SIST EN 300 162-1 V1.2.2:2003

• Abstract:

  Editorial update to include changes consequential to the publication of part 2.

• Status: Published
• Publication Date: 30-Nov-2003
• ICS: 33.060.20 - Receiving and transmitting equipment
• ICS: 33.100.01 - Electromagnetic compatibility in general
• ICS: 47.020.70 - Navigation and control equipment
• Technical Committee: SS EIT - Technical Board for the electrotechnical, information technology and telecommunications fields
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 01-Dec-2003
• Due Date: 01-Dec-2003
• Completion Date: 01-Dec-2003
• Ref Project: ETSI EN 300 162-1 V1.2.2 (2000-12) - ElectroMagnetic Compatibility and Radio Spectrum Matters (ERM); Radiotelephone transmitters and receivers for the maritime mobile service operating in VHF bands; Part 1: Technical characteristics and methods of measurement

Overview

SIST EN 300 162-1 V1.2.2:2003 is an international standard developed by the Slovenski inštitut za standardizacijo (SIST), aligning with ETSI standards. This document specifies the minimum technical requirements and methods of measurement for shipborne Very High Frequency (VHF) radiotelephone transmitters and receivers used in the maritime mobile service. Focusing on both voice and Digital Selective Calling (DSC) capabilities, it applies to equipment with external antenna connectors installed on vessels operating in VHF maritime bands.

This part of the standard underwent an editorial update to reflect changes resulting from the publication of Part 2, ensuring it remains harmonized and consistent with evolving regulatory and technical requirements.

Keywords: Electromagnetic compatibility (EMC), maritime radio, VHF, DSSC, nautical communication, radio spectrum, measurement methods.

Key Topics

• Technical Characteristics: Outlines the essential features and minimum performance requirements for VHF maritime radiotelephone equipment. This includes specifications for how equipment should be constructed, operated, and labeled for safety and functionality.
• Measurement Methods: Details standardized procedures for testing both transmitters and receivers, ensuring compliance with international maritime standards and EMC regulations.
• Operational Requirements: Addresses construction, control functions, safety precautions, interfaces (including DSC), and environmental tolerance (temperature, humidity, vibration).
• Frequency Bands: Focuses on the 156-174 MHz frequency range, in accordance with international marine allocations.
• Testing Conditions: Specifies normal and extreme test conditions including power sources, temperature parameters, and measurement uncertainties for reliable, reproducible results.
• Environmental Testing: Includes vibration, dry heat, damp heat, and low temperature cycles to assess equipment resilience in harsh marine environments.
• Signal Performance: Defines limits and testing procedures for audio response, spurious emissions, frequency error, carrier power, adjacent channel characteristics, and receiver selectivity.
• DSC Capabilities: Incorporates requirements for Digital Selective Calling, supporting modern GMDSS (Global Maritime Distress and Safety System) operations.

Applications

SIST EN 300 162-1 V1.2.2:2003 is vital for:

• Marine Equipment Manufacturers: Guides the design, testing, and certification of VHF radio equipment to ensure compliance with international safety and performance norms.
• Ship Operators and Owners: Assists in the selection of reliable radio communication systems that meet regulatory requirements for global maritime operations, especially for vessels subject to the GMDSS mandate.
• Testing Laboratories: Provides standardized methods for assessing EMC and radio frequency performance of maritime VHF radio equipment.
• Regulatory Bodies: Supports maritime safety and spectrum management through harmonized technical guidelines.
• Installers and Maintainers: Ensures that on-board VHF radio systems function reliably under various environmental and operational conditions.

Related Standards

SIST EN 300 162-1 V1.2.2:2003 is part of a series and cross-references several notable standards, including:

• SIST EN 300 162-2: Harmonized EN for essential requirements of the R&TTE Directive, Part 2.
• EN 300 162-3: Covering additional essential requirements (e.g., for safety or additional regulatory compliance).
• ITU Radio Regulations Appendix 18 & 19: Governing allocation and technical characteristics for the maritime mobile VHF bands.
• ITU-T Recommendation E.161: On arrangements of digits and symbols for telecommunication devices.
• IMO Recommendations: Requirements set by the International Maritime Organization relevant to VHF radio and GMDSS.

These references ensure interoperability, safety, and uniformity across national and international maritime communication systems.

---

Staying compliant with SIST EN 300 162-1 V1.2.2:2003 is essential for safe, effective maritime communication and contributes to global harmonization of radio equipment standards in the VHF maritime bands.

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.ElectroMagnetic Compatibility and Radio Spectrum Matters (ERM); Radiotelephone transmitters and receivers for the maritime mobile service operating in VHF bands; Part 1: Technical characteristics and methods of measurement47.020.70Navigacijska in krmilna opremaNavigation and control equipment33.100.01Elektromagnetna združljivost na splošnoElectromagnetic compatibility in general33.060.20Sprejemna in oddajna opremaReceiving and transmitting equipmentICS:Ta slovenski standard je istoveten z:EN 300 162-1 Version 1.2.2SIST EN 300 162-1 V1.2.2:2003en01-december-2003SIST EN 300 162-1 V1.2.2:2003SLOVENSKI
STANDARD
ETSIEN300162-1V1.2.2(2000-12)EuropeanStandard(Telecommunicationsseries)ElectromagneticcompatibilityandRadiospectrumMatters(ERM);RadiotelephonetransmittersandreceiversforthemaritimemobileserviceoperatinginVHFbands;Part1:TechnicalcharacteristicsandmethodsofmeasurementSIST EN 300 162-1 V1.2.2:2003

ETSIETSIEN300162-1V1.2.2(2000-12)2ReferenceDEN/ERM-RP01-046-1KeywordsEMC,GMDSS,maritime,radio,telephony,testing,VHFETSI650RoutedesLuciolesF-06921SophiaAntipolisCedex-FRANCETel.:[phone]Fax:[phone]SiretN°34862356200017-NAF742CAssociationàbutnonlucratifenregistréeàlaSous-PréfecturedeGrasse(06)N°7803/88ImportantnoticeIndividualcopiesofthepresentdocumentcanbedownloadedfrom:http://www.etsi.orgThepresentdocumentmaybemadeavailableinmorethanoneelectronicversionorinprint.Inanycaseofexistingorperceiveddifferenceincontentsbetweensuchversions,thereferenceversionisthePortableDocumentFormat(PDF).Incaseofdispute,thereferenceshallbetheprintingonETSIprintersofthePDFversionkeptonaspecificnetworkdrivewithinETSISecretariat.Usersofthepresentdocumentshouldbeawarethatthedocumentmaybesubjecttorevisionorchangeofstatus.InformationonthecurrentstatusofthisandotherETSIdocumentsisavailableathttp://www.etsi.org/tb/status/Ifyoufinderrorsinthepresentdocument,sendyourcommentto:[e-mail]opartmaybereproducedexceptasauthorizedbywrittenpermission.Thecopyrightandtheforegoingrestrictionextendtoreproductioninallmedia.©EuropeanTelecommunicationsStandardsInstitute2000.Allrightsreserved.SIST EN 300 162-1 V1.2.2:2003

ETSIETSIEN300162-1V1.2.2(2000-12)3ContentsIntellectualPropertyRights.8Foreword.81Scope.92References.93Definitions,symbolsandabbreviations.103.1Definitions.103.2Symbols.103.3Abbreviations.104Generalandoperationalrequirements.104.1Construction.104.2Controlsandindicators.114.3Handsetandloudspeaker.124.4Safetyprecautions.124.5Labelling.124.6Warmup.125Technicalrequirements.135.1Switchingtime.135.2Classofemissionandmodulationcharacteristics.135.3Multiplewatchfacilities.135.3.1Additionalperformancestandards.135.3.2Scanningcharacteristics.145.4DSCcontrollerinterfaces.145.4.1Operationalinterfaces.146Generalconditionsofmeasurement.146.1Arrangementsfortestsignalsappliedtothereceiverinput.146.2Squelch.146.3Normaltestmodulation.146.4Artificialantenna.156.5Arrangementsfortestsignalsappliedtothetransmitterinput.156.6Testchannels.156.7Measurementuncertaintyandinterpretationofthemeasuredresults.156.7.1Measurementuncertainty.156.7.2Interpretationofthemeasurementresults.156.8Testconditions,powersourcesandambienttemperatures.166.8.1Normalandextremetestconditions.166.8.2Testpowersource.166.9Normaltestconditions.166.9.1Normaltemperatureandhumidity.166.9.2Normalpowersources.166.9.2.1Mainsvoltageandfrequency.166.9.2.2Batterypowersource.166.9.2.3Otherpowersources.166.10Extremetestconditions.176.10.1Extremetemperatures.176.10.2Extremevaluesoftestpowersources.176.10.2.1Mainsvoltage.176.10.2.2Batterypowersource.176.10.2.3Otherpowersources.176.11Procedurefortestsatextremetemperatures.177Environmentaltests.177.1Procedure.177.2Performancecheck.18SIST EN 300 162-1 V1.2.2:2003

ETSIETSIEN300162-1V1.2.2(2000-12)47.3Vibrationtest.187.3.1Definition.187.3.2Methodofmeasurement.187.3.3Requirement.187.4Temperaturetests.197.4.1Definition.197.4.2Dryheat.197.4.2.1Definition.197.4.2.2Methodofmeasurement.197.4.2.3Requirement.197.4.3Dampheat.197.4.3.1Definition.197.4.3.2Methodofmeasurement.197.4.3.3Requirement.197.4.4Lowtemperaturecycle.207.4.4.1Definition.207.4.4.2Methodofmeasurement.207.4.4.3Requirement.208Transmitter.208.1Frequencyerror.208.1.1Definition.208.1.2Methodofmeasurement.208.1.3Limits.208.2Carrierpower.208.2.1Definitions.208.2.2Methodofmeasurement.218.2.3Limits.218.2.3.1Normaltestconditions.218.2.3.2Extremetestconditions.218.3Frequencydeviation.218.3.1Definition.218.3.2Maximumpermissiblefrequencydeviation.218.3.2.1Methodofmeasurement.218.3.2.2Limits.218.3.3Reductionoffrequencydeviationatmodulationfrequenciesabove3kHz.218.3.3.1Methodofmeasurement.218.3.3.2Limits.228.4Sensitivityofthemodulator,includingmicrophone.228.4.1Definition.228.4.2Methodofmeasurement.228.4.3Limits.228.5Audiofrequencyresponse.228.5.1Definition.228.5.2Methodofmeasurement.238.5.3Limit.238.6Audiofrequencyharmonicdistortionoftheemission.238.6.1Definition.238.6.2Methodofmeasurement.238.6.2.1Normaltestconditions.248.6.2.2Extremetestconditions.248.6.3Limits.248.7Adjacentchannelpower.248.7.1Definition.248.7.2Methodofmeasurement.248.7.3Limits.248.8Conductedspuriousemissionsconveyedtotheantenna.258.8.1Definition.258.8.2Methodofmeasurement.258.8.3Limit.258.9Cabinetradiationandconductedspuriousemissionsotherthanthoseconveyedtotheantenna.258.9.1Definitions.25SIST EN 300 162-1 V1.2.2:2003

ETSIETSIEN300162-1V1.2.2(2000-12)58.9.2Methodofmeasurement.258.9.3Limits.268.10Residualmodulationofthetransmitter.268.10.1Definition.268.10.2Methodofmeasurement.268.10.3Limit.268.11DSCaudioinputcharacteristics.278.11.1Definition.278.11.2Methodofmeasurement.278.11.3Limits.278.12DSCaudioinputlimitation.278.12.1Definition.278.12.2Methodofmeasurement.278.12.3Limit.278.13Modulationattacktime.278.13.1Definition.278.13.2Methodofmeasurement.278.13.3Limit.288.14Transientfrequencybehaviourofthetransmitter.298.14.1Definitions.298.14.2Methodofmeasurement.298.14.3Limits.329Receiver.329.1Harmonicdistortionandratedaudiofrequencyoutputpower.329.1.1Definition.329.1.2Methodsofmeasurement.329.1.3Limits.339.2Audiofrequencyresponse.339.2.1Definition.339.2.2Methodofmeasurement.339.2.3Limits.339.3Maximumusablesensitivity.349.3.1Definition.349.3.2Methodofmeasurement.349.3.3Limits.359.4Co-channelrejection.359.4.1Definition.359.4.2Methodofmeasurement.359.4.3Limit.359.5Adjacentchannelselectivity.359.5.1Definition.359.5.2Methodofmeasurement.359.5.3Limits.369.6Spuriousresponserejection.369.6.1Definition.369.6.2Methodofmeasurement.369.6.3Limit.369.7Intermodulationresponse.369.7.1Definition.369.7.2Methodofmeasurement.379.7.3Limit.379.8Blockingordesensitization.379.8.1Definition.379.8.2Methodofmeasurement.379.8.3Limit.379.9Conductedspuriousemissions.379.9.1Definition.379.9.2Methodofmeasurement.389.9.3Limit.389.10Radiatedspuriousemissions.389.10.1Definition.38SIST EN 300 162-1 V1.2.2:2003

ETSIETSIEN300162-1V1.2.2(2000-12)69.10.2Methodofmeasurements.389.10.3Limit.399.11Receivernoiseandhumlevel.399.11.1Definition.399.11.2Methodofmeasurement.399.11.3Limit.399.12Squelchoperation.399.12.1Definition.399.12.2Methodofmeasurement.399.12.3Limits.409.13Squelchhysteresis.409.13.1Definition.409.13.2Methodofmeasurement.409.13.3Limit.409.14Multiplewatchcharacteristic.409.14.1Definition.409.14.2Methodofmeasurement.419.14.3Limits.419.15DSCaudiooutputcharacteristic.419.15.1Definition.419.15.2Methodsofmeasurement.419.15.3Limit.4110Duplexoperation.4110.1Receiverdesensitizationwithsimultaneoustransmissionandreception.4210.1.1Definition.4210.1.2Methodofmeasurement.4210.1.3Limits.4210.2Duplextransceiverinternalmixing.4210.2.1Definition.4210.2.2Methodofmeasurement.4210.2.3Limits.43AnnexA(normative):Measuringreceiverforadjacentchannelpowermeasurement.44A.1Powermeasuringreceiverspecification.44A.1.1IFfilter.44A.1.2Attenuationindicator.45A.1.3RMSvalueindicator.45A.1.4Oscillatorandamplifier.45AnnexB(normative):ProtocolfortheIEC1162-1commandsFrequencySetInformation(FSI).46B.1FrequencySetInformation(FSI).46AnnexC(normative):Radiatedmeasurements.47C.1Testsitesandgeneralarrangementsformeasurementsinvolvingtheuseofradiatedfields.47C.1.1Outdoortestsite.47C.1.2Testantenna.47C.1.3Substitutionantenna.48C.1.4Optionaladditionalindoorsite.48C.2Guidanceontheuseofradiationtestsites.49C.2.1Measuringdistance.49C.2.2Testantenna.49C.2.3Substitutionantenna.49C.2.4Artificialantenna.50C.2.5Auxiliarycables.50C.2.6Acousticmeasuringarrangement.50C.3Furtheroptionalalternativeindoortestsiteusingananechoicchamber.50C.3.1Exampleoftheconstructionofashieldedanechoicchamber.51SIST EN 300 162-1 V1.2.2:2003

ETSIETSIEN300162-1V1.2.2(2000-12)7C.3.2Influenceofparasiticreflectionsinanechoicchambers.51C.3.3Calibrationoftheshieldedanechoicchamber.51History.54SIST EN 300 162-1 V1.2.2:2003

ETSIETSIEN300162-1V1.2.2(2000-12)8IntellectualPropertyRightsIPRsessentialorpotentiallyessentialtothepresentdocumentmayhavebeendeclaredtoETSI.TheinformationpertainingtotheseessentialIPRs,ifany,ispubliclyavailableforETSImembersandnon-members,andcanbefoundinETSISR000314:"IntellectualPropertyRights(IPRs);Essential,orpotentiallyEssential,IPRsnotifiedtoETSIinrespectofETSIstandards",whichisavailablefromtheETSISecretariat.LatestupdatesareavailableontheETSIWebserver(http://www.etsi.org/ipr).PursuanttotheETSIIPRPolicy,noinvestigation,includingIPRsearches,hasbeencarriedoutbyETSI.NoguaranteecanbegivenastotheexistenceofotherIPRsnotreferencedinETSISR000314(ortheupdatesontheETSIWebserver)whichare,ormaybe,ormaybecome,essentialtothepresentdocument.ForewordThisEuropeanStandard(Telecommunicationsseries)hasbeenproducedbyETSITechnicalCommitteeElectromagneticcompatibilityandRadiospectrumMatters(ERM).Thepresentdocumentispart1ofamulti-partdeliverablecoveringtheRadiotelephonetransmittersandreceiversforthemaritimemobileserviceoperatinginVHFbands,asidentifiedbelow:Part1:"Technicalcharacteristicsandmethodsofmeasurement";Part 2: "Harmonized EN covering essential requirements for article 3.2 of the R&TTE Directive";Part3:"HarmonizedENcoveringessentialrequirementsofarticle3.3(e)oftheR&TTEDirective".NationaltranspositiondatesDateoflatestannouncementofthisEN(doa):31March2001DateoflatestpublicationofnewNationalStandardorendorsementofthisEN(dop/e):30September2001DateofwithdrawalofanyconflictingNationalStandard(dow):30September2001SIST EN 300 162-1 V1.2.2:2003

ETSIETSIEN300162-1V1.2.2(2000-12)91ScopeThepresentdocumentspecifiestheminimumrequirementsforshipborneVeryHighFrequency(VHF)transmittersandreceiverscapableofvoiceandDigitalSelectiveCalling(DSC),fittedwithanexternalantennaconnectorforuseonboardships.ThepresentdocumentlaysdownminimumrequirementsforVHFradiotransmittersandreceiversoperatingincertainfrequencybandsallocatedtothemaritimemobileservice,andincorporatestherequirementsoftherelevantrecommendationsoftheInternationalMaritimeOrganization(IMO).2ReferencesThefollowingdocumentscontainprovisionswhich,throughreferenceinthistext,constituteprovisionsofthepresentdocument.• Referencesareeitherspecific(identifiedbydateofpublicationand/oreditionnumberorversionnumber)ornon-specific.• Foraspecificreference,subsequentrevisionsdonotapply.• Foranon-specificreference,thelatestversionapplies.[1]RadioRegulations,Appendix18(1990):"TableofTransmittingFrequenciesintheBand156-174MHzforStationsintheMaritimeMobileService".[2]RadioRegulations,Appendix19(1990):"TechnicalCharacteristicsforTransmittersandReceiversusedintheMaritimeMobileServiceintheBand156-174MHz".[3]ITU-TRecommendationE.161(1995):"Arrangementofdigits,lettersandsymbolsontelephonesandotherdevicesthatcanbeusedforgainingaccesstoatelephonenetwork".[4]ITU-RRecommendationM.493-8(1997):"Digitalselective-callingsystemforuseinthemaritimemobileservice".[5]ITU-RRecommendationM.541-7(1997):"Operationalproceduresfortheuseofdigitalselective-calling(DSC)equipmentinthemaritimemobileservice".[6]IMOResolutionA.803(19):"PerformanceStandardsforShipborneVHFRadioInstallationscapableofVoiceCommunicationsandDigitalSelectiveCalling".[7]IMOResolutionA.524(13):"PerformanceStandardforVHFMultipleWatchfacilities".[8]ITU-TRecommendationP.53(1988):"Psophometerforuseontelephone-typecircuits".[9]IEC1162-1(1995-11):"Maritimenavigationandradiocommunicationequipmentandsystems-Digitalinterfaces-Part1:Singletalkerandmultiplelisteners".[10]ETSIETS300828(1997):"RadioEquipmentandSystems(RES);ElectroMagneticCompatibility(EMC)forradiotelephonetransmittersandreceiversforthemaritimemobileserviceoperatingintheVHFbands".[11]ETSIETR028:"RadioEquipmentandSystems(RES);Uncertaintiesinthemeasurementofmobileradioequipmentcharacteristics".[12]ETSIEN300338:"ElectromagneticcompatibilityandRadiospectrumMatters(ERM);Technicalcharacteristicsandmethodsofmeasurementforequipmentforgeneration,transmissionandreceptionofDigitalSelectiveCalling(DSC)inthemaritimeMF,MF/HFand/orVHFmobileservice".[13]ITU-RRecommendationSM332-4:"Selectivityofreceivers".SIST EN 300 162-1 V1.2.2:2003

ETSIETSIEN300162-1V1.2.2(2000-12)103Definitions,symbolsandabbreviations3.1DefinitionsForthepurposeofthepresentdocument,thefollowingtermsanddefinitionsapply:Channel16:frequencyof156,800MHzG3E:Phase-modulation(Frequencymodulationwithapre-emphasisof6dB/octave)forspeechG2B:Phase-modulationwithdigitalinformation,withasub-carrierforDigitalSelectiveCalling(DSC)operationmodulationindex:ratiobetweenthefrequencydeviationandthemodulationfrequencyperformancecheck:checkof:-thetransmittercarrierpowerandfrequency;and-receiversensitivity(seeclause7.2)3.2SymbolsForthepurposesofthepresentdocument,thefollowingsymbolsapply:dBAdBrelativeto2x10-5Pae.m.f.electromotiveforce3.3AbbreviationsForthepurposesofthepresentdocument,thefollowingabbreviationsapply:adamplitudedifferenceDSCDigitalSelectiveCallingEUTEquipmentUnderTestfdfrequencydifferenceFSIFrequencySetInformationRFRadioFrequencyrmsrootmeansquareSFIScanningFrequencyInformationSINADSignal+Noise+Distortion/Noise+DistortionVHFVeryHighFrequency4Generalandoperationalrequirements4.1ConstructionThemanufacturershalldeclarethatcompliancetotherequirementofclause4isachievedandshallproviderelevantdocumentation.Themechanicalandelectricalconstructionandfinishoftheequipmentshallconforminallrespectstogoodengineeringpractice,andtheequipmentshallbesuitableforuseonboardships.Allcontrolsshallbeofsufficientsizetoenabletheusualcontrolfunctionstobeeasilyperformedandthenumberofcontrolsshouldbetheminimumnecessaryforsimpleandsatisfactoryoperation.Allpartsoftheequipmenttobecheckedduringinspectionormaintenanceoperationsshallbereadilyaccessible.Thecomponentsshallbereadilyidentifiable.SIST EN 300 162-1 V1.2.2:2003

ETSIETSIEN300162-1V1.2.2(2000-12)11Technicaldocumentationshallbesuppliedwiththeequipment.TheVHFmaritimemobileserviceusesbothsingle-frequencyandtwo-frequencychannels.Fortwo-frequencychannelsthereshallbeaseparationof4,6MHzbetweenthetransmittingfrequencyandthereceivingfrequency(seeRadioRegulations[1]).Theequipment,whichcanconsistofmorethanoneunit,shallbecapableofoperatingonsinglefrequencyandtwo-frequencychannelswithmanualcontrol(simplex).Itmayalsobecapableofoperatingontwo-frequencychannelswithoutmanualcontrol(duplex).TheequipmentshallbeabletooperateonallchannelsdefinedinAppendix18totheRadioRegulations[1].Operationonchannels75and76shallbepreventedbyappropriatemeans.AdditionalVHFchannelsoutsidethosedefinedbyAppendix18totheRadioRegulations[1]mayalsobeprovided,butmeansshallbeprovidedtoblockanyoralloftheseadditionalchannels,asmayberequiredbyanAdministration,beforeinstallationonboardships.Itshallnotbepossiblefortheusertounblockorblocktheseadditionalchannels.Theequipmentshallbesodesignedthatuseofchannel70forpurposesotherthanDigitalSelectiveCalling(DSC)isprevented(seeITU-RRecommendationM.493-8[4]andITU-RRecommendationM.541-7[5]).Itshallnotbepossibletotransmitwhileanyfrequencysynthesizerusedwithinthetransmitterisoutoflock.Itshallnotbepossibletotransmitduringchannelswitchingoperations.4.2ControlsandindicatorsTheequipmentshallhaveachannelselectorandshallindicatethedesignator,asshowninAppendix18totheRadioRegulations[1],ofthechannelatwhichtheinstallationisset.Thechanneldesignatorshallbelegibleirrespectiveoftheexternallightingconditions.Channels16and70shouldbedistinctivelymarked.Selectionofchannel16,andifpossiblechannel70,shallbebyreadilyaccessiblemeans(e.g.adistinctivelymarkedkey).Whereaninputpanelontheequipmentforenteringthedigits0-9isprovided,thisshallconformtoITU-TRecommendationE.161[3].Theequipmentshallhavethefollowingadditionalcontrolsandindicators(seeIMOResolutionA.803(19)[6]):-on/offswitchfortheentireinstallationwithavisualindicationthattheinstallationisinoperation;-amanualnon-lockingpushtotalkswitchtooperatethetransmitter;-on/offswitchfortheloudspeaker;-aswitchforreducingtransmitteroutputpowertonomoretha
...