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54 Cards in this Set
- Front
- Back
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#01. If the tech order states a transmitter has a frequency accuracy of 0.0001 percent, which of the following is an acceptable output with an operating frequency of 225 MHz?
a. 224.999975 to 225.000225 b. 224.997750 to 225.225000 c. 224. 999000 to 225.001000 d. 224.975 to 225.225 |
A. 224.999975 to 225.000225
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#02. If an oscilloscope display a modulation envelope having an Emax of 200 volts and an Emin of 20 volts, what is the percent of modulation
a. 81.8 b. 85.5 c. 88 d. 122 |
A. 81.8
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#03. Reducing modulation to less than 100 percent gives
a. more total power b. a reduction in carrier power c. no reduction in carrier power d. a reduction in carrier and sideband power |
C. no reduction in carrier power
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#04. In the AN/GRT-21 and AN/GRT-22, what circuit sets the audio-frequency response?
a. Filter circuit in the A4 module b. Detector circuit in the A4 module c. Amplifier circuit in the A1 module d. Compression circuit in the A1 module |
A. Filter circuit in the A4 module
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#05*. In the AN/GRT-22 transmitter, the purpose of the E/L relay when operating in the 50-watt mode is to
a. Bypass the LPA in the event of high VSWR b. Route the high current directly to the antenna c. bypass the LPA in the event of overmodultation d bypass the antenna in the event of high vswr |
A. Bypass the LPA in the event of high VSWR
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#06*. Comparing the AN/GRT-21 and AN/GRT-22, the UHF multiplier module possesses one more stage of amplification than the VHF multiplier because the
a. VHF version has more power in the preamplification circuitry b. VHF multiplier is followed by a stronger power amplifier c. filter/amplifier in the UHF radio is considerably waker d. fourth harmonic is weaker than the second harmonic |
D. fourth harmonic is weaker than the second harmonic
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#07. Referring to foldout 6, if the 50-watt output decreases,
a. the E/L relay energizes b. AR1 increases its amplification and brings the output back up c. conduction of Q3 increases, which causes a more positive APC voltage d. the increase at AR1's output causes the APC amplifier to conduct less |
C. conduction of Q3 increases, which causes a more positive APC voltage
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#08. Referring to the tuned cavity in foldout 9, C1 and C2 are tuned to pass what signals?
a. Operating frequency only b. AC voltages required for tube operation c. Operating frequency and the fourth harmonic d. Operating frequency and the second harmonic |
A. Operating frequency only
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#09. In foldout 9, what is the purpose of the tuned cavity's low-pass filter (FL2)
a. Attenuates harmonics b. Removes any remaining DC ripple c. Decouple the tube from exciter feedback d. Provide differential voltage through forward power output P1, jack L |
A. Attenuates harmonics
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#10*. The LPA FWD and RVS pwr sensor voltages are amplified and level-shifted in the LPA A5 module for what purpose?
a. To provide AGC b. To operate the T/R relay in the exciter c. To develop the APC voltage and to detect VSWR d. To enable development of plate and screen voltages |
C. To develop the APC voltage and to detect VSWR
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#11. In a receiver, why can the antenna not be connected directly to the mixer circuit?
a. because the intelligence has not been extracted yet b. the signals frequency is too high to be converted c. the oscillator signal must be radiated out into space d. If the receiver were keyed, high vswr may damage the mixer circuit |
C. the oscillator signal must be radiated out into space
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#12. Which of the following statements is true concerning rx operation?
a. in order to change the operating fx, we must change the IF only b. When we change fx's, the IF does not change; local oscillator frequency does c. changing the local oscillator frequency has no effect on our operating frequency d. When we change frequencies, the IF changes by an amount equal to the change in the local oscillator fx. |
B. When we change fx's, the IF does not change; local oscillator frequency does
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#13. In what section of a superheterodyne rx does most of the amplification take place
a. IF section b. RF amplifier c. Audio amplifier d. Input tuning section |
A. IF section
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#14. With an operating frequency of 150 MHz and an IF of 10.7 MHz, which of the following is a possible image freq.
a. 21.4 b. 140.7 c. 160.14 d. 171.4 |
D. 171.4
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#15*. What are the basic requirements for any type of demodulation?
a. Sensitivity and nonlinearity b. Sensitivity, nonlinearity, RF carrier signal, and filtering c. Selectivity, nonlinearity, RF carrier signal, and filtering d. Sensitivity, nonlinearity, RF carrier signal, filtering, and conversion |
B. Sensitivity, nonlinearity, RF carrier signal, and filtering
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#16*. Which of the following statements is true concerning diode detectors?
a. They are relatively complex devices b. They can only handle relatively small signals c. They give high-fidelity detection for signals of sufficient amplitude d. They are relatively simple devices and provide a tremendous amount of pwr gain |
C. They give high-fidelity detection for signals of sufficient amplitude
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#17. Which module of an AN/GRR-24 rx prevents interference from radar pulses?
a. Noise limiter b. Buffer amplifier A5 c. Crystal pulse filter A3 d. Preamplifier, Af/AGC-squelch module A3 |
A. Noise limiter
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#18. The purpose of the AGC voltage is to
a. provide a comparison voltage in the power supply b. vary the output level when the output impedeance changes c. ensure a constant output level with varying input signal strength d. decrease the amplification of the IF section when the input signal decreases |
C. ensure a constant output level with varying input signal strength
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#19. In the AN/GRR-24 mixer/multiplier in foldout 12, what frequency is C12 tuned to pass.
a. Intermediate frequency b. Oscillator input frequency c. Frequency of the AC pwr source d. Fourth harmonic of the oscillator input frequency |
D. Fourth harmonic of the oscillator input frequency
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#20*. In the AN/GRR-24 mixer/miltiplier in foldout 12, the output of Q8 is tuned to pass what frequency?
a. Audio signal b. Injection frequency c. Operation frequency d. Intermediate frequency |
D. Intermediate frequency
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#22. Concerning HAVE QUICK 2 communications (MWOD), how long can each WOD be used?
a. Until it is manually changed b. A total of 3 days c. 48 hours d. 24 hours |
D. 24 hours
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#21*. Which of the following statements best identifies the requirments for two transceivers to establish HAVE QUICK communications?
a. They must be the same version of transceiver b. They must be using the same encryption variables c. They must have the same WOD and TOD d. They must have the same memory module programmed with the WOD and TOD |
C. They must have the same WOD and TOD
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#23. What is the purpose of the tactical digital information link?
a. Enable real-time JCS approval of battle tactics b. Transmission of analog communications c. Prevention of jamming by enemy forces d. The exchange of real-time tactical data |
D. The exchange of real-time tactical data
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#24. In foldout 15, grid B6, what functions are performed by the A7 module's low-pass filter?
a. Image-frequency rejection in rx and harmonic attenuation in tx b. Image-frequency rejection in tx and harmonic attenuation in rx c. RF decoupling in tx and harmonic suppression in rx d. RF decoupling in rx and harmonic supression in tx |
A. Image-frequency rejection in rx and harmonic attenuation in tx
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#25*. Which of the following identifies the output power of the AN/GRC-171b4 tranceiver
A. 25 watts in both AM and FM b. 20 watts in AM, 50 watts in FM c. 20 watts in AM, 20 watts in FM d. 50 watts in narrowband, 25 in wide band |
B. 20 watts in AM, 50 watts in FM
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#26. Which of the following is responsible for preventing spurious RF outputs while the AN/GRC-171B(V)4 transceiver is changing frequencies during HAVE QUICK operation?
a. A11 FM modem and control b. A2 frequency synthesizer c. A1A1 control processor d. A1A2 ECCM processor |
D. A1A2 ECCM processor
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#27. In the AN/GRC-171B(V)4, what is the operating frequency of the guard receiver?
a. 300 b. 243 c. 225 d. 121.5 |
B. 243
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#28. On the AN/GRC-171B(V)4 radio set control, what condition causes the RT FLT lamp to illuminate
a. A pwr outage b. Keying the RT unit c. A signal being rx'd d. A receiver-tx fault has been detected |
D. A receiver-tx fault has been detected
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#29. During tx operation, what is the purpose of the compressor circuit in the RT-1446 HF transceiver?
a. Equalizes varying voice levels so the audio signal is more uniform in amplitude b. Amplifies the microphone audio level to ensure it is of adequate amplitude c. Provides a tune-select signal to the antenna coupler d. Provides heterodyning of the audio and RF carrier |
A. Equalizes varying voice levels so the audio signal is more uniform in amplitude
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#30. Referring to foldout 16, what determines which specific filter is used in the IF filter assembly?
a. An error voltage generated from the TGC circuitry b. Front-panel LPF selector switch c. The balanced modulator d. The mode of operation |
D. The mode of operation
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#31*. The purpose of the input overload protection circuit shown in foldout 16 to prevent
a. the regulated pwr supply voltage from exceeding limits b. the AC line input voltage from exceeding limits c. any rx damage due to excessively strong signals d. exceedingly strong audio from damaging the speakers |
C. any rx damage due to excessively strong signals
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#32. In foldout 16, which of the following best describes the output of the product detector shown in grid A5?
a. The sum of the second IF and the first IF signals b. The difference between the second and first IF signals c. The sum of the second IF and the BFO signal, which is the audio d. The difference between the second IF and the BFO signal, which is the audio |
D. The difference between the second IF and the BFO signal, which is the audio
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#33. In figure 3-2, which circuit provides impedence matching between the antenna and the AM-7223?
a. A6 pwr ctl pwb b. A2 tank assembly c. VSWR bridge d. Low-pass filter |
B. A2 tank assembly
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#34. In the AM-7223 LPA, which circuit provides outputs that are directly proportional to the forward and reflected pwr.
a. VSWR bridge b. Directional filter c. Pwr and ctl subgroup d. Tank's signal detection circuit |
A. VSWR bridge
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#35. When using the C-11329 remote control unit, how do we route tx audio to the RT-1446?
a. Via a low-power wireless transmitter b. Using a 600-ohm transmission line c. by any available existing cables d. Using a 50 ohm coaxial cable |
B. Using a 600-ohm transmission line
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#36*. The amount of skin-affect loss is directly proportional to
a. line length b. signal frequency c. signal voltage level d. the amount of I2R loss |
B. signal frequency
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#37*. Leakage loss in a transmission line can be minimized by using a
a. thinner conductor b. thicker conductor c. very-low-resistance dielectric d. very-high-resistance dielectric |
D. very-high-resistance dielectric
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#38*. What two properties of a transmission line determine its characteristic impedance?
a. Inductance and resistance b. Inductance and capacitance c. Resistance and capacitance d. Length and type of shielding |
B. Inductance and capacitance
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#39*. Which of the following best describes "cutoff fx" when discussing transmission line properties?
a. The fx where Xl becomes so low that the signal is shunted b. The frequency where Xc causes the signal to be shunted c. The lowest fx that the line can pass successfully d. The frequency at which standing waves are maximum |
B. The frequency where Xc causes the signal to be shunted
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#40. Which of the following statements concerning wavelength is true?
a. Wavelength is inversely related to fx b. Wavelength is directly related to fx c. Wavelength is determined by length of line d. Wavelength is expressed in lambdas |
A. Wavelength is inversely related to fx
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#43. Which of the following statements concerning line lengths is true?
a. Frequency and electrical length are inversely proportional b. Frequency and physical length are directly proportional c. With constant physical length, fx and electrical length are directly related d. With constant physical length, fx and electrical length are inversely related |
C. With constant physical length, fx and electrical length are directly related
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#44*. A nonresonant transmission line is a line
a. having reflected waves b. having no reflected waves c. with maximum voltage across its open termination d. with maximum voltage across its shorted termination |
B. having no reflected waves
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#45. When discussing transmission lines,
a. resonant lines are often referred to as "flat lines." b. maximum power transfer results from a resonant line c. maximum power transfer results from a nonresonant line d. significant loss and damage to equipment will result if a nonresonant line is used |
C. maximum power transfer results from a nonresonant line
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#46. If a transmission line is terminated in an open, which of the following will likely result?
a. Signal loss would be negligable b. There would be significant signal loss c. Current would be at a maximum at the termination d. Voltage would be at minimum at the temination |
B. There would be significant signal loss
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#47. The pupose of a balun is to
a. enable us to weigh a transmission line b. provide an impedance match between two antennas c. allow multiple antennas to be connected to one reciever d. provide an impedance match between transmission line and antenna |
D. provide an impedance match between transmission line and antenna
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#48. which of the following is a major advantage of a waveguide over a coaxial cable
a. the hollow construction allows for water drainage b. much lower ac current leakage c. much lower dc loss d. cost |
c. much lower dc loss
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#49. which of the following is the primary limiting factor concerning the use of waveguides at lower frequencies
a. arcing would be substantial at the lower frequencies b. high loss due to the increased capacitive reactance c. the need for increased amplification d. physical size |
d. physical size
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#50. Which of the following statements concerning waveguides is false?
a. Very slight damage to the internal surface of a waveguide can cause arcing b. The flexible nature of waveguides makes them easy to install c. The effectiveness of waveguides is hindered by moisture d. Waveguides can be destroyed by corrosion |
B. The flexible nature of waveguides makes them easy to install
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#51. The path above the horizon through which an antenna radiates the largest amount of its RF energy is called the
a. skip angle b. escape angle c. radiation angle d. critical frequency angle |
C. radiation angle
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#52. If an antenna's electric lines of force lie in a vertical direction, it can be said that the antenna is
a. vertically polarized b. highly bidirectional c. horizontally polarized d. Impervious to man-made interference |
A. vertically polarized
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#53. An antenna that radiates well in all directions is said to be
a. bidirectional b. unidirectional c. omnidirectional d. quad-directional |
C. omnidirectional
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#54. If an antenna concentrates its signal in one direction while reducing the signal in other directions, it can be classified as
a. directional b. reciprocal c. bidirectional d. omnidirectional |
A. directional
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#55*. Log-periodic antennas
a. cannot be rotated, whereas the AN/FLTR-9 can b. are commonly used in direction-finding applications c. automatically rotate toward the distant end when RF is detected d. exhibit essentially constant characteristics over the entire frequency range |
D. exhibit essentially constant characteristics over the entire frequency range
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#56. How many channels can be connected to the CU-547/GR antenna multicoupler?
a. 1 b. 2 c. 3 d. 4 |
C. 3
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