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Amateur Radio Question PoolsNew! View the differences between the 2008 Extra question pool and the previous pool. General Class Question PoolPrev 1 2 3 4 5 6 7 8 9 0 NextG4A01 Which of the following is one use for a DSP in an amateur station? To provide adequate grounding To remove noise from received signals To increase antenna gain To increase antenna bandwidth G4A02 Which of the following instruments may be used to measure the output of a single- sideband transmitter when performing a two-tone test of amplitude linearity? An audio distortion analyzer An oscilloscope A directional wattmeter A high impedance audio voltmeter G4A03 Which of the following is needed for a DSP IF filter? An Analog to Digital Converter Digital to Analog Converter A Digital Processor Chip All of the these answers are correct G4A04 Which of the following is an advantage of a receiver IF filter created with a DSP as compared to an analog filter? A wide range of filter bandwidths and shapes can be created Fewer digital components are required Mixing products are greatly reduced The DSP filter is much more effective at VHF frequencies G4A05 How is DSP filtering accomplished? By using direct signal phasing By converting the signal from analog to digital and using digital processing By up-converting the signal to VHF By converting the signal from digital to analog and taking the difference of mixing products G4A06 What reading on the plate current meter of a vacuum tube RF power amplifier indicates correct adjustment of the plate tuning control? A pronounced peak A pronounced dip No change will be observed A slow, rhythmic oscillation G4A07 What is the correct adjustment for the "Load" or "Coupling" control of a vacuum tube RF power amplifier? Minimum SWR on the antenna Minimum plate current without exceeding maximum allowable grid current Highest plate voltage while minimizing grid current Maximum power output without exceeding maximum allowable plate current G4A08 Which of the following techniques is used to neutralize an RF amplifier? Feed-forward compensation Feed-forward cancellation Negative feedback Positive feedback G4A09 What does a neutralizing circuit do in an RF amplifier? It controls differential gain It cancels the effects of positive feedback It eliminates AC hum from the power supply It reduces incidental grid modulation G4A10 What is the reason for neutralizing the final amplifier stage of a transmitter? To limit the modulation index To eliminate self oscillations To cut off the final amplifier during standby periods To keep the carrier on frequency G4A11 What type of transmitter performance does a two-tone test analyze? Linearity Carrier and undesired sideband suppression Percentage of frequency modulation Percentage of carrier phase shift G4A12 What type of signals are used to conduct a two-tone test? Two audio signals of the same frequency shifted 90-degrees Two non-harmonically related audio signals Two swept frequency tones Two audio frequency range square wave signals of equal amplitude G4A13 Which of the following performs automatic notching of interfering carriers? Band pass tuning A DSP filter Balanced mixing A noise limiter G4B01 What item of test equipment contains horizontal and vertical channel amplifiers? An ohmmeter A signal generator An ammeter An oscilloscope G4B02 Which of the following is an advantage of an oscilloscope versus a digital voltmeter? An oscilloscope uses less power Complex impedances can be easily measured Input impedance is much lower Complex waveforms can be measured G4B03 How would a signal tracer normally be used? To identify the source of radio transmissions To make exact drawings of signal waveforms To show standing wave patterns on open-wire feed-lines To identify an inoperative stage in a receiver G4B04 How is a noise bridge normally used? It is connected at an antenna's feed point and reads the antenna's noise figure It is connected between a transmitter and an antenna and tuned for minimum SWR It is connected between a receiver and an antenna of unknown impedance and is adjusted for minimum noise It is connected between an antenna and ground and tuned for minimum SWR G4B05 Which of the following is the best instrument to use to check the keying waveform of a CW transmitter? A monitoring oscilloscope A field-strength meter A sidetone monitor A wavemeter G4B06 What signal source is connected to the vertical input of a monitoring oscilloscope when checking the quality of a transmitted signal? The local oscillator of the transmitter The audio input of the transmitter The transmitter balanced mixer output The attenuated RF output of the transmitter G4B07 What is an advantage of a digital voltmeter as compared to an analog voltmeter? Better for measuring computer circuits Better for RF measurements Significantly better precision for most uses Faster response G4B08 What instrument may be used to monitor relative RF output when making antenna and transmitter adjustments? A field-strength meter An antenna noise bridge A multimeter A Q meter G4B09 How much must the power output of a transmitter be raised to change the "S" meter reading on a distant receiver from S8 to S9? Approximately 2 times Approximately 3 times Approximately 4 times Approximately 5 times G4B10 Which of the following can be determined with a field strength meter? The radiation resistance of an antenna The radiation pattern of an antenna The presence and amount of phase distortion of a transmitter The presence and amount of amplitude distortion of a transmitter G4B11 Which of the following might be a use for a field strength meter? Close-in radio direction-finding A modulation monitor for a frequency or phase modulation transmitter An overmodulation indicator for a SSB transmitter A keying indicator for a RTTY or packet transmitter G4B12 What is one way a noise bridge might be used? Determining an antenna's gain in dBi Pre-tuning an antenna tuner Pre-tuning a linear amplifier Determining the line loss of the antenna system G4B13 What is one measurement that can be made with a dip meter? The resonant frequency of a circuit The tilt of the ionosphere The gain of an antenna The notch depth of a filter G4B14 Which of the following must be connected to an antenna analyzer when it is being used for SWR measurements? Receiver Transmitter Antenna and feedline All of these answers are correct G4B15 Which of the following can be measured with a directional wattmeter? Standing Wave Ratio Antenna front-to-back ratio RF interference Radio wave propagation G4B16 Why is high input impedance desirable for a voltmeter? It improves the frequency response It decreases battery consumption in the meter It improves the resolution of the readings It decreases the loading on circuits being measured G4C01 Which of the following might be useful in reducing RF interference to audio-frequency devices? Bypass inductor Bypass capacitor Forward-biased diode Reverse-biased diode G4C02 Which of the following should be installed if a properly operating amateur station is interfering with a nearby telephone? An RFI filter on the transmitter An RFI filter at the affected telephone A high pass filter on the transmitter A high pass filter at the affected telephone G4C03 What sound is heard from a public-address system if there is interference from a nearby single-sideband phone transmitter? A steady hum whenever the transmitter is on the air On-and-off humming or clicking Distorted speech Clearly audible speech G4C04 What is the effect on a public-address system if there is interference from nearby CW transmitter? On-and-off humming or clicking A CW signal at a nearly pure audio frequency A chirpy CW signal Severely distorted audio G4C05 What might be the problem if you receive an RF burn when touching your equipment while transmitting on a HF band, assuming the equipment is connected to a ground rod? Flat braid rather than round wire has been used for the ground wire Insulated wire has been used for the ground wire The ground rod is resonant The ground wire is resonant G4C06 Which of the following is an important reason to have a good station ground? To reduce the likelihood of RF burns To reduce the likelihood of electrical shock To reduce interference All of these answers are correct G4C07 What is one good way to avoid stray RF energy in an amateur station? Keep the station's ground wire as short as possible Install an RF filter in series with the ground wire Use a ground loop for best conductivity Install a few ferrite beads on the ground wire where it connects to your station G4C08 Which of the following is a reason to place ferrite beads around audio cables to reduce common mode RF interference? They act as a series inductor They act as a shunt capacitor They lower the impedance of the cable They increase the admittance of the cable G4C09 Which of the following statements about station grounding is true? The chassis of each piece of station equipment should be tied together with high-impedance conductors If the chassis of all station equipment is connected with a good conductor, there is no need to tie them to an earth ground RF hot spots can occur in a station located above the ground floor if the equipment is grounded by a long ground wire A ground loop is an effective way to ground station equipment G4C10 Which of the following is covered in the National Electrical Code? Acceptable bandwidth limits Acceptable modulation limits Electrical safety inside the ham shack RF exposure limits of the human body G4C11 Which of the following can cause unintended rectification of RF signal energy and can result in interference to your station as well as nearby radio and TV receivers? Induced currents in conductors that are in poor electrical contact Induced voltages in conductors that are in good electrical contact Capacitive coupling of the RF signal to ground Excessive standing wave ratio (SWR) of the transmission line system G4C12 What is one cause of broadband radio frequency interference at an amateur radio station? Not using a balun or line isolator to feed balanced antennas Lack of rectification of the transmitter's signal in power conductors Arcing at a poor electrical connection The use of horizontal, rather than vertical antennas G4C13 How can a ground loop be avoided? Series connect all ground conductors Connect the AC neutral conductor to the ground wire Avoid using lock washers and star washers in making ground connections Connect all ground conductors to a single point G4D01 What is the reason for using a properly adjusted speech processor with a single sideband phone transmitter? It reduces average transmitter power requirements It reduces unwanted noise pickup from the microphone It improves voice-frequency fidelity It improves signal intelligibility at the receiver G4D02 Which of the following describes how a speech processor affects a transmitted single sideband signal? It increases the peak power It increases the average power It reduces harmonic distortion It reduces intermodulation distortion G4D03 Which of the following can be the result of an incorrectly adjusted speech processor? Distorted speech Splatter Excessive background pickup All of these answers are correct G4D04 What does an S-meter measure? Conductance Impedance Received signal strength Transmitter power output G4D05 How does an S-meter reading of 20 db over S-9 compare to an S-9 signal, assuming a properly calibrated S meter? It is 10 times weaker It is 20 times weaker It is 20 times stronger It is 100 times stronger G4D06 Where is an S-meter generally found? In a receiver In a SWR bridge In a transmitter In a conductance bridge G4D07 Which of the following describes a Type-N connector? A moisture resistant RF connector useful to 10 GHz A small bayonet connector used for data circuits A threaded connector used for hydraulic systems An audio connector used in surround sound installations G4D08 Which of the following connectors would be a good choice for a serial data port? PL-259 Type N Type SMA DB-9 G4D09 Which of these connector types is commonly used for RF service at frequencies up to 150 MHz? Octal RJ-11 UHF DB-25 G4D10 Which of these connector types is commonly used for audio signals in amateur radio stations? PL-259 BNC RCA Phono Type N G4D11 What is the main reason to use keyed connectors over non-keyed types? Prevention of use by unauthorized persons Reduced chance of damage due to incorrect mating Higher current carrying capacity All of these choices are correct G4E01 Which of the following emission types are permissible while operating HF mobile? CW SSB FM All of these choices are correct G4E02 What is alternator whine? A DC emission from the alternator A constant pitched tone or buzz in transmitted or received audio that occurs whenever the ignition key is in the on position A tone or buzz in transmitted or received audio that varies with engine speed A mechanical sound from the alternator indicating current overload G4E03 Which of the following power connections would be the best for a 100-watt HF mobile installation? A direct, fused connection to the battery using heavy gauge wire A direct, fused connection to the alternator or generator using heavy gauge wire A direct, fused connection to the battery using resistor wire A direct, fused connection to the alternator or generator using resistor wire G4E04 Why is it best NOT to draw the DC power for a 100-watt HF transceiver from an automobile's cigarette lighter socket? The socket is not wired with an RF-shielded power cable The socket's wiring may be inadequate for the current being drawn by the transceiver The DC polarity of the socket is reversed from the polarity of modern HF transceivers The power from the socket is never adequately filtered for HF transceiver operation G4E05 Which of the following most limits the effectiveness of an HF mobile transceiver operating in the 75 meter band? "Picket Fencing" signal variation The wire gauge of the DC power line to the transceiver The HF mobile antenna system FCC rules limiting mobile output power on the 75 meter band G4E06 Which of the following is true of an emergency generator installation? The generator should be located in a well ventilated area The generator should be insulated from ground Fuel should be stored near the generator for rapid refueling in case of an emergency All of these choices are correct G4E07 When might a lead-acid storage battery give off explosive hydrogen gas? When stored for long periods of time When being discharged When being charged When not placed on a level surface G4E08 What is the name of the process by which sunlight is changed directly into electricity? Photovoltaic conversion Photon emission Photosynthesis Photon decomposition G4E09 What is the approximate open-circuit voltage from a modern, well illuminated photovoltaic cell? 0.02 VDC 0.5 VDC 0.2 VDC 1.38 VDC G4E10 Which of these materials is used as the active element of a solar cell? Doped Silicon Nickel Hydride Doped Platinum Aluminum nitride G4E11 Which of the following is a disadvantage to using wind power as the primary source of power for an emergency station? The conversion efficiency from mechanical energy to electrical energy is less that 2 percent The voltage and current ratings of such systems are not compatible with amateur equipment A large energy storage system is needed to supply power when the wind is not blowing All of these choices are correct G4E12 Which of the following is a primary reason for not placing a gasoline-fueled generator inside an occupied area? Danger of carbon monoxide poisoning Danger of engine over torque Lack of oxygen for adequate combustion Lack of nitrogen for adequate combustion G4E13 Why would it be unwise to power your station by back feeding the output of a gasoline generator into your house wiring by connecting the generator through an AC wall outlet? It might present a hazard for electric company workers It is prone to RF interference It may disconnect your RF ground None of the above; this is an excellent expedient |
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