Table of Contents
1.0INTRODUCTIONANDDESCRIPTION
1.1PurposeofthisCharacteristic
1.2FunctionsoftheEquipment
1.3UnitDescription
1.3.1ReceiverUnit
1.3.2CombinedLoop/SenseAntenna
1.3.3FrequencyControl
1.3.4Indicator
1.4Interchangeability
1.4.1General
1.4.2InterchangeabilityDesiredfortheARINC712ADF
System
1.4.3"GenerationInterchangeability"Considerations
1.5RegulatoryApproval
1.6Reliability
2.0INTERCHANGEABILITYSTANDARDS
2.1Introduction
2.2FormFactors,Connectors,andIndexPinCoding
2.2.1ReceiverUnit
2.2.2"StandardControlPanel"
2.2.3Antennas
2.2.4RFTransmissionLines
2.2.5AntennaLightningandP-StaticDischarge
Protection
2.3StandardInterwiring
2.4PowerCircuitry
2.4.1PrimaryPowerInput
2.4.2PowerControlCircuitry
2.4.3TheCommonGround
2.4.4TheACCommonCold
2.5StandardOutputs
2.6EnvironmentalConditions
2.7CoolingGeneral
2.7.1ReceiverUnit
2.7.2ADFControlPanel
2.8QuadrantalErrorCorrection(QEC)
2.9GroundandBonding
3.0ADFSYSTEMDESIGN
3.1General
3.1.1ControlofDigitalStandards
3.1.2FrequencyRangeandChanneling
3.1.3TransmitterFrequencyStability
3.1.4ModesofOperation
3.1.5FrequencySelection
3.1.6SystemSensitivity
3.1.6.1AuralSensitivity(MCW)
3.1.6.2NavigationSensitivity
3.1.7Selectivity
3.1.7.1RF/IFSelectivity
3.1.7.2ADFSelectivity
3.1.8UndesiredResponses
3.1.9CrossModulation
3.1.10Intermodulation
3.1.11AGC
3.1.12"BFO"Function
3.2DigitalInputControlFunctions
3.3ADFBearingDigitalOutput
3.3.1DigitalBearingAccuracy
3.3.2BearingOutputDamping
3.4ADFReceiverAuralOutput
3.4.1Gain
3.4.2AudioOutputLevelVariationwithLoadImpedance
3.4.3AudioFrequencyResponse
3.4.4HarmonicDistortion
3.4.5AudioOutputServiceAdjustment
3.4.6AudioPhaseShift
3.5Monitoring
3.5.1InputSignalMonitoring
3.5.2FailureMonitoring
3.6FunctionalTest
3.7QuadrantalErrorCompensation
3.8LoopInputImpedance
3.9ReceiverSenseInputImpedance
3.10GroundStationIdentReporting
4.0ANTENNAS
4.1ADFAntenna
4.2AntennaTransmissionLineConsiderations
4.3ElectricalCharacteristics
5.0PROVISIONSFORAUTOMATICTESTEQUIPMENT
5.1General
5.2UnitIdentification
5.2.1PinAllocation
5.3UseofATLASLanguage
6.0BUILT-INTESTEQUIPMENT(BITE)
6.1Built-InTestEquipment(BITE)
6.2BITEDisplay
6.3FaultMonitor
6.4Self-TestInitiation
6.5MonitorMemoryOutput
ATTACHMENTS
1NotesApplicabletotheStandardInterwiring
2StandardInterwiring
3ADFReceiverConnectorLayoutInsertB
4ReceiverUnitConnectorPositioning
5TearDropADFAntenna
6AntennaDetails
7StandardADFControlPanel
8DigitalDataStandards
9ElectricalCharacteristicsofAntennaUnit
10EnvironmentalTestCategories
APPENDIXES
1SpecificationsforNon-DirectionRadioBeacons
(NDB)ExcerptsfromICAOAnnex10
2GuidanceforADFAntennaandRFTransmission
LineInstallation
3ChronologyandBibliography
4ADFAntennaVibrationEnvironment Abstract
Describes the characteristics of an ADF system for installation in commercial transport aircraft. Function is to receive and process signals from non-directional range and other transmitters in the frequency band 190 kHz to 1750 kHz, to provide serial digital outputs of bearing, and to provide aural identification of the selected station.
