Foundation Licence Theory - hamradio.org.au Licence Theory Lecture Part...Foundation Licence Licence Training Part 2 ... output power remains constant independent of voice level. ...

8 September 2008 TrainSafe Australia 1

Foundation Foundation LicenceLicence Training Part 2Training Part 2

Gateway to Amateur RadioGateway to Amateur RadioFred SwainstonFred Swainston

VK3DACVK3DAC

8 September 20088 September 2008 TrainSafe Australia TrainSafe Australia 22

Section 4 Transmitters and Section 4 Transmitters and ReceiversReceivers

Presenter

Presentation Notes

Typical amateur radio station set-up Transceiver, SWR meter and ATU with hand held


Section 4 Transmitters and Section 4 Transmitters and ReceiversReceivers

Foundation licence holders are not Foundation licence holders are not permitted to build or modify permitted to build or modify transmitters transmitters Radio transmitters generate high Radio transmitters generate high frequency electrical energyfrequency electrical energyThe generated energy is radiated by The generated energy is radiated by the antenna as an electromagnetic the antenna as an electromagnetic wavewave


Section 4 Transmitter and ReceiverSection 4 Transmitter and Receiver

The basis of the transmitter is the The basis of the transmitter is the oscillator oscillator The oscillator generates radio The oscillator generates radio frequency energy at a specific frequency energy at a specific frequencyfrequencyThe radio frequency is called the The radio frequency is called the carriercarrierTurning the oscillator on and off with Turning the oscillator on and off with a key allows Morse Code to be senta key allows Morse Code to be sent





ModulationModulationVoice over radio is Voice over radio is ““Radio TelephonyRadio Telephony””Superimposing the voice frequencies on to Superimposing the voice frequencies on to the carrier wave is called modulationthe carrier wave is called modulationSuperimposing the voice onto the Superimposing the voice onto the amplitude of the carrier is called amplitude amplitude of the carrier is called amplitude modulationmodulationSuperimposing the voice frequency onto Superimposing the voice frequency onto the frequency of the carrier is called the frequency of the carrier is called frequency modulationfrequency modulation







Single Sideband (SSB) is a form of Single Sideband (SSB) is a form of amplitude modulationamplitude modulationThe power transmitted on SSB is The power transmitted on SSB is dependent of the volume of the dependent of the volume of the operators voiceoperators voiceThe level of the voice signal fed into The level of the voice signal fed into the transmitter is controlled by the the transmitter is controlled by the microphone gain control microphone gain control



Foundation licence holders are Foundation licence holders are permitted to transmit no more than permitted to transmit no more than 10 watts on SSB10 watts on SSBOn SSB the voice peaks (loudest On SSB the voice peaks (loudest volume) should not cause the volume) should not cause the transmitter to exceed 10 watts.transmitter to exceed 10 watts.This power is 10 watts peak This power is 10 watts peak envelope power (PEP)envelope power (PEP)



With With FrequencyFrequency Modulation (FM) the Modulation (FM) the output power remains constant output power remains constant independent of voice level.independent of voice level.A 10 watt FM transmitter will transmit 10 A 10 watt FM transmitter will transmit 10 watts at all timeswatts at all timesThe The frequencyfrequency of the carrier changes when of the carrier changes when voice signals are fed into the transmittervoice signals are fed into the transmitterThe amount of The amount of frequencyfrequency change is called change is called deviationdeviationDeviation is FM modulationDeviation is FM modulation



The amount the carrier deviates is The amount the carrier deviates is dependent on the level (volume) of the dependent on the level (volume) of the voice signalvoice signalThe more deviation the greater the The more deviation the greater the bandwidth required to transmit the signalbandwidth required to transmit the signalEither AM or FM carriers that are over Either AM or FM carriers that are over modulated may cause distorted output modulated may cause distorted output and interference to adjacent frequenciesand interference to adjacent frequencies

Presenter

Presentation Notes

Page 18 of manual


Crystal ReceiverCrystal Receiver


Capacitance and ResonanceCapacitance and Resonance This is additional informationThis is additional information

The symbol in the The symbol in the crystal set consisting crystal set consisting of two parallel lines is of two parallel lines is a capacitor.a capacitor.The capacitors with The capacitors with the arrow are variablethe arrow are variableThe capacitor is two The capacitor is two plate separated by an plate separated by an insulating material insulating material called a dielectriccalled a dielectric

The capacitor can The capacitor can store electrical energy store electrical energy in electric lines of in electric lines of force the form of a force the form of a chargechargeThis charge behaves This charge behaves like a small batterylike a small batteryAs the capacitor As the capacitor discharges the energy discharges the energy is depletedis depleted


Capacitance and ResonanceCapacitance and Resonance This is additional informationThis is additional information

Resonance is a very Resonance is a very special electrical special electrical conditionconditionResonance occurs at a Resonance occurs at a specific frequencyspecific frequencyA resonant circuit A resonant circuit consists of a capacitor consists of a capacitor and a coil (inductor)and a coil (inductor)At resonance energy At resonance energy is transferred between is transferred between the capacitor and the the capacitor and the inductorinductor

The capacitor stores The capacitor stores the energy in its the energy in its electric field and the electric field and the inductor in its inductor in its magnetic fieldmagnetic fieldAt resonance current At resonance current and voltages can be and voltages can be very high very high –– many many times higher than the times higher than the supply voltagesupply voltageMany radio circuits are Many radio circuits are tuned to resonance.tuned to resonance.



The receiver is designed to select the The receiver is designed to select the required signal, detect the modulation and required signal, detect the modulation and amplify the voice signalamplify the voice signalThe receiver converts the voice signal The receiver converts the voice signal back to the way it was when spokenback to the way it was when spokenA simple receiver is the tuned radio A simple receiver is the tuned radio frequency receiverfrequency receiverThe circuit that converts the modulated The circuit that converts the modulated signal back into audio is called a detectorsignal back into audio is called a detectorFM detectors are called discriminatorsFM detectors are called discriminators



Presenter

Presentation Notes

Tuned radio frequency receiver Discuss inductor and capacitor symbols – note that they are not in the Foundations Syllabus. Discuss resonance in terms of selectivity – i.e. a filter at the resonate frequency



Receiver sensitivity is the ability of the Receiver sensitivity is the ability of the receiver to receive weak signalsreceiver to receive weak signalsReceiver selectivity is the ability of the Receiver selectivity is the ability of the receiver to select between stations that receiver to select between stations that are close together in frequencyare close together in frequencyStability is the ability of the receiver to Stability is the ability of the receiver to stay on the same frequency over long stay on the same frequency over long periods of time where there are significant periods of time where there are significant changes in temperature.changes in temperature.



FM stands for:FM stands for:

A. Frequency modulationA. Frequency modulationB. Fine modulationB. Fine modulationC. Forced modulationC. Forced modulationD. Flat modulationD. Flat modulation

Presenter

Presentation Notes

Answer is A



The device that generates the carrier The device that generates the carrier in a transmitter is the:in a transmitter is the:

A. Audio amplifierA. Audio amplifierB. ModulatorB. ModulatorC. Power supplyC. Power supplyD. OscillatorD. Oscillator

Presenter

Presentation Notes

The answer is D



If a transmitter is over modulated it If a transmitter is over modulated it is likely to:is likely to:

A. Get hotA. Get hotB. Generate FM instead of AMB. Generate FM instead of AMC. Generate SSBC. Generate SSBD. Cause interferenceD. Cause interference

Presenter

Presentation Notes

Answer is D



The ability of a receiver to receive The ability of a receiver to receive weak signals is called the receivers:weak signals is called the receivers:

A. sensitivityA. sensitivityB. selectivityB. selectivityC. stabilityC. stabilityD. superD. super--heterodyneheterodyne

Presenter

Presentation Notes

Answer is A


Section 5 Antennas and Section 5 Antennas and Transmission Lines Transmission Lines

Presenter

Presentation Notes

144 MHz earth moon earth antenna array


Section 5 Antennas and Section 5 Antennas and Transmission LinesTransmission Lines

The transmission line connects the The transmission line connects the transmitter to the antennatransmitter to the antennaThe transmission line is sometimes The transmission line is sometimes called a called a ““feederfeeder”” because it feeds the because it feeds the radio frequency to the antennaradio frequency to the antennaThe size of the antenna is dependent The size of the antenna is dependent on the frequency to be transmittedon the frequency to be transmitted



There are two basic There are two basic types of feedline. types of feedline. These are coaxial and These are coaxial and parallel.parallel.Coaxial cable used in Coaxial cable used in radio is unbalanced radio is unbalanced and is usually 50 ohm and is usually 50 ohm impedanceimpedanceParallel line is Parallel line is balanced transmission balanced transmission line usually 300 or line usually 300 or 600 ohm impedance600 ohm impedanceImpedance can be Impedance can be considered as considered as resistance to ACresistance to AC

Presenter

Presentation Notes

Explain the word impedance as resistance to AC Explain balanced and unbalanced transmission lines Explain that the longer the feedline the more loss it has Explain the parallel feeders are effected by proximity to ground and metallic objects whereas coaxial is not.



Presenter

Presentation Notes

Top left PL259 or UHF female and male Bottom Left BNC Male and female Top right N Type female Bottom Right N type male



The The balbalunun is a type of transformer that is a type of transformer that can connect a can connect a balbalanced antenna to an anced antenna to an ununbalanced transmission line balanced transmission line The balun can also be used to match The balun can also be used to match impedances of transmission lines and impedances of transmission lines and antennasantennas

Presenter

Presentation Notes

Example TV antenna 300 folded dipole to 75 ohm coaxial cable



The antenna (aerial) couples power from The antenna (aerial) couples power from the transmitter to the space around the the transmitter to the space around the antennaantennaThe antenna radiates an electromagnetic The antenna radiates an electromagnetic wave by converting electrical signals to wave by converting electrical signals to radio waves and vice versaradio waves and vice versaThe antenna should be resonant at the The antenna should be resonant at the frequency to be transmitted/received frequency to be transmitted/received The antenna that radiates well also The antenna that radiates well also receives wellreceives wellAntenna are affected by their height Antenna are affected by their height above ground and proximity to buildings, above ground and proximity to buildings, trees etctrees etc

Presenter

Presentation Notes

Explain resonate Explain the size of the antenna in relation to transmitted frequency



The electromagnetic wave The electromagnetic wave radiated from an antenna is made radiated from an antenna is made up of electric lines of force and up of electric lines of force and magnetic lines of forcemagnetic lines of forceGenerally the orientation of the Generally the orientation of the antenna with respect to the antenna with respect to the ground will indicate the ground will indicate the polarisationpolarisationGenerally vertical antennas Generally vertical antennas produce vertically polarised produce vertically polarised signals and horizontal antennas signals and horizontal antennas produce horizontally polarised produce horizontally polarised signalssignalsTransmitter and receiver antenna Transmitter and receiver antenna should be the same polarisation should be the same polarisation for best resultsfor best results

Presenter

Presentation Notes

Explain polarisation



The dipole is a half The dipole is a half wavelength long and wavelength long and fed at the centrefed at the centre

This is a broadside This is a broadside antennaantenna(bi(bi--directional)directional)

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Presentation Notes

Explain bidirectional



The quarter wave The quarter wave antenna is the antenna is the shortest of the full shortest of the full size antennassize antennasThe driven element is The driven element is a quarter wavelength a quarter wavelength longlongThe inner of the The inner of the coaxial cable is coaxial cable is connected to the connected to the driven element and driven element and the braid connected to the braid connected to the ground plane the ground plane

Presenter

Presentation Notes

Explain omni-directional antenna



The folded dipole The folded dipole has the has the characteristic of characteristic of being a broad band being a broad band antennaantennaFed with 300 ohm Fed with 300 ohm TV ribbonTV ribbon

Presenter

Presentation Notes

Explain broadband in terms of frequency coverage


Section 5 Antennas and Section 5 Antennas and Transmission LineTransmission Line

A Yagi antenna is A Yagi antenna is unidirectional and unidirectional and sends signals and sends signals and receives signals in receives signals in the direction the the direction the antenna is pointed.antenna is pointed.

Presenter

Presentation Notes

Gain, ERP and polarisation of the antenna



Antennas such as YagiAntennas such as Yagi’’s have gain, and s have gain, and are unidirectional. This means the are unidirectional. This means the electromagnetic wave is concentrated into electromagnetic wave is concentrated into one directionone directionGain of antennas is measured in decibelsGain of antennas is measured in decibelsThe directivity of antennas has a similar The directivity of antennas has a similar effect as using a higher powered effect as using a higher powered transmitter transmitter The effective radiated power (ERP) of the The effective radiated power (ERP) of the transmitting system is increasedtransmitting system is increased

Presenter

Presentation Notes

The gain of an antenna is measured in db gain over a dipole antenna or a single point theoretical antenna. 3db is twice the ERP



End fed antennas are usually fed with End fed antennas are usually fed with open wire transmission line and require an open wire transmission line and require an antenna tuning unit to match the antenna antenna tuning unit to match the antenna to the output of the transmitter.to the output of the transmitter.


Section 5 Antennas and Transmission LinesSection 5 Antennas and Transmission Lines Antenna SchematicsAntenna Schematics


Section 5 Antennas and Transmission LinesSection 5 Antennas and Transmission Lines Antenna SchematicsAntenna Schematics



Antenna impedance is measured in ohmsAntenna impedance is measured in ohmsImpedance can be considered AC resistance Impedance can be considered AC resistance Most modern transmitting equipment has an Most modern transmitting equipment has an output impedance of 50 or 75 ohmsoutput impedance of 50 or 75 ohmsThe output impedance of the transmitter should The output impedance of the transmitter should be matched (have the same impedance) as the be matched (have the same impedance) as the transmission line and the antenna.transmission line and the antenna.Mismatched transmitter outputs, transmission Mismatched transmitter outputs, transmission line and antenna will cause power to be reflected line and antenna will cause power to be reflected back and forth along the transmission lineback and forth along the transmission lineThe reflected wave is called a standing waveThe reflected wave is called a standing wave



A standing wave ratio (SWR) meter is A standing wave ratio (SWR) meter is used to measure how well the antenna used to measure how well the antenna system is matched.system is matched.SWR meter is connected between the SWR meter is connected between the output of the transmitter and the antennaoutput of the transmitter and the antennaSWR should be checked each time you SWR should be checked each time you change frequencychange frequencyChecking the SWR on a transmission line Checking the SWR on a transmission line using a SWR meter is a component of the using a SWR meter is a component of the practical for the Foundation Licencepractical for the Foundation Licence



Checking SWR allows for the adjustment Checking SWR allows for the adjustment of your antenna to bring the antenna of your antenna to bring the antenna closer to resonance by lengthening or closer to resonance by lengthening or shortening the antennashortening the antennaAn SWR of more than 2:1 is likely to An SWR of more than 2:1 is likely to indicate a fault in the antenna systemindicate a fault in the antenna systemA good SWR on an antenna system is A good SWR on an antenna system is 1.5:1 or less1.5:1 or lessAn SWR greater than 1.5:1 may indicate An SWR greater than 1.5:1 may indicate the antenna needs tuning or a fault the antenna needs tuning or a fault condition is developingcondition is developing



An Antenna Tuning Unit (ATU) sometimes An Antenna Tuning Unit (ATU) sometimes called a Transmatch can be used to called a Transmatch can be used to provide the correct operating impedance provide the correct operating impedance for the transmitter.for the transmitter.The ATU tunes the antenna system The ATU tunes the antenna system allowing operation on multiple bands using allowing operation on multiple bands using the one antennathe one antennaAdjusting the ATU is Adjusting the ATU is notnot a requirement for a requirement for the practical component of the Foundation the practical component of the Foundation Licence but knowing its purpose and Licence but knowing its purpose and location between the transmitter output location between the transmitter output and the antenna is a requirementand the antenna is a requirement



Presenter

Presentation Notes

See manual page 28 Transmitter with typical 50 ohm output. SWR meter next to the transmitter to measure SWR at the transmitter output/input Low pass filter to remove and unwanted frequencies high than the transmitted frequency. The ATU to match the antenna system to the output of the transmitter. Many transmitters have internal SWR meters and ATU’s The order of equipment must be understood as the Foundation Licence requires the candidate to correctly assemble a station with discreete components



A dummy load is a resistor typically A dummy load is a resistor typically the same output impedance as the the same output impedance as the transmitter ie 50 ohmstransmitter ie 50 ohmsThe dummy load allows the The dummy load allows the transmitter to be tested with minimal transmitter to be tested with minimal radiation ie not tested radiation ie not tested ““on airon air”” via via the aerial.the aerial.The dummy load also allows the The dummy load also allows the output power of the transmitter to be output power of the transmitter to be adjusted.adjusted.



The power for SSB is The power for SSB is 10 watts PEP. For CW, 10 watts PEP. For CW, FM and AM average FM and AM average power is not to exceed power is not to exceed 10 watts10 wattsSome power meters Some power meters can be very can be very inaccurate. Care must inaccurate. Care must be taken in the be taken in the selection of a power selection of a power meter to measure meter to measure output power.output power.

Presenter

Presentation Notes

Page 58 of manual


The purpose of an antenna is to:The purpose of an antenna is to:A. A. Let people know you are a Let people know you are a

radio amateurradio amateurB.B. Provide a convenient place for Provide a convenient place for

birds to landbirds to landC.C. Allow balanced transmission Allow balanced transmission

lines to be usedlines to be usedD.D. Convert electrical signals into Convert electrical signals into

radio waves and visa versa.radio waves and visa versa.


Presenter

Presentation Notes

Answer is D



The longer the antenna:The longer the antenna:

A. The higher the frequency of A. The higher the frequency of operationoperation

B. The lower the frequency of B. The lower the frequency of operationoperation

C. The better the antenna will workC. The better the antenna will workD. The more vertical polarisation will D. The more vertical polarisation will

be obtainedbe obtained

Presenter

Presentation Notes

Answer is B



The reason the antenna and transmission The reason the antenna and transmission line are matched in impedance to the line are matched in impedance to the transmitter output is to:transmitter output is to:

A. Increase the SWRA. Increase the SWRB. Eliminate the use of a dummy B. Eliminate the use of a dummy loadloadC. Keep SWR to a minimumC. Keep SWR to a minimumD. Keep the transmitted power to 10 D. Keep the transmitted power to 10

watts.watts.

Presenter

Presentation Notes

Answer is C



An antenna with a 3 dB gain An antenna with a 3 dB gain operating with at 10 watt transmitter operating with at 10 watt transmitter will result in and effective radiated will result in and effective radiated power (ERP) of:power (ERP) of:

A. 3 wattsA. 3 wattsB. 10 wattsB. 10 wattsC. 20 wattsC. 20 wattsD. 30 wattsD. 30 watts


Section 6 PropagationSection 6 Propagation

Presenter

Presentation Notes

Parkes Radio Telescope tracking the moon


Section 6 PropagationSection 6 PropagationRadio waves are electromagnetic wavesRadio waves are electromagnetic wavesHow these waves travel from the How these waves travel from the transmitting antenna to the receiving transmitting antenna to the receiving antenna is called propagationantenna is called propagationRadio waves travel in straight lines Radio waves travel in straight lines although they can be reflected, refracted although they can be reflected, refracted or diffractedor diffractedThe further the radio wave gets from the The further the radio wave gets from the transmitting antenna the weaker it transmitting antenna the weaker it becomesbecomesAny time a radio wave travels through Any time a radio wave travels through anything other than anything other than ““free Spacefree Space”” it will it will travel slower and lose strengthtravel slower and lose strength


Section 6 PropagationSection 6 PropagationThe height of the The height of the ionospheric layers is ionospheric layers is approximateapproximateThe sun ionises or The sun ionises or charges the air charges the air particlesparticlesWhen radio waves hit When radio waves hit the ionosphere they the ionosphere they can be bent back to can be bent back to earthearthThe bending is The bending is dependent on the dependent on the layer, its density and layer, its density and the frequency of the frequency of operationoperation


Section 6 PropagationSection 6 PropagationThe ionosphere refracts The ionosphere refracts the radio wavethe radio waveThe amount of The amount of refraction is dependent refraction is dependent on:on:

Sun spot activitySun spot activityTime of dayTime of dayThe seasonThe season

The ionosphere is The ionosphere is reliant on ultraviolet reliant on ultraviolet radiation from the sunradiation from the sunSunspots are in an 11 Sunspots are in an 11 year cycleyear cycle



A signal travelling from the transmitter to the A signal travelling from the transmitter to the receiver via two paths can cause multipath fadingreceiver via two paths can cause multipath fadingSelective fading occurs when the frequency Selective fading occurs when the frequency components that make up the signal are components that make up the signal are refracted by different amountsrefracted by different amounts


Section 6 PropagationSection 6 PropagationVHF, UHF and frequencies above UHF are VHF, UHF and frequencies above UHF are dependent on an almost clear line of sight dependent on an almost clear line of sight path from transmitter to receiverpath from transmitter to receiverVHF and UHF are generally obstructed by VHF and UHF are generally obstructed by hills and other large structureshills and other large structuresVHF and UHF signals can be bent or VHF and UHF signals can be bent or diffracted over some obstaclesdiffracted over some obstaclesTemperature changes in the troposphere Temperature changes in the troposphere results in ducts that can cause VHF and results in ducts that can cause VHF and UHF signals to be propagated over long UHF signals to be propagated over long distancesdistances

Presenter

Presentation Notes

Explain troposphere





As a radio wave is radiated from the As a radio wave is radiated from the antenna. As the wave travels further antenna. As the wave travels further it becomes:it becomes:

A. A. StrongerStrongerB.B. WeakerWeakerC.C. IonisedIonisedD.D. DuctedDucted

Presenter

Presentation Notes

Answer is B



Long distance HF propagation is a Long distance HF propagation is a result of:result of:

A. A. Ground waveGround waveB. B. Knife edge diffractionKnife edge diffractionC.C. Tropospheric ductingTropospheric ductingD. D. Ionospheric refractionIonospheric refraction

Presenter

Presentation Notes

Answer is D



VHF and UHF signals can be VHF and UHF signals can be obstructed by:obstructed by:

A.A. Large obstaclesLarge obstaclesB. B. Transmission during night Transmission during night

timetimeC.C. Strong north windsStrong north windsD.D. Transmission over waterTransmission over water

Presenter

Presentation Notes

Answer is A


Section 7 InterferenceSection 7 Interference



Interference can generally be resolved by Interference can generally be resolved by introducing technical solutions, however introducing technical solutions, however these can be complex and a qualified these can be complex and a qualified person should be sought to resolve these person should be sought to resolve these problems.problems.Electronic equipment can operate within Electronic equipment can operate within an electromagnetic field without an electromagnetic field without interference. This is called interference. This is called Electromagnetic Compatibility (EMC) or Electromagnetic Compatibility (EMC) or radio frequency immunityradio frequency immunity


Section 7 InterferenceSection 7 InterferenceAn amateur station must not cause harmful An amateur station must not cause harmful interference to radio communications including:interference to radio communications including:•• Other usersOther users•• Other servicesOther services

EMC issues are likely to cause neighbourhood EMC issues are likely to cause neighbourhood disputes. To resolve a dispute:disputes. To resolve a dispute:•• Discuss the problem with the person concerned, obtain Discuss the problem with the person concerned, obtain

dates and times of interferencedates and times of interference•• Try and identify the source of interferenceTry and identify the source of interference•• Seek advice and where necessary involve the ACMASeek advice and where necessary involve the ACMA

It may be necessary to shut down your station It may be necessary to shut down your station for a time to identify the interference source but for a time to identify the interference source but this is this is notnot mandatorymandatory

Presenter

Presentation Notes

Harmful interference is when interference is caused to a licenced radio communication service



There are many sources of potential There are many sources of potential RF noise generation that can RF noise generation that can interfere with broadcast radio and interfere with broadcast radio and television receivers. These sources television receivers. These sources of man made noise include:of man made noise include:

Power toolsPower toolsComputersComputersArc WeldersArc WeldersPower lines etcPower lines etc

Presenter

Presentation Notes

Explain broadcast radio and television in terms of domestic receiving equipment.



Interference can be caused to:Interference can be caused to:•• Telephones Telephones –– mobile and fixedmobile and fixed•• TelevisionTelevision•• Radio receptionRadio reception•• Audio equipmentAudio equipment•• ComputersComputers•• Vehicle electronic equipmentVehicle electronic equipment•• Blasting devicesBlasting devices


Section 7 InterferenceSection 7 InterferenceThere are sources of natural There are sources of natural noise that can cause noise that can cause interference such as interference such as lightning, electrostatic lightning, electrostatic buildbuild--up etc.up etc.Amateur stations can cause Amateur stations can cause interference to other radio interference to other radio communication services and communication services and television services. television services. The cause of the The cause of the interference from an interference from an amateur station is often as amateur station is often as a result of incorrect a result of incorrect operation of amateur operation of amateur transmitting equipmenttransmitting equipment



Potential reasons for interference Potential reasons for interference from an amateur station is:from an amateur station is:•• Over modulation Over modulation ---- excessive excessive

microphone gainmicrophone gain•• Incorrectly tuned antennas Incorrectly tuned antennas –– high SWRhigh SWR•• Breakthrough on FM or SSB Breakthrough on FM or SSB –– close close

proximity of transmit antenna to proximity of transmit antenna to receiving antennareceiving antenna

•• Mains fed interference Mains fed interference –– signals fed by signals fed by the 240 volt mains supplythe 240 volt mains supply



Interference as a result of EMC Interference as a result of EMC issues is dependent on:issues is dependent on:•• Transmitted powerTransmitted power•• Frequency of operationFrequency of operation•• Type of emission from the transmitter ie Type of emission from the transmitter ie

AM, SSB, FM etcAM, SSB, FM etc•• Distance the transmitter is from the Distance the transmitter is from the

affected equipment affected equipment –– selection and selection and location of antennas can significantly location of antennas can significantly reduce the likelihood of interference.reduce the likelihood of interference.


Section 7 InterferenceSection 7 InterferenceFilters can be used to Filters can be used to reduce the likelihood reduce the likelihood of interferenceof interferenceOther filters can be Other filters can be used in the power used in the power supply or supply or interconnections interconnections between the between the equipmentequipmentFilters must be fitted Filters must be fitted as close to the as close to the affected device as affected device as possiblepossible

Presenter

Presentation Notes

Low pass filter in the output of transmitter, ATU as a filter



Ferrite rods with Ferrite rods with wire wound onto wire wound onto them can be used them can be used to make effective to make effective RF filtersRF filtersThese filters are These filters are sometimes call sometimes call coils or chokes coils or chokes

Presenter

Presentation Notes

Explain ferrite as a granulated magnetic material compacted into a form required by radio and exhibit specific RF characteristics.


Section 7 InterferenceSection 7 InterferenceToroids can also be Toroids can also be used as RF filtersused as RF filtersFor the practical For the practical you will be you will be required to make required to make an RF filter using a an RF filter using a toroid or a ferrite toroid or a ferrite rodrodThe RF is blocked The RF is blocked by the filterby the filter

Presenter

Presentation Notes

Explain toroid


Section 7 InterferenceSection 7 InterferenceAn RF earth connection in an amateur An RF earth connection in an amateur station is to provide a path to minimise RF station is to provide a path to minimise RF ground currents entering the mains earth ground currents entering the mains earth system and causing interferencesystem and causing interferenceNote the earth symbolNote the earth symbol

Power SupplyPower Supply

RF Earth

Mains Earth

240v Mains



EMC problems are dependent on EMC problems are dependent on four factors; transmitted power, four factors; transmitted power, frequency and type of emission the frequency and type of emission the fourth is:fourth is:A. Brand of radio transmitterA. Brand of radio transmitterB. WeatherB. WeatherC. Distance from the affected C. Distance from the affected

equipmentequipmentD. Sun spot cycleD. Sun spot cycle

Presenter

Presentation Notes

Answer is C



One way interference can be fed into One way interference can be fed into nearby electronic equipment via:nearby electronic equipment via:

A. The 240 volt mainsA. The 240 volt mainsB. Moist atmosphereB. Moist atmosphereC. PVC gas pipesC. PVC gas pipesD. RF chokes wound on toroidsD. RF chokes wound on toroids

Presenter

Presentation Notes

Answer is A



Interference resulting in EMC Interference resulting in EMC problems can be minimised by:problems can be minimised by:

A. Only using dipolesA. Only using dipolesB. Using vertically polarised antennasB. Using vertically polarised antennasC. Careful selection and locating of C. Careful selection and locating of

antennasantennasD. Only operating from a base D. Only operating from a base

stationstation

Presenter

Presentation Notes

Answer is C


Section 8 Operating Practices and Section 8 Operating Practices and ProceduresProcedures

This is the practical This is the practical section and will be section and will be covered by your covered by your you instructor you instructor where you will be where you will be required to required to compete practical compete practical exercises.exercises.See practical See practical assessment assessment checklist checklist

Presenter

Presentation Notes

Note the practical checklist is a public domain document and should be made available to all candidates


Section 9 SafetySection 9 Safety


Section 9 SafetySection 9 SafetyThe dangers in amateur radio include:The dangers in amateur radio include:•• High voltagesHigh voltages•• High currentsHigh currents•• Electromagnetic fieldsElectromagnetic fields•• High sound levelsHigh sound levels•• Working at heightsWorking at heights•• Working with chemicalsWorking with chemicalsThe Foundation licence does not permit The Foundation licence does not permit modification to your transmitting modification to your transmitting equipment.equipment.Foundation licence transmitting equipment Foundation licence transmitting equipment must be commercially manufactured.must be commercially manufactured.


Section 9 SafetySection 9 SafetyElectrical safetyElectrical safety•• 12mA of current can 12mA of current can

killkill•• 240v mains can 240v mains can

provide the voltage provide the voltage and current to and current to electrocute a personelectrocute a person

•• Vacuum tube Vacuum tube equipment will have equipment will have high voltages high voltages presentpresent

Presenter

Presentation Notes

Valve equipment has high voltages.



Always treat the circuit as if it is liveAlways treat the circuit as if it is liveNever remove the covers from any Never remove the covers from any equipmentequipmentBeware of old equipment, it may not be up Beware of old equipment, it may not be up to current safety standardsto current safety standardsLook up and live when installing antennasLook up and live when installing antennasNever remove an earth from a piece of Never remove an earth from a piece of equipmentequipmentAlways replace fuses with exactly the Always replace fuses with exactly the same type and rating of fusesame type and rating of fuse


Section 9 SafetySection 9 SafetyProtective EarthProtective Earth•• The Australian 240 volt mains system has The Australian 240 volt mains system has

an earth (ground) to protect against an earth (ground) to protect against electric shock, short circuits and faults.electric shock, short circuits and faults.

•• The earth wire is usually green/yellow or The earth wire is usually green/yellow or green in some older installations.green in some older installations.

•• The protective earth shall never be The protective earth shall never be removed other than by a qualified removed other than by a qualified electricianelectrician



Power supplies have a protective Power supplies have a protective earth via a standard 3 pin plugearth via a standard 3 pin plugSome power supplies such as plug Some power supplies such as plug packs are double insulated and the packs are double insulated and the earth pin is not connectedearth pin is not connectedNever connect earths to gas pipesNever connect earths to gas pipes



Switch OffSwitch OffOrOr

RemoveRemoveFrom From TheThe

PowerPower



Electric ShockElectric ShockCheck for danger Check for danger –– hazards, risks, safetyhazards, risks, safetyResponsive Responsive –– if not call 000if not call 000Open Airway Open Airway –– look for signs of lifelook for signs of lifeGive 2 initial breathsGive 2 initial breathsGive 30 chest compressions then 2 Give 30 chest compressions then 2 breathsbreathsDefibrillate as soon as possibleDefibrillate as soon as possibleContinue CPR until qualified person arrives Continue CPR until qualified person arrives or life signs returnor life signs return

Australian Resuscitation CouncilAustralian Resuscitation Council



FusesFuses•• Fuses are to protect from high Fuses are to protect from high

currentscurrents•• Fuses have a predetermined current Fuses have a predetermined current

melt and open the circuitmelt and open the circuit•• High currents can burnHigh currents can burn•• Replace fuses with same type and Replace fuses with same type and

current ratingcurrent rating


Section 9 SafetySection 9 SafetyEarth leakage breakers are sensitive to Earth leakage breakers are sensitive to fault conditions and will tripfault conditions and will tripMost often installed in switchboardsMost often installed in switchboardsApproved mains operated appliances in Approved mains operated appliances in Australia will have a manufacturers labelAustralia will have a manufacturers labelAll states have regulations for All states have regulations for maintenance of mains operated equipment maintenance of mains operated equipment and the requirements in relation to the and the requirements in relation to the qualifications of those who can work on qualifications of those who can work on such equipment. such equipment.



BatteriesBatteries•• Some batteries have toxic or corrosive Some batteries have toxic or corrosive

chemicals or produce gaseschemicals or produce gases•• Never short circuit a batteryNever short circuit a battery•• Never dispose of a battery in a fireNever dispose of a battery in a fire•• Use protective fuses with batteriesUse protective fuses with batteries•• Children should not play with batteriesChildren should not play with batteries



Radiation SafetyRadiation SafetyElectromagnetic radiation may be Electromagnetic radiation may be harmful if concentrated into a narrow harmful if concentrated into a narrow beam of very high powerbeam of very high powerElectromagnetic radiation may burn Electromagnetic radiation may burn or heat parts of the human body or or heat parts of the human body or organsorgansKeep distance between you and Keep distance between you and electromagnetic radiationelectromagnetic radiation



Other safety issues:Other safety issues:Slips trips and fallsSlips trips and fallsLightningLightningHeadphones and loud tonesHeadphones and loud tonesVoltages and currents on antennasVoltages and currents on antennasRF earthingRF earthing



Fuses are placed in circuits to protect Fuses are placed in circuits to protect against:against:

A. High currentsA. High currentsB. High voltageB. High voltageC. High resistanceC. High resistanceD. High frequencyD. High frequency

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Answer is A



Batteries should be disposed of correctly Batteries should be disposed of correctly because of the environmental issues the because of the environmental issues the chemicals in them can cause. Batteries chemicals in them can cause. Batteries can also:can also:A. Produce electromagnetic radiationA. Produce electromagnetic radiationB. Go flat very quickly if unusedB. Go flat very quickly if unusedC. Make loud noisesC. Make loud noisesD. Explode or emit fumes if puncturedD. Explode or emit fumes if punctured

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Answer D


Section 9 SafetySection 9 SafetyProtective mains earths:Protective mains earths:

A. Should be removed during fault A. Should be removed during fault findingfinding

B. Are not necessary in amateur B. Are not necessary in amateur radio radio stationsstations

C. Can only be removed or replaced by C. Can only be removed or replaced by qualified personsqualified persons

D. Are always represented by a purple D. Are always represented by a purple wirewire

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Answer is C


IRLPIRLP

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Mention echolink Cover DTMF


Continuous Tone Coded Squelch Continuous Tone Coded Squelch System (CTCSS)System (CTCSS)

This system is designed to reduce This system is designed to reduce annoying signals and will assist in masking annoying signals and will assist in masking coco--channel interferencechannel interferenceA tone is transmitted each time the press A tone is transmitted each time the press to talk button is pressed that is detected to talk button is pressed that is detected in the receiver and allows the mute (or in the receiver and allows the mute (or squelch) to open.squelch) to open.The transmitted tone is in the 67 to 257Hz The transmitted tone is in the 67 to 257Hz range and often referred to as a subrange and often referred to as a sub--audible toneaudible tone


Duel Tone Multiple Frequency Duel Tone Multiple Frequency (DTMF)(DTMF)

DTMF is used for telephone signaling over DTMF is used for telephone signaling over a medium such as a telephone line or a medium such as a telephone line or radio linkradio linkDTMF is the signal produced by your DTMF is the signal produced by your mobile phone keypadmobile phone keypadTwo voice frequency tones of different Two voice frequency tones of different frequencies are transmitted frequencies are transmitted simultaneouslysimultaneouslyOften used to switch on or off and control Often used to switch on or off and control remote equipment.remote equipment.


Repeater OperationRepeater Operation

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Cover CTCSS

Foundation Licence Theory - hamradio.org.au Licence Theory Lecture Part...Foundation Licence Licence Training Part 2 ... output power remains constant independent of voice level. ...

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