General study3
How is an LED biased when emitting light? A. Beyond cutoff B. At the Zener voltage C. Reverse biased D. Forward biased
D
In what units is RF feed line loss usually expressed? A. Ohms per 1000 feet B. Decibels per 1000 feet C. Ohms per 100 feet D. Decibels per 100 feet
D
What circuit is used in analog FM receivers to convert IF output signals to audio? A. Product detector B. Phase inverter C. Mixer D. Discriminator
D
What circuit is used to combine signals from the IF amplifier and BFO and send the result to the AF amplifier in some single sideband receivers? A. RF oscillator B. IF filter C. Balanced modulator D. Product detector
D
What configuration of the loops of a two-element quad antenna must be used for the antenna to operate as a beam antenna, assuming one of the elements is used as a reflector? A. The driven element must be fed with a balun transformer B. There must be an open circuit in the driven element at the point opposite the feed point C. The reflector element must be approximately 5 percent shorter than the driven element D. The reflector element must be approximately 5 percent longer than the driven element
D
What does "time averaging" mean in reference to RF radiation exposure? A. The average amount of power developed by the transmitter over a specific 24-hour period B. The average time it takes RF radiation to have any long-term effect on the body C. The total time of the exposure D. The total RF exposure averaged over a certain time
D
What is an advantage of using a ferrite core toroidal inductor? A. Large values of inductance may be obtained B. The magnetic properties of the core may be optimized for a specific range of frequencies C. Most of the magnetic field is contained in the core D. All these choices are correct
D
The bandwidth of a band-pass filter is measured between what two frequencies? A. Upper and lower half-power B. Cutoff and rolloff C. Pole and zero D. Image and harmonic
A
Approximately how long is each side of the driven element of a quad antenna? A. 1/4 wavelength B. 1/2 wavelength C. 3/4 wavelength D. 1 wavelength
A
How do the lengths of a three-element Yagi reflector and director compare to that of the driven element? A. The reflector is longer, and the director is shorter B. The reflector is shorter, and the director is longer C. They are all the same length D. Relative length depends on the frequency of operation
A
How does a ferrite bead or core reduce common-mode RF current on the shield of a coaxial cable? A. By creating an impedance in the current's path B. It converts common-mode current to differential mode C. By creating an out-of-phase current to cancel the common-mode current D. Ferrites expel magnetic fields
A
How does increasing boom length and adding directors affect a Yagi antenna? A. Gain increases B. Beamwidth increases C. Front-to-back ratio decreases D. Front-to-side ratio decreases
A
How does the feed point impedance of a 1/2 wave dipole change as the feed point is moved from the center toward the ends? A. It steadily increases B. It steadily decreases C. It peaks at about 1/8 wavelength from the end D. It is unaffected by the location of the feed point
A
How does the forward gain of a two-element quad antenna compare to the forward gain of a three-element Yagi antenna? A. About the same B. About 2/3 as much C. About 1.5 times as much D. About twice as much
A
In the PACTOR protocol, what is meant by a NAK response to a transmitted packet? A. The receiver is requesting the packet be retransmitted B. The receiver is reporting the packet was received without error C. The receiver is busy decoding the packet D. The entire file has been received correctly
A
What are the stable operating points for a bipolar transistor used as a switch in a logic circuit? A. Its saturation and cutoff regions B. Its active region (between the cutoff and saturation regions) C. Its peak and valley current points D. Its enhancement and depletion modes
A
What does the number 31 represent in "PSK31"? A. The approximate transmitted symbol rate B. The version of the PSK protocol C. The year in which PSK31 was invented D. The number of characters that can be represented by PSK31
A
What effect does transmitter duty cycle have when evaluating RF exposure? A. A lower transmitter duty cycle permits greater short-term exposure levels B. A higher transmitter duty cycle permits greater short-term exposure levels C. Low duty cycle transmitters are exempt from RF exposure evaluation requirements D. High duty cycle transmitters are exempt from RF exposure requirements
A
What is a beta or hairpin match? A. It is a shorted transmission line stub placed at the feed point of a Yagi antenna to provide impedance matching B. It is a ¼ wavelength section of 75 ohm coax in series with the feed point of a Yagi to provide impedance matching C. It is a series capacitor selected to cancel the inductive reactance of a folded dipole antenna D. It is a section of 300 ohm twinlead used to match a folded dipole antenna
A
What is a shift register? A. A clocked array of circuits that passes data in steps along the array B. An array of operational amplifiers used for tri-state arithmetic operations C. A digital mixer D. An analog mixer
A
What is an advantage of a half-wave rectifier in a power supply? A. Only one diode is required B. The ripple frequency is twice that of a full-wave rectifier C. More current can be drawn from the half-wave rectifier D. The output voltage is two times the peak output voltage of the transformer
A
What is another term for the mixing of two RF signals? A. Heterodyning B. Synthesizing C. Cancellation D. Phase inverting
A
What is meant by the term "software-defined radio" (SDR)? A. A radio in which most major signal processing functions are performed by software B. A radio that provides computer interface for automatic logging of band and frequency C. A radio that uses crystal filters designed using software D. A computer model that can simulate performance of a radio to aid in the design process
A
What is meant by the terms dBi and dBd when referring to antenna gain? A. dBi refers to an isotropic antenna, dBd refers to a dipole antenna B. dBi refers to an ionospheric reflecting antenna, dBd refers to a dissipative antenna C. dBi refers to an inverted-vee antenna, dBd refers to a downward reflecting antenna D. dBi refers to an isometric antenna, dBd refers to a discone antenna
A
What is one way that RF energy can affect human body tissue? A. It heats body tissue B. It causes radiation poisoning C. It causes the blood count to reach a dangerously low level D. It cools body tissue
A
What is the approximate length for a 1/4 wave vertical antenna cut for 28.5 MHz? A. 8 feet B. 11 feet C. 16 feet D. 21 feet
A
What is the common name of a dipole with a single central support? A. Inverted V B. Inverted L C. Sloper D. Lazy H
A
What is the effect of transmission line loss on SWR measured at the input to the line? A. The higher the transmission line loss, the more the SWR will read artificially low B. The higher the transmission line loss, the more the SWR will read artificially high C. The higher the transmission line loss, the more accurate the SWR measurement will be D. Transmission line loss does not affect the SWR measurement
A
What is the modulation envelope of an AM signal? A. The waveform created by connecting the peak values of the modulated signal B. The carrier frequency that contains the signal C. Spurious signals that envelop nearby frequencies D. The bandwidth of the modulated signal
A
What is the output waveform of an unfiltered full-wave rectifier connected to a resistive load? A. A series of DC pulses at twice the frequency of the AC input B. A series of DC pulses at the same frequency as the AC input C. A sine wave at half the frequency of the AC input D. A steady DC voltage
A
What is the primary purpose of a screen grid in a vacuum tube? A. To reduce grid-to-plate capacitance B. To increase efficiency C. To increase the control grid resistance D. To decrease plate resistance
A
What is the primary purpose of antenna traps? A. To permit multiband operation B. To notch spurious frequencies C. To provide balanced feed-point impedance D. To prevent out-of-band operation
A
What is the primary use of a Beverage antenna? A. Directional receiving for low HF bands B. Directional transmitting for low HF bands C. Portable direction finding at higher HF frequencies D. Portable direction finding at lower HF frequencies
A
What is the radiation pattern of a dipole antenna in free space in a plane containing the conductor? A. It is a figure-eight at right angles to the antenna B. It is a figure-eight off both ends of the antenna C. It is a circle (equal radiation in all directions) D. It has a pair of lobes on one side of the antenna and a single lobe on the other side
A
What is the total resistance of a 10 ohm, a 20 ohm, and a 50 ohm resistor connected in parallel? A. 5.9 ohms B. 0.17 ohms C. 10000 ohms D. 80 ohms
A
What must you do if an evaluation of your station shows RF energy radiated from your station exceeds permissible limits? A. Take action to prevent human exposure to the excessive RF fields B. File an Environmental Impact Statement (EIS-97) with the FCC C. Secure written permission from your neighbors to operate above the controlled MPE limits D. All these choices are correct
A
What must you do when powering your house from an emergency generator? A. Disconnect the incoming utility power feed B. Insure that the generator is not grounded C. Insure that all lightning grounds are disconnected D. All these choices are correct
A
What process combines two signals in a non-linear circuit or connection to produce unwanted spurious outputs? A. Intermodulation B. Heterodyning C. Detection D. Rolloff
A
What standing wave ratio will result when connecting a 50 ohm feed line to a non-reactive load having 200 ohm impedance? A. 4:1 B. 1:4 C. 2:1 D. 1:2
A
What term specifies a filter's attenuation inside its passband? A. Insertion loss B. Return loss C. Q D. Ultimate rejection
A
What type of modulation is used by the FT8 digital mode? A. 8-tone frequency shift keying B. Vestigial sideband C. Amplitude compressed AM D. Direct sequence spread spectrum
A
Which digital mode is used as a low-power beacon for assessing HF propagation? A. WSPR B. Olivia C. PSK31 D. SSB-SC
A
Which element of a triode vacuum tube is used to regulate the flow of electrons between cathode and plate? A. Control grid B. Heater C. Screen grid D. Trigger electrode
A
Which of the following antenna types will be most effective as a Near Vertical Incidence Skywave (NVIS) antenna for short-skip communications on 40 meters during the day? A. A horizontal dipole placed between 1/10 and 1/4 wavelength above the ground B. A vertical antenna placed between 1/4 and 1/2 wavelength above the ground C. A left-hand circularly polarized antenna D. A right-hand circularly polarized antenna
A
Which of the following describes a log periodic antenna? A. Element length and spacing vary logarithmically along the boom B. Impedance varies periodically as a function of frequency C. Gain varies logarithmically as a function of frequency D. SWR varies periodically as a function of boom length
A
Which of the following describes a type N connector? A. A moisture-resistant RF connector useful to 10 GHz B. A small bayonet connector used for data circuits C. A threaded connector used for hydraulic systems D. An audio connector used in surround-sound installations
A
Which of the following factors determine the characteristic impedance of a parallel conductor antenna feed line? A. The distance between the centers of the conductors and the radius of the conductors B. The distance between the centers of the conductors and the length of the line C. The radius of the conductors and the frequency of the signal D. The frequency of the signal and the length of the line
A
Which of the following is a characteristic of a liquid crystal display? A. It utilizes ambient or back lighting B. It offers a wide dynamic range C. It consumes relatively high power D. It has relatively short lifetime
A
Which of the following is a danger from lead-tin solder? A. Lead can contaminate food if hands are not washed carefully after handling the solder B. High voltages can cause lead-tin solder to disintegrate suddenly C. Tin in the solder can "cold flow," causing shorts in the circuit D. RF energy can convert the lead into a poisonous gas ~~
A
Which of the following is a primary reason for not placing a gasoline-fueled generator inside an occupied area? A. Danger of carbon monoxide poisoning B. Danger of engine over torque C. Lack of oxygen for adequate combustion D. Lack of nitrogen for adequate combustion
A
Which of the following is a typical application for a Direct Digital Synthesizer? A. A high-stability variable frequency oscillator in a transceiver B. A digital voltmeter C. A digital mode interface between a computer and a transceiver D. A high-sensitivity radio direction finder
A
Which of the following is an advantage of CMOS integrated circuits compared to TTL integrated circuits? A. Low power consumption B. High power handling capability C. Better suited for RF amplification D. Better suited for power supply regulation
A
Which of the following is an advantage of a horizontally polarized as compared to a vertically polarized HF antenna? A. Lower ground reflection losses B. Lower feed-point impedance C. Shorter radials D. Lower radiation resistance
A
Which of the following is an advantage of a log periodic antenna? A. Wide bandwidth B. Higher gain per element than a Yagi antenna C. Harmonic suppression D. Polarization diversity
A
Which of the following is an advantage of using a gamma match with a Yagi antenna? A. It does not require that the driven element be insulated from the boom B. It does not require any inductors or capacitors C. It is useful for matching multiband antennas D. All these choices are correct
A
Which of the following is true of an emergency generator installation? A. The generator should be located in a well-ventilated area B. The generator must be insulated from ground C. Fuel should be stored near the generator for rapid refueling in case of an emergency D. All these choices are correct
A
Which of the following phone emissions uses the narrowest bandwidth? A. Single sideband B. Double sideband C. Phase modulation D. Frequency modulation
A
Which of the following would increase the bandwidth of a Yagi antenna? A. Larger-diameter elements B. Closer element spacing C. Loading coils in series with the element D. Tapered-diameter elements
A
Which symbol in Figure G7-1 represents a tapped inductor? A. Symbol 7 B. Symbol 11 C. Symbol 6 D. Symbol 1
A
Which type of code is used for sending characters in a PSK31 signal? A. Varicode B. Viterbi C. Volumetric D. Binary
A
Which type of rectifier circuit uses two diodes and a center-tapped transformer? A. Full-wave B. Full-wave bridge C. Half-wave D. Synchronous
A
Which wire or wires in a four-conductor connection should be attached to fuses or circuit breakers in a device operated from a 240 VAC single phase source? A. Only the two wires carrying voltage B. Only the neutral wire C. Only the ground wire D. All wires
A
For which of the following modes is a Class C power stage appropriate for amplifying a modulated signal? A. SSB B. FM C. AM D. All these choices are correct
B
How does a "screwdriver" mobile antenna adjust its feed-point impedance? A. By varying its body capacitance B. By varying the base loading inductance C. By extending and retracting the whip D. By deploying a capacitance hat
B
How does antenna gain stated in dBi compare to gain stated in dBd for the same antenna? A. dBi gain figures are 2.15 dB lower than dBd gain figures B. dBi gain figures are 2.15 dB higher than dBd gain figures C. dBi gain figures are the same as the square root of dBd gain figures multiplied by 2.15 D. dBi gain figures are the reciprocal of dBd gain figures + 2.15 dB
B
How does the attenuation of coaxial cable change as the frequency of the signal it is carrying increases? A. Attenuation is independent of frequency B. Attenuation increases C. Attenuation decreases D. Attenuation reaches a maximum at approximately 18 MHz ~~
B
How does the feed-point impedance of a 1/2 wave dipole antenna change as the antenna is lowered below 1/4 wave above ground? A. It steadily increases B. It steadily decreases C. It peaks at about 1/8 wavelength above ground D. It is unaffected by the height above ground
B
How does the gain of two three-element, horizontally polarized Yagi antennas spaced vertically 1/2 wavelength apart typically compare to the gain of a single three-element Yagi? A. Approximately 1.5 dB higher B. Approximately 3 dB higher C. Approximately 6 dB higher D. Approximately 9 dB higher
B
How does the receiving station respond to an ARQ data mode packet containing errors? A. It terminates the contact B. It requests the packet be retransmitted C. It sends the packet back to the transmitting station D. It requests a change in transmitting protocol
B
How is an FSK signal generated? A. By keying an FM transmitter with a sub-audible tone B. By changing an oscillator's frequency directly with a digital control signal C. By using a transceiver's computer data interface protocol to change frequencies D. By reconfiguring the CW keying input to act as a tone generator
B
How is the efficiency of an RF power amplifier determined? A. Divide the DC input power by the DC output power B. Divide the RF output power by the DC input power C. Multiply the RF input power by the reciprocal of the RF output power D. Add the RF input power to the DC output power
B
If a receiver mixes a 13.800 MHz VFO with a 14.255 MHz received signal to produce a 455 kHz intermediate frequency (IF) signal, what type of interference will a 13.345 MHz signal produce in the receiver? A. Quadrature noise B. Image response C. Mixer interference D. Intermediate interference
B
If the SWR on an antenna feed line is 5 to 1, and a matching network at the transmitter end of the feed line is adjusted to 1 to 1 SWR, what is the resulting SWR on the feed line? A. 1 to 1 B. 5 to 1 C. Between 1 to 1 and 5 to 1 depending on the characteristic impedance of the line D. Between 1 to 1 and 5 to 1 depending on the reflected power at the transmitter
B
In which direction or directions does an electrically small loop (less than 1/3 wavelength in circumference) have nulls in its radiation pattern? A. In the plane of the loop B. Broadside to the loop C. Broadside and in the plane of the loop D. Electrically small loops are omnidirectional
B
What action results from a failure to exchange information due to excessive transmission attempts when using PACTOR or WINMOR? A. The checksum overflows B. The connection is dropped C. Packets will be routed incorrectly D. Encoding reverts to the default character set
B
What are the typical characteristic impedances of coaxial cables used for antenna feed lines at amateur stations? A. 25 and 30 ohms B. 50 and 75 ohms C. 80 and 100 ohms D. 500 and 750 ohms
B
What emission is produced by a reactance modulator connected to a transmitter RF amplifier stage? A. Multiplex modulation B. Phase modulation C. Amplitude modulation D. Pulse modulation
B
What is a type SMA connector? A. A large bayonet connector usable at power levels more than 1 KW B. A small threaded connector suitable for signals up to several GHz C. A connector designed for serial multiple access signals D. A type of push-on connector intended for high-voltage applications
B
What is an advantage of the low internal resistance of nickel-cadmium batteries? A. Long life B. High discharge current C. High voltage D. Rapid recharge
B
What is an advantage of using I and Q signals in software-defined radios (SDRs)? A. The need for high resolution analog-to-digital converters is eliminated B. All types of modulation can be created with appropriate processing C. Minimum detectible signal level is reduced D. Converting the signal from digital to analog creates mixing products
B
What is meant by the term MMIC? A. Multi-Megabyte Integrated Circuit B. Monolithic Microwave Integrated Circuit C. Military Manufactured Integrated Circuit D. Mode Modulated Integrated Circuit
B
What is meant by the term ROM? A. Resistor Operated Memory B. Read Only Memory C. Random Operational Memory D. Resistant to Overload Memory
B
What is one disadvantage of a directly fed random-wire HF antenna? A. It must be longer than 1 wavelength B. You may experience RF burns when touching metal objects in your station C. It produces only vertically polarized radiation D. It is more effective on the lower HF bands than on the higher bands
B
What is the approximate junction threshold voltage of a germanium diode? A. 0.1 volt B. 0.3 volts C. 0.7 volts D. 1.0 volts
B
What is the approximate length of the driven element of a Yagi antenna? A. 1/4 wavelength B. 1/2 wavelength C. 3/4 wavelength D. 1 wavelength
B
What is the capacitance of a 20 microfarad capacitor connected in series with a 50 microfarad capacitor? A. 0.07 microfarads B. 14.3 microfarads C. 70 microfarads D. 1000 microfarads
B
What is the frequency deviation for a 12.21 MHz reactance modulated oscillator in a 5 kHz deviation, 146.52 MHz FM phone transmitter? A. 101.75 Hz B. 416.7 Hz C. 5 kHz D. 60 kHz
B
What is the interaction between high standing wave ratio (SWR) and transmission line loss? A. There is no interaction between transmission line loss and SWR B. If a transmission line is lossy, high SWR will increase the loss C. High SWR makes it difficult to measure transmission line loss D. High SWR reduces the relative effect of transmission line loss
B
What is the name of the process that changes the phase angle of an RF signal to convey information? A. Phase convolution B. Phase modulation C. Phase transformation D. Phase inversion
B
What is the phase difference between the I and Q signals that software-defined radio (SDR) equipment uses for modulation and demodulation? A. Zero B. 90 degrees C. 180 degrees D. 45 degrees
B
What is the reason for neutralizing the final amplifier stage of a transmitter? A. To limit the modulation index B. To eliminate self-oscillations C. To cut off the final amplifier during standby periods D. To keep the carrier on frequency
B
What is the relationship between transmitted symbol rate and bandwidth? A. Symbol rate and bandwidth are not related B. Higher symbol rates require wider bandwidth C. Lower symbol rates require wider bandwidth D. Bandwidth is always half the symbol rate
B
What portion of the AC cycle is converted to DC by a half-wave rectifier? A. 90 degrees B. 180 degrees C. 270 degrees D. 360 degrees
B
What precaution should you take whenever you adjust or repair an antenna? A. Ensure that you and the antenna structure are grounded B. Turn off the transmitter and disconnect the feed line C. Wear a radiation badge D. All these choices are correct
B
What should be done by any person preparing to climb a tower that supports electrically powered devices? A. Notify the electric company that a person will be working on the tower B. Make sure all circuits that supply power to the tower are locked out and tagged C. Unground the base of the tower D. All these choices are correct
B
What should be the impedance of a low-pass filter as compared to the impedance of the transmission line into which it is inserted? A. Substantially higher B. About the same C. Substantially lower D. Twice the transmission line impedance
B
What standing wave ratio will result when connecting a 50 ohm feed line to a non-reactive load having 50 ohm impedance? A. 2:1 B. 1:1 C. 50:50 D. 0:0
B
What type of instrument can be used to accurately measure an RF field? A. A receiver with an S meter B. A calibrated field strength meter with a calibrated antenna C. An SWR meter with a peak-reading function D. An oscilloscope with a high-stability crystal marker generator
B
What useful feature does a power supply bleeder resistor provide? A. It acts as a fuse for excess voltage B. It ensures that the filter capacitors are discharged when power is removed C. It removes shock hazards from the induction coils D. It eliminates ground loop current
B
Which mixer input is varied or tuned to convert signals of different frequencies to an intermediate frequency (IF)? A. Image frequency B. Local oscillator C. RF input D. Beat frequency oscillator
B
Which of the following conditions will cause a Ground Fault Circuit Interrupter (GFCI) to disconnect the 120 or 240 Volt AC line power to a device? A. Current flowing from one or more of the voltage-carrying wires to the neutral wire B. Current flowing from one or more of the voltage-carrying wires directly to ground C. Overvoltage on the voltage-carrying wires D. All these choices are correct
B
Which of the following describes a linear amplifier? A. Any RF power amplifier used in conjunction with an amateur transceiver B. An amplifier in which the output preserves the input waveform C. A Class C high efficiency amplifier D. An amplifier used as a frequency multiplier
B
Which of the following describes the construction of a MOSFET? A. The gate is formed by a back-biased junction B. The gate is separated from the channel with a thin insulating layer C. The source is separated from the drain by a thin insulating layer D. The source is formed by depositing metal on silicon
B
Which of the following describes the function of a two-input AND gate? A. Output is high when either or both inputs are low B. Output is high only when both inputs are high C. Output is low when either or both inputs are high D. Output is low only when both inputs are high
B
Which of the following is a common way to adjust the feed-point impedance of a quarter wave ground-plane vertical antenna to be approximately 50 ohms? A. Slope the radials upward B. Slope the radials downward C. Lengthen the radials D. Shorten the radials
B
Which of the following is a reason not to use wire-wound resistors in an RF circuit? A. The resistor's tolerance value would not be adequate for such a circuit B. The resistor's inductance could make circuit performance unpredictable C. The resistor could overheat D. The resistor's internal capacitance would detune the circuit
B
Which of the following is used to process signals from the balanced modulator then send them to the mixer in some single sideband phone transmitters? A. Carrier oscillator B. Filter C. IF amplifier D. RF amplifier
B
Which of the following narrow-band digital modes can receive signals with very low signal-to-noise ratios? A. MSK144 B. FT8 C. AMTOR D. MFSK32
B
Which of the following statements is true about PSK31? A. Upper case letters are sent with more power B. Upper case letters use longer Varicode bit sequences and thus slow down transmission C. Error correction is used to ensure accurate message reception D. Higher power is needed as compared to RTTY for similar error rates
B
What is the inductance of a 20 millihenry inductor connected in series with a 50 millihenry inductor? A. 0.07 millihenries B. 14.3 millihenries C. 70 millihenries D. 1000 millihenries
C
Which of these choices should be observed when climbing a tower using a safety belt or harness? A. Never lean back and rely on the belt alone to support your weight B. Confirm that the belt is rated for the weight of the climber and that it is within its allowable service life C. Ensure that all heavy tools are securely fastened to the belt D-ring D. All these choices are correct
B
Which symbol in figure G7-1 represents an NPN junction transistor? A. Symbol 1 B. Symbol 2 C. Symbol 7 D. Symbol 11
B
Why is it important to know the duty cycle of the mode you are using when transmitting? A. To aid in tuning your transmitter B. Some modes have high duty cycles that could exceed the transmitter's average power rating C. To allow time for the other station to break in during a transmission D. The attenuator will have to be adjusted accordingly
B
Why is the conductor of the primary winding of many voltage step-up transformers larger in diameter than the conductor of the secondary winding? A. To improve the coupling between the primary and secondary B. To accommodate the higher current of the primary C. To prevent parasitic oscillations due to resistive losses in the primary D. To ensure that the volume of the primary winding is equal to the volume of the secondary
B
According the National Electrical Code, what is the minimum wire size that may be used safely for wiring with a 20 ampere circuit breaker? A. AWG number 20 B. AWG number 16 C. AWG number 12 D. AWG number 8
C
How does antenna height affect the horizontal (azimuthal) radiation pattern of a horizontal dipole HF antenna? A. If the antenna is too high, the pattern becomes unpredictable B. Antenna height has no effect on the pattern C. If the antenna is less than 1/2 wavelength high, the azimuthal pattern is almost omnidirectional D. If the antenna is less than 1/2 wavelength high, radiation off the ends of the wire is eliminated
C
How does forward error correction (FEC) allow the receiver to correct errors in received data packets? A. By controlling transmitter output power for optimum signal strength B. By using the Varicode character set C. By transmitting redundant information with the data D. By using a parity bit with each character
C
How many states does a 3-bit binary counter have? A. 3 B. 6 C. 8 D. 16
C
In which direction is the maximum radiation from a portable VHF/UHF "halo" antenna? A. Broadside to the plane of the halo B. Opposite the feed point C. Omnidirectional in the plane of the halo D. Toward the halo's supporting mast
C
On what band do amateurs share channels with the unlicensed Wi-Fi service? A. 432 MHz B. 902 MHz C. 2.4 GHz D. 10.7 GHz
C
What circuit is used to process signals from the RF amplifier and local oscillator then send the result to the IF filter in a superheterodyne receiver? A. Balanced modulator B. IF amplifier C. Mixer D. Detector
C
What combination of a mixer's Local Oscillator (LO) and RF input frequencies is found in the output? A. The ratio B. The average C. The sum and difference D. The arithmetic product
C
What determines the frequency of an LC oscillator? A. The number of stages in the counter B. The number of stages in the divider C. The inductance and capacitance in the tank circuit D. The time delay of the lag circuit
C
What determines the performance of a ferrite core at different frequencies? A. Its conductivity B. Its thickness C. The composition, or "mix," of materials used D. The ratio of outer diameter to inner diameter
C
What does "front-to-back ratio" mean in reference to a Yagi antenna? A. The number of directors versus the number of reflectors B. The relative position of the driven element with respect to the reflectors and directors C. The power radiated in the major radiation lobe compared to that in the opposite direction D. The ratio of forward gain to dipole gain
C
What happens when an inductor is operated above its self-resonant frequency? A. Its reactance increases B. Harmonics are generated C. It becomes capacitive D. Catastrophic failure is likely
C
What is meant by the term "flat-topping," when referring to a single sideband phone transmission? A. Signal distortion caused by insufficient collector current B. The transmitter's automatic level control (ALC) is properly adjusted C. Signal distortion caused by excessive drive D. The transmitter's carrier is properly suppressed
C
What is meant when memory is characterized as non-volatile? A. It is resistant to radiation damage B. It is resistant to high temperatures C. The stored information is maintained even if power is removed D. The stored information cannot be changed once written
C
What is the approximate junction threshold voltage of a conventional silicon diode? A. 0.1 volt B. 0.3 volts C. 0.7 volts D. 1.0 volts
C
What is the approximate length for a 1/2 wave dipole antenna cut for 3.550 MHz? A. 42 feet B. 84 feet C. 132 feet D. 263 feet
C
What is the capacitance of three 100 microfarad capacitors connected in series? A. 0.30 microfarads B. 0.33 microfarads C. 33.3 microfarads D. 300 microfarads
C
What is the combined vertical and horizontal polarization pattern of a multi-wavelength, horizontal loop antenna? A. A figure-eight, similar to a dipole B. Four major loops with deep nulls C. Virtually omnidirectional with a lower peak vertical radiation angle than a dipole D. Radiation maximum is straight up
C
What is the frequency above which a low-pass filter's output power is less than half the input power? A. Notch frequency B. Neper frequency C. Cutoff frequency D. Rolloff frequency
C
What is the inductance of three 10 millihenry inductors connected in parallel? A. 0.30 henries B. 3.3 henries C. 3.3 millihenries D. 30 millihenries
C
What is the minimum allowable discharge voltage for maximum life of a standard 12 volt lead-acid battery? A. 6 volts B. 8.5 volts C. 10.5 volts D. 12 volts
C
What is the purpose of a power supply interlock? A. To prevent unauthorized changes to the circuit that would void the manufacturer's warranty B. To shut down the unit if it becomes too hot C. To ensure that dangerous voltages are removed if the cabinet is opened D. To shut off the power supply if too much voltage is produced
C
What is the simplest combination of stages that implement a superheterodyne receiver? A. RF amplifier, detector, audio amplifier B. RF amplifier, mixer, IF discriminator C. HF oscillator, mixer, detector D. HF oscillator, prescaler, audio amplifier
C
What is the value in nanofarads (nF) of a 22,000 picofarad (pF) capacitor? A. 0.22 B. 2.2 C. 22 D. 220
C
What might cause reflected power at the point where a feed line connects to an antenna? A. Operating an antenna at its resonant frequency B. Using more transmitter power than the antenna can handle C. A difference between feed-line impedance and antenna feed-point impedance D. Feeding the antenna with unbalanced feed line
C
What part of a packet radio frame contains the routing and handling information? A. Directory B. Preamble C. Header D. Footer
C
What precaution should you take if you install an indoor transmitting antenna? A. Locate the antenna close to your operating position to minimize feed-line radiation B. Position the antenna along the edge of a wall to reduce parasitic radiation C. Make sure that MPE limits are not exceeded in occupied areas D. Make sure the antenna is properly shielded
C
Where should the radial wires of a ground-mounted vertical antenna system be placed? A. As high as possible above the ground B. Parallel to the antenna element C. On the surface of the Earth or buried a few inches below the ground D. At the center of the antenna
C
Which HF antenna would be the best to use for minimizing interference? A. A quarter-wave vertical antenna B. An isotropic antenna C. A directional antenna D. An omnidirectional antenna
C
Which of the following components should be added to a capacitor to increase the capacitance? A. An inductor in series B. A resistor in series C. A capacitor in parallel D. A capacitor in series
C
Which of the following describes Baudot code? A. A 7-bit code with start, stop, and parity bits B. A code using error detection and correction C. A 5-bit code with additional start and stop bits D. A code using SELCAL and LISTEN
C
Which of the following describes a waterfall display? A. Frequency is horizontal, signal strength is vertical, time is intensity B. Frequency is vertical, signal strength is intensity, time is horizontal C. Frequency is horizontal, signal strength is intensity, time is vertical D. Frequency is vertical, signal strength is horizontal, time is intensity
C
Which of the following describes the function of a two input NOR gate? A. Output is high when either or both inputs are low B. Output is high only when both inputs are high C. Output is low when either or both inputs are high D. Output is low only when both inputs are high
C
Which of the following is an advantage of a switchmode power supply as compared to a linear power supply? A. Faster switching time makes higher output voltage possible B. Fewer circuit components are required C. High-frequency operation allows the use of smaller components D. All these choices are correct
C
Which of the following is an advantage of an electrolytic capacitor? A. Tight tolerance B. Much less leakage than any other type C. High capacitance for a given volume D. Inexpensive RF capacitor
C
Which of the following is covered by the National Electrical Code? A. Acceptable bandwidth limits B. Acceptable modulation limits C. Electrical safety inside the ham shack D. RF exposure limits of the human body
C
Which of the following steps must an amateur operator take to ensure compliance with RF safety regulations when transmitter power exceeds levels specified in FCC Part 97.13? A. Post a copy of FCC Part 97.13 in the station B. Post a copy of OET Bulletin 65 in the station C. Perform a routine RF exposure evaluation D. Contact the FCC for a visit to conduct a station evaluation
C
Which of these connector types is commonly used for RF connections at frequencies up to 150 MHz? A. Octal B. RJ-11 C. PL-259 D. DB-25
C
Which of these connector types is commonly used for audio signals in Amateur Radio stations? A. PL-259 B. BNC C. RCA Phono D. Type N
C
Which symbol in Figure G7-1 represents a solid core transformer? A. Symbol 4 B. Symbol 7 C. Symbol 6 D. Symbol 1
C
Which symbol in figure G7-1 represents a field effect transistor? A. Symbol 2 B. Symbol 5 C. Symbol 1 D. Symbol 4
C
How are the two separate frequencies of a Frequency Shift Keyed (FSK) signal identified? A. Dot and dash B. On and off C. High and low D. Mark and space
D
How can you determine that your station complies with FCC RF exposure regulations? A. By calculation based on FCC OET Bulletin 65 B. By calculation based on computer modeling C. By measurement of field strength using calibrated equipment D. All these choices are correct
D
What is an advantage of vertical stacking of horizontally polarized Yagi antennas? A. It allows quick selection of vertical or horizontal polarization B. It allows simultaneous vertical and horizontal polarization C. It narrows the main lobe in azimuth D. It narrows the main lobe in elevation
D
What is indicated on a waterfall display by one or more vertical lines on either side of a digital signal? A. Long path propagation B. Backscatter propagation C. Insufficient modulation D. Overmodulation
D
What is meant by the "main lobe" of a directive antenna? A. The magnitude of the maximum vertical angle of radiation B. The point of maximum current in a radiating antenna element C. The maximum voltage standing wave point on a radiating element D. The direction of maximum radiated field strength from the antenna
D
What is one thing that can be done if evaluation shows that a neighbor might receive more than the allowable limit of RF exposure from the main lobe of a directional antenna? A. Change to a non-polarized antenna with higher gain B. Post a warning sign that is clearly visible to the neighbor C. Use an antenna with a higher front-to-back ratio D. Take precautions to ensure that the antenna cannot be pointed in their direction
D
What is the approximate bandwidth of a PACTOR-III signal at maximum data rate? A. 31.5 Hz B. 500 Hz C. 1800 Hz D. 2300 Hz
D
What is the approximate length for a 1/2 wave dipole antenna cut for 14.250 MHz? A. 8 feet B. 16 feet C. 24 feet D. 33 feet
D
What is the feed-point impedance of an end-fed half-wave antenna? A. Very low B. Approximately 50 ohms C. Approximately 300 ohms D. Very high
D
What is the name of the process that changes the instantaneous frequency of an RF wave to convey information? A. Frequency convolution B. Frequency transformation C. Frequency conversion D. Frequency modulation
D
What is the stage in a VHF FM transmitter that generates a harmonic of a lower frequency signal to reach the desired operating frequency? A. Mixer B. Reactance modulator C. Pre-emphasis network D. Multiplier
D
What is the total bandwidth of an FM phone transmission having 5 kHz deviation and 3 kHz modulating frequency? A. 3 kHz B. 5 kHz C. 8 kHz D. 16 kHz
D
What is the typical characteristic impedance of "window line" parallel transmission line? A. 50 ohms B. 75 ohms C. 100 ohms D. 450 ohms
D
What is the value in microfarads of a 4700 nanofarad (nF) capacitor? A. 47 B. 0.47 C. 47,000 D. 4.7
D
What kind of device is an integrated circuit operational amplifier? A. Digital B. MMIC C. Programmable Logic D. Analog
D
What must be done to prevent standing waves on an antenna feed line? A. The antenna feed point must be at DC ground potential B. The feed line must be cut to a length equal to an odd number of electrical quarter wavelengths C. The feed line must be cut to a length equal to an even number of physical half wavelengths D. The antenna feed point impedance must be matched to the characteristic impedance of the feed line
D
What portion of the AC cycle is converted to DC by a full-wave rectifier? A. 90 degrees B. 180 degrees C. 270 degrees D. 360 degrees
D
What precaution should be taken when installing a ground-mounted antenna? A. It should not be installed higher than you can reach B. It should not be installed in a wet area C. It should be limited to 10 feet in height D. It should be installed such that it is protected against unauthorized access ~~
D
What standing wave ratio will result when connecting a 50 ohm feed line to a non-reactive load having 10 ohm impedance? A. 2:1 B. 50:1 C. 1:5 D. 5:1
D
What term specifies a filter's maximum ability to reject signals outside its passband? A. Notch depth B. Rolloff C. Insertion loss D. Ultimate rejection
D
What type of modulation varies the instantaneous power level of the RF signal? A. Frequency shift keying B. Phase modulation C. Frequency modulation D. Amplitude modulation
D
Which circuit is used to combine signals from the carrier oscillator and speech amplifier then send the result to the filter in some single sideband phone transmitters? A. Discriminator B. Detector C. IF amplifier D. Balanced modulator
D
Which of the following are basic components of a sine wave oscillator? A. An amplifier and a divider B. A frequency multiplier and a mixer C. A circulator and a filter operating in a feed-forward loop D. A filter and an amplifier operating in a feedback loop
D
Which of the following best describes the radiation pattern of a quarter-wave, ground-plane vertical antenna? A. Bi-directional in azimuth B. Isotropic C. Hemispherical D. Omnidirectional in azimuth
D
Which of the following can be adjusted to optimize forward gain, front-to-back ratio, or SWR bandwidth of a Yagi antenna? A. The physical length of the boom B. The number of elements on the boom C. The spacing of each element along the boom D. All these choices are correct
D
Which of the following components are used in a power supply filter network? A. Diodes B. Transformers and transducers C. Quartz crystals D. Capacitors and inductors
D
Which of the following components should be added to an inductor to increase the inductance? A. A capacitor in series B. A resistor in parallel C. An inductor in parallel D. An inductor in series
D
Which of the following is a disadvantage of multiband antennas? A. They present low impedance on all design frequencies B. They must be used with an antenna tuner C. They must be fed with open wire line D. They have poor harmonic rejection
D
Which of the following is an advantage of a direct digital synthesizer (DDS)? A. Wide tuning range and no need for band switching B. Relatively high-power output C. Relatively low power consumption D. Variable frequency with the stability of a crystal oscillator
D
Which of the following is an advantage of ceramic capacitors as compared to other types of capacitors? A. Tight tolerance B. High stability C. High capacitance for given volume D. Comparatively low cost
D
Which of the following is an effect of overmodulation? A. Insufficient audio B. Insufficient bandwidth C. Frequency drift D. Excessive bandwidth
D
Which of the following is characteristic of QPSK31? A. It is sideband sensitive B. Its encoding provides error correction C. Its bandwidth is approximately the same as BPSK31 D. All these choices are correct
D
Which of the following is good practice for lightning protection grounds? A. They must be bonded to all buried water and gas lines B. Bends in ground wires must be made as close as possible to a right angle C. Lightning grounds must be connected to all ungrounded wiring D. They must be bonded together with all other grounds
D
Which of the following properties is important in estimating whether an RF signal exceeds the maximum permissible exposure (MPE)? A. Its duty cycle B. Its frequency C. Its power density D. All these choices are correct
D
Which of these classes of amplifiers has the highest efficiency? A. Class A B. Class B C. Class AB D. Class C
D
Which size of fuse or circuit breaker would be appropriate to use with a circuit that uses AWG number 14 wiring? A. 100 amperes B. 60 amperes C. 30 amperes D. 15 amperes
D
Which symbol in figure G7-1 represents a Zener diode? A. Symbol 4 B. Symbol 1 C. Symbol 11 D. Symbol 5
D
Why is it good to match receiver bandwidth to the bandwidth of the operating mode? A. It is required by FCC rules B. It minimizes power consumption in the receiver C. It improves impedance matching of the antenna D. It results in the best signal-to-noise ratio
D
Why is the polarity of applied voltages important for polarized capacitors? A. Incorrect polarity can cause the capacitor to short-circuit B. Reverse voltages can destroy the dielectric layer of an electrolytic capacitor C. The capacitor could overheat and explode D. All these choices are correct
D