		42	1116	30
29Z	−	5050.5	565	1053	−		21		27	1116	15
30X	109.30	5034.6	512	1054	12		12		18	991	12
30W	−	5034.9	513	1054	−		24		30	991	24
30Y	109.35	5050.8	566	1054	36		36		42	1117	30
30Z	−	5051.1	567	1054	−		21		27	1117	15
31X	109.40	−	−	1055	12		−		−	992	12
31Y	109.45	5051.4	568	1055	36		36		42	1118	30
31Z	−	5051.7	569	1055	−		21		27	1118	15
32X	109.50	5035.2	514	1056	12		12		18	993	12
32W	−	5035.5	515	1056	−		24		30	993	24
32Y	109.55	5052.0	570	1056	36		36		42	1119	30
32Z	−	5052.3	571	1056	−		21		27	1119	15
33X	109.60	−	−	1057	12		−		−	994	12
33Y	109.65	5052.6	572	1057	36		36		42	1120	30
33Z	−	5052.9	573	1057	−		21		27	1120	15
34X	109.70	5035.8	516	1058	12		12		18	995	12
34W	−	5036.1	517	1058	−		24		30	995	24
34Y	109.75	5053.2	574	1058	36		36		42	1121	30
34Z	−	5053.5	575	1058	−		21		27	1121	15
35X	109.80	−	−	1059	12		−		−	996	12
35Y	109.85	5053.8	576	1059	36		36		42	1122	30
35Z	−	5054.1	577	1059	−		21		27	1122	15
36X	109.90	5036.4	518	1060	12		12		18	997	12
36W	−	5036.7	519	1060	−		24		30	997	24
36Y	109.95	5054.4	578	1060	36		36		42	1123	30
36Z	−	5054.7	579	1060	−		21		27	1123	15
37X	110.00	−	−	1061	12		−		−	998	12
37Y	110.05	5055.0	580	1061	36		36		42	1124	30
37Z	−	5055.3	581	1061	−		21		27	1124	15
38X	110.10	5037.0	520	1062	12		12		18	999	12
38W	−	5037.3	521	1062	−		24		30	999	24
38Y	110.15	5055.6	582	1062	36		36		42	1125	30
38Z	−	5055.9	583	1062	−		21		27	1125	15
39X	110.20	−	−	1063	12		−		−	1000	12
39Y	110.25	5056.2	584	1063	36		36		42	1126	30
39Z	−	5056.5	585	1063	−		21		27	1126	15
40X	110.30	5037.6	522	1064	12		12		18	1001	12
40W	−	5037.9	523	1064	−		24		30	1001	24
40Y	110.35	5056.8	586	1064	36		36		42	1127	30
40Z	−	5057.1	587	1064	−		21		27	1127	15

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THALES Italia S.p.A.- A. S. D.

Vers. D, September 2005

	DME 415/435 -Technical Manual	955 900 031C
	Vol. 1-Section 1-General Information

Table 1-2. Frequencies and Code Pulses for DME Channels (41 to 52)

							DME PARAMETERS
	CHANNEL PAIRING				INTERROGATION					REPLY
						Pulse Codes
							DME/P
	VHF	MLS									Pulse
DME	FREQ.	FREQ.	MLS	Frequency	DME/N		IAM		FAM	Frequency	Codes
Channel	MHz	MHz	Channel	MHz	µs		µs		µs	MHz	µs
41X	110.40	−	−	1065	12		−		−	1002	12
41Y	110.45	5057.4	588	1065	36		36		42	1128	30
41Z	−	5057.7	589	1065	−		21		27	1128	15
42X	110.50	5038.2	524	1066	12		12		18	1003	12
42W	−	5038.5	525	1066	−		24		30	1003	24
42Y	110.55	5058.0	590	1066	36		36		42	1129	30
42Z	−	5058.3	591	1066	−		21		27	1129	15
43X	110.60	−	−	1067	12		−		−	1004	12
43Y	110.65	5058.6	592	1067	36		36		42	1130	30
43Z	−	5058.9	593	1067	−		21		27	1130	15
44X	110.70	5038.8	526	1068	12		12		18	1005	12
44W	−	5039.1	527	1068	−		24		30	1005	24
44Y	110.75	5059.2	594	1068	36		36		42	1131	30
44Z	−	5059.5	595	1068	−		21		27	1131	15
45X	110.80	−	−	1069	12		−		−	1006	12
45Y	110.85	5059.8	596	1069	36		36		42	1132	30
45Z	−	5060.1	597	1069	−		21		27	1132	15
46X	110.90	5039.4	528	1070	12		12		18	1007	12
46W	−	5039.7	529	1070	−		24		30	1007	24
46Y	110.95	5060.4	598	1070	36		36		42	1133	30
46Z	−	5060.7	599	1070	−		21		27	1133	15
47X	111.00	−	−	1071	12		−		−	1008	12
47Y	111.05	5061.0	600	1071	36		36		42	1134	30
47Z	−	5061.3	601	1071	−		21		27	1134	15
48X	111.10	5040.0	530	1072	12		12		18	1009	12
48W	−	5040.3	531	1072	−		24		30	1009	24
48Y	111.15	5061.6	602	1072	36		36		42	1135	30
48Z	−	5061.9	603	1072	−		21		27	1135	15
49X	111.20	−	−	1073	12		−		−	1010	12
49Y	111.25	5062.2	604	1073	36		36		42	1136	30
49Z	−	5062.5	605	1073	−		21		27	1136	15
50X	111.30	5040.6	532	1074	12		12		18	1011	12
50W	−	5040.9	533	1074	−		24		30	1011	24
50Y	111.35	5062.8	606	1074	36		36		42	1137	30
50Z	−	5063.1	607	1074	−		21		27	1137	15
51X	111.40	−	−	1075	12		−		−	1012	12
51Y	111.45	5063.4	608	1075	36		36		42	1138	30
51Z	−	5063.7	609	1075	−		21		27	1138	15
52X	111.50	5041.2	534	1076	12		12		18	1013	12
52W	−	5041.5	535	1076	−		24		30	1013	24
52Y	111.55	5064.0	610	1076	36		36		42	1139	30
52Z	−	5064.3	611	1076	−		21		27	1139	15

Vers. D, September 2005

THALES Italia S.p.A.- A. S. D.

1-7

	955 900 031C	DME 415/435 -Technical Manual
		Vol. 1-Section 1-General Information

Table 1-2. Frequencies and Code Pulses for DME Channels (53 to 68)

							DME PARAMETERS
	CHANNEL PAIRING				INTERROGATION					REPLY
						Pulse Codes
							DME/P
	VHF	MLS									Pulse
DME	FREQ.	FREQ.	MLS	Frequency	DME/N		IAM		FAM	Frequency	Codes
Channel	MHz	MHz	Channel	MHz	µs		µs		µs	MHz	µs
53X	111.60	−	−	1077	12		−		−	1014	12
53Y	111.65	5064.5	612	1077	36		36		42	1140	30
53Z	−	5064.9	613	1077	−		21		27	1140	15
54X	111.70	5041.8	536	1078	12		12		18	1015	12
54W	−	5042.1	537	1078	−		24		30	1015	24
54Y	111.75	5065.2	614	1078	36		36		42	1141	30
54Z	−	5065.5	615	1078	−		21		27	1141	15
55X	111.80	−	−	1079	12		−		−	1016	12
55Y	111.85	5065.8	616	1079	36		36		42	1142	30
55Z	−	5066.1	617	1079	−		21		27	1142	15
56X	111.90	5042.4	538	1080	12		12		18	1017	12
56W	−	5042.7	539	1080	−		24		30	1017	24
56Y	111.95	5066.4	618	1080	36		36		42	1143	30
56Z	−	5066.7	619	1080	−		21		27	1143	15
57X	112.00	−	−	1081	12		−		−	1018	12
57Y	112.05	−	−	1081	36		−		−	1144	30
58X	112.10	−	−	1082	12		−		−	1019	12
58Y	112.15	−	−	1082	36		−		−	1145	30
59X	112.20	−	−	1083	12		−		−	1020	12
59Y	112.25	−	−	1083	36		−		−	1146	30
60X	−	−	−	1084	12		−		−	1021	12
60Y	−	−	−	1084	36		−		−	1147	30
61X	−	−	−	1085	12		−		−	1022	12
61Y	−	−	−	1085	36		−		−	1148	30
62X	−	−	−	1086	12		−		−	1023	12
62Y	−	−	−	1086	36		−		−	1149	30
63X	−	−	−	1087	12		−		−	1024	12
63Y	−	−	−	1087	36		−		−	1150	30
64X	−	−	−	1088	12		−		−	1151	12
64Y	−	−	−	1088	36		−		−	1025	30
65X	−	−	−	1089	12		−		−	1152	12
65Y	−	−	−	1089	36		−		−	1026	30
66X	−	−	−	1090	12		−		−	1153	12
66Y	−	−	−	1090	36		−		−	1027	30
67X	−	−	−	1091	12		−		−	1154	12
67Y	−	−	−	1091	36		−		−	1028	30
68X	−	−	−	1092	12		−		−	1155	12
68Y	−	−	−	1092	36		−		−	1029	30

1-8

THALES Italia S.p.A.- A. S. D.

Vers. D, September 2005

	DME 415/435 -Technical Manual	955 900 031C
	Vol. 1-Section 1-General Information

Table 1-2. Frequencies and Code Pulses for DME Channels (69 to 85)

							DME PARAMETERS
	CHANNEL PAIRING				INTERROGATION					REPLY
						Pulse Codes
							DME/P
	VHF	MLS									Pulse
DME	FREQ.	FREQ.	MLS	Frequency	DME/N		IAM		FAM	Frequency	Codes
Channel	MHz	MHz	Channel	MHz	µs		µs		µs	MHz	µs
69X	−	−	−	1093	12		−		−	1156	12
69Y	−	−	−	1093	36		−		−	1030	30
70X	112.30	−	−	1094	12		−		−	1157	12
70Y	112.35	−	−	1094	36		−		−	1031	30
71X	112.40	−	−	1095	12		−		−	1158	12
71Y	112.45	−	−	1095	36		−		−	1032	30
72X	112.50	−	−	1096	12		−		−	1159	12
72Y	112.55	−	−	1096	36		−		−	1033	30
73X	112.60	−	−	1097	12		−		−	1160	12
73Y	112.65	−	−	1097	36		−		−	1034	30
74X	112.70	−	−	1098	12		−		−	1161	12
74Y	112.75	−	−	1098	36		−		−	1035	30
75X	112.80	−	−	1099	12		−		−	1162	12
75Y	112.85	−	−	1099	36		−		−	1036	30
76X	112.90	−	−	1100	12		−		−	1163	12
76Y	112.95	−	−	1100	36		−		−	1037	30
77X	113.00	−	−	1101	12		−		−	1164	12
77Y	113.05	−	−	1101	36		−		−	1038	30
78Y	113.10	−	−	1102	12		−		−	1165	12
78Y	113.15	−	−	1102	36		−		−	1039	30
79X	113.20	−	−	1103	12		−		−	1166	12
79Y	113.25	−	−	1103	36		−		−	1040	30
80X	113.30	−	−	1104	12		−		−	1167	12
80Y	113.35	5067.0	620	1104	36		36		42	1041	30
80Z	−	5067.3	621	1104	−		21		27	1041	15
81X	113.40	−	−	1105	12		−		−	1168	12
81Y	113.45	5067.6	622	1105	36		36		42	1042	30
81Z	−	5067.9	623	1105	−		21		27	1042	15
82X	113.50	−	−	1106	12		−		−	1169	12
82Y	113.55	5068.2	624	1106	36		36		42	1043	30
82Z	−	5068.5	625	1106	−		21		27	1043	15
83X	113.60	−	−	1107	12		−		−	1170	12
83Y	113.65	5068.8	626	1107	36		36		42	1044	30
83Z	−	5069.1	627	1107	−		21		27	1044	15
84X	113.70	−	−	1108	12		−		−	1171	12
84Y	113.75	5069.4	628	1108	36		36		42	1045	30
84Z	−	5069.7	629	1108	−		21		27	1045	15
85X	113,80			1109	12		-		-	1172	12
85Y	113,85	5070.0		1109	36		36		42	1046	30
85Z	-	5071.3		1109	-		21		27	1046	15

Vers. D, September 2005

THALES Italia S.p.A.- A. S. D.

1-9

	955 900 031C	DME 415/435 -Technical Manual
		Vol. 1-Section 1-General Information

Table 1-2. Frequencies and Code Pulses for DME Channels (86 to 99)

							DME PARAMETERS
	CHANNEL PAIRING				INTERROGATION					REPLY
						Pulse Codes
							DME/P
	VHF	MLS									Pulse
DME	FREQ.	FREQ.	MLS	Frequency	DME/N		IAM		FAM	Frequency	Codes
Channel	MHz	MHz	Channel	MHz	µs		µs		µs	MHz	µs
86X	113.90	−	−	1110	12		−		−	1173	12
86Y	113.95	5070.6	632	1110	36		36		42	1047	30
86Z	−	5070.9	633	1110	−		21		27	1047	15
87X	114.00	−	−	1111	12		−		−	1174	12
87Y	114.05	5071.2	634	1111	36		36		42	1048	30
87Z	−	5071.5	635	1111	−		21		27	1048	15
88X	114.10	−	−	1112	12		−		−	1175	12
88Y	114.15	5071.8	636	1112	36		36		42	1049	30
88Z	−	5072.1	637	1112	−		21		27	1049	15
89X	114.20	−	−	1113	12		−		−	1176	12
89Y	114.25	5072.4	638	1113	36		36		42	1050	30
89Z	−	5072.7	639	1113	−		21		27	1050	15
90X	114.30	−	−	1114	12		−		−	1177	12
90Y	114.35	5073.0	640	1114	36		36		42	1051	30
90Z	−	5073.3	641	1114	−		21		27	1051	15
91X	114.40	−	−	1115	12		−		−	1178	12
91Y	114.45	5073.6	642	1115	36		36		42	1052	30
91Z	−	5073.9	643	1115	−		21		27	1052	15
92X	114.50	−	−	1116	12		−		−	1179	12
92Y	114.55	5074.2	644	1116	36		36		42	1053	30
92Z	−	5074.5	645	1116	−		21		27	1053	15
93X	114.60	−	−	1117	12		−		−	1180	12
93Y	114.65	5074.8	646	1117	36		36		42	1054	30
93Z	−	5075.1	647	1117	−		21		27	1054	15
94X	114.70	−	−	1118	12		−		−	1181	12
94Y	114.75	5075.4	648	1118	36		36		42	1055	30
94Z	−	5075.7	649	1118	−		21		27	1055	15
95X	114.80	−	−	1119	12		−		−	1182	12
95Y	114.85	5076.0	650	1119	36		36		42	1056	30
95Z	−	5076.3	651	1119	−		21		27	1056	15
96X	114.90	−	−	1120	12		−		−	1183	12
96Y	114.95	5076.6	652	1120	36		36		42	1057	30
96Z	−	5076.9	653	1120	−		21		27	1057	15
97X	115.00	−	−	1121	12		−		−	1184	12
97Y	115.05	5077.2	654	1121	36		36		42	1058	30
97Z	−	5077.5	655	1121	−		21		27	1058	15
98X	115.10	−	−	1122	12		−		−	1185	12
98Y	115.15	5077.8	656	1122	36		36		42	1059	30
98Z	−	5078.1	657	1122	−		21		27	1059	15
99X	115.20	−	−	1123	12		−		−	1186	12
99Y	115.25	5078.4	658	1123	36		36		42	1060	30
99Z	−	5078.7	659	1123	−		21		27	1060	15

1-10

THALES Italia S.p.A.- A. S. D.

Vers. D, September 2005