t6_&_qa
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Amateur Radio Technician ClassElement 2
ELEMENT 2 SUB-ELEMENTS
• T1 - FCC Rules, station license responsibilities• T2 - Control operator duties• T3 - Operating practices• T4 - Radio and electronic fundamentals• T5 - Station setup and operation• T6 - Communications modes and methods• T7 - Special operations• T8 - Emergency and Public Service Communications• T9 - Radio waves, propagation, and antennas• T0 - Electrical and RF Safety
Communications modes and methods T6A
Modulation modes, descriptions and bandwidth (AM, FM, SSB)
An amateur radio station used to connect other amateur radio stations to the internet is called a gateway.
Repeater
Internet
Repeater
GatewayGateway
PC User
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Communications modes and methods T6A
Modulation modes, descriptions and bandwidth (AM,
FM, SSB) (cont)
•Phone transmissions are voice transmissions by radio.
•Single sideband (SSB) is a form of amplitude modulation.
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Amplitude Modulation
An unmodulated RFAn unmodulated RFcarrier requires narrowcarrier requires narrowBandwidthBandwidth
Modulation of the carrierModulation of the carriercreates sidebands. Thiscreates sidebands. Thisrequires more bandwidth.requires more bandwidth.Transmitter power is Transmitter power is spread across this spread across this bandwidthbandwidth
(on and off is (on and off is CW)CW)
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AM and SSB
The carrier contains noThe carrier contains noaudio information.audio information.
The sidebands containThe sidebands containduplicate audio duplicate audio informationinformation
By filtering out the carrier and one sideband, we By filtering out the carrier and one sideband, we save spectrum and concentrate our RF energy save spectrum and concentrate our RF energy into a narrower bandwidth. SSB is therefore into a narrower bandwidth. SSB is therefore more efficient.more efficient.
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Communications modes and methods T6A
Modulation modes, descriptions and bandwidth (AM, FM, SSB) (cont)
• Upper sideband is normally used for VHF and UHF SSB communications.
• The primary advantage of single sideband over FM for voice transmissions is that SSB signals use much less bandwidth than FM signals.
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Communications modes and methods T6A
Modulation modes, descriptions and bandwidth (AM, FM, SSB) (cont)
•Single sideband (SSB) voice modulation is most often used for long distance and weak signal contacts on the VHF and UHF bands.
•Frequency Modulation (FM) is most commonly used for VHF and UHF voice repeaters.
•The emission type, CW, has the narrowest bandwidth
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Communications modes and methods T6A
Modulation modes, descriptions and bandwidth (AM, FM,
SSB) (cont)
• The approximate bandwidth of a single-sideband voice signal is between 2 and 3 kHz.
• The approximate bandwidth of a frequency-modulated voice signal is between 5 and 15 kHz.
• The normal bandwidth required for a conventional fast-scan TV transmission using combined video and audio on the 70-centimeter band is about 6 MHz.
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Communications modes and methods T6B
Voice communications, EchoLink and IRLP
• Information is transmitted between stations via the Internet using Echolink.
• EchoLink allows computer-to-radio linking for voice transmission.
• Any licensed amateur radio operator may operate on the Echolink system.
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Communications modes and methods T6B
Voice communications, EchoLink and IRLP (cont)
• If you hear a brief tone and then a station from Russia calling CQ on a 2-meter repeater you are listening to an Internet linked DX station.
• Voice over Internet Protocol is the method used to transfer data by IRLP.
• IRLP is a method of linking between two or more amateur stations using the Internet.
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Communications modes and methods T6B
Voice communications, EchoLink and IRLP (cont)
• You might find a list of active nodes using VoIP in a repeater directory or the Internet.
• When using a portable transceiver you select a specific IRLP node by using the keypad to transmit the IRLP node numbers.
• Echolink and IRLP have in common: Voice over Internet Protocol technology.
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Communications modes and methods T6C
• Packet Radio is an example of a digital communications method.
• Point-to-point digital message forwarding emission mode may be used by a Technician class operator in the 219 - 220 MHz frequency range.
• Phase Shift Keying (PSK)• PSK31 is a low-rate data
transmission mode that works well in noisy conditions.
Non-voice communications - image communications, data, CW, packet, PSK31, Morse code techniques, Q signals
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Communications modes and methods T6C
Non-voice communications - image communications, data, CW, packet, PSK31, Morse code techniques, Q signals (cont)
• Automatic Position Reporting System (APRS)
• A global positioning system receiver is required along with your normal radio for sending automatic location reports.
• A standard fast scan color television signal transmission is indicated by the term NTSC.
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Communications modes and methods T6C
Non-voice communications - image communications, data, CW, packet, PSK31, Morse code techniques, Q signals (cont)
• Any sending speed at which you can reliably receive is recommended when using Morse code.
• A practical reason for being able to copy CW when using repeaters is to recognize a repeater ID sent in Morse code.
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Communications modes and methods T6C
Non-voice communications - image communications, data, CW, packet, PSK31, Morse code techniques, Q signals (cont)
• QRM is the "Q" signal used to indicate that you are receiving interference from other stations.
• QSY is the "Q" signal used to indicate that you are changing frequency.
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Q-SignalsQ-Signals
Something is causing interference I am troubled by static/noise.I am troubled by static/noise.I am running low power.I am running low power.I am going off the air.I am going off the air.Who is calling me?Who is calling me?Your signal is fading.Your signal is fading.I received the message.I received the message.I will communicate with ________ I will communicate with ________
directly.directly.I am changing frequency to _____.I am changing frequency to _____.My location is _______.My location is _______.
QRMQRN
QRP
QRZ
QSBQSL
QSO
QSYQTH
QRT
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Take Aways
• Connect radio stations to the Internet…Gateway
• Phone is voice transmission
• SSB a form of AM
• USB normally used for VHF & UHF SSB
• SSB advantage over FM…less bandwidth
• SSB used for long distance and weak signal contacts on VHF/UHF
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Take Aways (cont)
• FM most common on VHF/UHF repeaters
• CW has narrowest bandwidth
• Bandwidth of SSB… 2-3 kHz
• Bandwidth of FM…5-15 kHz
• Bandwidth of Fast-scan TV on 70-centimeter … 6 mHz
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Take Aways (cont)
• Echolink uses the Internet
• Echolink allows computer-to-radio linking for voice
• Any licensed amateur can use Echolink
• Echolink & IRLP have VoIP in common
• Hear a tone and CQ on 2-meter repeater… Internet linked DX station
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Take Aways (cont)
• VoIP method for data transfer by IRLP
• IRLP links two or more stations using the Internet
• Active nodes using VoIP listed in repeater directory or on Internet
• Select IRLP node with keypad
• Standard fast color TV…NTSC
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Take Aways (cont)
• Packet Radio is digital communications
• 219-220 mHz for Point-to-point digital message forwarding
• PSK … Phase Shift Keying
• PSK31 low-rate data mode that works well in noisy conditions
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Take Aways (cont)
• APRS … Automatic Position Reporting System
• A GPS receiver needed for APRS
• Send at speed you can reliably receive
• Copy CW to recognize ID sent in Morse code
• QRM … receiving interference
• QSY … Change frequency
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T6A01 What are phone transmissions?
A. The use of telephones to set up an amateur radio contact
B. A phone patch between amateur radio and the telephone system
C. Voice transmissions by radioD. Placing the telephone handset near a
radio transceiver's microphone and speaker to relay a telephone call
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T6A02 Which of the following is a form of amplitude modulation?
A. Frequency modulationB. Phase modulationC. Single sidebandD. Phase shift keying
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T6A03 What name is given to an amateur radio station that is used to connect other amateur stations to the Internet?
A. A gatewayB. A repeaterC. A digipeaterD. A beacon station
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T6A04 Which type of voice modulation is most often used for long distance and weak
signal contacts on the VHF and UHF bands?
A. FMB. AMC. SSBD. PM
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T6A05 Which type of modulation is most commonly used for VHF and UHF
voice repeaters?
A. AMB. SSBC. PSKD. FM
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T6A06 Which emission type has the narrowest bandwidth?
A. FM voiceB. SSB voiceC. CWD. Slow-scan TV
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T6A07 Which sideband is normally used for VHF and UHF SSB communications?
A. Upper sidebandB. Lower sidebandC. Suppressed sideband D. Inverted sideband
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T6A08 What is the primary advantage of single sideband over FM for voice transmissions?
A. SSB signals are easier to tune in than FM signals
B. SSB signals are less likely to be bothered by noise interference than FM signals.
C. SSB signals use much less bandwidth than FM signals
D. SSB signals have no advantages at all in comparison to other modes.
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T6A09 What is the approximate bandwidth of a single-sideband voice signal?
A. 1 kHzB. 2 kHzC. Between 3 and 6 kHzD. Between 2 and 3 kHz
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T6A10 What is the approximate bandwidth of a frequency-modulated voice signal?
A. Less than 500 Hz B. About 150 kHzC. Between 5 and 15 kHzD. More than 30 kHz
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T6A11 What is the normal bandwidth required for a conventional fast-scan TV transmission using
combined video and audio on the 70-centimeter band?
A. More than 10 MHzB. About 6 MHzC. About 3 MHzD. About 1 MHz
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T6B01 How is information transmitted between stations using Echolink?
A. APRSB. PSK31C. InternetD. Atmospheric ducting
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T6B02 What does the abbreviation IRLP mean?
A. Internet Radio Linking Project B. Internet Relay Language ProtocolC. International Repeater Linking ProjectD. International Radio Linking Project
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T6B03 Who may operate on the Echolink system?
A. Only club stationsB. Any licensed amateur radio operatorC. Technician class licensed amateur
radio operators onlyD. Any person, licensed or not, who is
registered with the Echolink system
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T6B04 What technology do Echolink and IRLP have in common?
A. Voice over Internet protocolB. Ionospheric propagationC. AC power linesD. PSK31
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T6B05 What method is used to transfer data by IRLP?
A. VHF Packet radioB. PSK31C. Voice over Internet protocol D. None of these answers are correct
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T6B06 What does the term IRLP describe?
A. A method of encrypting dataB. A method of linking between two or
more amateur stations using the Internet
C. A low powered radio using infra-red frequencies
D. An international logging program.
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T6B07 Which one of the following allows computer-to-radio linking for voice transmission?
A. Grid modulationB. EchoLinkC. AMTORD. Multiplex
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T6B08 What are you listening to if you hear a brief tone and then a station from Russia calling CQ on a 2-meter repeater?
A. An ionospheric band opening on VHFB. A prohibited transmissionC. An Internet linked DX stationD. None of these answers are correct
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T6B10 Where might you find a list of active nodes using VoIP?
A. The FCC RulebookB. From your local emergency
coordinatorC. A repeater directory or the Internet D. The local repeater frequency
coordinator
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T6B11 When using a portable transceiver how do you select a specific IRLP node?
A. Choose a specific CTCSS toneB. Choose the correct DSC toneC. Access the repeater autopatchD. Use the keypad to transmit the
IRLP node numbers
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T6C01 Which of the following is an example
of a digital communications method?
A. Single sideband voiceB. Amateur televisionC. FM voiceD. Packet radio
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T6C02 What does the term APRS mean?
A. Automatic Position Reporting SystemB. Associated Public Radio StationC. Auto Planning Radio Set-upD. Advanced Polar Radio System
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T6C03 What item is required along with your normal radio for sending automatic location reports?
A. A connection to the vehicle speedometer
B. A connection to a WWV receiverC. A connection to a broadcast FM sub-
carrier receiverD. A global positioning system receiver
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T6C04 What type of transmission is indicated by the term NTSC?
A. A Normal Transmission mode in Static Circuit
B. A special mode for earth satellite uplink
C. A standard fast scan color television signal
D. A frame compression scheme for TV signal
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T6C05 What emission mode may be used by a Technician class operator in the 219 - 220 MHz frequency range?
A. Slow-scan televisionB. Point-to-point digital message
forwardingC. FM voiceD. Fast-scan television
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T6C06 What does the abbreviation PSK mean?
A. Pulse Shift KeyingB. Phase Shift KeyingC. Packet Short KeyingD. Phased Slide Keying
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T6C07 What is PSK31?
A. A high-rate data transmission mode used to transmit files
B. A method of reducing noise interference to FM signals
C. A type of television signalD. A low-rate data transmission
mode that works well in noisy conditions
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T6C08 What sending speed is recommended when using Morse code?
A. Only speeds below five WPMB. The highest speed your keyer will
operateC. Any speed at which you can reliably
receiveD. The highest speed at which you can
control the keyer
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T6C09 What is a practical reason for being able to copy CW when using repeaters?
A. To send and receive messages others cannot overhear
B. To conform with FCC licensing requirements
C. To decode packet radio transmissionsD. To recognize a repeater ID sent in
Morse code
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T6C10 What is the "Q" signal used to indicate that you are receiving interference from other stations?
A. QRMB. QRNC. QTHD. QSB
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T6C11 What is the "Q" signal used to indicate that you are changing frequency?
A. QRUB. QSYC. QSLD. QRZ
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