SIST EN 301 688:2001
(Main)ElectroMagnetic Compatibility and Radio Spectrum Matters (ERM); Technical characteristics and methods of measurement for fixed and portable VHF equipment operating on 121,5 MHz and 123,1 MHz
General Information
- Abstract
Equipment to be used for communications between ships in distress and rescuing aircraft.
- Status
- Published
- Publication Date
- 31-Jan-2001
- Technical Committee
- RES - Radio equipment and systems
- Current Stage
- 6060 - National Implementation/Publication (Adopted Project)
- Start Date
- 01-Feb-2001
- Due Date
- 01-Feb-2001
- Completion Date
- 01-Feb-2001
Overview
SIST EN 301 688:2001 is an international standard focused on Electromagnetic Compatibility (EMC) and Radio Spectrum Matters (ERM) for maritime communication equipment. Specifically, this standard outlines the technical characteristics and test methods for both fixed and portable VHF equipment operating on 121.5 MHz and 123.1 MHz. Such equipment is essential for communication between ships in distress and rescue aircraft, ensuring critical communication capability in emergency maritime situations.
Published by SIST and harmonized with EN 301 688 by the European Telecommunications Standards Institute (ETSI), this standard defines the minimum requirements for equipment design, performance, and environmental resilience, supporting safety of life at sea in line with international regulations.
Key Topics
- Scope and Purpose: This standard applies strictly to VHF radiotelephone apparatus utilized for distress communication between ships and rescuing aircraft.
- Technical Requirements: It defines minimum mechanical, electrical, and operational requirements for fixed and portable VHF equipment to ensure reliable operation in maritime emergencies.
- Electromagnetic Compatibility: Addresses EMC to prevent communication interference and ensure clear signaling on designated emergency frequencies.
- Operational Frequencies: Equipment must operate exclusively on the aeronautical emergency channels 121.5 MHz and 123.1 MHz, supporting simplex mode communication.
- Environmental Testing: Outlines rigorous test procedures for temperature, vibration, humidity, and mechanical shock to verify durability onboard ships and in harsh conditions.
- Power Supply Requirements: Details minimum performance expectations for both battery-operated portable units and mains-powered fixed installations, including backup arrangements and battery capacity.
- Labeling and Controls: Prescribes clear labeling, operational simplicity, and safety warnings tailored for quick, reliable use by rescue and maritime personnel.
Applications
SIST EN 301 688:2001 is crucial for organizations involved in designing, manufacturing, and certifying maritime VHF radios, particularly those supporting Search and Rescue (SAR) operations. Its applications include:
- Distress Communication Systems: Integration into shipboard emergency communication devices that link vessels with aircraft engaged in rescue operations.
- Portable Search and Rescue Equipment: Guides manufacturers in constructing lightweight, durable, and user-friendly VHF radios for use in life rafts or by on-deck personnel during emergencies.
- Fixed Installation Units: Provides standards for equipment hardwired into ship infrastructure, ensuring continuous operation and seamless transition to backup power.
- Compliance and Certification: Used by certification bodies and maritime authorities to assess equipment suitability for compliance with international safety conventions like SOLAS.
By following this standard, maritime stakeholders ensure that communication equipment is robust, interoperable, and ready for critical emergency scenarios, ultimately safeguarding human life at sea.
Related Standards
For broader context and compliance, SIST EN 301 688:2001 references and complements several key international standards:
- ITU Radio Regulations – Governing use of the radio-frequency spectrum.
- IMO SOLAS (International Convention for the Safety of Life at Sea) – Safety requirements for ships' emergency equipment.
- ICAO Annex 10 – Standards for aeronautical telecommunication.
- ISO/R 694 – Positioning of magnetic compasses on ships.
- EUROCAE ED-14C – Environmental conditions and test procedures for airborne equipment.
- ETSI EN 300 225 – Technical requirements for survival craft portable VHF radiotelephones.
Compliance with these related standards, in combination with SIST EN 301 688:2001, ensures holistic safety, operational reliability, and electromagnetic compatibility for maritime distress communication systems.
Keywords: VHF equipment, maritime emergency communication, electromagnetic compatibility, radio spectrum, distress frequencies, search and rescue radio, ship-aircraft communication, SIST EN 301 688:2001, 121.5 MHz, 123.1 MHz, EMC standards, portable VHF radio.
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Frequently Asked Questions
SIST EN 301 688:2001 is a standard published by the Slovenian Institute for Standardization (SIST). Its full title is "ElectroMagnetic Compatibility and Radio Spectrum Matters (ERM); Technical characteristics and methods of measurement for fixed and portable VHF equipment operating on 121,5 MHz and 123,1 MHz". This standard covers: Equipment to be used for communications between ships in distress and rescuing aircraft.
Equipment to be used for communications between ships in distress and rescuing aircraft.
SIST EN 301 688:2001 is classified under the following ICS (International Classification for Standards) categories: 33.060.20 - Receiving and transmitting equipment; 33.100.01 - Electromagnetic compatibility in general. The ICS classification helps identify the subject area and facilitates finding related standards.
SIST EN 301 688:2001 is available in PDF format for immediate download after purchase. The document can be added to your cart and obtained through the secure checkout process. Digital delivery ensures instant access to the complete standard document.
Standards Content (Sample)
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.ElectroMagnetic Compatibility and Radio Spectrum Matters (ERM); Technical characteristics and methods of measurement for fixed and portable VHF equipment operating on 121,5 MHz and 123,1 MHz33.100.01Elektromagnetna združljivost na splošnoElectromagnetic compatibility in general33.060.20Sprejemna in oddajna opremaReceiving and transmitting equipmentICS:Ta slovenski standard je istoveten z:EN 301 688 Version 1.1.1SIST EN 301 688:2001en01-februar-2001SIST EN 301 688:2001SLOVENSKI
STANDARD
ETSIEN301688V1.1.1(2000-07)EuropeanStandard(Telecommunicationsseries)ElectromagneticcompatibilityandRadiospectrumMatters(ERM);TechnicalcharacteristicsandmethodsofmeasurementforfixedandportableVHFequipmentoperatingon121,5MHzand123,1MHzSIST EN 301 688:2001
ETSIETSIEN301688V1.1.1(2000-07)2ReferenceDEN/ERM-RP01-031KeywordsMaritime,radio,SARETSI650RoutedesLuciolesF-06921SophiaAntipolisCedex-FRANCETel.:+33492944200Fax:+33493654716SiretN°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:editor@etsi.frCopyrightNotificationNopartmaybereproducedexceptasauthorizedbywrittenpermission.Thecopyrightandtheforegoingrestrictionextendtoreproductioninallmedia.©EuropeanTelecommunicationsStandardsInstitute2000.Allrightsreserved.SIST EN 301 688:2001
ETSIETSIEN301688V1.1.1(2000-07)3ContentsIntellectualPropertyRights.6Foreword.61Scope.72References.73Symbolsandabbreviations.73.1Symbols.73.2Abbreviations.84Generalrequirements.84.1Construction.84.2Controls.84.3Operatingfrequencies.94.4Labelling.94.5Powersource.95Testconditions,powersourcesandambienttemperatures.105.1Determinationofthelowerextremetestvoltage.105.2Normalandextremetestconditions.105.3Testpowersource.105.4Normaltestconditions.105.4.1Normaltemperatureandhumidity.105.4.2Normalpowersource.105.5Extremetestconditions.115.5.1Extremetemperatures.115.5.1.1Upperextremetemperature.115.5.1.2Lowerextremetemperature.115.5.2Extremetestpowersupplyvalues.115.5.2.1Upperextremetestvoltage.115.5.2.2Lowerextremetestvoltage.115.6Procedurefortestsatextremetemperatures.116Generalconditionsofmeasurements.126.1Testconnections.126.2Arrangementsfortestsignalsappliedtoreceiverinput.126.3Squelch.126.4Normaltestmodulation.126.5Artificialantenna.126.6Testfrequencies.126.7Measurementuncertaintyandinterpretationofthemeasuringresults.136.7.1Measurementuncertainty.136.7.2Interpretationofthemeasurementresults.137Environmentaltests.137.1Introduction.137.2Procedure.137.3Performancecheck.147.4Droptestonhardsurface.147.4.1Definition.147.4.2Methodofmeasurement.147.4.3Limit.147.5Vibrationtest.147.5.1Methodofmeasurement.147.5.2Limits.157.6Temperaturetests.157.6.1General.15SIST EN 301 688:2001
ETSIETSIEN301688V1.1.1(2000-07)47.6.2Dryheatcycle.157.6.2.1Methodofmeasurement.157.6.2.2Limits.157.6.3Dampheatcycle.157.6.3.1Methodofmeasurement.157.6.3.2Limits.167.6.4Lowtemperaturecycle.167.6.4.1Methodofmeasurement.167.6.4.2Limits.167.7Immersiontest.167.7.1Methodofmeasurement.167.7.2Requirements.168Transmitter.178.1Carrierpower.178.1.1Definition.178.1.2Methodofmeasurement.178.1.3Limit.178.2Frequencyerror.178.2.1Definition.178.2.2Methodofmeasurement.178.2.3Limit.178.3Modulationofthetransmitter.178.3.1Definition.178.3.2Methodofmeasurement.178.3.3Limit.188.4.Conductedspuriousemissionsconveyedtotheantenna.188.4.1Definition.188.4.2Methodofmeasurement.188.4.3Limit.188.5Cabinetradiation.188.5.1Definitions.188.5.2Methodofmeasurement.188.5.3Limits.199Receiver.199.1Harmonicdistortionandaudiofrequencyoutputpower.199.1.1Definition.199.1.2Methodofmeasurement.209.1.3Limit.209.2Maximumusablesensitivity.209.2.1Definition.209.2.2Methodofmeasurement.209.2.3Limit.209.3Spuriousresponserejection.209.3.1Definition.219.3.2Introductiontothemethodofmeasurement.219.3.3Methodofsearchofthelimitedfrequencyrange.219.3.4Methodofmeasurement.219.3.5Limit.229.4Conductedspuriousemissions.229.4.1Definition.229.4.2Methodofmeasurement.229.4.3Limit.22AnnexA(normative):Radiatedmeasurements.23A.1Testsitesandgeneralarrangementsformeasurementsinvolvingtheuseofradiatedfields.23A.1.1Outdoortestsite.23A.1.2Testantenna.23A.1.3Substitutionantenna.24A.1.4Optionaladditionalindoorsite.24SIST EN 301 688:2001
ETSIETSIEN301688V1.1.1(2000-07)5A.2Guidanceontheuseofradiationtestsites.25A.2.1Measuringdistance.25A.2.2Testantenna.25A.2.3Substitutionantenna.25A.2.4Artificialantenna.26A.2.5Auxiliarycables.26A.2.6Acousticmeasuringarrangement.26A.3Furtheroptionalalternativeindoortestsiteusingananechoicchamber.26A.3.1Exampleoftheconstructionofashieldedanechoicchamber.27A.3.2Influenceofparasiticreflectionsinanechoicchambers.29A.3.3Calibrationoftheshieldedanechoicchamber.29History.30SIST EN 301 688:2001
ETSIETSIEN301688V1.1.1(2000-07)6IntellectualPropertyRightsIPRsessentialorpotentiallyessentialtothepresentdocumentmayhavebeendeclaredtoETSI.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).NationaltranspositiondatesDateofadoptionofthisEN:26May2000DateoflatestannouncementofthisEN(doa):31August2000DateoflatestpublicationofnewNationalStandardorendorsementofthisEN(dop/e):28February2001DateofwithdrawalofanyconflictingNationalStandard(dow):28February2001SIST EN 301 688:2001
ETSIETSIEN301688V1.1.1(2000-07)71ScopeThepresentdocumentspecifiestheminimumtechnicalrequirementsformaritimetwo-wayAMVHFradiotelephoneapparatusforcommunicationsbetweenshipsindistressandrescuingaircraft.ThestandardincorporatesrelevantprovisionsoftheITURadioRegulations[1],ofIMOAssemblyResolutions[2]andofAnnex10totheICAOConvention[3].ThemaritimeVHFequipmentdescribedinthepresentdocumentisintendedforcommunicationsontheaeronauticalemergencyfrequencies121,5MHzand123,1MHzonly.Thepresentdocumentisapplicabletoportableandfixedinstalledequipment.Theintentionofthepresentdocumentistodefineequipmentthatinallrespectshavemechanicalandelectricaldesign,constructionandfinishinconformancewithgoodengineeringpracticeandthatissuitableforuseonboardshipsatseaindistresssituations.2ReferencesThefollowingdocumentscontainprovisionswhich,throughreferenceinthistext,constituteprovisionsofthepresentdocument.• Referencesareeitherspecific(identifiedbydateofpublication,editionnumber,versionnumber,etc.)ornon-specific.• Foraspecificreference,subsequentrevisionsdonotapply.• Foranon-specificreference,thelatestversionapplies.• Anon-specificreferencetoanETSshallalsobetakentorefertolaterversionspublishedasanENwiththesamenumber.[1]ITURadioRegulations.[2]IMOInternationalConventionfortheSafetyOfLifeAtSea(SOLAS).[3]ICAOConventiononInternationalCivilAviation,annex10.[4]ETSIETS300225:"RadioEquipmentandSystems(RES);TechnicalcharacteristicsandmethodsofmeasurementforsurvivalcraftportableVHFradiotelephoneapparatus".[5]ISO/R694:"Positioningofmagneticcompassesinships".[6]EUROCAEED-14C:"Environmentalconditionsandtestproceduresforairborneequipment".[7]ETSIETR028:"RadioEquipmentandSystems(RES);Uncertaintiesinthemeasurementofmobileradioequipmentcharacteristics".3Symbolsandabbreviations3.1SymbolsForthepurposesofthepresentdocument,thefollowingsymbolsapply:A3EamplitudemodulationwithdoublesidebandandfullcarrierdBAacousticlevelindBrelativeto2×10-5PadBdantennagainindBrelativetodipoleradiationSIST EN 301 688:2001
ETSIETSIEN301688V1.1.1(2000-07)83.2AbbreviationsForthepurposesofthepresentdocument,thefollowingabbreviationsapply:AMAmplitudeModulationemfelectro-motiveforceERPEffectiveRadiatedPowerEUTEquipmentUnderTestpeppeakenvelopepowerRFRadioFrequencyrmsrootmeansquareSINADSignal+Noise+Distortion/Noise+DistortionVHFVeryHighFrequency4Generalrequirements4.1ConstructionPortableequipmentshallinoneunitcompriseatleasttransmitter,receiver,antenna,battery,operatingcontrolsincludingpress-to-transmitswitch,microphoneandloudspeaker.Forportableequipment,theantennagainshallbedeclaredbythemanufacturerandshallbeatleast-12dBd.Equipmentintendedforfixedinstallationsshallhavean50ΩRFsocket.Portableequipmentshallbeofsmallsizeandlightinweight.Portableequipmentshallincludeprovisionfortheconnectionofexternalmicrophoneandheadset.TheequipmentshallhaveacolourwhichdistinguishesitfromtheportableVHFequipmentspecifiedinETS300225[4].Theequipmentshallbeoperationalwithin5secondsofswitchingon.Anypartoftheequipmentrequiredtobecheckedduringinspectionormaintenanceoperationsaslaiddownbythemanufacturer,shallbereadilyaccessible.4.2ControlsThenumberofcontrolsshallbetheminimumnecessaryforsimpleoperation.Withthepossibleexceptionofchannelselection,itshallbepossibletooperatetheequipmentusingonlyonehand.Theequipmentshallbeprovidedwithanon-offswitchandavisualindicationthattheequipmentisswitchedon.Theequipmentshallbeprovidedwithamanualvolumecontrolbywhichtheaudiooutputmaybevaried.Thepress-to-transmitswitchshallbenon-lockingandreturntostandby(receive)modewhenreleased.Thetimenecessarytochangefromtransmissiontoreception,orviceversa,shallnotexceed0,3seconds.Theequipmentshallhaveachannelselectorandshallclearlyindicatewhichfrequencytheequipmentissetto.Thechannelswitchingarrangementshallbesuchthatthetimenecessarytochangefromonefrequencytotheotherdoesnotexceed5seconds.Itshallnotbepossibletotransmitduringchannelswitchingoperations.Independentselectionoftransmittingandreceivingfrequenciesshallnotbepossible.Inthetransmissionmode,theoutputofthereceivershallbemuted.Iftheequipmentincludesatestfacility,theswitchwhichoperatesthisfacilityshallbesodesignedthatitautomaticallyreturnstonormalpositionwhenreleased.SIST EN 301 688:2001
ETSIETSIEN301688V1.1.1(2000-07)94.3OperatingfrequenciesTheequipmentshallbecapableofoperatingonthesinglefrequencychannels121,5MHzand123,1MHzonly,withmanualcontrol(simplex).TheequipmentshalloperatewithclassofemissionA3E.4.4LabellingThelabelsontheequipmentshallbepermanentlyfixedtotheexterioroftheequipment.Allcontrolsandindicatorsshallbeclearlylabelled.Thelabellingshallatleastcomprisethefollowinginformation:-textcontainingthewords:"Onlyforemergencycommunicationswithaircraft";-briefoperatinginstructions;-typedesignationoftheequipmentandserialnumber;-expirydateforanyprimarybatteries;-forportableequipment,compasssafedistance,accordingtoISORecommendation694MethodB[5]orEurocae[6].4.5PowersourceForportableequipment,thesourceofenergyshallbeaprimarybatterythatmaybereplaceablebytheuserwithouttheuseofspecialtoolsandwithoutdegradingtheperformanceoftheequipment.Inaddition,provisionsmaybemadetooperatetheequipmentusinganexternalsourceofelectricalenergy.Fixedradioinstallationshouldbepoweredfromtheship’smainsourceofelectricalenergy.Inaddition,itshouldbepossibletooperatetheinstallationfromanalternativesourceofelectricalenergy.Alternatively,thesourceofenergymaybeaprimarybatteryintegratedintheequipmentandmaybereplaceablebytheuser.Primarybatteriesshallhaveashelflifeofatleast2years.Provisionsshallbemadeforprotectingtheequipmentfromdamageduetoaccidentalreversalofthepolarityofthebatteryorofanyexternalpowersupply.Thecapacityoftheprimarybatteryshallbesufficienttooperatetheequipmentcontinuouslyforatleast10hoursatnormaltemperaturecondition(seesubclause5.4.1)withthefollowingdutycycle:-6secondstransmitwithoutmodulationfollowedby6secondsreceptionwithanRFinputsignalatthenominalfrequencyofthereceiveratalevelof+60dBµVusingnormaltestmodulation(subclause6.4)withtheaudiovolumecontrolsettogiveminimum200mWoutputpowerfollowedby48secondsreceptionwithoutinputsignalundermutedcondition(operationalsquelchcondition).SIST EN 301 688:2001
ETSIETSIEN301688V1.1.1(2000-07)105Testconditions,powersourcesandambienttemperatures5.1DeterminationofthelowerextremetestvoltageWhendeterminingthecapacityoftheprimarybattery,thebatteryvoltageshallbemeasuredattheendofadurationtest.Duringthisdurationtest,whenactivated,thetransmittershouldbemodulatedtogivemaximumoutputpower(pepat100%modulation).However,thismeasurementwouldrequireanacousticmodulationsignalandiscomplicatedtoperform.Thistestmaythereforebeperformedwithnomodulation(unmodulatedcarrier)ofthetransmitterduringtheperiodswhenthetransmitterisactivatedanditisestimatedthatan8hoursdurationtestwiththetransmittermodulatedto100%modulationdepthcorrespondstoa10hoursdurationtestwiththetransmitterkeyedwithoutmodulation.Theequipmentshallbeoperatedwiththefollowingdutycycle:-6secondstransmissionwithoutmodulationfollowedby6secondsreceptionwithanRFinputsignalatthenominalfrequencyofthereceiveratalevelof+60dBµVusingnormaltestmodulation(subclause6.4)withtheaudiovolumecontrolsettogiveminimum200mWoutputpowerfollowedby48secondsreceptionwithoutinputsignalundermutedcondition(operationalsquelchcondition).Thelowerextremetestvoltageisthevoltageofthebatteryattheendofthisdurationtestmeasuredwiththetransmitteractivated.5.2NormalandextremetestconditionsTestingoftheequipmentshallbemadeundernormaltestconditionsandalso,wherestated,underextremetestconditions.5.3TestpowersourceDuringtesting,theequipmentshallbesuppliedfromatestpowersourcecapableofproducingnormalandextremetestvoltagesasspecifiedinsubclauses5.4.2and5.5.2.Thetestspowersourceshallonlybeusedinmeasurementswhereitseffectonthetestresultsarenegligible.Thepowersourcevoltageshallbemeasuredattheinputterminalsoftheequipment.Duringtesting,thepowersourcevoltagesshallbemaintainedwithinatoleranceof±3%relativetothevoltagelevelatthebeginningofeachtest.5.4Normaltestconditions5.4.1NormaltemperatureandhumidityThenormaltemperatureandhumidityconditionsfortestsshallbeacombinationoftemperatureandhumiditywithinthefollowinglimits:-Temperature+15°Cto+35°C;-Relativehumidity20%to75%.5.4.2NormalpowersourceForportableequipment,thenormaltestvoltageshallbethenominalvoltageofthebatteryasdeclaredbythemanufacturer.Forfixedinstallationequipment,thenormaltestvoltageshallbethenominalmainsvoltage.Thefrequencyofthetestvoltageshallbe50Hz±1Hz.SIST EN 301 688:2001
ETSIETSIEN301688V1.1.1(2000-07)115.5Extremetestconditions5.5.1Extremetemperatures5.5.1.1UpperextremetemperatureTestsattheupperextremetemperatureshallbemadeatatemperatureof+55°C.5.5.1.2LowerextremetemperatureTestsatthelowerextremetemperatureshallbemadeatatemperatureof-20°C.5.5.2Extremetestpowersupplyvalues5.5.2.1UpperextremetestvoltageForportableequipment,theupperextremetestvoltageshallbedeterminedineachcaseandshouldbethevoltagecorrespondingtothevoltagethatthebatterygivesattheupperextremetemperatureatthebeginningofthebatterytestcyclewithaloadequaltothatoftheequipmentinthetransmitconditionwithoutmodulation.Forfixedinstallationequipment,theupperextremetestvoltageshallbethenominalmainsvoltage+10%.Thefrequencyshallbe50Hz±1Hz.5.5.2.2LowerextremetestvoltageTheequipmentfittedwithanunusedprimarybatteryshallbeplacedinaclimaticchamberandcooledto-20°Callowingastabilizationperiodof2hours.Theequipmentshallbeactivatedasdescribedinsubclause4.5.Afterthistestthebatteryvoltageshallbemeasuredduringequipmenttransmission.Thisvoltageshallbetakenasthelowerextremetestvoltage,andshallbemeasuredbeforedisconnectingtheload.Forfixedinstallationequipment,thelowerextremetestvoltageshallbethenominalmainsvoltage-10%.Thefrequencyshallbe50Hz±1Hz.5.6ProcedurefortestsatextremetemperaturesTheequipmentshallbeswitchedoffduringthetemperature-stabilizingperiods.Beforeconductingtestsattheuppertemperature,theequipmentshallbeplacedinthetestchamberandleftuntilthermalequilibriumisreached.Theequipmentshallthenbeswitchedonforhalfanhourduringwhichthetransmittershallbekeyedwithadutycycleof5minutestransmissionand5minutesreception.Fortestsatthelowertemperature,theequipmentshallbeleftinthetestchamberuntilthermalequilibriumisreachedandshallthenbeswitchedtothestandbyorreceivepositionfor1minute.SIST EN 301 688:2001
ETSIETSIEN301688V1.1.1(2000-07)126Generalconditionsofmeasurements6.1TestconnectionsForthepurposeoftesting,theequipmentshallbeprovidedwithsuitableconnectionstotestpointswithintheequipment,whichalloweasyaccessto:-thetransmitteroutput(for50Ωconnection);-thereceiverinput(for50Ωconnection);-thetransmitteraudioinput(s);-thereceiveraudiooutput(s);-thepush-
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