ETSI EN V1.5.2 ( ) European Standard

Transcription

1 EN V1.5.2 ( ) European Standard Ground-based VHF hand-held, mobile and fixed radio transmitters, receivers and transceivers for the VHF aeronautical mobile service using amplitude modulation; Part 1:Technical characteristics and methods of measurement

2 2 EN V1.5.2 ( ) Reference REN/ERM-JTFEA-008 Keywords aeronautical, AM, DSB, radio, testing, VHF 650 Route des Lucioles F Sophia Antipolis Cedex - FRANCE Tel.: Fax: Siret N NAF 742 C Association à but non lucratif enregistrée à la Sous-Préfecture de Grasse (06) N 7803/88 Important notice Individual copies of the present document can be downloaded from: The present document may be made available in more than one electronic version or in print. In any case of existing or perceived difference in contents between such versions, the reference version is the Portable Document Format (PDF). In case of dispute, the reference shall be the printing on printers of the PDF version kept on a specific network drive within Secretariat. Users of the present document should be aware that the document may be subject to revision or change of status. Information on the current status of this and other documents is available at If you find errors in the present document, please send your comment to one of the following services: Copyright Notification No part may be reproduced except as authorized by written permission. The copyright and the foregoing restriction extend to reproduction in all media. European Telecommunications Standards Institute All rights reserved. DECT TM, PLUGTESTS TM, UMTS TM, TIPHON TM, the TIPHON logo and the logo are Trade Marks of registered for the benefit of its Members. 3GPP TM is a Trade Mark of registered for the benefit of its Members and of the 3GPP Organizational Partners. LTE is a Trade Mark of currently being registered for the benefit of its Members and of the 3GPP Organizational Partners. GSM and the GSM logo are Trade Marks registered and owned by the GSM Association.

3 3 EN V1.5.2 ( ) Contents Intellectual Property Rights... 7 Foreword... 7 Introduction Scope References Normative references Informative references Definitions and abbreviations Definitions Abbreviations General requirements Controls and indicators Class of emission and modulation characteristics Warm up Test conditions, power sources and ambient temperatures Normal and extreme test conditions Test power source Normal test conditions Normal temperature and humidity Normal power sources Mains voltage and frequency Regulated lead-acid battery power sources used on vehicles Other power sources Extreme test conditions Extreme temperatures Extreme values of test power sources Mains voltage Other power sources Extended temperatures Performance test Environmental tests General Procedure for tests at extreme temperatures Temperature tests High temperature Low temperature General conditions of measurement Receiver test signal arrangement Test signal sources Nominal frequency Normal test signal Squelch Normal audio output power Audio AGC Transmitter test signal arrangement Coaxial termination Signal sources Normal test signal Test channels Transmitter Protection of the transmitter... 16

4 4 EN V1.5.2 ( ) Definition Method of measurement Requirement Frequency error Definition Method of measurement Limits Carrier power Definitions Method of measurement Tolerances Normal test conditions Extreme test conditions Amplitude modulation characteristic Modulation depth (speech) Definitions Method of measurement Limits Modulation depth (analogue data mode) Method of measurement Limits Modulation compression (speech mode) Definition Method of measurement Limits Amplitude modulation distortion Definition Method of measurement Limits Audio frequency response Definition Method of measurement Limits 8,33 khz channel spacing Limits 25 khz channel spacing Limits 25 khz channel spacing (Data) Group delay variation (data mode only) Definition Transmitter method of measurement Limits Adjacent channel power Definition Measurement Limits Broadband noise measurement Definition Method of measurement Limit Conducted spurious emissions Definition Method of measurement Limits Intermodulation attenuation Definition Method of measurement Limits RF power attack time and release time Definitions Method of measurement Attack time Release time Limits Keying Transient frequency behaviour of the transmitter... 26

5 5 EN V1.5.2 ( ) Definitions Method of measurement Limits Sidetone Limits Cabinet Radiation Receiver Sensitivity Definition Method of measurement Limits Harmonic distortion Definition Method of measurement Limits Audio frequency response Definition Method of measurement Limits Limit for DATA operation Audio noise Definition Method of measurement Limits Effective acceptance bandwidth Definition Method of measurement Limits Adjacent channel rejection Definition Method of measurement Limits Spurious response rejection Definition Introduction to the method of measurement Method of search of the limited frequency range Method of measurement Limit Intermodulation response rejection Definition Method of measurement Limit Blocking or desensitization Definition Method of measurement Limit Conducted spurious emissions Definition Method of measuring the power level Limits Squelch operation Definition Method of measurement Limits Cross modulation rejection Definition Method of measurement Limits Receiver dynamic range Definition Method of measurement... 35

6 6 EN V1.5.2 ( ) Limit AGC attack time and release time (data mode only) Definitions Method of measurement Attack time AGC Decay time Limits AF AGC Definition Method of measurement Limit Group delay variation (data mode only) Definition Receiver method of measurement Limits Cabinet Radiation Measurement uncertainty and interpretation of the measured results Maximum measurement uncertainties Interpretation of the measurement results Annex A (normative): Annex B (normative): Auxiliary cables Specification for adjacent channel power measurement arrangements B.1 Power measuring receiver specification B.1.1 IF filter B.1.2 Attenuation indicator B.1.3 RMS value indicator B.1.4 Oscillator and amplifier Annex C (informative): Bibliography History... 44

7 7 EN V1.5.2 ( ) Intellectual Property Rights IPRs essential or potentially essential to the present document may have been declared to. The information pertaining to these essential IPRs, if any, is publicly available for members and non-members, and can be found in SR : "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to in respect of standards", which is available from the Secretariat. Latest updates are available on the Web server ( Pursuant to the IPR Policy, no investigation, including IPR searches, has been carried out by. No guarantee can be given as to the existence of other IPRs not referenced in SR (or the updates on the Web server) which are, or may be, or may become, essential to the present document. Foreword This European Standard (EN) has been produced by Technical Committee Electromagnetic compatibility and Radio spectrum Matters (ERM). The present document is part 1 of a multi-part deliverable covering the Ground-based VHF hand-held, mobile and fixed radio transmitters, receivers and transceivers for the VHF aeronautical mobile service using amplitude modulation, as identified below: Part 1: "Technical characteristics and methods of measurement"; Part 2: "Harmonized EN covering essential requirements of article 3.2 of the R&TTE Directive". National transposition dates Date of latest announcement of this EN (doa): 30 June 2011 Date of latest publication of new National Standard or endorsement of this EN (dop/e): 31 December 2011 Date of withdrawal of any conflicting National Standard (dow): 31 December 2011 Introduction The present document states the minimum performance requirements for ground based radio transmitters, transceivers and receivers for the aeronautical mobile service operating in the VHF band (118 MHz to 136,975 MHz), using Double Sideband Amplitude Modulation with 8,33 khz or 25 khz channel spacing. NOTE: For equipment designed to cover the extended VHF frequency bands 108 MHz to 117,975 MHz and 137 MHz to 155,975 MHz the same test methods and procedures may be applied to show technical acceptance of the product in the band 108 MHz to 155,975 MHz. Additional requirements, outside the scope of the present document, may be required to ensure operation in the 108 MHz to 117,975 MHz band does not cause interference to the FM broadcast band. The present document may be used by accredited test laboratories for the assessment of the performance of the equipment. The performance of the equipment submitted for type testing should be representative for the performance of the corresponding production model.

8 8 EN V1.5.2 ( ) The present document has been written on the assumption that: - the type test measurements will be performed only once, in an accredited test laboratory and the measurements accepted by the various authorities in order to grant type approval; - if equipment available on the market is required to be checked it will be tested in accordance with the methods of measurement specified in the present document.

9 9 EN V1.5.2 ( ) 1 Scope The present document states the minimum performance requirements for radio transmitters, receivers and transceivers at ground-based aeronautical stations operating in the VHF band (118 MHz to 136,975 MHz) allocated to the aeronautical mobile service. In situations where transmitters and receivers are located in close proximity there is the possibility of interference. In such cases, external filters and isolators may be necessary as part of the installation to achieve an isolation performance in excess of the minima defined in the present document to overcome the interference. The present document applies to DSB AM systems, with channel separations of 8,33 khz or 25 khz intended for analogue speech and ground base stations with a channel spacing of 25 khz intended for ACARS data communication. NOTE: The test methods and procedures in the present document may also be used to show technical acceptance for radio transmitters, receivers and transceivers at ground based aeronautical stations operating with 25 khz channel spacing in the extended VHF bands (108 MHz to 117,975 MHz and 137 MHz to 155,975 MHz). The scope of the present document is limited to ground base stations, ground mobile and hand held radios for ground use. 2 References References are either specific (identified by date of publication and/or edition number or version number) or non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the reference document (including any amendments) applies. Referenced documents which are not found to be publicly available in the expected location might be found at NOTE: While any hyperlinks included in this clause were valid at the time of publication cannot guarantee their long term validity. 2.1 Normative references The following referenced documents are necessary for the application of the present document. [1] ITU-T Recommendation O.41: "Psophometer for use on telephone-type circuits". [2] ICAO Annex 10 Volume V (July 2001, including amendments up to amendment 84): "Aeronautical Radio Frequency Spectrum Utilization". [3] EN : "Electromagnetic compatibility and Radio spectrum Matters (ERM); Land mobile service; Radio equipment intended for the transmission of data (and/or speech) using constant or non-constant envelope modulation and having an antenna connector; Part 1: Technical characteristics and methods of measurement". 2.2 Informative references The following referenced documents are not necessary for the application of the present document but they assist the user with regard to a particular subject area. [i.1] [i.2] TR (all parts): "Electromagnetic compatibility and Radio spectrum Matters (ERM); Uncertainties in the measurement of mobile radio equipment characteristics". ISO 7637 (parts 1 and 2): "Road vehicles - Electrical disturbances from conduction and coupling".

10 10 EN V1.5.2 ( ) [i.3] Directive 1999/5/EC of the European Parliament and of the Council of 9 March 1999 on radio equipment and telecommunications terminal equipment and the mutual recognition of their conformity (R&TTE Directive). 3 Definitions and abbreviations 3.1 Definitions For the purposes of the present document, the following terms and definitions apply: aeronautical mobile service: mobile service between aeronautical stations and aircraft stations, or between aircraft stations, in which survival craft stations may participate conducted measurements: measurements which are made using a direct RF connection to the equipment under test ground base station: aeronautical station equipment, in the aeronautical mobile service, for use with an external antenna and intended for use at a fixed location hand held: radio equipment with integral batteries, designed to be hand portable and operated hand held integral antenna equipment: radio communications equipment with an antenna integrated into the equipment without the use of an external connector and considered to be part of the equipment NOTE: An integral antenna may be internal or external to the equipment. In equipment of this type, a 50 Ω RF connection point should be provided for test purposes. A connection point for an AF modulating input and for AF output measurements should also be provided. mobile station: radio equipment designed for permanent or temporary vehicle installation and operation, including provision for vehicle DC power supply, and connections for external antenna, PTT key, microphone, speaker and/or headphone non-integral antenna equipment: radio communications equipment with a connector intended for connection to an antenna portable station: radio equipment with integral battery for independent hand-carried use NOTE: Provisions may be made for connections of an external antenna, PTT key, microphone, headphone and charger, but principally to be operated as a self contained unit. radiated measurements: measurements which involve the measurement of a radiated field 3.2 Abbreviations For the purposes of the present document, the following abbreviations apply: ACARS AF AGC AM dbc DSB ICAO IF ppm RF rms SINAD VSWR Aircraft Communications Addressing and Reporting System Audio Frequency Automatic Gain Control Amplitude Modulation db relative to the carrier power Double Side Band International Civil Aviation Organization Intermediate Frequency parts per million Radio Frequency root mean square (Signal + Noise + Distortion)/(Noise + Distortion) Voltage Standing Wave Ratio

11 11 EN V1.5.2 ( ) 4 General requirements 8,33 khz equipment shall be able to operate on all channels in the List of Assignable Frequencies defined in Appendix 2, chapter 4, Group F (see clause ) of the ICAO Annex 10 Volume V [2]. The channel labelling used for 8,33 khz channel spacing is based on a frequency-channel pairing in accordance with table 4.1 (bis) of ICAO Annex 10 Volume V [2] clause khz equipment shall be able to operate on the frequencies 118,0 MHz to 136,975 MHz in accordance with ICAO Annex 10 Volume V [2], Appendix to Chapter 4. It shall not be possible to transmit while any frequency synthesizer used within the transmitter is out of lock. It shall not be possible to transmit during channel switching operations. 4.1 Controls and indicators The equipment shall have the following controls and indicators as a minimum: a visual indication that the device is switched on; a facility to disable the squelch for test purposes; a visual indication that the carrier is being produced. The equipment shall also meet the following requirements: the user shall not have access to any control which, if wrongly set, might impair the technical characteristics of the equipment. 4.2 Class of emission and modulation characteristics The equipment shall use Double Side Band (DSB) Amplitude Modulation (AM) full carrier, (6K80A3EJN for 25 khz, 5K00A3EJN for 8,33 khz), for speech and 13k0A2D for data. The equipment shall be designed to operate satisfactorily with a channel separation of 8,33 khz or 25 khz. 4.3 Warm up After being switched on the equipment shall meet the requirements of the present document within one minute under normal test conditions (see clause 5.3). If the equipment includes parts which require to be heated in order to operate correctly (e.g. crystal ovens) a warming up period of 10 minutes of those parts shall be allowed. 5 Test conditions, power sources and ambient temperatures 5.1 Normal and extreme test conditions Measurements shall be made under normal test conditions (see clause 5.3) and also, where stated, under extreme test conditions (see clauses and 5.4.2).

12 12 EN V1.5.2 ( ) 5.2 Test power source During testing, the equipment shall be supplied from a test power source capable of producing normal and extreme test voltages. The internal impedance of the test power source shall be low enough for its effect on the test results to be negligible. For the purpose of testing the power source voltage shall be measured at the input terminals of the equipment. During testing, the power source voltages shall be maintained within a tolerance of ±3 % relative to the voltage level at the beginning of each test. 5.3 Normal test conditions Normal temperature and humidity The normal temperature and humidity conditions for tests shall be a combination of temperature and humidity within the following ranges: temperature: +15 C to +35 C; relative humidity: 20 % to 75 %. When it is impracticable to carry out the tests under these conditions, a note to this effect, stating the ambient temperature and relative humidity during the tests, shall be added to the test report Normal power sources Mains voltage and frequency The normal test voltage for equipment to be connected to the mains shall be the nominal mains voltage. For the purpose of the present document, the nominal voltage shall be the declared voltage or any of the declared voltages for which the equipment was designed. The frequency of the test power source corresponding to the AC mains shall be between 49 Hz and 51 Hz Regulated lead-acid battery power sources used on vehicles When the radio equipment is intended for operation from the usual types of regulated lead-acid battery power source used on vehicles, the normal test voltage shall be 1,1 times the nominal voltage of the battery (6 V, 12 V, etc.) Other power sources For operation from other power sources or types of battery (primary or secondary), the normal test voltage shall be that declared by the equipment manufacturer. 5.4 Extreme test conditions Extreme temperatures For tests at extreme temperatures, measurements shall be made in accordance with clause 5.5, at a lower temperature of -20 C and an upper temperature of +55 C. This test shall be performed at the nominal supply voltage as defined in clause

13 13 EN V1.5.2 ( ) Extreme values of test power sources Mains voltage The extreme test voltages shall be between 207 V and 253 V. This test shall be performed at the normal temperature and humidity as defined in clause The frequency of the test voltage shall be between 49 Hz and 51 Hz Other power sources For equipment using other power sources, or capable of being operated from a variety of power sources, the extreme test voltages shall be those agreed between the equipment manufacturer and the testing laboratory and shall be recorded in the test report. Equipment intended for vehicle installation shall meet the power supply requirements of ISO 7637 [i.2] Extended temperatures For tests at extended temperatures, measurements shall be made in accordance with clause 5.5, at a lower temperature of 0 C and an upper temperature of +40 C. This test shall be performed at the nominal supply voltage as defined in clause Performance test For the purposes of the present document, the term "performance test" shall be taken to mean the following measurements and limits: for the transmitter: - frequency error: with the transmitter connected to a coaxial termination (see clause 6.2.1), the frequency error shall be as in clause 7.2; - carrier power: with the transmitter connected to a coaxial termination (see clause 6.2.1), the transmitter shall be keyed without modulation and the output power shall be as defined in clause 7.3; - modulation: with the transmitter connected to a coaxial termination (see clause 6.2.1), the transmitter shall be keyed. The modulation distortion shall be as in clause 7.4.3; for the receiver: - sensitivity: with the AGC operative, a normal test signal (see clause 6.1.3) shall be applied to the receiver. The sensitivity shall be as defined in clause Environmental tests General Environmental tests shall follow checking the protection of the transmitter (see clause 7.1) which follows the first application of the Performance test (see clause 5.5).

14 14 EN V1.5.2 ( ) Procedure for tests at extreme temperatures Before tests at the upper extreme temperature (55 ºC ± 3 ºC), the equipment shall be placed in the test chamber and left until thermal balance is attained. The equipment shall then be switched on for 30 minutes. The transmitter shall then be keyed for 1 minute in the transmit condition, after which the equipment shall meet the specified requirements. Transmitters shall be operated in the highest rated power transmit condition. For tests at the lower extreme temperature (-20 ºC ± 3 ºC), the equipment shall be left in the test chamber until thermal balance is attained, then switched to the standby or receive condition for 1 minute after which the equipment shall meet the specified requirements. NOTE: It is assumed that equipment intended for off-set carrier operation will be installed in a building with facilities suitable to provide protection from temperature extremes, therefore extreme temperature tests need not be applied to such equipment Temperature tests The chamber must be able to maintain the required temperature value during the measurement High temperature Place the equipment in a chamber and heat to the required temperature value and allow to stabilize for 1 hour. Switch on the equipment. After 30 minutes carry out the performance test as detailed in clause 5.5. Switch off the equipment and allow the chamber to cool to room temperature over a 1 hour period. Allow time for the equipment to stabilize to normal room temperature and humidity before carrying out the next test Low temperature Place the equipment in a chamber and cool to the required temperature value for 2 hours. Switch on the equipment and maintain the chamber at the required operating temperature. After 10 minutes carry out the performance test as detailed in clause 5.5. Switch off the equipment and allow the chamber to rise to room temperature over a 1 hour period. Allow time for the equipment to stabilize to normal room temperature and for moisture to disperse before carrying out the next test. 6 General conditions of measurement 6.1 Receiver test signal arrangement Test signal sources Test signal sources shall be connected to the receiver input in such a way that the impedance presented to the receiver input is 50 Ω, irrespective of whether one or more test signals are applied to the receiver simultaneously Nominal frequency The nominal frequency of the receiver is the carrier frequency of the selected channel.

15 15 EN V1.5.2 ( ) Normal test signal The normal test signal shall be a Double Side Band signal with carrier, amplitude modulated with 1 khz sinewave to a depth of 30 % Squelch Unless otherwise stated the receiver squelch facility shall be made inoperative for the duration of the tests Normal audio output power The rated audio frequency output power is the value stated by the manufacturer to be the maximum power available at the output, for which all the requirements of the present document are met. The audio frequency output power shall be maintained at 50 % of the rated output in the presence of a desired signal unless otherwise defined Audio AGC When an audio AGC function is provided, this shall be disabled (where possible) unless otherwise stated. 6.2 Transmitter test signal arrangement Coaxial termination When tests are carried out with a coaxial termination, this shall be a non-reactive, non radiating 50 Ω load Signal sources The modulating signals shall be applied to the transmitter through the modulating audio input Normal test signal The normal test signal shall be a 1 khz sinewave at a level which produces a 30 % amplitude modulation depth, of the transmitter RF output, unless otherwise defined. 6.3 Test channels Tests shall be carried out on three frequencies unless otherwise stated: 118,000 MHz; 127,500 MHz; 136,975 MHz. NOTE: Where technical acceptance performance will be measured in the extended frequency bands 108 MHz to 117,975 MHz and 137 MHz to 155,975 MHz additional tests using the techniques and limits defined in the present document may apply at the upper and lower band edge frequencies. 7 Transmitter All tests on the transmitter shall be carried out at the maximum rated output power (see clause 7.3.1) except where otherwise stated.

16 16 EN V1.5.2 ( ) 7.1 Protection of the transmitter Definition The protection of the transmitter represents the ability of the transmitter to be protected against malfunction due to faults in the antenna system. This shall be the first test applied to a transmitter Method of measurement While the transmitter is transmitting at the rated output power, the antenna port shall first be short-circuited and then open circuited, in each case for a period of 1 minute. This test shall be performed on 127,5 MHz only Requirement This test shall not result in any damage to the transmitter. After removal of the short-circuit and open circuit conditions, the transmitter shall be able to operate normally when re-keyed. 7.2 Frequency error Definition The frequency error is the difference between the measured carrier frequency and its nominal value Method of measurement The carrier frequency shall be measured in the absence of modulation, with the transmitter connected to a coaxial termination (see clause 6.2.1). Measurements shall be made under normal test conditions (see clause 5.3) and under extreme test conditions on 127,5 MHz Limits The frequency error shall be within the requirements of table 1. Table 1 Frequency Error Normal Temperature +15 C to +35 C Extreme Temperature -20 C to +55 C Extended Temperature 0 C to 40 C 8,33 khz Fixed Base ±1 ppm N/A ±1 ppm 8,33 khz Mobile/portable ±1 ppm N/A ±1 ppm 8,33 khz Hand held ±1 ppm N/A ±1 ppm 25 khz Fixed Base ±5 ppm ±10 ppm N/A 25 khz Mobile/portable ±10 ppm ±15 ppm N/A 25 khz Hand held ±10 ppm ±15 ppm N/A 2-/3-carrier offset system ±5 ppm N/A ±5 ppm (25 khz channel spacing) 4-carrier offset system (25 khz ±3,8 ppm N/A ±3,8 ppm channel spacing) 5-carrier offset system (25 khz ±0,3 ppm N/A ±0,3 ppm channel spacing) 2-carrier offset system (8,33 khz channel spacing) ±1 ppm N/A ±1 ppm NOTE: Offset carrier frequencies will be those defined in ICAO Annex 10 [2].

17 17 EN V1.5.2 ( ) 7.3 Carrier power Definitions The carrier power is the mean power delivered to the coaxial termination during transmission in the absence of modulation. The requirements of the present document shall be met for all power output levels at which the transmitter is intended to operate into 50 Ω. For practical reasons measurements shall be performed only at the lowest and the highest power output level at which the transmitter is intended to operate, unless otherwise stated Method of measurement The transmitter shall be connected to a coaxial termination (see clause 6.2.1) and the output power delivered to this coaxial termination shall be measured at the output connector. The measurements shall be made under normal test conditions (see clause 5.3) for the highest and lowest transmitter power output level and at the highest transmitter power output level under extended or extreme test conditions as applicable. Measurements shall be made on the test channels (see clause 6.3) Tolerances Normal test conditions The carrier power measured under normal test conditions (see clause 5.3) with the output power adjusted to maximum, shall not vary by more than ±1,5 db from the rated maximum output power Extreme test conditions The carrier power measured under extreme test conditions (see clause 5.4) with the output adjusted to maximum rated power, shall not vary by more than +1,5 db and -3 db from the rated maximum output power. 7.4 Amplitude modulation characteristic Modulation depth (speech) Definitions Amplitude modulation depth: The amplitude modulation depth is the fractional ratio, expressed as a percentage, of the difference and the sum of the numerical values of the largest and smallest amplitudes encountered in one cycle of the modulating waveform. Limiting threshold: The limiting threshold is defined as the minimum audio input level required to produce the manufacturers declared modulation depth for the equipment (85 % minimum at 1 khz) Method of measurement The normal 1 khz test signal shall be applied to the modulation input of the transmitter. The test signal level shall then be set at a level 3 db above the limiting threshold. The modulation depth shall be measured at the output of the transmitter connected to a coaxial termination (see clause 6.2.1), by means of a modulation analyser.

18 18 EN V1.5.2 ( ) Limits The amplitude modulation depth shall be at least 85 % under normal temperature conditions and at least 80 % for extreme temperature measurements Modulation depth (analogue data mode) Method of measurement The normal 1 khz test signal shall be applied to the data modulation input of the transmitter. The test signal level shall then be set to 0 dbm into 600 Ω. The modulation depth shall be measured at the output of the transmitter connected to a coaxial termination (see clause 6.2.1), by means of a modulation analyser Limits The amplitude modulation depth shall be 85 % under normal temperature conditions Modulation compression (speech mode) Definition Modulation compression is the reduction of the modulation sensitivity at input signal levels above the limiting threshold determined in clause Method of measurement The normal test signal of 1 khz shall be applied to the modulation input of the transmitter tuned to 127,5 MHz. The modulation depth shall be measured at the output of the transmitter connected to a coaxial termination (see clause 6.2.1), by means of a modulation analyser. Adjust the audio level applied to the modulation input to produce a modulation level of 30 %. Set the audio signal to produce modulation levels of 10 % and at the threshold that produces 85 %. Confirm that when the level is varied between the values in table 2, the corresponding modulation depth changes are achieved within the stated tolerances. With the audio input level set at the threshold that produces 85 % modulation, increase the level by 20 db and record the maximum usable modulation depth Limits The modulation shall be linear up to 85 % within ±2 db. The maximum usable modulation depth shall not exceed 95 %. Table 2 Level Increase Modulation Change Level Tolerance 10 db 10 % to 30 % ± 2 db 9 db 30 % to 85 % +1 db/-2 db

19 19 EN V1.5.2 ( ) Amplitude modulation distortion Definition The amplitude modulation distortion is the ratio of the total rms voltage of all the harmonics of the modulated waveform to the total rms voltage Method of measurement The normal test signal of 1 khz set at a level 3 db above the limiting threshold determined in clause shall be applied to the modulation input of the transmitter. The modulation distortion shall be measured at the output of the transmitter connected to a coaxial termination (see clause 6.2.1), by means of a distortion analyser. For equipment designed for data operation, the test shall be repeated for an input signal of 0 dbm applied to the data modulation input of the transmitter Limits The amplitude modulation distortion shall be less than 10 % Audio frequency response Definition The audio frequency response expresses the ability of the transmitter to operate without excessive degradation of its frequency response as a function of the modulation frequency Method of measurement The audio frequency response shall be measured at 127,5 MHz. The Normal test signal (see clause 6.2.3) shall be applied to the transmitter input and the level adjusted to give a modulation depth of 60 %. The modulation frequency shall be varied between 300 Hz and 5 khz, with the level of the audio input test signal kept constant. The modulation depth shall be measured at the output of the transmitter connected to a coaxial termination (see clause 6.2.1), by means of a modulation analyser. The results shall be expressed in db relative to 1 khz in tabular and/or graphical format. Where a data input is provided the test shall be made in both modes Limits 8,33 khz channel spacing The modulation depth as measured over the modulating frequency range of 350 Hz to 2,5 khz shall be less than +2 db and -4 db (referred to 1 khz). At 3,2 khz the modulation depth shall be at least -25 db referred to 1 khz Limits 25 khz channel spacing The modulation depth as measured over the modulating frequency range of 300 Hz to 3,4 khz shall be less than +2 db and -4 db (referred to 1 khz). The necessary modulating frequency range for mobile, portable and handheld equipment can be reduced to 350 Hz to 2,5 khz. At 5 khz the modulation depth shall be at least -25 db referred to 1 khz.

20 20 EN V1.5.2 ( ) Limits 25 khz channel spacing (Data) The modulation depth as measured over the modulating frequency range of 1,2 khz to 2,4 khz shall be within ±3 db of the level at 1 khz Group delay variation (data mode only) Definition Audio filters do not provide a uniform transmission speed for all frequencies. Consequently, a phase difference can occur between frequencies within the passband. Group delay (or envelope delay) is proportional to the change in slope of the phase shift response versus frequency curve Transmitter method of measurement Data Line Input Transmitter Modulation audio 30 db Attenuator Resistive splitter Modulation Meter AF O/P Ref. I/P Test port Source Network Analyser NOTE: a) The output of the network analyser is connected to a resistive splitter to give two audio signal outputs. b) One signal is connected to the network analyser's reference input, whilst the second feeds the transmitter with a modulation signal to be applied to the data input port. c) The modulation meter shall be set to wideband operation to prevent delay variation occurring in the test equipment. d) The source level is adjusted at the network analyser to produce a 85 % modulated signal at 1 khz. e) The modulation meters audio output is fed into the test port on the analyser and the network analyser adjusted to sweep from 100 Hz to 3 khz with a 30 Hz resolution bandwidth. f) Set the analyser's markers to show the group delay variation between 1,2 khz and 2,4 khz. g) The group delay variation shall be measured at 127,5 MHz. Figure 1: Transmitter group delay diagram Limits The group delay variation between 1,2 khz and 2,4 khz shall be < 60 us. 7.5 Adjacent channel power Definition The adjacent channel power is that part of the total power output of a transmitter under defined conditions of modulation, which falls within a specified passband centered on the nominal frequency of either of the adjacent channels. This power is the sum of the mean power produced by the modulation, hum and noise of the transmitter.

21 21 EN V1.5.2 ( ) Measurement The adjacent channel power shall be measured with a power measuring receiver, or an equivalent analyser here referred to as the "measurement receiver", conforming to annex B: a) the transmitter shall be operated at the maximum carrier power determined in clause 7.3 under normal test conditions. The output of the transmitter shall be linked to the input of the "measurement receiver" by a connecting device such that the impedance presented to the transmitter is 50 Ω and the level at the "measurement receiver" input is appropriate; b) the transmitter shall be modulated with a signal at 1 khz for 8,33 khz and 25 khz channels at a level required to produce a modulation depth of 85 %; c) with the transmitter modulated, the tuning of the "measurement receiver" shall be adjusted so that a maximum response is obtained. This is the 0 db response point. The "measurement receiver" attenuator setting and the reading of the meter shall be recorded; d) the tuning of the "measurement receiver" shall be adjusted away from the carrier so that the "receiver" -6 db response nearest to the transmitter carrier frequency is located at a displacement from the nominal carrier frequency of 4,83 khz (8,33 khz channel spacing) or 17 khz (25 khz channel spacing); e) the "measurement receiver" variable attenuator shall be adjusted to obtain the same meter reading as in step c) or a known relation to it; f) the ratio of adjacent channel power to carrier power is the difference between the attenuator settings in steps c) and e), corrected for any differences in the reading of the meter; g) the measurement shall be repeated with the "measurement receiver" tuned to the other side of the carrier Limits The adjacent channel power shall not exceed the following values below the carrier power of the transmitter: 8,33 khz Channel spacing: 50 db; 25 khz Channel spacing: 60 db. 7.6 Broadband noise measurement Definition The broadband noise test determines the phase noise generated by the transmitter, (when keyed), between the adjacent channel and within the spurious emission exclusion band. It is necessary to minimize the effects of this noise in order to prevent desensitization of receivers operating on frequencies close to the transmitter.

22 22 EN V1.5.2 ( ) Method of measurement Transmitter S Attenuator X db A Crystal Filter 127,5 MHz BW 24 khz Low noise amplifier e.g db B Spectrum analyser Reference generator NOTE 0: Measurements shall be made at 127,5 MHz. NOTE 1: When using crystal filters, the input power shall not exceed 0 dbm. The power attenuator should be chosen such that the level appearing at the filter input never exceeds this limit. A RF fuse may be placed at the input to the filter in order to provide additional protection. NOTE 2: For output powers of > 25 W the attenuator should provide 50 db of attenuation in order to protect the crystal filter. NOTE 3: a) Connect equipment as shown in figure 2. b) Initially connect the spectrum analyser to the 50 db attenuator output (point A). Set the transmitter to produce an unmodulated carrier at the crystal filter frequency. Using a 50 khz span and a 1 khz bandwidth, note the output reference power (Pr). c) Reconnect the analyser to the amplifier output (point B). d) Adjust the transmitter frequency to 300 khz above the crystal filter frequency. Key the transmitter and apply modulation at 1 khz at a level to give 85 % modulation depth. Monitor the noise level on the spectrum analyser. Use the analysers averaging function to find the mean level within the crystal filter bandwidth. Note this level as (Pm). e) De-key the transmitter and apply an unmodulated signal from the reference generator at the crystal filter frequency. Increase the RF level until it is the same amplitude as the noise level noted above (Pm). Record this level as Pmref. f) The wide band noise at 300 khz offset is then determined from the following formulae: - WB noise = Pmref + Pr + BW correction (dbc/hz) where BW correction for 1 khz = 30 db. g) Adjust the transmitter frequency to 300 khz below the crystal filter frequency and ±500 khz offset from the filter frequency and repeat the test for each transmitter frequency. Figure 2: Broadband noise measurement Limit The broadband noise limit shall be: < -130 dbc/hz. 7.7 Conducted spurious emissions Definition Conducted spurious emissions are RF emissions appearing at the RF output port on a frequency or frequencies which are outside the necessary bandwidth and the level of which may be reduced without affecting the corresponding transmission of information. Conducted spurious emissions include harmonic emissions, parasitic emissions, intermodulation products and frequency conversion products, but exclude out of band emissions.

23 23 EN V1.5.2 ( ) Method of measurement a) Conducted spurious emissions shall be measured with the unmodulated transmitter connected to the coaxial termination (see clause 6.2.1) and operating on the centre test frequency (see clause 6.3). b) The measurements shall be made over a range from 9 khz to 4 GHz, excluding the channel on which the transmitter is operating and separated from the centre frequency of the emission by ±1 MHz. c) The measurements for each spurious emission shall be made using a tuned radio measuring instrument or a spectrum analyser. d) The measurements shall be repeated with the transmitter in standby mode Limits Environmental phenomena Spurious conducted RF Emissions Spurious conducted RF Emissions Spurious conducted RF Emissions Spurious conducted RF Emissions Frequency range 9 khz to 150 khz > 150 khz to 30 MHz > 30 MHz to 1 GHz > 1 GHz to 4 GHz Table 3 Units Test limits, Test limits Reference Tx Standby Tx active mode bandwidth dbm -57 (2 nw) -46 dbm B = 1 khz dbm -57 (2 nw) -46 dbm B = 9 khz to 10 khz dbm -57 (2 nw) -36 dbm for harmonics, B = 10 khz -46 dbm for non-harmonic (notes 1 and 2) spurious dbm -47 (20 nw) -30 dbm for harmonics B = 10 khz -40 dbm for non-harmonic spurious NOTE 1: For transmitters with an RF output above 50 W a limit of -80 dbc will be applied for harmonically related spurious. NOTE 2: An exclusion band of ±1 MHz about the carrier shall be used in active transmit mode. 7.8 Intermodulation attenuation Definition Intermodulation attenuation is the capability of a transmitter to avoid the generation of signals in the non-linear elements caused by the presence of the carrier and an interfering signal entering the transmitter via the antenna. It is specified as the ratio, in db, of the power level of the third order intermodulation product to the carrier power level.

24 24 EN V1.5.2 ( ) Method of measurement Transmitter Directional coupler under test 50 Ω 10 db Ω db Interfering test signal source 50Ω termination Spectrum analyser 50 Ω attenuator NOTE: a) The measurement arrangement shown in figure 3 shall be used. b) The transmitter shall be connected to a 50 Ω, 10 db power attenuator and via a directional coupler to a spectrum analyser. An additional attenuator may be required between the directional coupler and the spectrum analyser to avoid overloading the spectrum analyser. c) In order to reduce the influence of mismatch errors it is important that the 10 db power attenuator is coupled to the transmitter under test with the shortest possible connection. d) The interfering test signal source is connected to the other end of the directional coupler via a 50 Ω, 20 db power attenuator. e) The interfering signal source may be either a transmitter providing the same power output as the transmitter under test and be of a similar type or a signal generator and a linear power amplifier capable of delivering the same output power as the transmitter under test. f) The directional coupler shall have an insertion loss of less than 1 db, a sufficient bandwidth and a directivity of more than 20 db. g) The transmitter under test and the test signal source shall be physically separated in such a way that the measurement is not influenced by direct radiation. h) The transmitter under test shall be unmodulated and the spectrum analyser adjusted to give a maximum indication with a frequency scan width of 500 khz. i) The interfering test signal source shall be unmodulated and the frequency shall be within 150 khz to 200 khz above the frequency of the transmitter under test. j) The frequency shall be chosen in such a way that the intermodulation components to be measured do not coincide with other spurious components. k) The power output of the interfering test signal source shall be adjusted to the carrier power level of the transmitter under test by the use of a power meter. l) The intermodulation component shall be measured by direct observation on the spectrum analyser and the ratio of the largest third order intermodulation component to the carrier recorded. m) This measurement shall be repeated with the interfering test signal source at a frequency within 150 khz to 200 khz below the frequency of the transmitter under test. Figure 3: Measurement arrangement Limits The intermodulation protection ratio shall be at least 40 db. 7.9 RF power attack time and release time Definitions The transmitter power attack time (t a ) is the time which elapses between: t on L : defined by the condition when the transmitter output power, measured at the antenna terminal, exceeds -20 dbc; t on H : defined by the condition when the transmitter output power has reached -1,5 dbc.

25 25 EN V1.5.2 ( ) The transmitter release time (t r ) is the time which elapses between: t off H : defined by the condition when the transmitter output power falls below -1,5 dbc; t off L : defined by the condition when the transmitter output power has reached -20 dbc. The measured value of t a and t r are respectively t am (transmitter attack measurement)and t rm (transmitter release measurement), the limits are respectively t al and t rl Method of measurement Attack time The following method of measurement shall be used: a) the transmitter is connected to a RF detector via a matched test load. The attenuation of the test load shall be chosen in such a way that the input of the RF detector is protected against overload and the detector operates as soon as the transmitter is keyed: - a dual trace storage oscilloscope (or a transient recorder) records the amplitude transient from the detector on a logarithmic scale; - a trigger device may be required to ensure that the start of the sweep of the oscilloscope time base occurs the instant at which the "transmitter t on L " function is initiated; - a spectrum analyser can also be used; b) the traces of the oscilloscope shall be calibrated in power (y-axis) and in time (x-axis), using the signal generator; c) the transmitter attack time shall be measured by direct reading on the oscilloscope while the transmitter is unmodulated and transmitting on 127,5 MHz Release time The following method of measurement shall be used: a) the transmitter is connected to a RF detector via a matched test load. The attenuation of the test load shall be chosen in such a way that the input of the RF detector is protected against overload and the detector operates as soon as the transmitter is keyed: - a dual trace storage oscilloscope (or a transient recorder) records the amplitude transient from the detector on a logarithmic scale; - a trigger device may be required to ensure that the start of the sweep of the oscilloscope timebase occurs the instant at which the "transmitter t off H " function is de-activated; - a spectrum analyser can also be used; b) the traces of the oscilloscope shall be calibrated in power (y-axis) and in time (x-axis), using the signal generator; c) the transmitter release time shall be measured by direct reading on the oscilloscope while the transmitter is unmodulated and transmitting on 127,5 MHz.