/603 Extra Study Mode (2024-2028) Online practice test for the U.S. ham radio extra license exam. 1 / 603 What is the purpose of making a Yagi's parasitic elements either longer or shorter than resonance? Mechanical balance Wind torque cancellation Control of phase shift Minimize losses 2 / 603 Atmospheric ducts capable of propagating microwave signals often form over what geographic feature? Mountain ranges Nimbus clouds Large bodies of water Stratocumulus clouds 3 / 603 How much does increasing a receiver's bandwidth from 50 Hz to 1,000 Hz increase the receiver's noise floor? 5 dB 13 dB 10 dB 3 dB 4 / 603 Which of the following file formats is used for exchanging amateur radio log data? OCF NEC ARLD ADIF 5 / 603 Why should antenna loading coils have a high ratio of reactance to resistance? To swamp out harmonics To maximize efficiency To minimize the Q To lower the radiation angle 6 / 603 What kind of receiver can be used to receive and decode SSTV using the Digital Radio Mondiale (DRM) protocol? AREDN AM SSB CDMA 7 / 603 What can cause the voltage across reactances in a series RLC circuit to be higher than the voltage applied to the entire circuit? Low quality factor (Q) Resonance Capacitance Resistance 8 / 603 How can the output voltage of a multiple-turn receiving loop antenna be increased? All these choices are correct By utilizing high impedance wire for the coupling loop By reducing the permeability of the loop shield By increasing the number of turns and/or the area enclosed by the loop 9 / 603 How can an oscillator's microphonic responses be reduced? Reduce noise on the oscillator's power supply Use NP0 capacitors Increase the gain Mechanically isolate the oscillator circuitry from its enclosure 10 / 603 What voltage gain can be expected from the circuit in Figure E7-3 when R1 is 10 ohms and RF is 470 ohms? 4700 47 24 0.21 11 / 603 How does the modulation index of a phase-modulated emission vary with RF carrier frequency? It does not depend on the RF carrier frequency It varies with the square root of the RF carrier frequency It decreases as the RF carrier frequency increases It increases as the RF carrier frequency increases 12 / 603 Which of the following operating arrangements allows an FCC-licensed US citizen to operate in many European countries, and amateurs from many European countries to operate in the US? All these choices are correct ITU reciprocal license CEPT IARP 13 / 603 What is frequency division multiplexing (FDM)? The transmitted signal is divided into packets of information Dividing the transmitted signal into separate frequency bands that each carry a different data stream Two or more information streams are merged into a digital combiner, which then pulse position modulates the transmitter The transmitted signal jumps from band to band at a predetermined rate 14 / 603 What is the purpose of a step-start circuit in a high-voltage power supply? To compensate for variations of the incoming line voltage To allow the filter capacitors to charge gradually To provide a dual-voltage output for reduced power applications To prevent arcing across the input power switch or relay contacts 15 / 603 What type of radiation pattern is created by a single-turn, terminated loop such as a pennant antenna? Hyperbolic Cardioid Omnidirectional Bidirectional 16 / 603 What do the letters in a satellite's mode designator specify? Power limits for uplink and downlink transmissions The polarization of uplink and downlink signals The location of the ground control station The uplink and downlink frequency ranges 17 / 603 Which S parameter represents input port return loss or reflection coefficient (equivalent to VSWR)? S21 S22 S11 S12 18 / 603 What signals SSTV receiving software to begin a new picture line? Specific tone frequencies Specific tone amplitudes A two-tone signal Elapsed time 19 / 603 Which is generally true for 160- and 80-meter receiving antennas? They must be erected at least 1/2 wavelength above the ground to attain good directivity Atmospheric noise is so high that directivity is much more important than losses All these choices are correct Low loss coax transmission line is essential for good performance 20 / 603 Which of the following test instruments is used to display spurious signals and/or intermodulation distortion products generated by an SSB transmitter? Differential resolver Logic analyzer Spectrum analyzer Network analyzer 21 / 603 Which of the following semiconductor materials contains excess free electrons? Insulated gate N-type P-type Bipolar 22 / 603 What impedance does a 1/4-wavelength transmission line present to an RF generator when the line is open at the far end? The same as the input impedance to the generator Very low impedance The same as the characteristic impedance of the line Very high impedance 23 / 603 What is the maximum bandwidth for a data emission on 60 meters? 1.5 kHz 60 Hz 170 Hz 2.8 kHz 24 / 603 What is the magnitude of the impedance of a parallel RLC circuit at resonance? High compared to the circuit resistance Approximately equal to circuit resistance Approximately equal to inductive reactance Low compared to the circuit resistance 25 / 603 Which method generates an SSB signal using digital signal processing? Signals are combined in quadrature phase relationship A frequency synthesizer removes unwanted sidebands Varying quartz crystal characteristics are emulated in digital form Mixing products are converted to voltages and subtracted by adder circuits 26 / 603 What may be the penalty for a VE who fraudulently administers or certifies an examination? All these choices are correct Revocation of the VE's amateur station license grant and the suspension of the VE's amateur operator license grant A fine of up to $1,000 per occurrence A sentence of up to one year in prison 27 / 603 Which of the following HF digital modes uses variable-length character coding? PSK31 MT63 PACTOR RTTY 28 / 603 What feature of a cardioid pattern antenna makes it useful for direction-finding antennas? High radiation angle Broadband response A single null A very sharp peak 29 / 603 What information replaces signal-to-noise ratio when using the FT8 or FT4 modes in a VHF contest? Serial number RST report Grid square State abbreviation 30 / 603 What is an effect of excessive phase noise in an SDR receiver's master clock oscillator? It limits the receiver's ability to receive strong signals It can combine with strong signals on nearby frequencies to generate interference It decreases the receiver's third-order intercept point It can affect the receiver's frequency calibration 31 / 603 In Figure E6-3, which is the schematic symbol for the NOT operation (inversion)? 5 2 6 4 32 / 603 What is "dither" with respect to analog-to-digital converters? A method of decimation by randomly skipping samples An error caused by irregular quantization step size A small amount of noise added to the input signal to reduce quantization noise An abnormal condition where the converter cannot settle on a value to represent the signal 33 / 603 Which of these materials is most commonly used to create photoconductive devices? Argon Polyphenol acetate Crystalline semiconductor All these choices are correct 34 / 603 What is an effect of increasing Q in a series resonant circuit? Internal voltages increase Parasitic effects are minimized Phase shift can become uncontrolled Fewer components are needed for the same performance 35 / 603 What is the resonant frequency of an RLC circuit if R is 22 ohms, L is 50 microhenries, and C is 40 picofarads? 22.36 MHz 3.56 MHz 44.72 MHz 1.78 MHz 36 / 603 What do the arcs on a Smith chart represent? Points with constant reactance Points with constant resistance Frequency SWR 37 / 603 What challenge is presented by a small wire-loop antenna for direction finding? It is practical for use only on VHF and higher bands All these choices are correct It does not have a clearly defined null It has a bidirectional null pattern 38 / 603 Which of the following digital logic families has the lowest power consumption? ECL NMOS Schottky TTL CMOS 39 / 603 How does the VHF/UHF radio horizon compare to the geographic horizon? It is approximately 15 percent farther They are approximately the same It is approximately 20 percent nearer It is approximately 50 percent farther 40 / 603 What does SAR measure? The rate of RF energy reflected from stationary terrain Signal amplification rating The rate at which RF energy is absorbed by the body Signal attenuation ratio 41 / 603 What is the highest legal carrier frequency on the 20-meter band for transmitting a 2.8 kHz wide USB data signal? 14.0708 MHz 14.1002 MHz 14.3490 MHz 14.1472 MHz 42 / 603 What is the bandwidth of an FT8 signal? 10 Hz 50 Hz 2.4 kHz 600 Hz 43 / 603 What is the benefit of making voltage measurements with a true-RMS calculating meter? RMS is measured for both sinusoidal and non-sinusoidal signals The calculated RMS value can be converted directly into phasor form An inverse Fourier transform can be used The signal's RMS noise factor is also calculated 44 / 603 What absolute voltage gain can be expected from the circuit in Figure E7-3 when R1 is 3,300 ohms and RF is 47 kilohms? 7 14 0.07 28 45 / 603 What is the typical output impedance of an op-amp? 10,000 ohms Very high 100 ohms Very low 46 / 603 What does VOACAP software model? AC voltage and impedance VHF radio propagation HF propagation AC current and impedance 47 / 603 Which of the following is required in order to operate in accordance with CEPT rules in foreign countries where permitted? You must have a copy of FCC Public Notice DA 16-1048 The US embassy must approve of your operation You must identify in the official language of the country in which you are operating You must append "/CEPT" to your call sign 48 / 603 Why are short connections used at microwave frequencies? To increase neutralizing resistance To increase compensating capacitance To reduce noise figure To reduce phase shift along the connection 49 / 603 Why is de-emphasis used in FM communications receivers? For compatibility with transmitters using phase modulation For higher efficiency To reduce impulse noise reception To remove third-order distortion products 50 / 603 Which of the following is the space-weather term for an extreme geomagnetic storm? B9 G5 M9 X5 51 / 603 Which matching system for Yagi antennas requires the driven element to be insulated from the boom? Gamma Shunt-fed Beta or hairpin T-match 52 / 603 Which of the following is required in the identification transmissions from a balloon-borne telemetry station? All these choices are correct The output power of the balloon transmitter The station's six-character Maidenhead grid locator Call sign 53 / 603 What is the most useful characteristic of a Zener diode? A constant current drop under conditions of varying voltage An internal capacitance that varies with the applied voltage A constant voltage drop under conditions of varying current A negative resistance region 54 / 603 Which of the following components can be used to reduce thermal drift in crystal oscillators? Non-inductive resistors Wirewound resistors Toroidal inductors NP0 capacitors 55 / 603 What is an advantage of having a variety of receiver bandwidths from which to select? The noise figure of the RF amplifier can be adjusted to match the modulation type, thus increasing receiver sensitivity Receive bandwidth can be set to match the modulation bandwidth, maximizing signal-to-noise ratio and minimizing interference Multiple frequencies can be received simultaneously if desired Receiver power consumption can be reduced when wider bandwidth is not required 56 / 603 How is an interlaced scanning pattern generated in a fast-scan (NTSC) television system? By scanning lines from left-to-right in one field and right-to-left in the next By scanning odd-numbered lines in one field and even-numbered lines in the next By scanning two fields simultaneously By scanning each field from bottom-to-top 57 / 603 How does a diode envelope detector function? By breakdown of the Zener voltage By sensing the change of reactance in the diode with respect to frequency By mixing signals with noise in the transition region of the diode By rectification and filtering of RF signals 58 / 603 Which of the following is an advantage of using an antenna analyzer compared to an SWR bridge? Antenna analyzers automatically tune your antenna for resonance All these choices are correct Antenna analyzers compute SWR and impedance automatically Antenna analyzers display a time-varying representation of the modulation envelope 59 / 603 Over what range of frequencies are the FCC human body RF exposure limits most restrictive? 30 - 300 MHz 300 - 3000 MHz 3 - 30 MHz 300 kHz - 3 MHz 60 / 603 Which type of detector is used for demodulating SSB signals? Discriminator Product detector Phase comparator Phase detector 61 / 603 Which of the following is often determined using a Smith chart? Beam headings and radiation patterns Point-to-point propagation reliability as a function of frequency Impedance and SWR values in transmission lines Satellite azimuth and elevation bearings 62 / 603 At what time of year is sporadic-E propagation most likely to occur? Around the equinoxes, especially the fall equinox Around the solstices, especially the winter solstice Around the equinoxes, especially the spring equinox Around the solstices, especially the summer solstice 63 / 603 What does a third-order intercept level of 40 dBm mean with respect to receiver performance? A pair of 1 mW input signals will produce a third-order intermodulation product that is 40 dB stronger than the input signal Signals less than 40 dBm will not generate audible third-order intermodulation products The receiver can tolerate signals up to 40 dB above the noise floor without producing third-order intermodulation products A pair of 40 dBm input signals will theoretically generate a third-order intermodulation product that has the same output amplitude as either of the input signals 64 / 603 What is a folded dipole antenna? A half-wave dipole with an additional parallel wire connecting its two ends A dipole one-quarter wavelength long A center-fed dipole with the ends folded down 90 degrees at the midpoint of each side A dipole configured to provide forward gain 65 / 603 How does the radiation pattern of a horizontally-polarized antenna mounted above a long slope compare with the same antenna mounted above flat ground? The main lobe takeoff angle decreases in the downhill direction The main lobe takeoff angle increases in the downhill direction The horizontal beamwidth decreases in the downhill direction The horizontal beamwidth increases in the uphill direction 66 / 603 Which VHF amateur bands have frequencies authorized for space stations? 6 meters and 2 meters 2 meters and 1.25 meters 6 meters, 2 meters, and 1.25 meters 2 meters 67 / 603 What indicator is required to be used by US-licensed operators when operating a station via remote control and the remote transmitter is located in the US? /R# where # is the district of the remote station No additional indicator is required / followed by the USPS two-letter abbreviation for the state in which the remote station is located / followed by the ARRL Section of the remote station 68 / 603 How many horizontal lines make up a fast-scan (NTSC) television frame? 1080 30 60 525 69 / 603 What are the major spectral impurity components of direct digital synthesizers? Broadband noise Spurious signals at discrete frequencies Harmonics of the local oscillator Digital conversion noise 70 / 603 What is the far field of an antenna? The region of the ionosphere where radiated power is not refracted The region where radiated field strengths are constant The region where radiated power dissipates over a specified time period The region where the shape of the radiation pattern no longer varies with distance 71 / 603 When may an amateur station send a message to a business? When the pecuniary interest of the amateur or his or her employer is less than $50 At no time When the pecuniary interest of the amateur or his or her employer is less than $25 When neither the amateur nor their employer has a pecuniary interest in the communications 72 / 603 What is the approximate maximum separation measured along the surface of the Earth between two stations communicating by EME? 2,000 miles, if the moon is at perigee 12,000 miles, if the moon is “visible†by both stations 5,000 miles, if the moon is at perigee 2,000 miles, if the moon is at apogee 73 / 603 What is the elevation angle of peak response in the antenna radiation pattern shown in Figure E9-2? 45 degrees 75 degrees 25 degrees 7.5 degrees 74 / 603 What type of semiconductor device is designed for use as a voltage-controlled capacitor? Tunnel diode Varactor diode Zener diode Silicon-controlled rectifier 75 / 603 What is the highest modulation index permitted at the highest modulation frequency for angle modulation below 29.0 MHz? 3 0.5 1 2 76 / 603 Which of the following is a common use of a Schottky diode? In oscillator circuits as the negative resistance element In power supplies as a constant voltage reference As a variable capacitance in an automatic frequency control circuit As a VHF/UHF mixer or detector 77 / 603 What is piezoelectricity? A characteristic of materials that generate a voltage when stressed and that flex when a voltage is applied The ability of materials to generate electromagnetic waves of a certain frequency when voltage is applied The ability of materials to generate voltage when an electromagnetic wave of a certain frequency is applied A characteristic of materials that have an index of refraction which depends on the polarization of the electromagnetic wave passing through it 78 / 603 What transmitter frequencies would create an intermodulation-product signal in a receiver tuned to 146.70 MHz when a nearby station transmits on 146.52 MHz? 146.30 MHz and 146.90 MHz 146.34 MHz and 146.61 MHz 146.88 MHz and 146.34 MHz 146.10 MHz and 147.30 MHz 79 / 603 What is the cause of short-term radio blackouts? Solar flares North-oriented interplanetary magnetic field Sunspots on the solar equator Coronal mass ejections 80 / 603 Which of the following limits the highest frequency signal that can be accurately displayed on a digital oscilloscope? Q of the circuit All these choices are correct Analog-to-digital converter reference frequency Sampling rate of the analog-to-digital converter 81 / 603 What coordinate system is often used to display the phase angle of a circuit containing resistance, inductive, and/or capacitive reactance? Faraday grid Polar coordinates Elliptical coordinates Maidenhead grid 82 / 603 What is the most common material used in power-generating photovoltaic cells? Silicon Cadmium sulfide Indium arsenide Selenium 83 / 603 What is one advantage of using ASCII code for data communications? It contains fewer information bits per character than any other code It is possible to transmit both uppercase and lowercase text It includes built-in error correction features It uses one character as a shift code to send numeric and special characters 84 / 603 What is vestigial sideband modulation? Narrow-band FM modulation achieved by filtering one sideband from the audio before frequency modulating the carrier A type of modulation in which one sideband is inverted Amplitude modulation in which one complete sideband and a portion of the other are transmitted Spread spectrum modulation achieved by applying FM modulation following single sideband amplitude modulation 85 / 603 What type of data is reported by amateur radio propagation reporting networks? Magnetic declination Electric field intensity Solar flux Digital-mode and CW signals 86 / 603 Which of the following can be measured with a vector network analyzer? All these choices are correct Reflection coefficient Output impedance Input impedance 87 / 603 Which of the following describes a Zepp antenna? An end-fed half-wavelength dipole An omni-directional antenna commonly used for satellite communications A horizontal array capable of quickly changing the direction of maximum radiation by changing phasing lines A vertical array capable of quickly changing the direction of maximum radiation by changing phasing lines 88 / 603 Who may be the control operator of an auxiliary station? Any licensed amateur operator Only Amateur Extra class operators Only Technician, General, Advanced, or Amateur Extra class operators Only General, Advanced, or Amateur Extra class operators 89 / 603 Which of the following digital modes is designed for meteor scatter communications? MSK144 APRS WSPR Hellschreiber 90 / 603 Which of the following methods measures intermodulation distortion in an SSB transmitter? Modulate the transmitter using two AF signals having non-harmonically related frequencies and observe the RF output with a spectrum analyzer Modulate the transmitter using two RF signals having non-harmonically related frequencies and observe the RF output with a spectrum analyzer Modulate the transmitter using two RF signals having harmonically related frequencies and observe the RF output with a logic analyzer Modulate the transmitter using two AF signals having harmonically related frequencies and observe the RF output with a peak reading wattmeter 91 / 603 What does PRB-1 require of state and local regulations affecting amateur radio antenna size and structures? Such structures must be permitted if certified by a registered professional engineer Such structures must be permitted when use for emergency communications can be demonstrated No limitations may be placed on antenna size or placement Reasonable accommodations of amateur radio must be made 92 / 603 What is an operational amplifier? A digital audio amplifier whose characteristics are determined by components external to the amplifier A RF amplifier used in the UHF and microwave regions An amplifier used to increase the average output of frequency modulated amateur signals to the legal limit A high-gain, direct-coupled differential amplifier with very high input impedance and very low output impedance 93 / 603 What is the purpose of connecting equal-value resistors across power supply filter capacitors connected in series? Provide a minimum load on the supply Equalize the voltage across each capacitor All these choices are correct Discharge the capacitors when voltage is removed 94 / 603 How is impedance in polar form converted to an equivalent admittance? Take the reciprocal of the magnitude and change the sign of the angle Take the reciprocal of the angle and change the sign of the magnitude Square the magnitude and subtract 90 degrees from the angle Take the square root of the magnitude and add 180 degrees to the angle 95 / 603 What is used to control the attenuation of RF signals by a PIN diode? Forward DC bias current Capacitance of an RF coupling capacitor A variable RF reference voltage Reverse voltage larger than the RF signal 96 / 603 What characterizes libration fading of an EME signal? The returning echo is several hertz lower in frequency than the transmitted signal A fluttery, irregular fading A slow change in the pitch of the CW signal A gradual loss of signal as the sun rises 97 / 603 What type of transmission line is often used for connections to MMICs? Parallel wire Circular waveguide Microstrip Miniature coax 98 / 603 What are the characteristics of an elliptical filter? Extremely flat response over its pass band with gradually rounded stop-band corners Gradual passband rolloff with extreme stop-band ripple Gradual passband rolloff with minimal stop-band ripple Extremely sharp cutoff with one or more notches in the stop band 99 / 603 Which of the following parameters does a spectrum analyzer display on the vertical and horizontal axes? Signal amplitude and frequency Signal amplitude and time SWR and time SWR and frequency 100 / 603 Why do CMOS digital integrated circuits have high immunity to noise on the input signal or power supply? Bandwidth is very limited Large bypass capacitance is inherent The input switching threshold is about twice the power supply voltage The input switching threshold is about half the power supply voltage 101 / 603 How does an impedance-matching circuit transform a complex impedance to a resistive impedance? Reactive currents are dissipated in matched resistances It introduces negative resistance to cancel the resistive part of impedance It cancels the reactive part of the impedance and changes the resistive part to the desired value It introduces transconductance to cancel the reactive part of impedance 102 / 603 What is the purpose of using multiple driven elements connected through phasing lines? To control the antenna's radiation pattern To allow single-band antennas to operate on other bands To prevent harmonic radiation from the transmitter To create a low-angle radiation pattern 103 / 603 Which of the following indicates that a silicon NPN junction transistor is biased on? Base-to-emitter voltage of approximately 6 volts to 7 volts Base-to-emitter resistance of approximately 0.6 ohms to 0.7 ohms Base-to-emitter resistance of approximately 6 ohms to 7 ohms Base-to-emitter voltage of approximately 0.6 volts to 0.7 volts 104 / 603 Why is it important to keep lead lengths short for components used in circuits for VHF and above? To increase the thermal time constant To maintain component lifetime To minimize inductive reactance All these choices are correct 105 / 603 How do ferrite and powdered iron compare for use in an inductor core? Ferrite cores generally require fewer turns to produce a given inductance value Ferrite cores generally have better temperature stability Ferrite cores generally have lower initial permeability Ferrite cores are easier to use with surface-mount technology 106 / 603 Which of the following is characteristic of the FST4 mode? Variable transmit/receive periods Seven different tone spacings Four-tone Gaussian frequency shift keying All these choices are correct 107 / 603 What is the maximum permissible duration of a remotely controlled station's transmissions if its control link malfunctions? 30 seconds 5 minutes 3 minutes 10 minutes 108 / 603 What is antenna efficiency? Effective radiated power divided by transmitter output Radiation resistance divided by total resistance Radiation resistance divided by transmission resistance Total resistance divided by radiation resistance 109 / 603 What is a use for a Wilkinson divider? To divide the frequency of the input to a counter to increase its frequency range To divide the operating frequency of a transmitter signal so it can be used on a lower frequency band To divide power equally between two 50-ohm loads while maintaining 50-ohm input impedance To feed high-impedance antennas from a low-impedance source 110 / 603 What type of analysis is commonly used for modeling antennas? Calculus differentiation with respect to physical properties Mutual impedance analysis Method of Moments Graphical analysis 111 / 603 What is the effective radiated power (ERP) of a repeater station with 200 watts transmitter power output, 4 dB feed line loss, 3.2 dB duplexer loss, 0.8 dB circulator loss, and 10 dBd antenna gain? 126 watts 2,000 watts 317 watts 300 watts 112 / 603 When constructing a Beverage antenna, which of the following factors should be included in the design to achieve good performance at the desired frequency? Its overall length must not exceed 1/4 wavelength It should be configured as a four-sided loop It must be mounted more than 1 wavelength above ground It should be at least one wavelength long 113 / 603 How much gain does an antenna have compared to a half-wavelength dipole if it has 6 dB gain over an isotropic radiator? 3.85 dB 6.0 dB 8.15 dB 2.79 dB 114 / 603 What is meant by "100% tie-off" regarding tower safety? All loose ropes and guys secured to a fixed structure At least one lanyard attached to the tower at all times All circuit breakers feeding power to the tower must be tied closed with tape, cable, or ties All tools secured to the climber's harness 115 / 603 What type of electrical interference can be caused by computer network equipment? The appearance of unstable modulated or unmodulated signals at specific frequencies A loud AC hum in the audio output of your station's receiver A clicking noise at intervals of a few seconds A whining-type noise that continually pulses off and on 116 / 603 What is the purpose of digital store-and-forward functions on an amateur radio satellite? To upload operational software for the transponder To delay download of telemetry between satellites To relay messages between satellites To hold digital messages in the satellite for later download 117 / 603 What is the relationship between the AC current through an inductor and the voltage across an inductor? Voltage and current are in phase Current leads voltage by 90 degrees Voltage leads current by 90 degrees Voltage and current are 180 degrees out of phase 118 / 603 What is the typical input impedance of an op-amp? Very low 10,000 ohms Very high 100 ohms 119 / 603 Which of the following describes problems caused by poor dynamic range in a receiver? Spurious signals caused by cross modulation and desensitization from strong adjacent signals Oscillator instability requiring frequent retuning and loss of ability to recover the opposite sideband Oscillator instability and severe audio distortion of all but the strongest received signals Poor weak signal reception caused by insufficient local oscillator injection 120 / 603 What type of frequency synthesizer circuit uses a phase accumulator, lookup table, digital-to-analog converter, and a low-pass anti-alias filter? A hybrid synthesizer A direct digital synthesizer A direct conversion synthesizer A phase-locked loop synthesizer 121 / 603 Which of the following represents pure capacitive reactance of 100 ohms in rectangular notation? 0 - j100 100 + j0 0 + j100 100 - j0 122 / 603 Which of the following materials has the highest temperature stability of its magnetic characteristics? Aluminum Powdered iron Ferrite Brass 123 / 603 What parameter evaluates distortion of an AFSK signal caused by excessive input audio levels? Intermodulation Distortion (IMD) Baud error rate Signal-to-noise ratio Repeat Request Rate (RRR) 124 / 603 How long must an operator wait after filing a notification with the Utilities Technology Council (UTC) before operating on the 2200-meter or 630-meter band? Operations may commence immediately, and may continue unless interference is reported by the UTC Operators must not operate until approval is received Operators may operate after 30 days, providing they have not been told that their station is within 1 kilometer of PLC systems using those frequencies Operators may not operate until a test signal has been transmitted in coordination with the local power company 125 / 603 What third family of circles is often added to a Smith chart during the process of designing impedance matching networks? Radiation-pattern circles Coaxial-length circles Transmission line length circles Constant-SWR circles 126 / 603 Which of the following determines ground losses for a ground-mounted vertical antenna operating on HF? The standing wave ratio Distance from the transmitter Take-off angle Soil conductivity 127 / 603 What is the function of hysteresis in a comparator? To increase the sensitivity To cause the output to continually change states To allow the comparator to be used with AC input signals To prevent input noise from causing unstable output signals 128 / 603 What is the function of a sense antenna? It increases the sensitivity of a DF antenna array It modifies the pattern of a DF antenna to provide a null in only one direction It provides diversity reception that cancels multipath signals It allows DF antennas to receive signals at different vertical angles 129 / 603 What happens to the radiation pattern of an unterminated long wire antenna as the wire length is increased? The elevation angle increases, while the front-to-rear ratio is unaffected Fewer lobes form with the major lobes increasing closer to broadside to the wire Additional lobes form with major lobes increasingly aligned with the axis of the antenna The elevation angle increases, and the front-to-rear ratio decreases 130 / 603 In what direction does an electromagnetic wave travel? It depends on the phase angle of the electric field It travels at a right angle to the electric and magnetic fields It depends on the phase angle of the magnetic field It travels parallel to the electric and magnetic fields 131 / 603 What is the most common method of reducing key clicks? Insert low-pass filters at the transmitter output Increase keying waveform rise and fall times Reduce keying waveform rise and fall times Insert high-pass filters at the transmitter output 132 / 603 Which of the following is good practice when using an oscilloscope probe? Minimize the length of the probe's ground connection All these choices are correct Never use a high-impedance probe to measure a low-impedance circuit Never use a DC-coupled probe to measure an AC circuit 133 / 603 Which of the following can be calculated using a Smith chart? Impedance along transmission lines Radiation resistance Antenna radiation pattern Radio propagation 134 / 603 For what portion of the signal cycle does each active element in a push-pull, Class AB amplifier conduct? Less than 180 degrees More than 180 degrees but less than 360 degrees The entire cycle Exactly 180 degrees 135 / 603 What absolute voltage gain can be expected from the circuit in Figure E7-3 when R1 is 1,800 ohms and RF is 68 kilohms? 76 1 0.03 38 136 / 603 What is the purpose of an inverter connected to a solar panel output? Prevent discharge when panel is not illuminated Convert the panel's output from DC to AC Reduce AC ripple on the output Maintain voltage with varying illumination levels 137 / 603 What is the effect of chordal-hop propagation? Atmospheric noise is reduced in the direction of chordal-hop propagation The MUF for chordal-hop propagation is much lower than for normal skip propagation Signals travel faster along ionospheric chords The signal experiences less loss compared to multi-hop propagation, which uses Earth as a reflector 138 / 603 What is a crystal lattice filter? A filter for low-level signals made using quartz crystals A filter using lattice-shaped quartz crystals for high-Q performance An audio filter made with four quartz crystals that resonate at 1 kHz intervals A power supply filter made with interlaced quartz crystals 139 / 603 What is the effect on the magnitude of pure reactance when it is converted to susceptance? It is replaced by its reciprocal The sign is reversed It is shifted by 90 degrees It is unchanged 140 / 603 When must an RF exposure evaluation be performed on an amateur station operating on 80 meters? When the output power from the transmitter is less than 100 watts When the station's operating mode is CW An evaluation must always be performed When the ERP of the station is less than 10 watts 141 / 603 Which of the following apply to communications transmitted to amateur stations in foreign countries? Communications must be limited to those incidental to the purpose of the amateur service and remarks of a personal nature Third party traffic must be limited to that intended for the exclusive use of government and non-Government Organization (NGOs) involved in emergency relief activities All transmissions must be in English All these choices are correct 142 / 603 Which UHF amateur bands have frequencies authorized for space stations? 33 centimeters and 13 centimeters 70 centimeters only 70 centimeters and 33 centimeters 70 centimeters and 13 centimeters 143 / 603 Why are optoisolators often used in conjunction with solid-state circuits that control 120 VAC circuits? Optoisolators provide impedance matching between the control circuit and power circuit Optoisolators eliminate the effects of reflected light in the control circuit Optoisolators provide an electrical isolation between a control circuit and the circuit being switched Optoisolators provide a low-impedance link between a control circuit and a power circuit 144 / 603 What type of antenna pattern is shown in Figure E9-2? Polarization Elevation Near field Azimuth 145 / 603 What technique do individual nodes use to form a mesh network? Custom code plugs for the local trunking systems Acting as store-and-forward digipeaters Forward error correction and Viterbi codes Discovery and link establishment protocols 146 / 603 What is the result of increasing the Q of an impedance-matching circuit? Losses increase Matching bandwidth is increased Matching bandwidth is decreased Harmonics increase 147 / 603 What best describes a pull-up or pull-down resistor? A resistor that ensures that an oscillator frequency does not drift A resistor connected to the positive or negative supply used to establish a voltage when an input or output is an open circuit A resistor in a keying circuit used to reduce key clicks A resistor connected to an op-amp output that prevents signals from exceeding the power supply voltage 148 / 603 What is the result of conductor skin effect? Resistance increases as temperature increases because of the change in thermal coefficient Resistance increases as frequency increases because RF current flows closer to the surface Resistance decreases as temperature increases because of the change in thermal coefficient Resistance decreases as frequency increases because electron mobility increases 149 / 603 Which of the following factors most affects the accuracy of a frequency counter? Time base accuracy Input attenuator accuracy Decade divider accuracy Temperature coefficient of the logic 150 / 603 What is the beta of a bipolar junction transistor? The frequency at which the current gain is reduced to 0.707 The breakdown voltage of the base-to-collector junction The switching speed The change in collector current with respect to base current 151 / 603 What will be the output voltage of the circuit shown in Figure E7-3 if R1 is 1,000 ohms, RF is 10,000 ohms, and 0.23 volts DC is applied to the input? 2.3 volts -2.3 volts 0.23 volts -0.23 volts 152 / 603 Why are cores of inductors and transformers sometimes constructed of thin layers? To increase the cutoff frequency by reducing capacitance To save cost by reducing the amount of magnetic material To reduce power loss from eddy currents in the core To simplify assembly during manufacturing 153 / 603 Which of the following digital modes is designed for EME communications? PACTOR III Q65 WSPR MSK144 154 / 603 What is the modulation index of an FM phone signal having a maximum carrier deviation of plus or minus 6 kHz if the highest modulating frequency is 2 kHz? 0.3 6 3 0.6 155 / 603 On which of the following amateur bands is long-path propagation most frequent? 40 meters and 20 meters 10 meters and 6 meters 6 meters and 2 meters 160 meters and 80 meters 156 / 603 What type of Y-axis scale is most often used for graphs of circuit frequency response? Scatter Linear Logarithmic Random 157 / 603 How is battery operating time calculated? Average current divided by internal resistance Internal resistance divided by average current Capacity in amp-hours divided by average current Average current divided by capacity in amp-hours 158 / 603 What power level does a receiver minimum discernible signal of -100 dBm represent? 0.1 microwatt 0.001 microwatts 100 microwatts 0.1 picowatts 159 / 603 What is the approximate feed point impedance at the center of a two-wire half-wave folded dipole antenna? 50 ohms 450 ohms 300 ohms 72 ohms 160 / 603 At what time of day is transequatorial propagation most likely to occur? Morning Noon Late at night Afternoon or early evening 161 / 603 Why does a PN-junction diode not conduct current when reverse biased? Excess holes in P-type material combine with the electrons in N-type material, converting the entire diode into an insulator Holes in P-type material and electrons in the N-type material are separated by the applied voltage, widening the depletion region Only N-type semiconductor material can conduct current Only P-type semiconductor material can conduct current 162 / 603 Which of the following types of noise can often be reduced by a digital noise reduction? All these choices are correct Ignition noise Broadband white noise Power line noise 163 / 603 How can unwanted ringing and audio instability be prevented in an op-amp audio filter? Increase both gain and Q Restrict both gain and Q Restrict gain but increase Q Restrict Q but increase gain 164 / 603 If a station in a message forwarding system inadvertently forwards a message that is in violation of FCC rules, who is primarily accountable for the rules violation? The control operators of all the stations in the system The control operator of the packet bulletin board station The control operator of the originating station The control operators of all the stations in the system not authenticating the source from which they accept communications 165 / 603 What is tri-state logic? Logic devices that utilize ternary math A counter with eight states Logic devices with 0, 1, and high-impedance output states Logic with three output impedances which can be selected to better match the load impedance 166 / 603 What causes intermodulation in an electronic circuit? Negative feedback Nonlinear circuits or devices Lack of neutralization Positive feedback 167 / 603 What logical operation does an OR gate perform? It produces a 0 at its output if all inputs are 1 It produces a 1 at its output if any input is 1 It produces a 1 at its output if all inputs are 0 It produces a 0 at its output if some but not all inputs are 1 168 / 603 Which of the following may transmit encrypted messages? Auxiliary relay links carrying repeater audio Telecommand signals to terrestrial repeaters Telecommand signals from a space telecommand station Mesh network backbone nodes 169 / 603 What is the purpose of using a prescaler with a frequency counter? Amplify low-level signals for more accurate counting Prevent oscillation in a low-frequency counter circuit Reduce the signal frequency to within the counter's operating range Multiply a higher frequency signal so a low-frequency counter can display the operating frequency 170 / 603 What parameter describes the interaction of a load and transmission line? Velocity factor Dielectric constant Characteristic impedance Reflection coefficient 171 / 603 What type of radiation pattern is created by two 1/4-wavelength vertical antennas spaced 1/4-wavelength apart and fed 90 degrees out of phase? Cardioid Omni-directional A figure-eight end-fire along the axis of the array A figure-eight broadside to the axis of the array 172 / 603 How many flip-flops are required to divide a signal frequency by 16? 16 8 4 6 173 / 603 What is the direction of an ascending pass for an amateur satellite? From east to west From north to south From west to east From south to north 174 / 603 An SDR receiver is overloaded when input signals exceed what level? One-half of the maximum sample rate The reference voltage of the analog-to-digital converter One-half of the maximum sampling buffer size The maximum count value of the analog-to-digital converter 175 / 603 What is chordal-hop propagation? Propagation across the geomagnetic equator Successive ionospheric refractions without an intermediate reflection from the ground Signals reflected back toward the transmitting station Propagation away from the great circle bearing between stations 176 / 603 What is the 3 dB beamwidth of the antenna radiation pattern shown in Figure E9-1? 75 degrees 25 degrees 50 degrees 30 degrees 177 / 603 When evaluating RF exposure levels from your station at a neighbor's home, what must you do? Ensure signals from your station are less than the uncontrolled maximum permissible emission (MPE) limits Ensure signals from your station are less than the controlled maximum permissible emission (MPE) limits Ensure signals from your station are less than the uncontrolled maximum permissible exposure (MPE) limits Ensure signals from your station are less than the controlled maximum permissible exposure (MPE) limits 178 / 603 What is a microphonic? An IC used for amplifying microphone signals Distortion caused by RF pickup on the microphone cable Excess loading of the microphone by an oscillator Changes in oscillator frequency caused by mechanical vibration 179 / 603 What is an IARP? An indication of increased antenna reflected power A permit that allows US amateurs to operate in certain countries of the Americas The internal amateur radio practices policy of the FCC A forecast of intermittent aurora radio propagation 180 / 603 What type of circuit is shown in Figure E7-2? Common base amplifier Common emitter amplifier Linear voltage regulator Switching voltage regulator 181 / 603 What do the subscripts of S parameters represent? Frequency order of the measurements Relative quality of the data The port or ports at which measurements are made The relative time between measurements 182 / 603 What is the approximate open-circuit voltage produced by a fully illuminated silicon photovoltaic cell? 0.5 volts 1.5 volts 1.1 volts 0.7 volts 183 / 603 What is digital time division multiplexing? Two or more signals are arranged to share discrete time slots of a data transmission Two or more data streams are assigned to discrete sub-carriers on an FM transmitter Two or more data streams share the same channel by transmitting time of transmission as the sub-carrier Two or more signals are quadrature modulated to increase bandwidth efficiency 184 / 603 What is the minimum number of bits required to sample a signal with a range of 1 volt at a resolution of 1 millivolt? 6 bits 4 bits 10 bits 8 bits 185 / 603 What is the gain-bandwidth of an operational amplifier? The frequency at which the amplifier's offset voltage is zero The frequency at which the open-loop gain of the amplifier equals one The maximum frequency for a filter circuit using that type of amplifier The gain of the amplifier at a filter's cutoff frequency 186 / 603 How does a linear electronic voltage regulator work? The conduction of a control element is varied to maintain a constant output voltage The control element duty cycle is proportional to the line or load conditions It eliminates the need for a pass transistor It has a ramp voltage as its output 187 / 603 What is the purpose of Q1 in the circuit shown in Figure E7-2? It provides a constant load for the voltage source It provides regulation by switching or “chopping†the input DC voltage It provides negative feedback to improve regulation It controls the current to keep the output voltage constant 188 / 603 What is the current that flows in the primary winding of a transformer when there is no load on the secondary winding? Stabilizing current Magnetizing current Excitation current Direct current 189 / 603 What is the photovoltaic effect? The effect that causes a photodiode to emit light when a voltage is applied The conversion of light to electrical energy The effect that causes a phototransistor's beta to decrease when exposed to light The conversion of voltage to current when exposed to light 190 / 603 How much does the gain of an ideal parabolic reflector antenna increase when the operating frequency is doubled? 3 dB 2 dB 4 dB 6 dB 191 / 603 What orientation of Bz (B sub z) increases the likelihood that charged particles from the Sun will cause disturbed conditions? Westward Southward Eastward Northward 192 / 603 Which of the following is an advantage of BiCMOS logic? It has the high input impedance of CMOS and the low output impedance of bipolar transistors It is immune to electrostatic damage Its simplicity results in much less expensive devices than standard CMOS All these choices are correct 193 / 603 Which of the following signal paths is most likely to experience high levels of absorption when the A-index or K-index is elevated? Sporadic-E Transequatorial NVIS Through the auroral oval 194 / 603 What does "positive logic" mean in reference to logic devices? The logic circuit is in the “true†condition The logic devices have high noise immunity High voltage represents a 1, low voltage a 0 1s and 0s are defined as different positive voltage levels 195 / 603 Which of the following device packages is a through-hole type? BGA DIP SOT PLCC 196 / 603 Which of the following is the likely result of using a Class C amplifier to amplify a single-sideband phone signal? Reduced intermodulation products Signal distortion and excessive bandwidth Reduced third-order intermodulation Increased overall intelligibility 197 / 603 In Figure E6-1, which is the schematic symbol for an N-channel dual-gate MOSFET? 6 4 5 2 198 / 603 What is the effect of adding a terminating resistor to a rhombic or long-wire antenna? It reflects the standing waves on the antenna elements back to the transmitter It decreases the ground loss It changes the radiation pattern from bidirectional to unidirectional It changes the radiation pattern from horizontal to vertical polarization 199 / 603 What is the purpose of connecting Zener diodes between a MOSFET gate and its source or drain? To keep the gate voltage within specifications and prevent the device from overheating To provide a voltage reference for the correct amount of reverse-bias gate voltage To protect the gate from static damage To protect the substrate from excessive voltages 200 / 603 Which frequency band has the smallest first Fresnel zone? 5.8 GHz 3.4 GHz 2.4 GHz 900 MHz 201 / 603 What information is contained in the lookup table of a direct digital synthesizer (DDS)? The phase relationship between a reference oscillator and the output waveform Amplitude values that represent the desired waveform Frequently used receiver and transmitter frequencies The phase relationship between a voltage-controlled oscillator and the output waveform 202 / 603 May an Extra class operator answer the CQ of a station on 3.601 MHz LSB phone? Yes, the displayed frequency is within the 75-meter phone band segment No, US stations are not permitted to use phone emissions below 3.610 MHz No, the sideband components will extend beyond the edge of the phone band segment Yes, the entire signal will be inside the SSB allocation for Extra class operators 203 / 603 What is the relationship between symbol rate and baud? The relationship depends on the specific code used Baud rate is half the symbol rate Baud is twice the symbol rate They are the same 204 / 603 What is the significance of voltmeter sensitivity expressed in ohms per volt? The reading in volts multiplied by the ohms per volt rating will determine the power drawn by the device under test The reading in ohms divided by the ohms per volt rating will determine the voltage applied to the circuit The full scale reading in amps divided by ohms per volt rating will determine the size of shunt needed The full scale reading of the voltmeter multiplied by its ohms per volt rating is the input impedance of the voltmeter 205 / 603 What is required to be accredited as a Volunteer Examiner? A VEC must confirm that the VE applicant meets FCC requirements to serve as an examiner The amateur operator applying must pass a VE examination administered by the FCC Enforcement Bureau The prospective VE must obtain accreditation from the FCC Each General, Advanced and Amateur Extra class operator is automatically accredited as a VE when the license is granted 206 / 603 Which point on Figure E5-1 best represents the impedance of a series circuit consisting of a 400-ohm resistor and a 38-picofarad capacitor at 14 MHz? Point 6 Point 4 Point 2 Point 5 207 / 603 During a VHF/UHF contest, in which band segment would you expect to find the highest level of SSB or CW activity? In the middle of the band, usually 25 kHz above the national calling frequency In the middle of each band, usually on the national calling frequency At the top of each band, usually in a segment reserved for contests In the weak signal segment of the band, with most of the activity near the calling frequency 208 / 603 What happens to photoconductive material when light shines on it? Resistance decreases Reflectivity increases Reflectivity decreases Resistance increases 209 / 603 What is the operating point of a Class A common emitter amplifier? Approximately halfway between the emitter voltage and the base voltage At a point where the load line intersects the zero bias current curve Approximately halfway between saturation and cutoff At a point where the bias resistor equals the load resistor 210 / 603 Which of the following ensures that a crystal oscillator operates on the frequency specified by the crystal manufacturer? Bias the crystal at a specified voltage Provide the crystal with a specified parallel inductance Bias the crystal at a specified current Provide the crystal with a specified parallel capacitance 211 / 603 How is a Smith chart normalized? Reassign the resistance axis with reactance values Reassign the prime center's impedance value Reassign the prime center to the reactance axis Reassign the reactance axis with resistance values 212 / 603 What is meant by the term "op-amp input offset voltage"? The differential input voltage needed to bring the open loop output voltage to zero The difference between the output voltage of the op-amp and the input voltage required in the immediately following stage The output voltage of the op-amp minus its input voltage The potential between the amplifier input terminals of the op-amp in an open loop condition 213 / 603 What type of digital signal processing filter is used to generate an SSB signal? A Hilbert-transform filter An elliptical filter A notch filter An adaptive filter 214 / 603 What is used to design the configuration of a field-programmable gate array (FPGA)? An auto-router Hardware description language (HDL) Karnaugh maps Machine and assembly language 215 / 603 What does the MDS of a receiver represent? The minimum discernible signal The modulation distortion specification The meter display sensitivity The maximum detectable spectrum 216 / 603 Which S parameter is equivalent to forward gain? S12 S21 S11 S22 217 / 603 What are "extraordinary" and "ordinary" waves? Extraordinary waves exhibit rare long-skip propagation, compared to ordinary waves, which travel shorter distances Refracted rays and reflected waves Long-path and short-path waves Independently propagating, elliptically polarized waves created in the ionosphere 218 / 603 What is added to an FM speech channel to boost the higher audio frequencies? A heterodyne enhancer A pre-emphasis network A harmonic enhancer A de-emphasis network 219 / 603 What is meant by the blocking dynamic range of a receiver? The difference in dB between the noise floor and the third-order intercept point The minimum difference in dB between the levels of two FM signals that will cause one signal to block the other The difference in dB between the noise floor and the level of an incoming signal that will cause 1 dB of gain compression The minimum difference in dB between two signals which produce third-order intermodulation products greater than the noise floor 220 / 603 Who is tasked by Part 97 with maintaining the pools of questions for all US amateur license examinations? The FCC The ARRL The VECs The VEs 221 / 603 What is the half-power bandwidth of a resonant circuit that has a resonant frequency of 7.1 MHz and a Q of 150? 47.3 kHz 157.8 Hz 315.6 Hz 23.67 kHz 222 / 603 What problem can occur when using an automatic notch filter (ANF) to remove interfering carriers while receiving CW signals? Any nearby signal passing through the DSP system will overwhelm the desired signal Removal of the CW signal as well as the interfering carrier All these choices are correct Excessive ringing 223 / 603 How does radiation resistance of a base-fed whip antenna change below its resonant frequency? Radiation resistance increases Radiation resistance becomes imaginary Radiation resistance does not depend on frequency Radiation resistance decreases 224 / 603 What technique allows commercial analog TV receivers to be used for fast-scan TV operations on the 70-centimeter band? Transmitting on the abandoned TV channel 2 Using converted satellite TV dishes Transmitting on channels shared with cable TV Using USB and demodulating the signal with a computer sound card 225 / 603 What is the magnitude of the current at the input of a parallel RLC circuit at resonance? Minimum Maximum R/L L/R 226 / 603 What aspect of receiver analog-to-digital conversion determines the maximum receive bandwidth of a direct-sampling software defined radio (SDR)? Sample width in bits Differential non-linearity Sample rate Integral non-linearity 227 / 603 Why does input attenuation reduce receiver overload on the lower frequency HF bands with little or no impact on signal-to-noise ratio? Signals are attenuated separately from the noise The attenuator has a low-pass filter to increase the strength of lower frequency signals The attenuator has a noise filter to suppress interference Atmospheric noise is generally greater than internally generated noise even after attenuation 228 / 603 What is the approximate maximum range for signals using transequatorial propagation? 2,500 miles 7,500 miles 5,000 miles 1,000 miles 229 / 603 To which of the following examinees may a VE not administer an examination? All these choices are correct Relatives of the VE as listed in the FCC rules Employees of the VE Friends of the VE 230 / 603 What is the dropout voltage of a linear voltage regulator? Maximum that the output voltage may decrease at rated load Minimum input voltage for rated power dissipation Minimum input-to-output voltage required to maintain regulation Maximum output voltage drop when the input voltage is varied over its specified range 231 / 603 Which describes a Pi-L network? A Pi-network with an additional output series inductor A Phase Inverter Load network A matching network in which all components are isolated from ground A network with only three discrete parts 232 / 603 Within what distance must an amateur station protect an FCC monitoring facility from harmful interference? 10 miles 30 miles 3 miles 1 mile 233 / 603 What is the effective radiated power (ERP) of a repeater station with 150 watts transmitter power output, 2 dB feed line loss, 2.2 dB duplexer loss, and 7 dBd antenna gain? 420 watts 286 watts 469 watts 78.7 watts 234 / 603 What are the principal frequencies that appear at the output of a mixer? Two and four times the input frequency The square root of the product of input frequencies 1.414 and 0.707 times the input frequency The two input frequencies along with their sum and difference frequencies 235 / 603 What is the purpose of a low-pass filter used at the output of a digital-to-analog converter? Remove spurious sampling artifacts from the output signal Lower the input bandwidth to increase the effective resolution Improve accuracy by removing out-of-sequence codes from the input All these choices are correct 236 / 603 Where is the impedance of a pure resistance plotted on rectangular coordinates? On a horizontal line, offset vertically above the horizontal axis On the horizontal axis On the vertical axis On a line through the origin, slanted at 45 degrees 237 / 603 How much real power is consumed in a circuit consisting of a 100-ohm resistor in series with a 100-ohm inductive reactance drawing 1 ampere? 200 watts 70.7 watts 100 watts 141.4 watts 238 / 603 What is the approximate bandwidth of a 13-WPM International Morse Code transmission? 52 Hz 26 Hz 13 Hz 104 Hz 239 / 603 What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 25 ohms, R is 100 ohms, and XL is 75 ohms? 27 degrees with the voltage lagging the current 63 degrees with the voltage leading the current 63 degrees with the voltage lagging the current 27 degrees with the voltage leading the current 240 / 603 What is the purpose of the receiver IF Shift control? To change frequency rapidly To tune in stations slightly off frequency without changing the transmit frequency To reduce interference from stations transmitting on adjacent frequencies To permit listening on a different frequency from the transmitting frequency 241 / 603 What is a truth table? A list of inputs and corresponding outputs for an op-amp A list of inputs and corresponding outputs for a digital device A diagram showing logic states when the digital gate output is true A table of logic symbols that indicate the logic states of an op-amp 242 / 603 How should you generally identify your station when attempting to contact a DX station during a contest or in a pileup? Send the call sign of the DX station three times, the words “this is,†then your call sign three times Send your full call sign once or twice Send only the last two letters of your call sign until you make contact Send your full call sign and grid square 243 / 603 Which of the following is indicated by a sudden rise in radio background noise across a large portion of the HF spectrum? Transequatorial propagation on 6 meters is likely Long-path propagation on the higher HF bands is likely A coronal mass ejection impact or a solar flare has occurred A temperature inversion has occurred 244 / 603 Why do most two-element Yagis with normal spacing have a reflector instead of a director? Lower SWR Greater front-to-side Higher receiving directivity factor Higher gain 245 / 603 What is a solid-state relay? A semiconductor switch that uses a monostable multivibrator circuit A mechanical relay that latches in the on or off state each time it is pulsed A relay that uses transistors to drive the relay coil A device that uses semiconductors to implement the functions of an electromechanical relay 246 / 603 What do the terms "L band" and "S band" specify? Which sideband to use The 2-meter and 70-centimeter bands The 23- and 13-centimeter bands FM and digital store-and-forward systems 247 / 603 At what time of day is sporadic-E propagation most likely to occur? Between midnight and sunrise Between sunset and sunrise Between sunrise and sunset Between sunset and midnight 248 / 603 Which of the following is a technique for providing highly accurate and stable oscillators needed for microwave transmission and reception? Use a rubidium stabilized reference oscillator Use a temperature-controlled high Q dielectric resonator All these choices are correct Use a GPS signal reference 249 / 603 What is the bandwidth of a 4,800-Hz frequency shift, 9,600-baud ASCII FM transmission? 5.76 kHz 4.8 kHz 9.6 kHz 15.36 kHz 250 / 603 Which of the following is used to measure SWR? Vector network analyzer Antenna analyzer Directional wattmeter All these choices are correct 251 / 603 What characteristics of MMICs make them a popular choice for VHF through microwave circuits? Extremely high Q factor and high stability over a wide temperature range The ability to retrieve information from a single signal, even in the presence of other strong signals Controlled gain, low noise figure, and constant input and output impedance over the specified frequency range Nearly infinite gain, very high input impedance, and very low output impedance 252 / 603 What is the maximum power permitted on the 2200-meter band? 5 watts EIRP (equivalent isotropic radiated power) 50 watts PEP (peak envelope power) 1 watt EIRP (equivalent isotropic radiated power) 100 watts PEP (peak envelope power) 253 / 603 What is the length of an FT8 transmission cycle? It varies with the amount of data 8 seconds 30 seconds 15 seconds 254 / 603 What is used to suppress radio frequency interference from a line-driven AC motor? A bypass capacitor in series with the motor's field winding A brute-force AC-line filter in series with the motor's power leads A high-pass filter in series with the motor's power leads A bypass choke in parallel with the motor's field winding 255 / 603 What is the deviation ratio of an FM phone signal having a maximum frequency swing of plus or minus 7.5 kHz if the highest modulation frequency is 3.5 kHz? 0.214 47 0.47 2.14 256 / 603 Amateur stations may not transmit in which of the following frequency segments if they are located in the contiguous 48 states and north of Line A? 420 MHz - 430 MHz 222 MHz - 223 MHz 440 MHz - 450 MHz 53 MHz - 54 MHz 257 / 603 What is the maximum mean power level for a spurious emission below 30 MHz with respect to the fundamental emission? - 73 dB - 43 dB - 53 dB - 63 dB 258 / 603 What are the two families of circles and arcs that make up a Smith chart? Reactance and voltage Inductance and capacitance Voltage and impedance Resistance and reactance 259 / 603 How are the capacitors and inductors of a low-pass filter Pi-network arranged between the network's input and output? A capacitor is connected between the input and ground, another capacitor is connected between the output and ground, and an inductor is connected between the input and output An inductor is connected between the input and ground, another inductor is connected between the output and ground, and a capacitor is connected between the input and output Two capacitors are in series between the input and output, and an inductor is connected between the two capacitors and ground Two inductors are in series between the input and output, and a capacitor is connected between the two inductors and ground 260 / 603 What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 300 ohms, R is 100 ohms, and XL is 100 ohms? 63 degrees with the voltage lagging the current 63 degrees with the voltage leading the current 27 degrees with the voltage leading the current 27 degrees with the voltage lagging the current 261 / 603 What is the function of decimation? Reducing the effective sample rate by removing samples Converting data to binary-coded decimal form Removing unnecessary significant digits Attenuating the signal 262 / 603 Which of the following component package types have the least parasitic effects at frequencies above the HF range? Radial lead TO-220 Axial lead Surface mount 263 / 603 What is a depletion-mode field-effect transistor (FET)? An FET that exhibits very high electron mobility due to a lack of holes in the N-type material An FET that has no current flow between source and drain when no gate voltage is applied An FET that exhibits a current flow between source and drain when no gate voltage is applied An FET for which holes are the majority carriers 264 / 603 Which filter type has ripple in the passband and a sharp cutoff? A Chebyshev filter A passive op-amp filter A Butterworth filter An active LC filter 265 / 603 How frequently must an analog signal be sampled to be accurately reproduced? At least half the rate of the highest frequency component of the signal At four times the rate of the highest frequency component of the signal At the same rate as the highest frequency component of the signal At least twice the rate of the highest frequency component of the signal 266 / 603 What is the front-to-back ratio of the antenna radiation pattern shown in Figure E9-1? 36 dB 18 dB 14 dB 24 dB 267 / 603 What is the magnitude of the impedance of a series RLC circuit at resonance? Approximately equal to circuit resistance High, compared to the circuit resistance Approximately equal to capacitive reactance Approximately equal to inductive reactance 268 / 603 Which of the following describes a signal in the time domain? Discrete impulses in time order Power at intervals of phase Frequency at different times Amplitude at different times 269 / 603 What impedance does a 1/2-wavelength transmission line present to an RF generator when the line is shorted at the far end? Very low impedance The same as the characteristic impedance of the line Very high impedance The same as the output impedance of the RF generator 270 / 603 What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 500 ohms, R is 1 kilohm, and XL is 250 ohms? 14.0 degrees with the voltage leading the current 14.0 degrees with the voltage lagging the current 68.2 degrees with the voltage lagging the current 68.2 degrees with the voltage leading the current 271 / 603 What is the resonant frequency of an RLC circuit if R is 33 ohms, L is 50 microhenries, and C is 10 picofarads? 23.5 kHz 7.12 kHz 7.12 MHz 23.5 MHz 272 / 603 What is the phase relationship between current and voltage for reactive power? They are in phase They are 45 degrees out of phase They are out of phase They are 90 degrees out of phase 273 / 603 What is deviation ratio? The ratio of the carrier center frequency to the audio modulating frequency The ratio of the audio modulating frequency to the center carrier frequency The ratio of the maximum carrier frequency deviation to the highest audio modulating frequency The ratio of the highest audio modulating frequency to the average audio modulating frequency 274 / 603 How does the gain of an ideal operational amplifier vary with frequency? It decreases logarithmically with increasing frequency It increases linearly with increasing frequency It decreases linearly with increasing frequency It does not vary with frequency 275 / 603 Which characteristic of a Schottky diode makes it a better choice than a silicon junction diode for use as a power supply rectifier? Lower forward voltage drop More constant reverse avalanche voltage Longer carrier retention time Much higher reverse voltage breakdown 276 / 603 Who is responsible for the proper conduct and necessary supervision during an amateur operator license examination session? The designated monitoring VE The VEC coordinating the session Each administering VE Only the VE session manager 277 / 603 In Figure E6-3, which is the schematic symbol for a NOR gate? 1 3 4 2 278 / 603 What does the value of Bz (B sub z) represent? Geomagnetic field stability North-south strength of the interplanetary magnetic field Duration of long-delayed echoes Critical frequency for vertical transmissions 279 / 603 Which of the following materials supports the highest frequency of operation when used in MMICs? Gallium nitride Silicon dioxide Silicon Silicon nitride 280 / 603 What is the effect of aliasing on a digital oscilloscope when displaying a waveform? The waveform DC offset will be inaccurate Excessive blanking occurs, which prevents display of the waveform Calibration of the vertical scale is no longer valid A false, jittery low-frequency version of the waveform is displayed 281 / 603 What is the purpose of a single point ground panel? Prevent common-mode transients in multi-wire systems Eliminate air gaps between protected and non-protected circuits Ensure all lightning protectors activate at the same time Remove AC power in case of a short-circuit 282 / 603 What is the term for the reduction in receiver sensitivity caused by a strong signal near the received frequency? Reciprocal mixing Cross modulation interference Desensitization Quieting 283 / 603 What is a characteristic of a monostable multivibrator? It stores one bit of data It maintains a constant output voltage, regardless of variations in the input voltage It switches temporarily to an alternate state for a set time It produces a continuous square wave 284 / 603 What happens to SWR bandwidth when one or more loading coils are used to resonate an electrically short antenna? It is unchanged if the loading coil is located at the feed point It is unchanged if the loading coil is located at a voltage maximum point It is increased It is decreased 285 / 603 What impedance does a 1/4-wavelength transmission line present to an RF generator when the line is shorted at the far end? Very low impedance The same as the generator output impedance The same as the characteristic impedance of the transmission line Very high impedance 286 / 603 How does the radiation pattern of a horizontally polarized antenna vary with increasing height above ground? The horizontal beamwidth increases The horizontal beamwidth decreases The takeoff angle of the lowest elevation lobe increases The takeoff angle of the lowest elevation lobe decreases 287 / 603 How is compensation of an oscilloscope probe performed? A high frequency sine wave is displayed, and the probe is adjusted for maximum amplitude A square wave is displayed, and the probe is adjusted until the horizontal portions of the displayed wave are as nearly flat as possible A DC voltage standard is displayed, and the probe is adjusted until the displayed voltage is accurate A frequency standard is displayed, and the probe is adjusted until the deflection time is accurate 288 / 603 What impedance does a 1/8-wavelength transmission line present to an RF generator when the line is open at the far end? The same as the characteristic impedance of the line An inductive reactance A capacitive reactance Infinite 289 / 603 What aspect of an analog slow-scan television signal encodes the brightness of the picture? Sync amplitude Tone frequency Sync frequency Tone amplitude 290 / 603 Orthogonal frequency-division multiplexing (OFDM) is a technique used for which types of amateur communication? Extremely low-power contacts EME Digital modes OFDM signals are not allowed on amateur bands 291 / 603 Which digital code allows only one bit to change between sequential code values? Gray code Binary Coded Decimal Code Extended Binary Coded Decimal Interchange Code Extended ASCII 292 / 603 On what frequencies are spread spectrum transmissions permitted? Only on amateur frequencies above 420 MHz Only on amateur frequencies above 222 MHz Only on amateur frequencies above 144 MHz Only on amateur frequencies above 50 MHz 293 / 603 Which of the following types of equipment are exempt from RF exposure evaluations? Transceivers with less than 7 watts of RF output Hand-held transceivers sold before May 3, 2021 Dish antennas less than one meter in diameter Antennas that radiate only in the near field 294 / 603 Which of the following improves the efficiency of a ground-mounted quarter-wave vertical antenna? Isolating the coax shield from ground Shortening the radiating element All these choices are correct Installing a ground radial system 295 / 603 What does the packet path WIDE3-1 designate? Three digipeater hops are requested with one remaining Three subcarriers are permitted, subcarrier one is being used Three stations are allowed on frequency, one transmitting at a time Three internet gateway stations may receive one transmission 296 / 603 What is described by the constellation diagram of a QAM or QPSK signal? Frequency response of the signal stream The number of bits used for error correction in the protocol The possible phase and amplitude states for each symbol How many carriers may be present at the same time 297 / 603 What type of addresses do nodes have in a mesh network? Talk group Internet Protocol (IP) Trust server Email 298 / 603 Which of the following choices is a good reason for selecting a high IF for a superheterodyne HF or VHF communications receiver? Fewer components in the receiver Improved receiver noise figure Reduced drift Easier for front-end circuitry to eliminate image responses 299 / 603 What indicates the correct value of terminating resistance for a Beverage antenna? Minimum variation in SWR over the desired frequency range Maximum feed point DC resistance at the center of the desired frequency range Minimum low-angle front-to-back ratio at the design frequency Maximum DC current in the terminating resistor 300 / 603 What is the term for the frequency at which the grounded-base current gain of a bipolar junction transistor has decreased to 0.7 of the gain obtainable at 1 kHz? Beta cutoff frequency Corner frequency Alpha rejection frequency Alpha cutoff frequency 301 / 603 What is a Volunteer Examiner Coordinator? The person who has entered into an agreement with the FCC to be the VE session manager An organization that has entered into an agreement with the FCC to coordinate, prepare, and administer amateur operator license examinations A person who has volunteered to administer amateur operator license examinations An organization paid by the volunteer examiner team to publicize and schedule examinations 302 / 603 What is the purpose of C2 in the circuit shown in Figure E7-2? To provide fixed DC bias for Q1 It bypasses rectifier output ripple around D1 It is a brute force filter for the output To prevent self-oscillation 303 / 603 Which of the following is characteristic of an inverting linear transponder? Signal position in the band is reversed Upper sideband on the uplink becomes lower sideband on the downlink, and vice versa Doppler shift is reduced because the uplink and downlink shifts are in opposite directions All these choices are correct 304 / 603 Where should a station AC surge protector be installed? At the AC service panel On the single point ground panel At an AC outlet On a ground rod outside the station 305 / 603 Approximately how long is a Yagi's driven element? 1/4 wavelength 1005 divided by frequency in MHz 1/2 wavelength 234 divided by frequency in MHz 306 / 603 Which of the following calculates power dissipated by a series linear voltage regulator? Voltage difference from input to output multiplied by output current Input voltage multiplied by input current Output voltage multiplied by output current Input voltage divided by output current 307 / 603 Which of the following synchronizes WSJT-X digital mode transmit/receive timing? Sync-field transmission Alignment of frequency shifts Synchronization of computer clocks Sync-pulse timing 308 / 603 For which types of out-of-pocket expenses do the Part 97 rules state that VEs and VECs may be reimbursed? No expenses are authorized for reimbursement Providing amateur operator license examination preparation training materials Teaching an amateur operator license examination preparation course Preparing, processing, administering, and coordinating an examination for an amateur radio operator license 309 / 603 Which of the following types of noise are removed by a noise blanker? Broadband white noise Impulse noise Hum and buzz All these choices are correct 310 / 603 What type of equipment is commonly used to implement an amateur radio mesh network? A 2-meter VHF transceiver with a 1,200-baud modem A computer running EchoLink to provide interface from the radio to the internet A 440 MHz transceiver with a 9,600-baud modem A wireless router running custom firmware 311 / 603 What are three common oscillator circuits? Taft, Hartley, and Pierce Colpitts, Hartley, and Pierce Pierce, Fenner, and Beane Taft, Pierce, and negative feedback 312 / 603 In what units are the wavelength scales on a Smith chart calibrated? In fractions of transmission line electrical frequency In fractions of transmission line electrical wavelength In fractions of antenna electrical wavelength In fractions of antenna electrical frequency 313 / 603 What is the primary function of an external earth connection or ground rod? Protect breaker panel from power surges Lightning charge dissipation Reduce RF current flow between pieces of equipment Prevent static build up on power lines 314 / 603 Who must be in physical control of the station apparatus of an amateur station aboard any vessel or craft that is documented or registered in the United States? Any person named in an amateur station license grant or a person holding an unrestricted Radiotelephone Operator Permit Only a person named in an amateur station license grant Any person holding an FCC issued amateur license or who is authorized for alien reciprocal operation Only a person with an FCC Marine Radio license grant 315 / 603 Which is the most common input and output impedance of MMICs? 50 ohms 300 ohms 450 ohms 75 ohms 316 / 603 Which of the following is a Schottky barrier diode? Metal-semiconductor junction Electrolytic rectifier Thermionic emission diode PIN junction 317 / 603 What is a disadvantage of decreasing the number of wire segments in an antenna model below 10 segments per half-wavelength? The computed feed point impedance may be incorrect Ground conductivity will not be accurately modeled The resulting design will favor radiation of harmonic energy The antenna will become mechanically unstable 318 / 603 Which of these emission modes is best for auroral propagation? CW FM SSB RTTY 319 / 603 In Figure E6-2, which is the schematic symbol for a Schottky diode? 1 2 6 3 320 / 603 What effect does lowering a signal's transmitted elevation angle have on ionospheric HF skip propagation? Faraday rotation becomes stronger The distance covered by each hop increases The MUF decreases The critical frequency increases 321 / 603 What is the frequency response of the circuit in E7-3 if a capacitor is added across the feedback resistor? Notch filter Band-pass filter Low-pass filter High-pass filter 322 / 603 How do APRS stations relay data? By packet ACK/NAK relay By C4FM repeaters By packet digipeaters By DMR repeaters 323 / 603 Which of the following amateur stations may transmit one-way communications? A space station, beacon station, or telecommand station All these choices are correct A message forwarding station or automatically controlled digital station A local repeater or linked repeater station 324 / 603 What circuit is required at the output of an RF switching amplifier? A high-pass filter to compensate for low gain at low frequencies A filter to remove harmonic content A matched load resistor to prevent damage by switching transients A temperature compensating load resistor to improve linearity 325 / 603 What must the administering VEs do after the administration of a successful examination for an amateur operator license? They must collect and send the documents directly to the FCC They must return the documents to the applicant for submission to the FCC according to the FCC instructions They must collect and submit the documents to the coordinating VEC for grading They must submit the application document to the coordinating VEC according to the coordinating VEC instructions 326 / 603 What is Quadrature Amplitude Modulation or QAM? A technique for digital data compression used in digital television which removes redundancy in the data by comparing bit amplitudes Transmission of data by modulating the amplitude of two carriers of the same frequency but 90 degrees out of phase A technique for analog modulation of television video signals using phase modulation and compression A method of performing single sideband modulation by shifting the phase of the carrier and modulation components of the signal 327 / 603 What logical operation is performed by a two-input exclusive NOR gate? It produces a 0 at its output only if all inputs are 0 It produces a 0 at its output if one and only one of its inputs is 1 It produces a 1 at its output if one and only one input is 1 It produces a 1 at its output only if all inputs are 1 328 / 603 What is the difference in radiated power between a lossless antenna with gain and an isotropic radiator driven by the same power? They are the same The power radiated from the directional antenna is increased by the gain of the antenna The power radiated from the isotropic radiator is 2.15 dB greater than that from the directional antenna The power radiated from the directional antenna is stronger by its front-to-back ratio 329 / 603 How does DC input impedance at the gate of a field-effect transistor (FET) compare with that of a bipolar transistor? They are both high impedance An FET has higher input impedance They are both low impedance An FET has lower input impedance 330 / 603 What is the principle of a Method of Moments analysis? A wire is modeled as a single sine-wave current generator A wire is modeled as a series of segments, each having a uniform value of current A wire is modeled as a single sine-wave voltage source A wire is modeled as a series of segments, each having a distinct value of voltage across it 331 / 603 What is the approximate physical length of an air-insulated, parallel conductor transmission line that is electrically 1/2 wavelength long at 14.10 MHz? 13.3 meters 10.6 meters 8.5 meters 7.0 meters 332 / 603 What is a Class D amplifier? An amplifier that uses switching technology to achieve high efficiency An amplifier biased to be relatively free from distortion An amplifier that uses drift-mode FETs for high efficiency A low power amplifier that uses a differential amplifier for improved linearity 333 / 603 What is the function of a decade counter? It produces 10 output pulses for every input pulse It produces one output pulse for every 10 input pulses It decodes a decimal number for display on a seven-segment LED display It decodes a binary number for display on a seven-segment LED display 334 / 603 What is the modulation index of an FM signal? The bandwidth of the transmitted signal divided by the modulating signal frequency The modulating signal frequency divided by the bandwidth of the transmitted signal The ratio of frequency deviation to modulating signal frequency The ratio of modulating signal amplitude to frequency deviation 335 / 603 What factors affect the bandwidth of a transmitted CW signal? Keying speed and shape factor (rise and fall time) Modulation index and output power IF bandwidth and Q All these choices are correct 336 / 603 What frequencies are authorized to an amateur station operating under RACES rules? All these choices are correct Specific segments in the amateur service MF, HF, VHF, and UHF bands All amateur service frequencies authorized to the control operator Specific local government channels 337 / 603 What device is used as a stable voltage reference? An analog-to-digital converter A digital-to-analog converter A Zener diode An SCR 338 / 603 Which amateur stations are eligible to operate as Earth stations? Any amateur licensee who has successfully completed the AMSAT space communications course Only those of General, Advanced or Amateur Extra class operators Only those of Amateur Extra class operators Any amateur station, subject to the privileges of the class of operator license held by the control operator 339 / 603 What is the purpose of feeding an off-center-fed dipole (OCFD) between the center and one end instead of at the midpoint? To resonate the antenna across a wider range of frequencies To reduce common-mode current coupling on the feed line shield To create a similar feed point impedance on multiple bands To suppress off-center lobes at higher frequencies 340 / 603 What is a frequency discriminator? An FM generator circuit A circuit for filtering closely adjacent signals A circuit for detecting FM signals An automatic band-switching circuit 341 / 603 What type of polarization is supported by ground-wave propagation? Horizontal Elliptical Circular Vertical 342 / 603 What does the term "foreground gain" mean? To force net gain to 0 dB by grounding part of the antenna An increase in signal strength from ground reflections in the environment of the antenna The change in signal strength caused by grounding the antenna The gain of the antenna with respect to a dipole at ground level 343 / 603 When using a transceiver that displays the carrier frequency of phone signals, which of the following displayed frequencies represents the lowest frequency at which a properly adjusted LSB emission will be totally within the band? The exact lower band edge 3 kHz above the lower band edge 1 kHz above the lower band edge 300 Hz above the lower band edge 344 / 603 Which of the following can be measured with an antenna analyzer? Cable length Velocity factor All these choices are correct Resonant frequency of a tuned circuit 345 / 603 In Figure E6-3, which is the schematic symbol for a NAND gate? 2 3 4 1 346 / 603 What causes inductor saturation? Operation at too high a frequency Operation at excessive magnetic flux Selecting a core with excessive permittivity Selecting a core with low permeability 347 / 603 What is the purpose of adding an inductor to a Pi-network to create a Pi-L-network? Greater harmonic suppression Greater transformation range Higher efficiency To eliminate one capacitor 348 / 603 What three test loads are used to calibrate an RF vector network analyzer? 50 ohms through 1/8 wavelength, 1/4 wavelength, and 1/2 wavelength of coaxial cable 50 ohms, 75 ohms, and 90 ohms Short circuit, open circuit, and 50 ohms Short circuit, open circuit, and resonant circuit 349 / 603 What digital protocol is used by APRS? AX.25 AMTOR PACTOR QAM 350 / 603 What advantage does surface-mount technology offer at RF compared to using through-hole components? All these choices are correct Shorter circuit board traces Smaller circuit area Components have less parasitic inductance and capacitance 351 / 603 What must be posted at the location of a station being operated by telecommand on or within 50 kilometers of the Earth's surface? A photocopy of the station license A label with the name, address, and telephone number of the control operator All these choices are correct A label with the name, address, and telephone number of the station licensee 352 / 603 What is characteristic of an emitter follower (or common collector) amplifier? Differential inputs and single output Low input impedance and phase inversion from input to output Acts as an OR circuit if one input is grounded Input and output signals in-phase 353 / 603 Which of the following is a common use for a Smith chart? Determine the loss/100 feet of a transmission line, given the velocity factor and conductor materials Determine the length and position of an impedance matching stub Determine the impedance of a transmission line, given the physical dimensions Determine the gain of an antenna given the physical and electrical parameters 354 / 603 How is the Q of an RLC parallel resonant circuit calculated? Reactance of the inductance multiplied by the reactance of the capacitance Resistance divided by the reactance of either the inductance or capacitance Reactance of either the inductance or capacitance multiplied by the resistance Reactance of either the inductance or capacitance divided by the resistance 355 / 603 What is the phase relationship between the current through and the voltage across a series resonant circuit at resonance? The current leads the voltage by 90 degrees The voltage leads the current by 90 degrees The voltage and current are 180 degrees out of phase The voltage and current are in phase 356 / 603 Which of the following constitutes a spurious emission? An emission outside the signal's necessary bandwidth that can be reduced or eliminated without affecting the information transmitted A signal transmitted to prevent its detection by any station other than the intended recipient Any transmitted signal that unintentionally interferes with another licensed radio station and whose levels exceed 40 dB below the fundamental power level An amateur station transmission made without the proper call sign identification 357 / 603 Which of these transmission line impedances would be suitable for constructing a quarter-wave Q-section for matching a 100-ohm feed point impedance to a 50-ohm transmission line? 75 ohms 62 ohms 90 ohms 50 ohms 358 / 603 How does parallel conductor transmission line compare to coaxial cable with a plastic dielectric? Lower velocity factor Lower loss Smaller reflection coefficient Higher SWR 359 / 603 How can conducted noise from an automobile battery charging system be suppressed? By installing a noise suppression resistor and a blocking capacitor at the battery By installing ferrite chokes on the charging system leads By installing filter capacitors in series with the alternator leads By installing a high-pass filter in series with the radio's power lead and a low-pass filter in parallel with the antenna feed line 360 / 603 What privileges are authorized in the US to persons holding an amateur service license granted by the government of Canada? None, they must obtain a US license Full privileges, up to and including those of the Amateur Extra class license, on the 80-, 40-, 20-, 15-, and 10-meter bands The operating terms and conditions of the Canadian amateur service license, not to exceed US Amateur Extra class license privileges Full privileges of the General class license on the 80-, 40-, 20-, 15-, and 10-meter bands 361 / 603 Which point in Figure E5-1 best represents the impedance of a series circuit consisting of a 300-ohm resistor and an 18-microhenry inductor at 3.505 MHz? Point 3 Point 1 Point 8 Point 7 362 / 603 Where is transequatorial propagation (TEP) most likely to occur? Between points located at each other's antipode Between points located 1,500 miles to 2,000 miles apart on the geomagnetic equator Through the region where the terminator crosses the geographic equator Between points separated by 2,000 miles to 3,000 miles over a path perpendicular to the geomagnetic equator 363 / 603 What type of coordinate system is used in a Smith chart? Voltage chords and current chords Voltage circles and current arcs Resistance circles and reactance arcs Resistance lines and reactance chords 364 / 603 What function is performed by a Fast Fourier Transform? Converting signals from the time domain to the frequency domain Converting digital signals to analog form Converting signals from the frequency domain to the time domain Converting analog signals to digital form 365 / 603 What is the purpose of the preselector in a communications receiver? To store frequencies that are often used To provide broadband attenuation before the first RF stage to prevent intermodulation To allow selection of the optimum RF amplifier device To increase the rejection of signals outside the band being received 366 / 603 What property of an LED's semiconductor material determines its forward voltage drop? Band gap Intrinsic resistance Junction depth Junction capacitance 367 / 603 Which of the following describes the use of vestigial sideband in analog fast-scan TV transmissions? Vestigial sideband provides high frequency emphasis to sharpen the picture The vestigial sideband carries the audio information Vestigial sideband reduces the bandwidth while increasing the fidelity of low frequency video components The vestigial sideband contains chroma information 368 / 603 What must the control operator of a repeater operating in the 70-centimeter band do if a radiolocation system experiences interference from that repeater? Reduce the repeater antenna HAAT (Height Above Average Terrain) All these choices are correct Cease operation or make changes to the repeater that mitigate the interference File an FAA NOTAM (Notice to Air Missions) with the repeater system's ERP, call sign, and six-character grid locator 369 / 603 Why is the electrical length of a coaxial cable longer than its physical length? Skin effect is more pronounced in the coaxial cable Electromagnetic waves move faster in coaxial cable than in air Electromagnetic waves move more slowly in a coaxial cable than in air Skin effect is less pronounced in the coaxial cable 370 / 603 Which of the following can be used to determine the Q of a series-tuned circuit? The resonant frequency of the circuit The frequency shift The bandwidth of the circuit's frequency response The ratio of inductive reactance to capacitive reactance 371 / 603 How many different input levels can be encoded by an analog-to-digital converter with 8-bit resolution? 8 multiplied by the gain of the input amplifier 8 256 256 divided by the gain of the input amplifier 372 / 603 Which of the following is used to shunt feed a grounded tower at its base? Beta or hairpin match Double-bazooka match Gamma match All these choices are correct 373 / 603 What is reactive power? Power consumed by an inductor's wire resistance Wattless, nonproductive power The power consumed in inductors and capacitors Power consumed in circuit Q 374 / 603 In Figure E7-1, what is the purpose of R3? Emitter bypass Self bias Output load resistor Fixed bias 375 / 603 What type of antenna can be used to minimize the effects of spin modulation and Faraday rotation? An isotropic antenna A circularly polarized antenna A linearly polarized antenna A log-periodic dipole array 376 / 603 What is the time constant of a circuit having two 220-microfarad capacitors and two 1-megohm resistors, all in parallel? 55 seconds 220 seconds 110 seconds 440 seconds 377 / 603 Why are received spread spectrum signals resistant to interference? Signals not using the spread spectrum algorithm are suppressed in the receiver The high power used by a spread spectrum transmitter keeps its signal from being easily overpowered Built-in error correction codes minimize interference If the receiver detects interference, it will signal the transmitter to change frequencies 378 / 603 How is positive feedback supplied in a Pierce oscillator? Through link coupling Through a tapped coil Through a neutralizing capacitor Through a quartz crystal 379 / 603 When using rectangular coordinates to graph the impedance of a circuit, what do the axes represent? The X axis represents the resistive component, and the Y axis represents the reactive component The X axis represents the reactive component, and the Y axis represents the resistive component The X axis represents the magnitude, and the Y axis represents the phase angle The X axis represents the phase angle, and the Y axis represents the magnitude 380 / 603 What parasitic characteristic creates an inductor's self-resonance? Coupling Dielectric loss Skin effect Inter-turn capacitance 381 / 603 Which trigger mode is most effective when using an oscilloscope to measure a linear power supply's output ripple? Line Single-shot Level Edge 382 / 603 How much power is being absorbed by the load when a directional power meter connected between a transmitter and a terminating load reads 100 watts forward power and 25 watts reflected power? 125 watts 75 watts 112.5 watts 100 watts 383 / 603 What is the name given to an impurity atom that adds holes to a semiconductor crystal structure? Insulator impurity Acceptor impurity Donor impurity N-type impurity 384 / 603 Which of the following circuits continuously alternates between two states without an external clock signal? Monostable multivibrator T flip-flop Astable multivibrator J-K flip-flop 385 / 603 Which of the following types of linear voltage regulator operates by loading the unregulated voltage source? A series regulator A shunt regulator A constant current source A shunt current source 386 / 603 Which of the following describes an optical shaft encoder? An optical computing device in which light is coupled between devices by fiber optics A device that detects rotation by interrupting a light source with a patterned wheel A device that measures the strength of a beam of light using analog-to-digital conversion A device for generating RTTY signals by means of a rotating light source 387 / 603 What is admittance? The inverse of impedance The inverse of reactance The term for the gain of a field effect transistor The term for the on-impedance of a field effect transistor 388 / 603 What core material property determines the inductance of an inductor? Permittivity Reactivity Resistance Permeability 389 / 603 Which of these digital modes has the narrowest bandwidth? PACTOR IV FT8 170 Hz shift, 45-baud RTTY MFSK16 390 / 603 Why should the phase of a PSK signal be changed at the zero crossing of the RF signal? To minimize bandwidth To simplify modulation To improve carrier suppression All these choices are correct 391 / 603 Which matching system places an inductance across the feed point of a vertical monopole antenna? Gamma Shunt-fed T-match Beta or hairpin 392 / 603 Which of these digital modes has the highest data throughput under clear communication conditions? PACTOR IV FT8 170 Hz shift, 45 baud RTTY MFSK16 393 / 603 Except in some parts of Alaska, what is the maximum power permitted on the 630-meter band? 1 watt EIRP (equivalent isotropic radiated power) 100 watts PEP (peak envelope power) 50 watts PEP (peak envelope power) 5 watts EIRP (equivalent isotropic radiated power) 394 / 603 What are Keplerian elements? High-emission heater filaments used in magnetron tubes Phase reversing elements in a Yagi antenna Parameters that define the orbit of a satellite Encrypting codes used for spread spectrum modulation 395 / 603 What is one way to produce a single-sideband phone signal? Use a balanced modulator followed by a filter Use a reactance modulator followed by a mixer Use a product detector with a DSB signal Use a loop modulator followed by a mixer 396 / 603 From which of the following bands is amateur radio contesting generally excluded? 6 meters 33 centimeters 70 centimeters 30 meters 397 / 603 When evaluating a site with multiple transmitters operating at the same time, the operators and licensees of which transmitters are responsible for mitigating over-exposure situations? Each transmitter operating with a duty cycle greater than 25 percent Each transmitter that produces 20 percent or more of its MPE limit in areas where the total MPE limit is exceeded Each transmitter operating with a duty cycle greater than 50 percent Each transmitter that produces 5 percent or more of its MPE limit in areas where the total MPE limit is exceeded 398 / 603 How do ALE stations establish contact? ALE constantly scans a list of frequencies, activating the radio when the designated call sign is received ALE radios monitor an internet site for the frequency they are being paged on ALE radios send a constant tone code to establish a frequency for future use ALE radios activate when they hear their signal echoed by back scatter 399 / 603 Under what circumstances may a dealer sell an external RF power amplifier capable of operation below 144 MHz if it has not been granted FCC certification? It was manufactured and certificated in a country which has a reciprocal certification agreement with the FCC It was purchased in used condition from an amateur operator and is sold to another amateur operator for use at that operator's station The equipment dealer assembled it from a kit Gain is less than 23 dB when driven by power of 10 watts or less 400 / 603 Where should a shock-absorbing lanyard be attached to a tower when working above ground? Above the climber's head level To the next lowest set of guys Even with the climber's waist To the belt of the fall-arrest harness 401 / 603 What undesirable effect can occur when using a noise blanker? Strong signals may be distorted and appear to cause spurious emissions The audio frequency bandwidth of the received signal might be compressed Received audio in the speech range might have an echo effect FM signals can no longer be demodulated 402 / 603 What is the link margin in a system with a transmit power level of 100 W (+40 dBm), a system antenna gain of 10 dBi, a cable loss of 3 dB, a path loss of 136 dB, a receiver minimum discernable signal of -103 dBm, and a required signal-to-noise ratio of 6 dB? +14dB -14dB +8dB -8dB 403 / 603 What is microstrip? Special shielding material designed for microwave frequencies Miniature coax used for low power applications Precision printed circuit conductors above a ground plane that provide constant impedance interconnects at microwave frequencies Short lengths of coax mounted on printed circuit boards to minimize time delay between microwave circuits 404 / 603 How are the component fields of an electromagnetic wave oriented? They are 90 degrees out of phase They are parallel They are at right angles They are tangential 405 / 603 What happens when the level of a comparator's input signal crosses the threshold voltage? The feedback loop becomes unstable The reference level appears at the output The IC input can be damaged The comparator changes its output state 406 / 603 Which of the following geographic descriptions approximately describes "Line A"? A line roughly parallel to and east of the US Pacific coastline A line roughly parallel to and west of the US Atlantic coastline A line roughly parallel to and north of the border between the US and Mexico A line roughly parallel to and south of the border between the US and Canada 407 / 603 What is the approximate ratio of PEP-to-average power in an unprocessed single-sideband phone signal? 1 to 1 2.5 to 1 13 to 1 25 to 1 408 / 603 What is the maximum permitted transmitter output power when operating a model craft by telecommand? 1 watt 100 watts 5 watts 2 watts 409 / 603 What is an advantage of top loading an electrically short HF vertical antenna? Lower Q Higher losses Greater structural strength Improved radiation efficiency 410 / 603 Which of the following types of modulation is used for data emissions below 30 MHz? Pulse modulation DTMF tones modulating an FM signal Spread spectrum FSK 411 / 603 How does a switchmode voltage regulator work? By switching between two Zener diode reference voltages By varying the duty cycle of pulses input to a filter By alternating the output between positive and negative voltages By varying the conductivity of a pass element 412 / 603 What type of radiation pattern is created by two 1/4-wavelength vertical antennas spaced 1/2-wavelength apart and fed in phase? Omni-directional A figure-eight broadside to the axis of the array A figure-eight end-fire along the axis of the array Cardioid 413 / 603 What is the relationship between the AC current through a capacitor and the voltage across a capacitor? Current leads voltage by 90 degrees Voltage leads current by 90 degrees Voltage and current are in phase Voltage and current are 180 degrees out of phase 414 / 603 What is meant by the term "baseband" in radio communications? The frequency range occupied by a message signal prior to modulation The lowest frequency band that the transmitter or receiver covers The unmodulated bandwidth of the transmitted signal The basic oscillator frequency in an FM transmitter that is multiplied to increase the deviation and carrier frequency 415 / 603 Which of the following is generally true of Finite Impulse Response (FIR) filters? FIR filters are easier to implement for a given set of passband rolloff requirements All these choices are correct FIR filters can respond faster to impulses FIR filters can delay all frequency components of the signal by the same amount 416 / 603 What logical operation does a NAND gate perform? It produces a 0 at its output only if all inputs are 0 It produces a 0 at its output only if all inputs are 1 It produces a 0 at its output if some but not all inputs are 1 It produces a 1 at its output only if all inputs are 1 417 / 603 Which of the following measures a filter's ability to reject signals in adjacent channels? Noise factor Passband ripple Shape factor Phase response 418 / 603 What is a common cause of overmodulation of AFSK signals? Excessive frequency deviation Excessive numbers of retries Excessive transmit audio levels Bit errors in the modem 419 / 603 What is most likely to result in auroral propagation? Quiet geomagnetic conditions Meteor showers Severe geomagnetic storms Extreme low-pressure areas in polar regions 420 / 603 How can data rate be increased without increasing bandwidth? Using forward error correction It is impossible Using a more efficient digital code Increasing analog-to-digital conversion resolution 421 / 603 How does Q65 differ from JT65? Keyboard-to keyboard operation is supported Quadrature modulation is used Multiple receive cycles are averaged All these choices are correct 422 / 603 Which of the following indicates the greatest solar flare intensity? Class A Class X Class Z Class M 423 / 603 What is the equivalent circuit of a quartz crystal? Parallel RLC, where C is the parallel combination of resonance capacitance of the crystal and electrode and stray capacitance Series RLC, where C is the parallel combination of resonance capacitance of the crystal and electrode and stray capacitance Parallel RLC, where C is the series combination of resonance capacitance of the crystal and electrode and stray capacitance Series RLC in parallel with a shunt C representing electrode and stray capacitance 424 / 603 What does a receiver noise floor of -174 dBm represent? The noise figure of a 1 Hz bandwidth receiver The receiver noise is 6 dB above the theoretical minimum The receiver noise is 3 dB above theoretical minimum The theoretical noise in a 1 Hz bandwidth at the input of a perfect receiver at room temperature 425 / 603 What hazard is created by operating at microwave frequencies? The high gain antennas commonly used can result in high exposure levels Microwaves are ionizing radiation Microwaves are in the frequency range where wave velocity is higher The extremely high frequency energy can damage the joints of antenna structures 426 / 603 What notifications must be given before transmitting on the 630- or 2200-meter bands? An environmental impact statement must be filed with the Department of the Interior A special endorsement must be requested from the FCC Operators must inform the Utilities Technology Council (UTC) of their call sign and coordinates of the station Operators must inform the FAA of their intent to operate, giving their call sign and distance to the nearest runway 427 / 603 What causes a junction diode to fail from excessive current? Excessive inverse voltage Excessive junction temperature Charge carrier depletion Insufficient forward voltage 428 / 603 What is the velocity factor of a transmission line? The ratio of its characteristic impedance to its termination impedance The velocity of a wave in the transmission line multiplied by the velocity of light in a vacuum The velocity of a wave in the transmission line divided by the velocity of light in a vacuum The ratio of its termination impedance to its characteristic impedance 429 / 603 What is the efficiency of a photovoltaic cell? The output in lumens divided by the input power in watts The open-circuit voltage divided by the short-circuit current under full illumination The relative fraction of light that is converted to current The output RF power divided by the input DC power 430 / 603 What is a typical range for tropospheric duct propagation of microwave signals? 100 miles to 300 miles 2,500 miles 10 miles to 50 miles 1,200 miles 431 / 603 What letter is commonly used to represent susceptance? X G Y B 432 / 603 Why are odd-order intermodulation products, created within a receiver, of particular interest compared to other products? Odd-order products are an indication of poor image rejection Odd-order products of two signals in the band being received are also likely to be within the band Odd-order products are more likely to overload the IF filters Odd-order intermodulation produces three products for every input signal within the band of interest 433 / 603 What are some of the differences between the Baudot digital code and ASCII? Baudot uses 7 data bits per character, ASCII uses 8; Baudot has no letters/figures shift code, ASCII uses 2 letters/figures shift codes Baudot uses 6 data bits per character, ASCII uses 7 or 8; Baudot has no letters/figures shift code, ASCII uses 2 letters/figures shift codes Baudot uses 4 data bits per character, ASCII uses 7 or 8; Baudot uses 1 character as a letters/figures shift code, ASCII has no letters/figures code Baudot uses 5 data bits per character, ASCII uses 7 or 8; Baudot uses 2 characters as letters/figures shift codes, ASCII has no letters/figures shift code 434 / 603 Which amateur stations may be operated under RACES rules? Any FCC-licensed amateur station except a Technician class Only stations meeting the FCC Part 97 technical standards for operation during an emergency Only those club stations licensed to Amateur Extra class operators Any FCC-licensed amateur station certified by the responsible civil defense organization for the area served 435 / 603 Which of the following is most frequently used as a band-pass or notch filter in VHF and UHF transceivers? A helical filter A finite impulse response filter A swinging choke filter A Sallen-Key filter 436 / 603 Which of the following paths is most likely to support long-distance propagation on 160 meters? A path entirely in sunlight Paths at high latitudes A path entirely in darkness A direct north-south path 437 / 603 What type of modulation is used by JT65? PSK QAM RTTY Multitone AFSK 438 / 603 Which of the following is a type of analog-to-digital conversion? Phase reversal Successive approximation Harmonic regeneration Level shifting 439 / 603 Which group of HF amateur bands include allocations for space stations? 40 meters, 20 meters, 15 meters, and 10 meters 30 meters, 17 meters, and 10 meters Only 10 meters Satellite operation is permitted on all HF bands 440 / 603 To what should lanyards be attached while climbing? Tower legs Tower rungs Guy brackets Antenna mast 441 / 603 What is the purpose of the series capacitor in a gamma match? To provide a rejection notch that prevents the radiation of harmonics To transform the antenna impedance to a higher value To provide DC isolation between the feed line and the antenna To cancel unwanted inductive reactance 442 / 603 Which of the following is an acceptable bandwidth for digital voice or slow-scan TV transmissions made on the HF amateur bands? 10 kHz 15 kHz 3 kHz 20 kHz 443 / 603 Which of the following represents a pure inductive reactance in polar coordinates? A positive 90 degree phase angle A negative 45 degree phase angle A positive 45 degree phase angle A negative 90 degree phase angle 444 / 603 What is the received signal level with a transmit power of 100 W (+40 dBm), a transmit antenna gain of 6 dBi, a receive antenna gain of 3 dBi, and a path loss of 100 dB? -54 dBm -57 dBm -51 dBm -60 dBm 445 / 603 What is susceptance? A measure of the efficiency of a transformer The imaginary part of admittance The magnetic impedance of a circuit The ratio of magnetic field to electric field 446 / 603 When scheduling EME contacts, which of these conditions will generally result in the least path loss? When the Moon is full When the MUF is above 30 MHz When the Moon is at apogee When the Moon is at perigee 447 / 603 What devices are commonly used as VHF and UHF parasitic suppressors at the input and output terminals of a transistor HF amplifier? Ferrite beads Steel-core toroids Butterworth filters Electrolytic capacitors 448 / 603 What happens as the Q of an antenna increases? More common-mode current is present on the feed line SWR bandwidth decreases Gain is reduced SWR bandwidth increases 449 / 603 Which of the following best describes one of the standards that must be met by an external RF power amplifier if it is to qualify for a grant of FCC certification? It must produce full legal output when driven by not more than 5 watts of mean RF input power It must exhibit a gain of less than 23 dB when driven by 10 watts or less It must have received an Underwriters Laboratory certification for electrical safety as well as having met IEEE standard 14.101(B) It must satisfy the FCC's spurious emission standards when operated at the lesser of 1500 watts or its full output power 450 / 603 What technique minimizes the bandwidth of a PSK31 signal? Zero-sum character encoding Use of linear data pulses Reed-Solomon character encoding Use of sinusoidal data pulses 451 / 603 Which of the following can create intermittent loud roaring or buzzing AC line interference? All these choices are correct A defective doorbell or doorbell transformer inside a nearby residence Arcing contacts in a thermostatically controlled device A malfunctioning illuminated advertising display 452 / 603 What is the Cabrillo format? A method of exchanging information during a contest QSO A standard for submission of electronic contest logs A digital protocol specifically designed for rapid contest exchanges The most common set of contest rules 453 / 603 What technology is used for real-time tracking of balloons carrying amateur radio transmitters? PACTOR III FT8 Bandwidth compressed LORAN APRS 454 / 603 Which of the following noise figure values is typical of a low-noise UHF preamplifier? -10 dB 0.5 dB 44 dBm -20 dBm 455 / 603 Which of the following frequency ranges is most suited for meteor-scatter communications? 220 MHz - 450 MHz 28 MHz - 148 MHz 1.8 MHz - 1.9 MHz 10 MHz - 14 MHz 456 / 603 What technique shows that a square wave is made up of a sine wave and its odd harmonics? Differential analysis Fourier analysis Numerical analysis Vector analysis 457 / 603 What can be done to prevent unwanted oscillations in an RF power amplifier? Use a phase inverter in the output filter Tune both the input and output for maximum power Tune the stage for minimum loading Install parasitic suppressors and/or neutralize the stage 458 / 603 What is considered an acceptable maximum IMD level for an idling PSK signal? +10 dB +15 dB +5 dB -30 dB 459 / 603 Which of the following additional rules apply if you are erecting an amateur station antenna structure at a site at or near a public use airport? You may have to enter the height above ground in meters, and the latitude and longitude in degrees, minutes, and seconds on the FAA website You may have to notify the Federal Aviation Administration and register it with the FCC as required by Part 17 of the FCC rules You must file an Environmental Impact Statement with the EPA before construction begins You must obtain a construction permit from the airport zoning authority per Part 119 of the FAA regulations 460 / 603 To what type of regulations does PRB-1 apply? Use of wireless devices in vehicles State and local zoning FAA tower height limits Homeowners associations 461 / 603 What matching system uses a short length of transmission line connected in parallel with the feed line at or near the feed point? Gamma match Delta match T-match Stub match 462 / 603 What is the advantage of including parity bits in ASCII characters? Faster transmission rate Signal-to-noise ratio is improved A larger character set is available Some types of errors can be detected 463 / 603 Why is gallium arsenide (GaAs) useful for semiconductor devices operating at UHF and higher frequencies? Higher noise figures Lower transconductance Higher electron mobility Lower junction voltage drop 464 / 603 What term describing total radiated power takes into account all gains and losses? Effective radiated power Power factor Apparent power Half-power bandwidth 465 / 603 What is the primary effect of extremely short rise or fall time on a CW signal? More difficult to copy More difficult to tune The generation of key clicks The generation of RF harmonics 466 / 603 What does the 304A solar parameter measure? The solar emission at 304 GHz, correlated to X-ray flare levels The ratio of X-ray flux to radio flux, correlated to sunspot number UV emissions at 304 angstroms, correlated to the solar flux index The solar wind velocity at an angle of 304 degrees from the solar equator, correlated to geomagnetic storms 467 / 603 What current flows equally on all conductors of an unshielded multiconductor cable? Reactive current only Common-mode current Magnetically-coupled current only Differential-mode current 468 / 603 What absorbs the energy from light falling on a photovoltaic cell? Photons Holes Protons Electrons 469 / 603 Which of the following has the biggest effect on the velocity factor of a transmission line? The insulating dielectric material The transmission line length The center conductor resistivity The characteristic impedance 470 / 603 How is power supplied to the most common type of MMIC? Through a resistor and/or RF choke connected to the amplifier output lead Directly to the bias voltage (Vcc) lead Through a capacitor and RF choke connected to the amplifier input lead MMICs require no operating bias 471 / 603 As a conductor's diameter increases, what is the effect on its electrical length? It decreases Thickness has no effect on electrical length It increases It varies randomly 472 / 603 What characteristic of a PIN diode makes it useful as an RF switch? Reverse bias controls its forward voltage drop Ability to dissipate large amounts of power Low junction capacitance Extremely high reverse breakdown voltage 473 / 603 What is the noise figure of a receiver? The ratio in dB of the noise generated in the receiver to atmospheric noise The ratio of atmospheric noise to phase noise The ratio of the noise bandwidth in hertz to the theoretical bandwidth of a resistive network The ratio in dB of the noise generated by the receiver to the theoretical minimum noise 474 / 603 What spread spectrum communications technique uses a high-speed binary bit stream to shift the phase of an RF carrier? Frequency hopping Phase compandored spread spectrum Binary phase-shift keying Direct sequence 475 / 603 In digital television, what does a coding rate of 3/4 mean? Three, four-bit words are used to transmit each pixel 1/4 of the time interval is used as a guard interval 25% of the data sent is forward error correction data Data compression reduces data rate by 3/4 476 / 603 Which of the following can be measured by a two-port vector network analyzer? Forward power Pulse rise time Phase noise Filter frequency response 477 / 603 Which point on Figure E5-1 best represents the impedance of a series circuit consisting of a 300-ohm resistor and a 19-picofarad capacitor at 21.200 MHz? Point 3 Point 7 Point 8 Point 1 478 / 603 What is a phase-locked loop? An electronic servo loop consisting of a phase detector, a low-pass filter, a voltage-controlled oscillator, and a stable reference oscillator An electronic circuit consisting of a precision push-pull amplifier with a differential phase input An electronic servo loop consisting of a ratio detector, reactance modulator, and voltage-controlled oscillator An electronic circuit also known as a monostable multivibrator 479 / 603 What is the term for the suppression in an FM receiver of one signal by another stronger signal on the same frequency? Cross-modulation interference Desensitization Frequency discrimination Capture effect 480 / 603 Which of the following techniques is used by digital satellites to relay messages? Store-and-forward Multisatellite relaying Node hopping Digipeating 481 / 603 What is the definition of telemetry? Two-way transmissions in excess of 1000 feet One-way transmission of measurements at a distance from the measuring instrument Two-way transmissions of data One-way transmission that initiates, modifies, or terminates the functions of a device at a distance 482 / 603 Why is it not legal to transmit a 3 kHz bandwidth USB signal with a carrier frequency of 14.348 MHz? The lower 1 kHz of the signal is outside the 20-meter band 14.348 MHz is outside the 20-meter band USB is not used on 20-meter phone The upper 1 kHz of the signal is outside the 20-meter band 483 / 603 What type of radiation pattern is created by two 1/4-wavelength vertical antennas spaced 1/2-wavelength apart and fed 180 degrees out of phase? A figure-eight broadside to the axis of the array Omni-directional Cardioid A figure-eight oriented along the axis of the array 484 / 603 On the Smith chart shown in Figure E9-3, what is the only straight line shown? The resistance axis The current axis The reactance axis The voltage axis 485 / 603 Which of the following can be used to generate FM phone signals? Balanced modulation of the audio amplifier Balanced modulation of a local oscillator Reactance modulation of a local oscillator Reactance modulation of the final amplifier 486 / 603 If an amateur station is installed aboard a ship or aircraft, what condition must be met before the station is operated? The amateur station must have a power supply that is completely independent of the main ship or aircraft power supply The amateur station must operate only in specific segments of the amateur service HF and VHF bands The amateur station operator must agree not to transmit when the main radio of the ship or aircraft is in use Its operation must be approved by the master of the ship or the pilot in command of the aircraft 487 / 603 In Figure E7-1, what is the purpose of R1 and R2? Voltage divider bias Load resistors Self bias Feedback 488 / 603 What is the purpose of placing an electrostatic shield around a small-loop direction-finding antenna? It increases signal strength by providing a better match to the feed line It eliminates unbalanced capacitive coupling to the antenna's surroundings, improving the depth of its nulls It eliminates tracking errors caused by strong out-of-band signals It adds capacitive loading, increasing the bandwidth of the antenna 489 / 603 Which of the following types of signals can be relayed through a linear transponder? All these choices are correct PSK and packet FM and CW SSB and SSTV 490 / 603 How is positive feedback supplied in a Colpitts oscillator? Through a capacitive divider Through a tapped coil Through a neutralizing capacitor Through link coupling 491 / 603 What combines to create the self-resonance of a component? The component's nominal and parasitic reactance The component's electrical length and impedance The component's inductance and capacitance The component's resistance and reactance 492 / 603 What is the characteristic of the JT65 mode? Permits fast-scan TV transmissions over narrow bandwidth Uses only a 65 Hz bandwidth Symbol rate is 65 baud Decodes signals with a very low signal-to-noise ratio 493 / 603 Which amateur stations are eligible to be telecommand stations of space stations, subject to the privileges of the class of operator license held by the control operator of the station? Any amateur station approved by AMSAT Any amateur station so designated by the space station licensee Any amateur station so designated by the ITU All these choices are correct 494 / 603 What is reciprocal mixing? In-phase signals cancelling in a mixer resulting in loss of receiver sensitivity Two out-of-band signals mixing to generate an in-band spurious signal Local oscillator phase noise mixing with adjacent strong signals to create interference to desired signals Two digital signals combining from alternate time slots 495 / 603 What creates intermodulation interference between two repeaters in close proximity? The output frequencies are harmonically related The output signals mix in the final amplifier of one or both transmitters The input frequencies are harmonically related The output signals cause feedback in the final amplifier of one or both transmitters 496 / 603 What causes interference received as a series of carriers at regular intervals across a wide frequency range? Wireless security camera transmitters Switch-mode power supplies Electric fences Radar transmitters 497 / 603 What is the function of the vertical interval signaling (VIS) code sent as part of an SSTV transmission? To identify the SSTV mode being used To provide vertical synchronization To lock the color burst oscillator in color SSTV images To identify the call sign of the station transmitting 498 / 603 What occurs when the input signal levels to a mixer are too high? Automatic limiting occurs Spurious mixer products are generated Excessive AGC voltage levels are generated Mixer blanking occurs 499 / 603 Which of the following HF digital modes can be used to transfer binary files? AMTOR RTTY PSK31 PACTOR 500 / 603 Which type of core material decreases inductance when inserted into a coil? Aluminum Ceramic Ferrite Brass 501 / 603 Which of the following contacts may be confirmed through the Logbook of The World (LoTW)? Contacts for Worked All States credit All these choices are correct Contacts between a US station and a non-US station Special event contacts between stations in the US 502 / 603 What Yagi driven element feed point impedance is required to use a beta or hairpin matching system? Purely resistive Inductive (driven element electrically longer than 1/2 wavelength) Purely reactive Capacitive (driven element electrically shorter than 1/2 wavelength) 503 / 603 Which describes spread spectrum frequency hopping? A binary bit stream is used to shift the phase of an RF carrier very rapidly in a pseudorandom sequence RF signals are clipped to generate a wide band of harmonics which provides redundancy to correct errors Rapidly varying the frequency of a transmitted signal according to a pseudorandom sequence If interference is detected by the receiver, it will signal the transmitter to change frequencies 504 / 603 What must the VE team do if an examinee scores a passing grade on all examination elements needed for an upgrade or new license? Three VEs must certify that the examinee is qualified for the license grant and that they have complied with the administering VE requirements All these choices are correct Photocopy all examination documents and forward them to the FCC for processing Issue the examinee the new or upgrade license 505 / 603 What is the frequency response of a T-network with series capacitors and a shunt inductor? High-pass Low-pass Notch Band-pass 506 / 603 Which of these functions can be performed by a phase-locked loop? Wide-band AF and RF power amplification Photovoltaic conversion and optical coupling Frequency synthesis and FM demodulation Comparison of two digital input signals and digital pulse counting 507 / 603 In what portion of the 630-meter band are phone emissions permitted? Only the bottom 3 kHz None The entire band Only the top 3 kHz 508 / 603 Which of the following describes a G5RV antenna? A wire antenna center-fed through a specific length of open-wire line connected to a balun and coaxial feed line A multi-band trap antenna A wide band dipole using shorted coaxial cable for the radiating elements and fed with a 4:1 balun A phased array antenna consisting of multiple loops 509 / 603 How can two linearly polarized Yagi antennas be used to produce circular polarization? Stack two Yagis to form an array with the respective elements in parallel planes fed 90 degrees out of phase Arrange two Yagis collinear to each other with the driven elements fed 180 degrees out of phase Stack two Yagis to form an array with the respective elements in parallel planes fed in phase Arrange two Yagis on the same axis and perpendicular to each other with the driven elements at the same point on the boom and fed 90 degrees out of phase 510 / 603 What is meant by the "mode" of an amateur radio satellite? The satellite's orientation with respect to the Earth The satellite's uplink and downlink frequency bands Whether the satellite is in a low earth or geostationary orbit Whether the satellite is in a polar or equatorial orbit 511 / 603 Which of the following types of amateur station communications are prohibited? Communications in a language other than English Communications transmitted for hire or material compensation, except as otherwise provided in the rules Communications that have religious content Communications that have political content, except as allowed by the Fairness Doctrine 512 / 603 Which of the following reduces the likelihood of receiver desensitization? Insert attenuation before the first RF stage Raise the receiver's IF frequency Increase the receiver's front-end gain Switch from fast AGC to slow AGC 513 / 603 What is the deviation ratio of an FM phone signal having a maximum frequency swing of plus or minus 5 kHz if the highest modulation frequency is 3 kHz? 0.167 6 0.6 1.67 514 / 603 What is a primary advantage of using a toroidal core instead of a solenoidal core in an inductor? Toroidal cores have lower Q characteristics Toroidal cores confine most of the magnetic field within the core material Toroidal cores make it easier to couple the magnetic energy into other components Toroidal cores exhibit greater hysteresis 515 / 603 What is a common use for point-contact diodes? As a high-voltage rectifier As an RF detector As a constant voltage source As a constant current source 516 / 603 Which of the following can cause shielded cables to radiate or receive interference? Tying all ground connections to a common point resulting in differential-mode currents in the shield Common-mode currents on the shield and conductors Use of braided shielding material Low inductance ground connections at both ends of the shield 517 / 603 When a meteor strikes the Earth's atmosphere, a linear ionized region is formed at what region of the ionosphere? The D region The E region The F2 region The F1 region 518 / 603 Why are DIP through-hole package ICs not typically used at UHF and higher frequencies? Epoxy coating is conductive above 300 MHz Excessive lead length Unsuitable for combining analog and digital signals Excessive dielectric loss 519 / 603 Which of the following frequencies can be used for amateur radio mesh networks? Cable TV channels 41-43 The 60-meter band channel centered on 5373 kHz HF frequencies where digital communications are permitted Frequencies shared with various unlicensed wireless data services 520 / 603 How is an upload signal processed by an inverting linear transponder? The signal is reduced to I and Q components, and the Q component is filtered out The signal is detected and remodulated on the reverse sideband The signal is mixed with a local oscillator signal and the difference product is transmitted The signal is passed through a nonlinear filter 521 / 603 What is the function of a loading coil in an electrically short antenna? To resonate the antenna by cancelling the capacitive reactance To lower the losses To increase the SWR bandwidth by increasing net reactance To lower the Q 522 / 603 What impedance does a 1/8-wavelength transmission line present to an RF generator when the line is shorted at the far end? The same as the characteristic impedance of the line A capacitive reactance An inductive reactance Zero 523 / 603 What antenna matching system matches coaxial cable to an antenna by connecting the shield to the center of the antenna and the conductor a fraction of a wavelength to one side? Delta match T-match Gamma match Stub match 524 / 603 What is the half-power bandwidth of a resonant circuit that has a resonant frequency of 3.7 MHz and a Q of 118? 31.4 kHz 436.6 kHz 218.3 kHz 15.7 kHz 525 / 603 What is the required transmit frequency of a CW signal for channelized 60 meter operation? On any frequency where the signal's sidebands are within the channel At the highest frequency of the channel At the lowest frequency of the channel At the center frequency of the channel 526 / 603 What sets the minimum detectable signal level for a direct-sampling software defined receiver in the absence of atmospheric or thermal noise? Data storage transfer rate Reference voltage level and sample width in bits Sample clock phase noise Missing codes and jitter 527 / 603 Under what situation may a station transmit third party communications while being automatically controlled? On any mode approved by the National Telecommunication and Information Administration Only when transmitting RTTY or data emissions Never Only when transmitting SSB or CW 528 / 603 How does ARQ accomplish error correction? Special binary codes provide automatic correction If errors are detected, redundant data is substituted Special polynomial codes provide automatic correction If errors are detected, a retransmission is requested 529 / 603 What is an isotropic radiator? A calibrated, unidirectional antenna used to make precise antenna gain measurements An omnidirectional, horizontally polarized, precisely calibrated antenna used to make field measurements of antenna gain A hypothetical, lossless antenna having equal radiation intensity in all directions used as a reference for antenna gain A spacecraft antenna used to direct signals toward Earth 530 / 603 What is the function of a Beverage antenna's termination resistor? Absorb signals from the reverse direction Decrease SWR bandwidth Eliminate harmonic reception Increase the front-to-side ratio 531 / 603 Which of the following factors affect the feed point impedance of an antenna? Transmission line length The input power level The settings of an antenna tuner at the transmitter Antenna height 532 / 603 Why are switching amplifiers more efficient than linear amplifiers? Linear amplifiers have high gain resulting in higher harmonic content The switching device is at saturation or cutoff most of the time Switching amplifiers use push-pull circuits Switching amplifiers operate at higher voltages 533 / 603 Which of the following is a method for establishing EME contacts? Judging optimum transmission times by monitoring beacons reflected from the moon Storing and forwarding digital messages High-speed CW identification to avoid fading Time-synchronous transmissions alternating between stations 534 / 603 How is color information sent in analog SSTV? Color is amplitude modulated on the frequency modulated intensity signal Color is sent in a color burst at the end of each line Color information is sent on a 2.8 kHz subcarrier Color lines are sent sequentially 535 / 603 What is the National Radio Quiet Zone? An area in New Mexico surrounding the White Sands Test Area An area in Florida surrounding Cape Canaveral An area surrounding the FCC monitoring station in Laurel, Maryland An area surrounding the National Radio Astronomy Observatory 536 / 603 What should be done to continue a long-distance contact when the MUF for that path decreases due to darkness? Change to an antenna with greater beam width Change to an antenna with a higher takeoff angle Switch to a lower frequency HF band Switch to a higher frequency HF band 537 / 603 Which of the following can divide the frequency of a pulse train by 2? An OR gate An XOR gate A flip-flop A multiplexer 538 / 603 Which of these digital modes does not support keyboard-to-keyboard operation? WSPR RTTY PSK31 MFSK16 539 / 603 Which of the following cannot be transmitted over an amateur radio mesh network? Messages encoded to obscure their meaning Email Third party traffic All these choices are correct 540 / 603 How does a narrow-band roofing filter affect receiver performance? All these choices are correct It improves intelligibility by using low Q circuitry to reduce ringing It improves blocking dynamic range by attenuating strong signals near the receive frequency It improves sensitivity by reducing front-end noise 541 / 603 How are impedances described in polar coordinates? By real and imaginary parts By Y and G values By X and R values By magnitude and phase angle 542 / 603 What type of satellite appears to stay in one position in the sky? Geomagnetic Geostationary HEO LEO 543 / 603 What is the function of taps in a digital signal processing filter? Select the point at which baseband signals are generated To reduce excess signal pressure levels Provide access for debugging software Provide incremental signal delays for filter algorithms 544 / 603 What is indicated by a rising A-index or K-index? An increase in the critical frequency Decreasing disturbance of the geomagnetic field Higher levels of solar UV radiation Increasing disturbance of the geomagnetic field 545 / 603 Which of the following filters is used in a 2-meter band repeater duplexer? An L-C filter A DSP filter A cavity filter A crystal filter 546 / 603 What is a characteristic of a grounded-grid amplifier? High power gain Low bandwidth High electrostatic damage protection Low input impedance 547 / 603 Under what circumstances might the FCC issue a Special Temporary Authority (STA) to an amateur station? To allow a licensee who has passed an upgrade exam to operate with upgraded privileges while waiting for posting on the FCC database To allow a VE group with less than three VEs to administer examinations in a remote, sparsely populated area To provide for experimental amateur communications To allow use of a special event call sign 548 / 603 What is the most common configuration of an optoisolator or optocoupler? A frequency-modulated helium-neon laser An LED and a phototransistor An amplitude-modulated helium-neon laser A lens and a photomultiplier 549 / 603 Which circuit is bistable? A bipolar amplifier An AND gate A flip-flop An OR gate 550 / 603 What indicates the delay between a control operator action and the corresponding change in the transmitted signal? Latency Jitter Anti-VOX Hang time 551 / 603 What kind of digital signal processing audio filter is used to remove unwanted noise from a received SSB signal? A crystal-lattice filter A phase-inverting filter An adaptive filter A Hilbert-transform filter 552 / 603 Which of the following is used to reduce or eliminate intermodulation interference in a repeater caused by a nearby transmitter? Utilizing a Class C final amplifier A properly terminated circulator at the output of the repeater's transmitter Utilizing a Class D final amplifier A band-pass filter in the feed line between the transmitter and receiver 553 / 603 What is the front-to-side ratio of the antenna radiation pattern shown in Figure E9-1? 14 dB 24 dB 12 dB 18 dB 554 / 603 How does the maximum range of ground-wave propagation change when the signal frequency is increased? It decreases It peaks at roughly 8 MHz It stays the same It increases 555 / 603 What is the primary cause of loss in film capacitors at RF? Skin effect Dielectric loss Self-discharge Inductance 556 / 603 What is the definition of symbol rate in a digital transmission? The maximum rate at which the forward error correction code can make corrections The rate at which the waveform changes to convey information The number of control characters in a message packet The number of characters carried per second by the station-to-station link 557 / 603 What is the function of a reactance modulator? Produce AM signals by varying an inductance Produce PM or FM signals by varying a resistance Produce AM signals by varying a resistance Produce PM or FM signals by varying a capacitance 558 / 603 What determines the speed of electromagnetic waves through a medium? The index of refraction Resistance and reactance Birefringence Evanescence 559 / 603 What determines the PEP-to-average power ratio of an unprocessed single-sideband phone signal? Amplifier gain The frequency of the modulating signal Speech characteristics The degree of carrier suppression 560 / 603 Which of the following would allow a digital signal processing filter to create a sharper filter response? Double-precision math routines Lower Q Higher data rate More taps 561 / 603 What licensing is required when operating an amateur station aboard a US-registered vessel in international waters? Any FCC-issued amateur license An unrestricted Radiotelephone Operator Permit Only General class or higher amateur licenses Any amateur license with an FCC Marine or Aircraft endorsement 562 / 603 What could be the cause of local AM broadcast band signals combining to generate spurious signals on the MF or HF bands? Your station receiver IF amplifier stage is overloaded Nearby corroded metal connections are mixing and reradiating the broadcast signals One or more of the broadcast stations is transmitting an over-modulated signal You are receiving skywave signals from a distant station 563 / 603 Why do DX stations often transmit and receive on different frequencies? All these choices are correct To improve operating efficiency by reducing interference Because the DX station may be transmitting on a frequency that is prohibited to some responding stations To separate the calling stations from the DX station 564 / 603 Which of the following describes an extended double Zepp antenna? An end-fed full-wave dipole antenna A center-fed 1.5-wavelength dipole antenna An end-fed 2-wavelength dipole antenna A center-fed 1.25-wavelength dipole antenna 565 / 603 What type of amplifier circuit is shown in Figure E7-1? Common collector Emitter follower Common base Common emitter 566 / 603 What limitations may the FCC place on an amateur station if its signal causes interference to domestic broadcast reception, assuming that the receivers involved are of good engineering design? The amateur station must cease operation on all frequencies above 30 MHz The amateur station must avoid transmitting during certain hours on frequencies that cause the interference The amateur station must cease operation on all frequencies below 30 MHz The amateur station must cease operation 567 / 603 Which of the following is a measure of the quality of an analog-to-digital converter? Total harmonic distortion Power factor Peak envelope power Reciprocal mixing 568 / 603 Which of the following receiver circuits can be effective in eliminating interference from strong out-of-band signals? A notch filter A narrow IF filter A front-end filter or preselector A properly adjusted product detector 569 / 603 What is the magnitude of the circulating current within the components of a parallel LC circuit at resonance? It is at a minimum It is at a maximum It equals 2 times pi, times the square root of (inductance L multiplied by capacitance C) It equals 1 divided by the quantity 2 times pi, times the square root of (inductance L multiplied by capacitance C) 570 / 603 What type of packet frame is used to transmit APRS beacon data? Burst Acknowledgement Connect Unnumbered Information 571 / 603 What kind of diagram is used to show the phase relationship between impedances at a given frequency? Venn diagram Far field diagram Phasor diagram Near field diagram 572 / 603 What parasitic characteristic causes electrolytic capacitors to be unsuitable for use at RF? Inductance Skin effect Shunt capacitance Dielectric leakage 573 / 603 Why is a switching type power supply less expensive and lighter than an equivalent linear power supply? The control circuitry uses less current, therefore smaller heat sinks are required It recovers power from the unused portion of the AC cycle, thus using fewer components The high frequency inverter design uses much smaller transformers and filter components for an equivalent power output The inverter design does not require an output filter circuit 574 / 603 What is the most efficient location for a loading coil on an electrically short whip? At a voltage maximum As low as possible on the vertical radiator Near the center of the vertical radiator At a voltage null 575 / 603 What is the effective isotropic radiated power (EIRP) of a repeater station with 200 watts transmitter power output, 2 dB feed line loss, 2.8 dB duplexer loss, 1.2 dB circulator loss, and 7 dBi antenna gain? 252 watts 632 watts 63.2 watts 159 watts 576 / 603 Which of the following is an aspect of the piezoelectric effect? Mechanical deformation of material due to the application of a magnetic field Mechanical deformation of material due to the application of a voltage Generation of electrical energy in the presence of light Increased conductivity in the presence of light 577 / 603 What is the front-to-back ratio of the radiation pattern shown in Figure E9-2? 38 dB 3 dB 15 dB 28 dB 578 / 603 What is meant by "direct sampling" in software defined radios? Software is converted from source code to object code during operation of the receiver A switching mixer is used to generate I and Q signals directly from the RF input I and Q signals are generated by digital processing without the use of RF amplification Incoming RF is digitized by an analog-to-digital converter without being mixed with a local oscillator signal 579 / 603 Why should effective radiated power (ERP) be limited to a satellite that uses a linear transponder? To prevent creating errors in the satellite telemetry To avoid reducing the downlink power to all other users To prevent the satellite from emitting out-of-band signals To avoid interfering with terrestrial QSOs 580 / 603 Why are there separate electric (E) and magnetic (H) MPE limits at frequencies below 300 MHz? Ground reflections and scattering cause the field strength to vary with location The body reacts to electromagnetic radiation from both the E and H fields E field and H field radiation intensity peaks can occur at different locations All these choices are correct 581 / 603 Which of the following is a significant difference between foam dielectric coaxial cable and solid dielectric coaxial cable, assuming all other parameters are the same? Foam dielectric coaxial cable has lower loss per unit of length Foam dielectric coaxial cable has higher velocity factor All these choices are correct Foam dielectric coaxial cable has lower safe maximum operating voltage 582 / 603 What should a VE do if a candidate fails to comply with the examiner's instructions during an amateur operator license examination? Immediately terminate the candidate's examination Immediately terminate everyone's examination and close the session Warn the candidate that continued failure to comply will result in termination of the examination Allow the candidate to complete the examination, but invalidate the results 583 / 603 What is the modulation index of an FM phone signal having a maximum frequency deviation of 3000 Hz either side of the carrier frequency if the highest modulating frequency is 1000 Hz? 3 0.3 6 0.6 584 / 603 What must the VE team do with the application form if the examinee does not pass the exam? Return the application document to the examinee Maintain the application form with the VEC's records Send the application form to the FCC and inform the FCC of the grade Destroy the application form 585 / 603 What is the function of a DX QSL Manager? Communicate to a DXpedition about propagation, band openings, pileup conditions, etc. Allocate frequencies for DXpeditions Run a net to allow many stations to contact a rare DX station Handle the receiving and sending of confirmations for a DX station 586 / 603 In what application is gallium arsenide used as a semiconductor material? In very low-frequency RF circuits In high-power audio circuits In high-current rectifier circuits In microwave circuits 587 / 603 What is a space telecommand station? An amateur station that transmits communications to initiate, modify, or terminate functions of a space station An amateur station located in a satellite or a balloon more than 50 kilometers above the surface of the Earth An amateur station located on the surface of the Earth for communication with other Earth stations by means of Earth satellites An amateur station that receives telemetry from a satellite or balloon more than 50 kilometers above the surface of the Earth 588 / 603 On the Smith chart shown in Figure E9-3, what is the name for the large outer circle on which the reactance arcs terminate? Reactance axis Polar axis Impedance axis Prime axis 589 / 603 What is the term for the time required for the capacitor in an RC circuit to be charged to 63.2% of the applied voltage or to discharge to 36.8% of its initial voltage? One exponential period An exponential rate of one A time factor of one One time constant 590 / 603 Which types of modulation are used for amateur television DVB-T signals? All these choices are correct AM and OOK QAM and QPSK FM and FSK 591 / 603 What does the impedance 50 - j25 ohms represent? 50 ohms resistance in series with 25 ohms capacitive reactance 25 ohms resistance in series with 50 ohms inductive reactance 25 ohms resistance in series with 50 ohms capacitive reactance 50 ohms resistance in series with 25 ohms inductive reactance 592 / 603 What is a characteristic of DIP packaging used for integrated circuits? Two chips in each package (dual in package) Extremely low stray capacitance (dielectrically isolated package) Two rows of connecting pins on opposite sides of package (dual in-line package) Extremely high resistance between pins (doubly insulated package) 593 / 603 Why is an anti-aliasing filter required in a decimator? It removes high-frequency signal components that would otherwise be reproduced as lower frequency components It peaks the response of the decimator, improving bandwidth It removes low-frequency signal components to eliminate the need for DC restoration It notches out the sampling frequency to avoid sampling errors 594 / 603 How is the far-field elevation pattern of a vertically polarized antenna affected by being mounted over seawater versus soil? Radiation at low angles increases Additional lobes appear at higher elevation angles Radiation at low angles decreases Separate elevation lobes will combine into a single lobe 595 / 603 To what does the "4" in FT4 refer? Multiples of 4 bits of user information Four transmit/receive cycles per minute All these choices are correct Four-tone continuous-phase frequency shift keying 596 / 603 In Figure E6-1, which is the schematic symbol for a P-channel junction FET? 3 6 1 2 597 / 603 Why are direct or flash conversion analog-to-digital converters used for a software defined radio? Very high speed allows digitizing high frequencies All these choices are correct Very low power consumption decreases frequency drift Immunity to out-of-sequence coding reduces spurious responses 598 / 603 What is the difference between direct FSK and audio FSK? Direct FSK can transmit higher baud rates Direct FSK modulates the transmitter VFO All these choices are correct Direct FSK occupies less bandwidth 599 / 603 What happens to reactive power in ideal inductors and capacitors? It is dissipated in the formation of inductive and capacitive fields It is canceled by Coulomb forces in the capacitor and inductor It is dissipated as heat in the circuit Energy is stored in magnetic or electric fields, but power is not dissipated 600 / 603 Which of the following describes a three-terminal voltage regulator? A shunt current source A series current source A series regulator A shunt regulator 601 / 603 What describes orthogonal frequency-division multiplexing (OFDM)? A digital modulation technique using subcarriers at frequencies chosen to avoid intersymbol interference A digital mode for narrow-band, slow-speed transmissions A frequency modulation technique that uses non-harmonically related frequencies A bandwidth compression technique using Fourier transforms 602 / 603 What are circularly polarized electromagnetic waves? Waves that circle Earth Waves with rotating electric and magnetic fields Waves with an electric field bent into a circular shape Waves produced by a loop antenna 603 / 603 What is receiving directivity factor (RDF)? Relative directivity compared to isotropic Forward gain compared to the gain in the reverse direction Relative directivity compared to a dipole Peak antenna gain compared to average gain over the hemisphere around and above the antenna Your score is 0% Restart quiz
