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Technician Licensing Class. Station equipment, common transmitter and receiver problems, antenna measurements and troubleshooting, basic repair and testing T7A - T7D. Valid July 1, 2014 Through June 30, 2018. 1. Developed by Bob Bytheway, K3DIO, and slightly modified by SPARC. T 7 A.
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Technician Licensing Class Station equipment, common transmitter and receiver problems,antenna measurements and troubleshooting, basic repair and testing T7A - T7D Valid July 1, 2014 Through June 30, 2018 1 Developed by Bob Bytheway, K3DIO, and slightly modified by SPARC
T 7 A Sensitivity is the term that describes the ability of a receiver to detect the presence of a signal.T7A01 2
T 7 A A transceiver is a unit combining the functions of a transmitter and receiver. T7A02 3
T 7 A A mixer is used to convert a radio signal from one frequency to another. T7A03 Station Signal Signal C at 455 kHz Signal A at 800 kHz (or at 1200 kHz) Intermediate Frequency Local Oscillator Signal B at 1255 kHz (or at 1655 kHz) 4
T 7 A The term that describes the ability of a receiver to discriminate between multiple signals is called selectivity. T7A04 5
T 7 A The name of a circuit that generates a signal of a desired frequency is called an oscillator. T7A05 A transverter takes the output of a low-powered 28 MHz SSB exciter and produces a 222 MHz output signal. T7A06 The push to talk function which switches between receive and transmit. It’s also called PTT.T7A07 6
T 7 A Modulation describes combining speech with an RF carrier signal. T7A08 Amplitude-modulated signal 7
T 7 A A multi-mode VHF transceiver is most useful for VHF weak-signal communications. T7A09 8
T 7 A An RF power amplifier will increase the low-power output from a handheld transceiver. T7A10 The RF preamplifier is installed between the antenna and the receiver. T7A11 9
T 7 B Talk farther away from the microphone if you are told your FM handheld or mobile transceiver is over-deviating. T7B01 If a broadcast AM or FM radio receives an amateur radio transmission unintentionally, the receiver is unable to reject strong signals from outside the AM or FM band. T7B02 Causes of radio frequency interference: Fundamental overload; Harmonics; Spurious emissions; All of these choices are correct.T7B03 10
T 7 B To reduce or eliminate interference by an amateur transmitter to a nearby telephone, put a RF filter on the telephone. T7B04 Overload of a non-amateur radio or TV receiver by an amateur signal can be reduced or eliminated by blocking the amateur signal with a filter at the antenna input of the affected receiver. T7B05 11
T 7 B If a neighbor tells you that your station’s transmissions are interfering with their TV reception, make sure that your station is functioning properly and that it does not cause interference to your own radio or television when it is tuned to the same channel. T7B06 Useful actions in correcting a radio frequency interference problem: Snap-on ferrite chokes; Low-pass and high-pass filters; Band-reject and band-pass filters; All of these choices are correct.T7B07 12
T 7 B If something in a neighbor’s home is causing harmful interference to your amateur station: Work with your neighbor to identify the offending device; Politely inform your neighbor about the rules that prohibit the use of devices which cause interference; Check your station and make sure it meets the standards of good amateur practice; All these choices are correct. T7B08 13
T 7 B A Part 15 device is an unlicensed device that may emit low powered radio signals on frequencies used by a licensed service. T7B09 Possible problems if you receive a report that your audio signal through the repeater is distorted or unintelligible. Your transmitter may be slightly off frequency; Your batteries may be running low; You could be in a bad location; All of these choices are correct.T7B10 14
T 7 B Reports of garbled, distorted, or unintelligible transmissions are symptoms of RF feedback in a transmitter or receiver. T7B11 Be sure all TV coaxial connectors are installed properly as the first step to resolve cable TV interference from your ham radio transmission. T7B12 15
T 7 C The primary purpose of a dummy load is to prevent the radiation of signals when making tests. T7C01 The instrument to use to determine if an antenna is resonant at the desired frequency is an antenna analyzer. T7C02 MFJ-269 SWR Analyzer Comet CAA-500 16
T 7 C In general terms, standing wave ratio (SWR) is a measure of how well a load is matched to a transmission line. T7C03 MFJ-822 Daiwa CN-801H 17
T 7 C The reading of 1 to 1 on an SWR meter indicates a perfect impedance match between the antenna and the feed line. T7C04 Comet CMX-200 SWR Reading Antenna Condition 1:1 Perfectly Matched 1.5:1 Good Match 2:1 Fair Match 3:1 Poor Match 4:1 Something definitely Wrong
T 7 C The approximate SWR value above which the protection circuits in most solid-state transmitters begin to reduce transmitter power is 2 to 1. T7C05 Meter indicating high SWR 19
T 7 C With an SWR reading of 4:1, this indicates an impedance mismatch. T7C06 Some HF rigs have the SWR meter built in. This station show the rig with external SWR meter. Kenwood TS-440SAT & Bird RF Watt meter 20
T 7 C The power lost in a feed line is converted to heat. T7C07 A directional wattmeter is an instrument other than an SWR meter than could be used to determine if a feed line and antenna are properly matched. T7C08 Single needle dual meters 21
T 7 C The most common cause for failure of coaxial cables is moisture contamination. T7C09 The outer jacket of coaxial cable should be resistant to ultraviolet light which can damage the jacket and allow water to enter the cable. T7C10 A disadvantage of air core coaxial cable when compared to foam or solid dielectric types is that it requires special techniques to prevent water absorption. T7C11 Large coax, with hollow center conductor, low loss 22
T 7 C A common use of coaxial cable is for carrying RF signals between a radio and antenna. T7C12 A dummy load consists of a non-inductive resistor and a heat sink.T7C13 23
T 7 D The instrument used to measure electric potential or electromotive force is the voltmeter. T7D01 The correct way to connect a voltmeter to a circuit is in parallel with the circuit. T7D02 An ammeter is usually connected to a circuit in series with the circuit. T7D03 24
T 7 D The instrument used to measure electric current is an ammeter. T7D04 The instrument used to measure resistance is the ohmmeter. T7D05 Measuring voltage when using the resistance setting might damage a multimeter. T7D06 25
T 7 D Voltage and resistance measurements are commonly made using a multimeter. T7D07 Analog Multimeter Digital Multimeter 26 26
D 7 D • Rosin-core solder is the best type of solder for radio and electronic use. T7D08 • A grainy or dull surface is the characteristic appearance of a cold solder joint. T7D09 27
T 7 D When an ohmmeter, connected across an unpowered circuit, initially indicates a low resistance and then shows increasing resistance with time indicates the circuit contains a large capacitor. T7D10 Take precautions when measuring circuit resistance to ensure that the circuit is not powered.T7D11 When measuring high voltages with a voltmeter ensure the voltmeter and leads are rated for use at the voltages being measured. T7D12 28
Element 2 Technician Class Question Pool T 7 A – T 7 D Valid July 1, 2014 Through June 30, 2018
T7A01 Which term describes the ability of a receiver to detect the presence of a signal? Linearity Sensitivity Selectivity Total Harmonic Distortion 30
T7A02What is a transceiver? A type of antenna switch A unit combining the functions of a transmitter and receiver A component in a repeater which filters out unwanted interference A type of antenna matching network 31
T7A03Which of the following is used to convert a radio signal from one frequency to another? Phase splitter Mixer Inverter Amplifier 32
T7A04Which term describes the ability of a receiver to discriminate between multiple signals? Discrimination ratio Sensitivity Selectivity Harmonic Distortion 33
T7A05What is the name of a circuit that generates a signal of a desired frequency? Reactance modulator Product detector Low-pass filter Oscillator 34
T7A06What device takes the output of a low-powered 28 MHz SSB exciter and produces a 222 MHz output signal? High-pass filter Low-pass filter Transverter Phase converter 35
T7A07What is meant by the term “PTT”? Pre-transmission tuning to reduce transmitter harmonic emission Precise tone transmissions used to limit repeater access to only certain signals A primary transformer tuner use to match antennas The push to talk function which switches between receive and transmit 36
T7A08Which of the following describes combining speech with an RF carrier signal? Impedance matching Oscillation Modulation Low-pass filtering 37
T7A09Which of the following devices is most useful for VHF weak-signal communication? A quarter-wave vertical antenna A multi-mode VHF transceiver An omni-directional antenna A mobile VHF FM transceiver 38
T7A10What device increases the low-power output from a handheld transceiver? A voltage divider An RF power amplifier An impedance network All of these choices is correct 39
T7A11Where is an RF preamplifier installed? Between the antenna and the receiver At the output of the transmitter’s power amplifier Between transmitter and antenna tuner At the receiver’s audio output 40
T7B01What can you do if you are told your FM handheld or mobile transceiver is over- deviating? Talk louder into the microphone Let the transceiver cool off Change to a higher power level Talk farther away from the microphone 41
T7B02What would cause a broadcast AM or FM radio to receive an amateur radio transmission unintentionally? The receiver is unable to reject strong signals outside the AM or FM band The microphone gain of the transmitter is turned up too high The audio amplifier of the transmitter is overloaded The deviation of an FM transmitter is set too low 42
T7B03Which of the following may be a cause of radio frequency interference? Fundamental overload Harmonics Spurious emissions All of these choices are correct 43
T7B04Which of the following is a way to reduce or eliminate interference by an amateur transmitter to a nearby telephone? Put a filter on the amateur transmitter Reduce the microphone gain Reduce the SWR on the transmitter transmission line Put an RF filter on the telephone 44
T7B05 How can overload of a non-amateur radio or TV receiver by an amateur signal be reduced or eliminated? Block the amateur signal with a filter at the antenna input of the affected receiver Block the interfering signal with a filter on the amateur transmitter Switch the transmitter from FM to SSB Switch the transmitter to a narrow-band mode 45
T7B06Which of the following actions should you take if a neighbor tells you that your station’s transmissions are interfering with their radio or TV reception? Make sure that your station is functioning properly and that it does not cause interference to your own radio or television when it is tuned to the same channel Immediately turn off your transmitter and contact the nearest FCC office for assistance Tell them that your license gives you the right to transmit and nothing can be done to reduce the interference Install a harmonic doubler on the output of your transmitter and tune it until the interference is eliminated 46
T7B07Which of the following may be useful in correcting a radio frequency interference problem? Snap-on ferrite chokes Low-pass and high-pass filters band-reject and band-pass filters All of these choices are correct 47
T7B08What should you do if something in a neighbor’s home is causing harmful interference to your amateur station? Work with your neighbor to identify the offending device Politely inform your neighbor about the rules that prohibit the use of devices which cause interference Check your station and make sure it meets the standards of good amateur practice All of these choices are correct 48
T7B09What is a Part 15 device? An unlicensed device that may emit low powered radio signals on frequencies used by a licensed service A type of amateur radio that can legally be used in the citizen’s band A device for long distance communications using special codes sanctioned by the International Amateur Radio Union A type of test set used to determine whether a transmitter is in compliance with FCC regulation 91.15 49
T7B10What might be the problem if you receive a report that your audio signal through the repeater is distorted or unintelligible? Your transmitter may be slightly off frequency Your batteries may be running low You could be in a bad location All of these choices are correct 50