General Radiotelephone Operator License (GROL)
Advanced radio theory, circuits, and regulations covering AM/FM transmitters, receivers, digital communications, and antenna systems.
Subelement Q: SAFETY
Topic 100: Safety Steps
What device can protect a transmitting station from a direct lightning hit?
3-100Q2What is the purpose of not putting sharp corners on the ground leads within a building?
3-100Q3Should you use a power drill without eye protection?
3-100Q4What class of fire is one that is caused by an electrical short circuit and what is the preferred substance used to extinguish that type of fire?
3-100Q5Do shorted-stub lightning protectors work at all frequencies?
3-100Q6What is a GFI electrical socket used for?
Topic 99: Radiation Exposure
Compliance with MPE, or Maximum Permissible Exposure to RF levels (as defined in FCC Part 1, OET Bulletin 65) for “controlled” environments, are averaged over _______ minutes, while “uncontrolled” RF environments are averaged over ______ minutes.
3-99Q2Sites having multiple transmitting antennas must include antennas with more than _______% of the maximum permissible power density exposure limit when evaluating RF site exposure.
3-99Q3RF exposure from portable radio transceivers may be harmful to the eyes because:
3-99Q4At what aggregate power level is an MPE (Maximum Permissible Exposure) study required?
3-99Q5Why must you never look directly into a fiber optic cable?
3-99Q6If the MPE (Maximum Permissible Exposure) power is present, how often must the personnel accessing the affected area be trained and certified?
Subelement B: Electrical Math
Topic 10: Ohm’s Law-2
What is the peak-to-peak RF voltage on the 50 ohm output of a 100 watt transmitter?
3-10B2What is the maximum DC or RMS voltage that may be connected across a 20 watt, 2000 ohm resistor?
3-10B3A 500-ohm, 2-watt resistor and a 1500-ohm, 1-watt resistor are connected in parallel. What is the maximum voltage that can be applied across the parallel circuit without exceeding wattage ratings?
3-10B4In Figure 3B1, what is the voltage drop across R1?
3-10B5In Figure 3B2, what is the voltage drop across R1?
3-10B6What is the maximum rated current-carrying capacity of a resistor marked “2000 ohms, 200 watts”?
Topic 11: Frequency
What is the most the actual transmit frequency could differ from a reading of 462,100,000 Hertz on a frequency counter with a time base accuracy of ± 0.1 ppm?
3-11B2The second harmonic of a 380 kHz frequency is:
3-11B3What is the second harmonic of SSB frequency 4146 kHz?
3-11B4What is the most the actual transmitter frequency could differ from a reading of 156,520,000 hertz on a frequency counter with a time base accuracy of ± 1.0 ppm?
3-11B5What is the most the actual transmitter frequency could differ from a reading of 156,520,000 Hertz on a frequency counter with a time base accuracy of +/- 10 ppm?
3-11B6What is the most the actual transmitter frequency could differ from a reading of 462,100,000 hertz on a frequency counter with a time base accuracy of ± 1.0 ppm?
Topic 12: Waveforms
At pi/3 radians, what is the amplitude of a sine-wave having a peak value of 5 volts?
3-12B2At 150 degrees, what is the amplitude of a sine-wave having a peak value of 5 volts?
3-12B3At 240 degrees, what is the amplitude of a sine-wave having a peak value of 5 volts?
3-12B4What is the equivalent to the root-mean-square value of an AC voltage?
3-12B5What is the RMS value of a 340-volt peak-to-peak pure sine wave?
3-12B6Determine the phase relationship between the two signals shown in Figure 3B3.
Topic 13: Power Relationships
What does the power factor equal in an R-L circuit having a 60 degree phase angle between the voltage and the current?
3-13B2If a resistance to which a constant voltage is applied is halved, what power dissipation will result?
3-13B3746 watts, corresponding to the lifting of 550 pounds at the rate of one-foot-per-second, is the equivalent of how much horsepower?
3-13B4In a circuit where the AC voltage and current are out of phase, how can the true power be determined?
3-13B5What does the power factor equal in an R-L circuit having a 45 degree phase angle between the voltage and the current?
3-13B6What does the power factor equal in an R-L circuit having a 30 degree phase angle between the voltage and the current?
Topic 14: RC Time Constants-1
What is the term for the time required for the capacitor in an RC circuit to be charged to 63.2% of the supply voltage?
3-14B2What is the meaning of the term “time constant of an RC circuit”? The time required to charge the capacitor in the circuit to:
3-14B3What is the term for the time required for the current in an RL circuit to build up to 63.2% of the maximum value?
3-14B4What is the meaning of the term “time constant of an RL circuit”? The time required for the:
3-14B5After two time constants, the capacitor in an RC circuit is charged to what percentage of the supply voltage?
3-14B6After two time constants, the capacitor in an RC circuit is discharged to what percentage of the starting voltage?
Topic 15: RC Time Constants-2
What is the time constant of a circuit having two 220-microfarad capacitors and two 1-megohm resistors all in parallel?
3-15B2What is the time constant of a circuit having two 100-microfarad capacitors and two 470-kilohm resistors all in series?
3-15B3What is the time constant of a circuit having a 100-microfarad capacitor and a 470-kilohm resistor in series?
3-15B4What is the time constant of a circuit having a 220-microfarad capacitor and a 1-megohm resistor in parallel?
3-15B5What is the time constant of a circuit having two 100-microfarad capacitors and two 470-kilohm resistors all in parallel?
3-15B6What is the time constant of a circuit having two 220-microfarad capacitors and two 1-megohm resistors all in series?
Topic 16: Impedance Networks-1
What is the impedance of a network composed of a 0.1-microhenry inductor in series with a 20-ohm resistor, at 30 MHz? Specify your answer in rectangular coordinates.
3-16B2In rectangular coordinates, what is the impedance of a network composed of a 0.1-microhenry inductor in series with a 30-ohm resistor, at 5 MHz?
3-16B3In rectangular coordinates, what is the impedance of a network composed of a 10-microhenry inductor in series with a 40-ohm resistor, at 500 MHz?
3-16B4In rectangular coordinates, what is the impedance of a network composed of a 1.0-millihenry inductor in series with a 200-ohm resistor, at 30 kHz?
3-16B5In rectangular coordinates, what is the impedance of a network composed of a 0.01-microfarad capacitor in parallel with a 300-ohm resistor, at 50 kHz?
3-16B6In rectangular coordinates, what is the impedance of a network composed of a 0.001-microfarad capacitor in series with a 400-ohm resistor, at 500 kHz?
Topic 17: Impedance Networks-2
What is the impedance of a network composed of a 100-picofarad capacitor in parallel with a 4000-ohm resistor, at 500 KHz? Specify your answer in polar coordinates.
3-17B2In polar coordinates, what is the impedance of a network composed of a 100-ohm-reactance inductor in series with a 100-ohm resistor?
3-17B3In polar coordinates, what is the impedance of a network composed of a 400-ohm-reactance capacitor in series with a 300-ohm resistor?
3-17B4In polar coordinates, what is the impedance of a network composed of a 300-ohm-reactance capacitor, a 600-ohm-reactance inductor, and a 400-ohm resistor, all connected in series?
3-17B5In polar coordinates, what is the impedance of a network comprised of a 400-ohm-reactance inductor in parallel with a 300-ohm resistor?
3-17B6Using the polar coordinate system, what visual representation would you get of a voltage in a sinewave circuit?
Topic 18: Calculations
What is the magnitude of the impedance of a series AC circuit having a resistance of 6 ohms, an inductive reactance of 17 ohms, and zero capacitive reactance?
3-18B2A 1-watt, 10-volt Zener diode with the following characteristics: I min. = 5 mA; I max. = 95 mA; and Z = 8 ohms, is to be used as part of a voltage regulator in a 20-V power supply. Approximately what size current- limiting resistor would be used to set its bias to the midpoint of its operating range?
3-18B3Given a power supply with a no load voltage of 12 volts and a full load voltage of 10 volts, what is the percentage of voltage regulation?
3-18B4What turns ratio does a transformer need in order to match a source impedance of 500 ohms to a load of 10 ohms?
3-18B5Given a power supply with a full load voltage of 200 volts and a regulation of 25%, what is the no load voltage?
3-18B6What is the conductance (G) of a circuit if 6 amperes of current flows when 12 volts DC is applied?
Topic 9: Ohm’s Law-1
What value of series resistor would be needed to obtain a full scale deflection on a 50 microamp DC meter with an applied voltage of 200 volts DC?
3-9B2Which of the following Ohms Law formulas is incorrect?
3-9B3If a current of 2 amperes flows through a 50-ohm resistor, what is the voltage across the resistor?
3-9B4If a 100-ohm resistor is connected across 200 volts, what is the current through the resistor?
3-9B5If a current of 3 amperes flows through a resistor connected to 90 volts, what is the resistance?
3-9B6A relay coil has 500 ohms resistance, and operates on 125 mA. What value of resistance should be connected in series with it to operate from 110 V DC?
Subelement C: Components
Topic 19: Photoconductive Devices
What happens to the conductivity of photoconductive material when light shines on it?
3-19C2What is the photoconductive effect?
3-19C3What does the photoconductive effect in crystalline solids produce a noticeable change in?
3-19C4What is the description of an optoisolator?
3-19C5What happens to the conductivity of a photosensitive semiconductor junction when it is illuminated?
3-19C6What is the description of an optocoupler?
Topic 20: Capacitors
What factors determine the capacitance of a capacitor?
3-20C2In Figure 3C4, if a small variable capacitor were installed in place of the dashed line, it would?
3-20C3In Figure 3C4, which component (labeled 1 through 4) is used to provide a signal ground?
3-20C4In Figure 3C5, which capacitor (labeled 1 through 4) is being used as a bypass capacitor?
3-20C5In Figure 3C5, the 1 μF capacitor is connected to a potentiometer that is used to:
3-20C6What is the purpose of a coupling capacitor?
Topic 21: Transformers
A capacitor is sometimes placed in series with the primary of a power transformer to:
3-21C2A transformer used to step up its input voltage must have:
3-21C3A transformer primary of 2250 turns connected to 120 VAC will develop what voltage across a 500-turn secondary?
3-21C4What is the ratio of the output frequency to the input frequency of a single-phase full-wave rectifier?
3-21C5A power transformer has a single primary winding and three secondary windings producing 5.0 volts, 12.6 volts, and 150 volts. Assuming similar wire sizes, which of the three secondary windings will have the highest measured DC resistance?
3-21C6A power transformer has a primary winding of 200 turns of #24 wire and a secondary winding consisting of 500 turns of the same size wire. When 20 volts are applied to the primary winding, the expected secondary voltage will be:
Topic 22: Voltage Regulators, Zener Diodes
In a linear electronic voltage regulator:
3-22C2A switching electronic voltage regulator:
3-22C3What device is usually used as a stable reference voltage in a linear voltage regulator?
3-22C4In a regulated power supply, what type of component will most likely be used to establish a reference voltage?
3-22C5A three-terminal regulator:
3-22C6What is the range of voltage ratings available in Zener diodes?
Topic 23: SCRs, Triacs
How might two similar SCRs be connected to safely distribute the power load of a circuit?
3-23C2What are the three terminals of an SCR?
3-23C3Which of the following devices acts as two SCRs connected back to back, but facing in opposite directions and sharing a common gate?
3-23C4What is the transistor called that is fabricated as two complementary SCRs in parallel with a common gate terminal?
3-23C5What are the three terminals of a TRIAC?
3-23C6What circuit might contain a SCR?
Topic 24: Diodes
What is one common use for PIN diodes?
3-24C2What is a common use of a hot-carrier diode?
3-24C3Structurally, what are the two main categories of semiconductor diodes?
3-24C4What special type of diode is capable of both amplification and oscillation?
3-24C5What type of semiconductor diode varies its internal capacitance as the voltage applied to its terminals varies?
3-24C6What is the principal characteristic of a tunnel diode?
Topic 25: Transistors-1
What is the meaning of the term “alpha” with regard to bipolar transistors? The change of:
3-25C2What are the three terminals of a bipolar transistor?
3-25C3What is the meaning of the term “beta” with regard to bipolar transistors? The change of:
3-25C4What are the elements of a unijunction transistor?
3-25C5The beta cutoff frequency of a bipolar transistor is the frequency at which:
3-25C6What does it mean for a transistor to be fully saturated?
Topic 26: Transistors-2
A common base amplifier has:
3-26C2What does it mean for a transistor to be cut off?
3-26C3An emitter-follower amplifier has:
3-26C4What conditions exists when a transistor is operating in saturation?
3-26C5For current to flow in an NPN silicon transistor’s emitter-collector junction, the base must be:
3-26C6When an NPN transistor is operating as a Class A amplifier, the base-emitter junction:
Topic 27: Light Emitting Diodes
What type of bias is required for an LED to produce luminescence?
3-27C2What determines the visible color radiated by an LED junction?
3-27C3What is the approximate operating current of a light-emitting diode?
3-27C4What would be the maximum current to safely illuminate a LED?
3-27C5An LED facing a photodiode in a light-tight enclosure is commonly known as a/an:
3-27C6What circuit component must be connected in series to protect an LED?
Topic 28: Devices
What describes a diode junction that is forward biased?
3-28C2Why are special precautions necessary in handling FET and CMOS devices?
3-28C3What do the initials CMOS stand for?
3-28C4What is the piezoelectric effect?
3-28C5An electrical relay is a:
3-28C6In which oscillator circuit would you find a quartz crystal?
Subelement A: Principles
Topic 1: Electrical Elements
The product of the readings of an AC voltmeter and AC ammeter is called:
3-1A2What is the basic unit of electrical power?
3-1A3What is the term used to express the amount of electrical energy stored in an electrostatic field?
3-1A4What device is used to store electrical energy in an electrostatic field?
3-1A5What formula would determine the inductive reactance of a coil if frequency and coil inductance are known?
3-1A6What is the term for the out-of-phase power associated with inductors and capacitors?
Topic 2: Magnetism
What determines the strength of the magnetic field around a conductor?
3-2A2What will produce a magnetic field?
3-2A3When induced currents produce expanding magnetic fields around conductors in a direction that opposes the original magnetic field, this is known as:
3-2A4The opposition to the creation of magnetic lines of force in a magnetic circuit is known as:
3-2A5What is meant by the term “back EMF”?
3-2A6Permeability is defined as:
Topic 3: Materials
What metal is usually employed as a sacrificial anode for corrosion control purposes?
3-3A2What is the relative dielectric constant for air?
3-3A3Which metal object may be least affected by galvanic corrosion when submerged in seawater?
3-3A4Skin effect is the phenomenon where:
3-3A5Corrosion resulting from electric current flow between dissimilar metals is called:
3-3A6Which of these will be most useful for insulation at UHF frequencies?
Topic 4: Resistance, Capacitance & Inductance
What formula would calculate the total inductance of inductors in series?
3-4A2Good conductors with minimum resistance have what type of electrons?
3-4A3Which of the 4 groups of metals listed below are the best low-resistance conductors?
3-4A4What is the purpose of a bypass capacitor?
3-4A5How would you calculate the total capacitance of three capacitors in parallel?
3-4A6How might you reduce the inductance of an antenna coil?
Topic 5: Semi-conductors
What are the two most commonly-used specifications for a junction diode?
3-5A2What limits the maximum forward current in a junction diode?
3-5A3MOSFETs are manufactured with THIS protective device built into their gate to protect the device from static charges and excessive voltages:
3-5A4What are the two basic types of junction field-effect transistors?
3-5A5A common emitter amplifier has:
3-5A6How does the input impedance of a field-effect transistor compare with that of a bipolar transistor?
Topic 6: Electrical Measurements
An AC ammeter indicates:
3-6A2By what factor must the voltage of an AC circuit, as indicated on the scale of an AC voltmeter, be multiplied to obtain the peak voltage value?
3-6A3What is the RMS voltage at a common household electrical power outlet?
3-6A4What is the easiest voltage amplitude to measure by viewing a pure sine wave signal on an oscilloscope?
3-6A5By what factor must the voltage measured in an AC circuit, as indicated on the scale of an AC voltmeter, be multiplied to obtain the average voltage value?
3-6A6What is the peak voltage at a common household electrical outlet?
Topic 7: Waveforms
What is a sine wave?
3-7A2How many degrees are there in one complete sine wave cycle?
3-7A3What type of wave is made up of sine waves of the fundamental frequency and all the odd harmonics?
3-7A4What is the description of a square wave?
3-7A5What type of wave is made up of sine waves at the fundamental frequency and all the harmonics?
3-7A6What type of wave is characterized by a rise time significantly faster than the fall time (or vice versa)?
Topic 8: Conduction
What is the term used to identify an AC voltage that would cause the same heating in a resistor as a corresponding value of DC voltage?
3-8A2What happens to reactive power in a circuit that has both inductors and capacitors?
3-8A3Halving the cross-sectional area of a conductor will:
3-8A4Which of the following groups is correct for listing common materials in order of descending conductivity?
3-8A5How do you compute true power (power dissipated in the circuit) in a circuit where AC voltage and current are out of phase?
3-8A6Assuming a power source to have a fixed value of internal resistance, maximum power will be transferred to the load when:
Subelement D: Circuits
Topic 29: R-L-C Circuits
What is the approximate magnitude of the impedance of a parallel R-L-C circuit at resonance?
3-29D2What is the approximate magnitude of the impedance of a series R-L-C circuit at resonance?
3-29D3How could voltage be greater across reactances in series than the applied voltage?
3-29D4What is the characteristic of the current flow in a series R-L-C circuit at resonance?
3-29D5What is the characteristic of the current flow within the parallel elements in a parallel R-L-C circuit at resonance?
3-29D6What is the relationship between current through a resonant circuit and the voltage across the circuit?
Topic 30: Op Amps
What is the main advantage of using an op-amp audio filter over a passive LC audio filter?
3-30D2What are the characteristics of an inverting operational amplifier (op-amp) circuit?
3-30D3Gain of a closed-loop op-amp circuit is determined by?
3-30D4Where is the external feedback network connected to control the gain of a closed-loop op-amp circuit?
3-30D5Which of the following op-amp circuits is operated open-loop?
3-30D6In the op-amp oscillator circuit shown in Figure 3D6, what would be the most noticeable effect if the capacitance of C were suddenly doubled?
Topic 31: Phase Locked Loops (PLLs); Voltage Controlled Oscillators (VCOs); Mixers
What frequency synthesizer circuit uses a phase comparator, look-up table, digital-to-analog converter, and a low-pass antialias filter?
3-31D2A circuit that compares the output of a voltage-controlled oscillator (VCO) to a frequency standard and produces an error voltage that is then used to adjust the capacitance of a varactor diode used to control frequency in that same VCO is called what?
3-31D3RF input to a mixer is 200 MHz and the local oscillator frequency is 150 MHz. What output would you expect to see at the IF output prior to any filtering?
3-31D4What spectral impurity components might be generated by a phase-locked-loop synthesizer?
3-31D5In a direct digital synthesizer, what are the unwanted components on its output?
3-31D6What is the definition of a phase-locked loop (PLL) circuit?
Topic 32: Schematics
Given the combined DC input voltages, what would the output voltage be in the circuit shown in Figure 3D7?
3-32D2Which lamps would be lit in the circuit shown in Figure 3D8?
3-32D3What will occur if an amplifier input signal coupling capacitor fails open?
3-32D4In Figure 3D9, determine if there is a problem with this regulated power supply and identify the problem.
3-32D5In Figure 3D10 with a square wave input what would be the output?
3-32D6With a pure AC signal input to the circuit shown in Figure 3D11, what output wave form would you expect to see on an oscilloscope display?
Subelement E: Digital Logic
Topic 33: Types of Logic
What is the voltage range considered to be valid logic low input in a TTL device operating at 5 volts?
3-33E2What is the voltage range considered to be a valid logic high input in a TTL device operating at 5.0 volts?
3-33E3What is the common power supply voltage for TTL series integrated circuits?
3-33E4TTL inputs left open develop what logic state?
3-33E5Which of the following instruments would be best for checking a TTL logic circuit?
3-33E6What do the initials TTL stand for?
Topic 34: Logic Gates
What is a characteristic of an AND gate?
3-34E2What is a characteristic of a NAND gate?
3-34E3What is a characteristic of an OR gate?
3-34E4What is a characteristic of a NOR gate?
3-34E5What is a characteristic of a NOT gate?
3-34E6Which of the following logic gates will provide an active high out when both inputs are active high?
Topic 35: Logic Levels
In a negative-logic circuit, what level is used to represent a logic 0?
3-35E2For the logic input levels shown in Figure 3E12, what are the logic levels of test points A, B and C in this circuit? (Assume positive logic.)
3-35E3For the logic input levels given in Figure 3E13, what are the logic levels of test points A, B and C in this circuit? (Assume positive logic.)
3-35E4In a positive-logic circuit, what level is used to represent a logic 1?
3-35E5Given the input levels shown in Figure 3E14 and assuming positive logic devices, what would the output be?
3-35E6What is a truth table?
Topic 36: Flip-Flops
A flip-flop circuit is a binary logic element with how many stable states?
3-36E2What is a flip-flop circuit? A binary sequential logic element with ___stable states.
3-36E3How many flip-flops are required to divide a signal frequency by 4?
3-36E4How many bits of information can be stored in a single flip-flop circuit?
3-36E5How many R-S flip-flops would be required to construct an 8 bit storage register?
3-36E6An R-S flip-flop is capable of doing all of the following except:
Topic 37: Multivibrators
The frequency of an AC signal can be divided electronically by what type of digital circuit?
3-37E2What is an astable multivibrator?
3-37E3What is a monostable multivibrator?
3-37E4What is a bistable multivibrator circuit commonly named?
3-37E5What is a bistable multivibrator circuit?
3-37E6What wave form would appear on the voltage outputs at the collectors of an astable, multivibrator, common-emitter stage?
Topic 38: Memory
What is the name of the semiconductor memory IC whose digital data can be written or read, and whose memory word address can be accessed randomly?
3-38E2What is the name of the semiconductor IC that has a fixed pattern of digital data stored in its memory matrix?
3-38E3What does the term “IO” mean within a microprocessor system?
3-38E4What is the name for a microprocessor’s sequence of commands and instructions?
3-38E5How many individual memory cells would be contained in a memory IC that has 4 data bus input/output pins and 4 address pins for connection to the address bus?
3-38E6What is the name of the random-accessed semiconductor memory IC that must be refreshed periodically to maintain reliable data storage in its memory matrix?
Topic 39: Microprocessors
In a microprocessor-controlled two-way radio, a “watchdog” timer:
3-39E2What does the term “DAC” refer to in a microprocessor circuit?
3-39E3Which of the following is not part of a MCU processor?
3-39E4What portion of a microprocessor circuit is the pulse generator?
3-39E5In a microprocessor, what is the meaning of the term “ALU”?
3-39E6What circuit interconnects the microprocessor with the memory and input/output system?
Topic 40: Counters, Dividers, Converters
What is the purpose of a prescaler circuit?
3-40E2What does the term “BCD” mean?
3-40E3What is the function of a decade counter digital IC?
3-40E4What integrated circuit device converts an analog signal to a digital signal?
3-40E5What integrated circuit device converts digital signals to analog signals?
3-40E6In binary numbers, how would you note the quantity TWO?
Subelement F: Receivers
Topic 41: Receiver Theory
What is the limiting condition for sensitivity in a communications receiver?
3-41F2What is the definition of the term “receiver desensitizing”?
3-41F3What is the term used to refer to a reduction in receiver sensitivity caused by unwanted high-level adjacent channel signals?
3-41F4What is meant by the term noise figure of a communications receiver?
3-41F5Which stage of a receiver primarily establishes its noise figure?
3-41F6What is the term for the ratio between the largest tolerable receiver input signal and the minimum discernible signal?
Topic 42: RF Amplifiers
How can selectivity be achieved in the front-end circuitry of a communications receiver?
3-42F2What is the primary purpose of an RF amplifier in a receiver?
3-42F3How much gain should be used in the RF amplifier stage of a receiver?
3-42F4Too much gain in a VHF receiver front end could result in this:
3-42F5What is the advantage of a GaAsFET preamplifier in a modern VHF radio receiver?
3-42F6In what stage of a VHF receiver would a low noise amplifier be most advantageous?
Topic 43: Oscillators
Why is the Colpitts oscillator circuit commonly used in a VFO (variable frequency oscillator)?
3-43F2What is the oscillator stage called in a frequency synthesizer?
3-43F3What are three major oscillator circuits found in radio equipment?
3-43F4Which type of oscillator circuit is commonly used in a VFO (variable frequency oscillator)?
3-43F5What condition must exist for a circuit to oscillate? It must:
3-43F6In Figure 3F15, which block diagram symbol (labeled 1 through 4) is used to represent a local oscillator?
Topic 44: Mixers
What is the image frequency if the normal channel is 151.000 MHz, the IF is operating at 11.000 MHz, and the LO is at 140.000 MHz?
3-44F2What is the mixing process in a radio receiver?
3-44F3In what radio stage is the image frequency normally rejected?
3-44F4What are the principal frequencies that appear at the output of a mixer circuit?
3-44F5If a receiver mixes a 13.8 MHz VFO with a 14.255 MHz receive signal to produce a 455 kHz intermediate frequency signal, what type of interference will a 13.345 MHz signal produce in the receiver?
3-44F6What might occur in a receiver if excessive amounts of signal energy overdrive the mixer circuit?
Topic 45: IF Amplifiers
What degree of selectivity is desirable in the IF circuitry of a wideband FM phone receiver?
3-45F2Which one of these filters can be used in micro-miniature electronic circuits?
3-45F3A receiver selectivity of 2.4 kHz in the IF circuitry is optimum for what type of signals?
3-45F4A receiver selectivity of 10 KHz in the IF circuitry is optimum for what type of signals?
3-45F5What is an undesirable effect of using too wide a filter bandwidth in the IF section of a receiver?
3-45F6How should the filter bandwidth of a receiver IF section compare with the bandwidth of a received signal?
Topic 46: Filters and IF Amplifiers
What is the primary purpose of the final IF amplifier stage in a receiver?
3-46F2What factors should be considered when selecting an intermediate frequency?
3-46F3What is the primary purpose of the first IF amplifier stage in a receiver?
3-46F4What parameter must be selected when designing an audio filter using an op-amp?
3-46F5What are the distinguishing features of a Chebyshev filter?
3-46F6When would it be more desirable to use an m-derived filter over a constant-k filter?
Topic 47: Filters
A good crystal band-pass filter for a single-sideband phone would be?
3-47F2Which statement is true regarding the filter output characteristics shown in Figure 3F16?
3-47F3What are the three general groupings of filters?
3-47F4What is an m-derived filter?
3-47F5What is an advantage of a constant-k filter?
3-47F6What are the distinguishing features of a Butterworth filter?
Topic 48: Detectors
What is a product detector?
3-48F2Which circuit is used to detect FM-phone signals?
3-48F3What is the process of detection in a radio diode detector circuit?
3-48F4What is a frequency discriminator in a radio receiver?
3-48F5In a CTCSS controlled FM receiver, the CTCSS tone is filtered out after the:
3-48F6What is the definition of detection in a radio receiver?
Topic 49: Audio & Squelch Circuits
What is the digital signal processing term for noise subtraction circuitry?
3-49F2What is the purpose of de-emphasis in the receiver audio stage?
3-49F3What makes a Digital Coded Squelch work?
3-49F4What causes a squelch circuit to function?
3-49F5What makes a CTCSS squelch work?
3-49F6What radio circuit samples analog signals, records and processes them as numbers, then converts them back to analog signals?
Topic 50: Receiver Performance
Where would you normally find a low-pass filter in a radio receiver?
3-50F2How can ferrite beads be used to suppress ignition noise? Install them:
3-50F3What is the term used to refer to the condition where the signals from a very strong station are superimposed on other signals being received?
3-50F4What is cross-modulation interference?
3-50F5In Figure 3F15 at what point in the circuit (labeled 1 through 4) could a DC voltmeter be used to monitor signal strength?
3-50F6Pulse type interference to automobile radio receivers that appears related to the speed of the engine can often be reduced by:
Subelement G: Transmitters
Topic 51: Amplifiers-1
What class of amplifier is distinguished by the presence of output throughout the entire signal cycle and the input never goes into the cutoff region?
3-51G2What is the distinguishing feature of a Class A amplifier?
3-51G3Which class of amplifier has the highest linearity and least distortion?
3-51G4Which class of amplifier provides the highest efficiency?
3-51G5What class of amplifier is distinguished by the bias being set well beyond cutoff?
3-51G6Which class of amplifier has an operating angle of more than 180 degrees but less than 360 degrees when driven by a sine wave signal?
Topic 52: Amplifiers-2
The class B amplifier output is present for what portion of the input cycle?
3-52G2What input-amplitude parameter is most valuable in evaluating the signal-handling capability of a Class A amplifier?
3-52G3The class C amplifier output is present for what portion of the input cycle?
3-52G4What is the approximate DC input power to a Class AB RF power amplifier stage in an unmodulated carrier transmitter when the PEP output power is 500 watts?
3-52G5The class AB amplifier output is present for what portion of the input cycle?
3-52G6What class of amplifier is characterized by conduction for 180 degrees of the input wave?
Topic 53: Oscillators & Modulators
What is the modulation index in an FM phone signal having a maximum frequency deviation of 3,000 Hz on either side of the carrier frequency when the modulating frequency is 1,000 Hz?
3-53G2What is the modulation index of a FM phone transmitter producing a maximum carrier deviation of 6 kHz when modulated with a 2 kHz modulating frequency?
3-53G3What is the total bandwidth of a FM phone transmission having a 5 kHz deviation and a 3 kHz modulating frequency?
3-53G4How does the modulation index of a phase-modulated emission vary with RF carrier frequency?
3-53G5How can a single-sideband phone signal be generated?
3-53G6What is a balanced modulator?
Topic 54: Resonance - Tuning Networks
What is an L-network?
3-54G2What is a pi-network?
3-54G3What is the resonant frequency in an electrical circuit?
3-54G4Which three network types are commonly used to match an amplifying device to a transmission line?
3-54G5What is a pi-L network?
3-54G6Which network provides the greatest harmonic suppression?
Topic 55: SSB Transmitters
What will occur when a non-linear amplifier is used with a single-sideband phone transmitter?
3-55G2To produce a single-sideband suppressed carrier transmission it is necessary to ____ the carrier and to ____ the unwanted sideband.
3-55G3In a single-sideband phone signal, what determines the PEP-to-average power ratio?
3-55G4What is the approximate ratio of peak envelope power to average power during normal voice modulation peak in a single-sideband phone signal?
3-55G5What is the output peak envelope power from a transmitter as measured on an oscilloscope showing 200 volts peak-to-peak across a 50-ohm load resistor?
3-55G6What would be the voltage across a 50-ohm dummy load dissipating 1,200 watts?
Topic 56: Technology
How can intermodulation interference between two transmitters in close proximity often be reduced or eliminated?
3-56G2How can parasitic oscillations be eliminated in a power amplifier?
3-56G3What is the name of the condition that occurs when the signals of two transmitters in close proximity mix together in one or both of their final amplifiers, and unwanted signals at the sum and difference frequencies of the original transmissions are generated?
3-56G4What term describes a wide-bandwidth communications system in which the RF carrier varies according to some pre-determined sequence?
3-56G5How can even-order harmonics be reduced or prevented in transmitter amplifier design?
3-56G6What is the modulation type that can be a frequency hopping of one carrier or multiple simultaneous carriers?
Subelement H: Modulation
Topic 57: Frequency Modulation
The deviation ratio is the:
3-57H2What is the deviation ratio for an FM phone signal having a maximum frequency deviation of plus or minus 5 kHz and accepting a maximum modulation rate of 3 kHz?
3-57H3What is the deviation ratio of an FM-phone signal having a maximum frequency swing of plus or minus 7.5 kHz and accepting a maximum modulation rate of 3.5 kHz?
3-57H4How can an FM-phone signal be produced in a transmitter?
3-57H5What is meant by the term modulation index?
3-57H6In an FM-phone signal, what is the term for the maximum deviation from the carrier frequency divided by the maximum audio modulating frequency?
Topic 58: SSB Modulation
In Figure 3H17, the block labeled 4 would indicate that this schematic is most likely a/an:
3-58H2In Figure 3H17, which block diagram symbol (labeled 1 through 4) represents where audio intelligence is inserted?
3-58H3What kind of input signal could be used to test the amplitude linearity of a single-sideband phone transmitter while viewing the output on an oscilloscope?
3-58H4What does a two-tone test illustrate on an oscilloscope?
3-58H5How can a double-sideband phone signal be produced?
3-58H6What type of signals are used to conduct an SSB two-tone test?
Topic 59: Pulse Modulation
What is an important factor in pulse-code modulation using time-division multiplex?
3-59H2In a pulse-width modulation system, what parameter does the modulating signal vary?
3-59H3What is the name of the type of modulation in which the modulating signal varies the duration of the transmitted pulse?
3-59H4Which of the following best describes a pulse modulation system?
3-59H5In a pulse-position modulation system, what parameter does the modulating signal vary?
3-59H6What is one way that voice is transmitted in a pulse-width modulation system?
Subelement I: Power Sources
Topic 60: Batteries-1
When a lead-acid storage battery is being charged, a harmful effect to humans is:
3-60I2A battery with a terminal voltage of 12.5 volts is to be trickle-charged at a 0.5 A rate. What resistance should be connected in series with the battery to charge it from a 110-V DC line?
3-60I3What capacity in amperes does a storage battery need to be in order to operate a 50 watt transmitter for 6 hours? Assume a continuous transmitter load of 70% of the key-locked demand of 40 A, and an emergency light load of 1.5 A.
3-60I4What is the total voltage when 12 Nickel-Cadmium batteries are connected in series?
3-60I5The average fully-charged voltage of a lead-acid storage cell is:
3-60I6A nickel-cadmium cell has an operating voltage of about:
Topic 61: Batteries-2
When an emergency transmitter uses 325 watts and a receiver uses 50 watts, how many hours can a 12.6 volt, 55 ampere-hour battery supply full power to both units?
3-61I2What current will flow in a 6 volt storage battery with an internal resistance of 0.01 ohms, when a 3-watt, 6-volt lamp is connected?
3-61I3A ship RADAR unit uses 315 watts and a radio uses 50 watts. If the equipment is connected to a 50 ampere-hour battery rated at 12.6 volts, how long will the battery last?
3-61I4If a marine radiotelephone receiver uses 75 watts of power and a transmitter uses 325 watts, how long can they both operate before discharging a 50 ampere-hour 12 volt battery?
3-61I5A 6 volt battery with 1.2 ohms internal resistance is connected across two light bulbs in parallel whose resistance is 12 ohms each. What is the current flow?
3-61I6A 12.6 volt, 8 ampere-hour battery is supplying power to a receiver that uses 50 watts and a RADAR system that uses 300 watts. How long will the battery last?
Topic 62: Motors & Generators
What occurs if the load is removed from an operating series DC motor?
3-62I2If a shunt motor running with a load has its shunt field opened, how would this affect the speed of the motor?
3-62I3The expression “voltage regulation” as it applies to a shunt-wound DC generator operating at a constant frequency refers to:
3-62I4What is the line current of a 7 horsepower motor operating on 120 volts at full load, a power factor of 0.8, and 95% efficient?
3-62I5A 3 horsepower, 100 V DC motor is 85% efficient when developing its rated output. What is the current?
3-62I6The output of a separately-excited AC generator running at a constant speed can be controlled by:
Subelement J: Antennas
Topic 63: Antenna Theory
Which of the following could cause a high standing wave ratio on a transmission line?
3-63J2Why is the value of the radiation resistance of an antenna important?
3-63J3A radio frequency device that allows RF energy to pass through in one direction with very little loss but absorbs RF power in the opposite direction is a:
3-63J4What is an advantage of using a trap antenna?
3-63J5What is meant by the term radiation resistance of an antenna?
3-63J6What is meant by the term antenna bandwidth?
Topic 64: Voltage, Current and Power Relationships
What is the current flowing through a 52 ohm line with an input of 1,872 watts?
3-64J2The voltage produced in a receiving antenna is:
3-64J3Which of the following represents the best standing wave ratio (SWR)?
3-64J4At the ends of a half-wave antenna, what values of current and voltage exist compared to the remainder of the antenna?
3-64J5An antenna radiates a primary signal of 500 watts output. If there is a 2nd harmonic output of 0.5 watt, what attenuation of the 2nd harmonic has occurred?
3-64J6There is an improper impedance match between a 30 watt transmitter and the antenna, with 5 watts reflected. How much power is actually radiated?
Topic 65: Frequency and Bandwidth
A vertical 1/4 wave antenna receives signals:
3-65J2The resonant frequency of a Hertz antenna can be lowered by:
3-65J3An excited 1/2 wavelength antenna produces:
3-65J4To increase the resonant frequency of a 1/4 wavelength antenna:
3-65J5What happens to the bandwidth of an antenna as it is shortened through the use of loading coils?
3-65J6To lengthen an antenna electrically, add a:
Topic 66: Transmission Lines
What is the meaning of the term velocity factor of a transmission line?
3-66J2What determines the velocity factor in a transmission line?
3-66J3Nitrogen is placed in transmission lines to:
3-66J4A perfect (no loss) coaxial cable has 7 dB of reflected power when the input is 5 watts. What is the output of the transmission line?
3-66J5Referred to the fundamental frequency, a shorted stub line attached to the transmission line to absorb even harmonics could have a wavelength of:
3-66J6If a transmission line has a power loss of 6 dB per 100 feet, what is the power at the feed point to the antenna at the end of a 200 foot transmission line fed by a 100 watt transmitter?
Topic 67: Effective Radiated Power
What is the effective radiated power of a repeater with 50 watts transmitter power output, 4 dB feedline loss, 3 dB duplexer and circulator loss, and 6 dB antenna gain?
3-67J2What is the effective radiated power of a repeater with 75 watts transmitter power output, 4 dB feedline loss, 3 dB duplexer and circulator loss, and 10 dB antenna gain?
3-67J3What is the effective radiated power of a repeater with 75 watts transmitter power output, 5 dB feedline loss, 4 dB duplexer and circulator loss, and 6 dB antenna gain?
3-67J4What is the effective radiated power of a repeater with 100 watts transmitter power output, 4 dB feedline loss, 3 dB duplexer and circulator loss, and 7 dB antenna gain?
3-67J5What is the effective radiated power of a repeater with 100 watts transmitter power output, 5 dB feedline loss, 4 dB duplexer and circulator loss, and 10 dB antenna gain?
3-67J6What is the effective radiated power of a repeater with 50 watts transmitter power output, 5 dB feedline loss, 4 dB duplexer and circulator loss, and 7 dB antenna gain?
Subelement K: K – Aircraft
Topic 68: Distance Measuring Equipment
What is the frequency range of the Distance Measuring Equipment (DME) used to indicate an aircraft’s slant range distance to a selected ground-based navigation station?
3-68K2The Distance Measuring Equipment (DME) measures the distance from the aircraft to the DME ground station. This is referred to as:
3-68K3The Distance Measuring Equipment (DME) ground station has a built-in delay between reception of an interrogation and transmission of the reply to allow:
3-68K4What is the main underlying operating principle of an aircraft’s Distance Measuring Equipment (DME)?
3-68K5What radio navigation aid determines the distance from an aircraft to a selected VORTAC station by measuring the length of time the radio signal takes to travel to and from the station?
3-68K6The majority of airborne Distance Measuring Equipment systems automatically tune their transmitter and receiver frequencies to the paired __ / __ channel.
Topic 69: VHF Omnidirectional Range (VOR)
All directions associated with a VOR station are related to:
3-69K2The rate that the transmitted VOR variable signal rotates is equivalent to how many revolutions per second?
3-69K3What is the frequency range of the ground-based Very-high-frequency Omnidirectional Range (VOR) stations used for aircraft navigation?
3-69K4Lines drawn from the VOR station in a particular magnetic direction are:
3-69K5The amplitude modulated variable phase signal and the frequency modulated reference phase signal of a Very-high-frequency Omnidirectional Range (VOR) station used for aircraft navigation are synchronized so that both signals are in phase with each other at ____________ of the VOR station.
3-69K6What is the main underlying operating principle of the Very-high-frequency Omnidirectional Range (VOR) aircraft navigational system?
Topic 70: Instrument Landing System (ILS)
What is the frequency range of the localizer beam system used by aircraft to find the centerline of a runway during an Instrument Landing System (ILS) approach to an airport?
3-70K2What is the frequency range of the marker beacon system used to indicate an aircraft's position during an Instrument Landing System (ILS) approach to an airport's runway?
3-70K3Which of the following is a required component of an Instrument Landing System (ILS)?
3-70K4What type of antenna is used in an aircraft’s Instrument Landing System (ILS) glideslope installation?
3-70K5Choose the only correct statement about the localizer beam system used by aircraft to find the centerline of a runway during an Instrument Landing System (ILS) approach to an airport. The localizer beam system:
3-70K6On runway approach, an ILS Localizer shows:
Topic 71: Automatic Direction Finding Equipment (ADF) & Transponders
What is the frequency range of an aircraft’s Automatic Direction Finding (ADF) equipment?
3-71K2What is meant by the term “night effect” when using an aircraft’s Automatic Direction Finding (ADF) equipment? Night effect refers to the fact that:
3-71K3What are the transmit and receive frequencies of an aircraft’s mode C transponder operating in the Air Traffic Control RADAR Beacon System (ATCRBS)?
3-71K4In addition to duplicating the functions of a mode C transponder, an aircraft’s mode S transponder can also provide:
3-71K5What type of encoding is used in an aircraft’s mode C transponder transmission to a ground station of the Air Traffic Control RADAR Beacon System (ATCRBS)?
3-71K6Choose the only correct statement about an aircraft’s Automatic Direction Finding (ADF) equipment.
Topic 72: Aircraft Antenna Systems and Frequencies
What type of antenna pattern is radiated from a ground station phased-array directional antenna when transmitting the PPM pulses in a Mode S interrogation signal of an aircraft’s Traffic alert and Collision Avoidance System (TCAS) installation?
3-72K2What type of antenna is used in an aircraft’s Instrument Landing System (ILS) marker beacon installation?
3-72K3What is the frequency range of an aircraft’s Very High Frequency (VHF) communications?
3-72K4Aircraft Emergency Locator Transmitters (ELT) operate on what frequencies?
3-72K5What is the frequency range of an aircraft’s radio altimeter?
3-72K6What type of antenna is attached to an aircraft’s Mode C transponder installation and used to receive 1030 MHz interrogation signals from the Air Traffic Control Radar Beacon System (ATCRBS)?
Topic 73: Equipment Functions
Some aircraft and avionics equipment operates with a prime power line frequency of 400 Hz. What is the principle advantage of a higher line frequency?
3-73K2Aviation services use predominantly ____ microphones.
3-73K3Typical airborne HF transmitters usually provide a nominal RF power output to the antenna of ____ watts, compared with ____ watts RF output from a typical VHF transmitter.
3-73K4Before ground testing an aircraft RADAR, the operator should:
3-73K5What type of antenna is used in an aircraft’s Very High Frequency Omnidirectional Range (VOR) and Localizer (LOC) installations?
3-73K6What is the function of a commercial aircraft’s SELCAL installation? SELCAL is a type of aircraft communications __________.
Subelement L: L – Installation, Maintenance & Repair
Topic 74: Indicating Meters
What is a 1/2 digit on a DMM?
3-74L2A 50 microampere meter movement has an internal resistance of 2,000 ohms. What applied voltage is required to indicate half-scale deflection?
3-74L3What is the purpose of a series multiplier resistor used with a voltmeter?
3-74L4What is the purpose of a shunt resistor used with an ammeter?
3-74L5What instrument is used to indicate high and low digital voltage states?
3-74L6What instrument may be used to verify proper radio antenna functioning?
Topic 75: Test Equipment
How is a frequency counter used?
3-75L2What is a frequency standard?
3-75L3What equipment may be useful to track down EMI aboard a ship or aircraft?
3-75L4On an analog wattmeter, what part of the scale is most accurate and how much does that accuracy extend to the rest of the reading scale?
3-75L5Which of the following frequency standards is used as a time base standard by field technicians?
3-75L6Which of the following contains a multirange AF voltmeter calibrated in dB and a sharp, internal 1000 Hz bandstop filter, both used in conjunction with each other to perform quieting tests?
Topic 76: Oscilloscopes
What is used to decrease circuit loading when using an oscilloscope?
3-76L2How does a spectrum analyzer differ from a conventional oscilloscope?
3-76L3What stage determines the maximum frequency response of an oscilloscope?
3-76L4What factors limit the accuracy, frequency response, and stability of an oscilloscope?
3-76L5An oscilloscope can be used to accomplish all of the following except:
3-76L6What instrument is used to check the signal quality of a single-sideband radio transmission?
Topic 77: Specialized Instruments
A(n) ____ and ____ can be combined to measure the characteristics of transmission lines. Such an arrangement is known as a time-domain reflectometer (TDR).
3-77L2What does the horizontal axis of a spectrum analyzer display?
3-77L3What does the vertical axis of a spectrum analyzer display?
3-77L4What instrument is most accurate when checking antennas and transmission lines at the operating frequency of the antenna?
3-77L5What test instrument can be used to display spurious signals in the output of a radio transmitter?
3-77L6What instrument is commonly used by radio service technicians to monitor frequency, modulation, check receiver sensitivity, distortion, and to generate audio tones?
Topic 78: Measurement Procedures
Can a P25 radio system be monitored with a scanner?
3-78L2Which of the following answers is true?
3-78L3What is a common method used to program radios without using a “wired” connection?
3-78L4What is the common method for determining the exact sensitivity specification of a receiver?
3-78L5A communications technician would perform a modulation-acceptance bandwidth test in order to:
3-78L6What is the maximum FM deviation for voice operation of a normal wideband channel on VHF and UHF?
Topic 79: Repair Procedures
When soldering or working with CMOS electronics products or equipment, a wrist strap:
3-79L2Which of the following is the preferred method of cleaning solder from plated-through circuit-board holes?
3-79L3What is the proper way to cut plastic wire ties?
3-79L4The ideal method of removing insulation from wire is:
3-79L5A “hot gas bonder” is used:
3-79L6When repairing circuit board assemblies it is most important to:
Topic 80: Installation Codes & Procedures
What color is the binder for pairs 51-75 in a 100-pair cable?
3-80L2What is most important when routing cables in a mobile unit?
3-80L3Why should you not use white or translucent plastic tie wraps on a radio tower?
3-80L4What is the 6th pair color code in a 25 pair switchboard cable as is found in building telecommunications interconnections?
3-80L5What tolerance off of plumb should a single base station radio rack be installed?
3-80L6What type of wire would connect an SSB automatic tuner to an insulated backstay?
Topic 81: Troubleshooting
On a 150 watt marine SSB HF transceiver, what would be indicated by a steady output of 75 watts when keying the transmitter on?
3-81L2The tachometer of a building’s elevator circuit experiences interference caused by the radio system nearby. What is a common potential “fix” for the problem?
3-81L3A common method of programming portable or mobile radios is to use a:
3-81L4In a software-defined transceiver, what would be the best way for a technician to make a quick overall evaluation of the radio’s operational condition?
3-81L5How might an installer verify correct GPS sentence to marine DSC VHF radio?
3-81L6What steps must be taken to activate the DSC emergency signaling function on a marine VHF?
Subelement M: M – Communications Technology
Topic 82: Types of Transmissions
What term describes a wide-bandwidth communications system in which the RF carrier frequency varies according to some predetermined sequence?
3-82M2Name two types of spread spectrum systems used in most RF communications applications?
3-82M3What is the term used to describe a spread spectrum communications system where the center frequency of a conventional carrier is altered many times per second in accordance with a pseudo-random list of channels?
3-82M4A TDMA radio uses what to carry the multiple conversations sequentially?
3-82M5Which of the following statements about SSB voice transmissions is correct?
3-82M6What are the two most-used PCS (Personal Communications Systems) coding techniques used to separate different calls?
Topic 83: Coding and Multiplexing
What is a CODEC?
3-83M2The GSM (Global System for Mobile Communications) uses what type of CODEC for digital mobile radio system communications?
3-83M3Which of the following codes has gained the widest acceptance for exchange of data from one computer to another?
3-83M4The International Organization for Standardization has developed a seven-level reference model for a packet-radio communications structure. What level is responsible for the actual transmission of data and handshaking signals?
3-83M5What CODEC is used in Phase 2 P25 radios?
3-83M6The International Organization for Standardization has developed a seven-level reference model for a packet-radio communications structure. The _______ level arranges the bits into frames and controls data flow.
Topic 84: Signal Processing, Software and Codes
What is a SDR?
3-84M2What does the DSP not do in a modern DSP radio?
3-84M3Which statement best describes the code used for GMDSS-DSC transmissions?
3-84M4Which is the code used for SITOR-A and -B transmissions?
3-84M5Which of the following statements is true?
3-84M6What principle allows multiple conversations to be able to share one radio channel on a GSM channel?
Subelement N: N – Marine
Topic 85: VHF
What is the channel spacing used for VHF marine radio?
3-85N2What VHF channel is assigned for distress and calling?
3-85N3What VHF Channel is used for Digital Selective Calling and acknowledgement?
3-85N4Maximum allowable frequency deviation for VHF marine radios is:
3-85N5What is the reason for the USA-INT control or function?
3-85N6How might an installer verify correct GPS sentence to marine DSC VHF radio?
Topic 86: MF-HF, SSB-SITOR
What is a common occurrence when voice-testing an SSB aboard a boat?
3-86N2What might contribute to apparent low voltage on marine SSB transmitting?
3-86N3What type of wire connects an SSB automatic tuner to an insulated backstay?
3-86N4Which of the following statements concerning SITOR communications is true?
3-86N5The sequence ARQ, FEC, SFEC best corresponds to which of the following sequences?
3-86N6Which of the following statements concerning SITOR communications is true?
Topic 87: Survival Craft Equipment: VHF, SARTs & EPIRBs
What causes the SART to begin a transmission?
3-87N2How should the signal from a Search And Rescue RADAR Transponder appear on a RADAR display?
3-87N3In which frequency band does a search and rescue transponder operate?
3-87N4Which piece of required GMDSS equipment is the primary source of transmitting locating signals?
3-87N5Which of the following statements concerning satellite EPIRBs is true?
3-87N6What statement is true regarding 406 MHz EPIRB transmissions?
Topic 88: FAX, NAVTEX
What is facsimile?
3-88N2What is the standard scan rate for high-frequency 3 MHz - 23 MHz weather facsimile reception from shore stations?
3-88N3What would be the bandwidth of a good crystal lattice band-pass filter for weather facsimile HF (high frequency) reception?
3-88N4Which of the following statements about NAVTEX is true?
3-88N5Which of the following is the primary frequency that is used exclusively for NAVTEX broadcasts internationally?
3-88N6What determines whether a NAVTEX receiver does not print a particular type of message content?
Topic 89: NMEA Data
What data language is bi-directional, multi-transmitter, multi-receiver network?
3-89N2How should shielding be grounded on an NMEA 0183 data line?
3-89N3What might occur in NMEA 2000 network topology if one device in line should fail?
3-89N4In an NMEA 2000 device, a load equivalence number (LEN) of 1 is equivalent to how much current consumption?
3-89N5An NMEA 2000 system with devices in a single location may be powered using this method:
3-89N6What voltage drop at the end of the last segment will satisfy NMEA 2000 network cabling plans?
Subelement O: RADAR
Topic 90: RADAR Theory
What is the normal range of pulse repetition rates?
3-90O2The RADAR range in nautical miles to an object can be found by measuring the elapsed time during a RADAR pulse and dividing this quantity by:
3-90O3What is the normal range of pulse widths?
3-90O4Shipboard RADAR is most commonly operated in what band?
3-90O5The pulse repetition rate (prr) of a RADAR refers to the:
3-90O6If the elapsed time for a RADAR echo is 62 microseconds, what is the distance in nautical miles to the object?
Topic 91: Components
The ATR box:
3-91O2What is the purpose or function of the RADAR duplexer/circulator? It is a/an:
3-91O3What device can be used to determine the performance of a RADAR system at sea?
3-91O4What is the purpose of a synchro transmitter and receiver?
3-91O5Digital signal processing (DSP) of RADAR signals (compared with analog) causes:
3-91O6The component or circuit providing the transmitter output power for a RADAR system is the:
Topic 92: Range, Pulse Width & Repetition Rate
When a RADAR is being operated on the 48 mile range setting, what is the most appropriate pulse width (PW) and pulse repetition rate (pps)?
3-92O2When a RADAR is being operated on the 6 mile range setting what is the most appropriate pulse width and pulse repetition rate?
3-92O3We are looking at a target 25 miles away. When a RADAR is being operated on the 25 mile range setting what is the most appropriate pulse width and pulse repetition rate?
3-92O4What pulse width and repetition rate should you use at long ranges?
3-92O5What pulse width and repetition rate should you use at short ranges?
3-92O6When a RADAR is being operated on the 1.5 mile range setting, what is the most appropriate pulse width and pulse repetition rate?
Topic 93: Antennas & Waveguides
How does the gain of a parabolic dish antenna change when the operating frequency is doubled?
3-93O2What type of antenna or pickup device is used to extract the RADAR signal from the wave guide?
3-93O3What happens to the beamwidth of an antenna as the gain is increased? The beamwidth:
3-93O4A common shipboard RADAR antenna is the:
3-93O5Conductance takes place in a waveguide:
3-93O6To couple energy into and out of a waveguide use:
Topic 94: RADAR Equipment
The permanent magnetic field that surrounds a traveling-wave tube (TWT) is intended to:
3-94O2Prior to testing any RADAR system, the operator should first:
3-94O3In the term “ARPA RADAR,” ARPA is the acronym for which of the following?
3-94O4Which of the following is NOT a precaution that should be taken to ensure the magnetron is not weakened:
3-94O5Exposure to microwave energy from RADAR or other electronics devices is limited by U.S. Health Department regulations to _______ mW/centimeter.
3-94O6RADAR collision avoidance systems utilize inputs from each of the following except your ship’s:
Subelement P: Satellite
Topic 95: Low Earth Orbit Systems
What is the orbiting altitude of the Iridium satellite communications system?
3-95P2What frequency band is used by the Iridium system for telephone and messaging?
3-95P3What services are provided by the Iridium system?
3-95P4Which of the following statements about the Iridium system is true?
3-95P5What is the main function of the COSPAS-SARSAT satellite system?
3-95P6How does the COSPAS-SARSAT satellite system determine the position of a ship in distress?
Topic 96: INMARSAT Communications Systems-1
What is the orbital altitude of INMARSAT Satellites?
3-96P2Which of the following describes the INMARSAT Satellite system?
3-96P3What are the directional characteristics of the INMARSAT-C SES antenna?
3-96P4When engaging in voice communications via an INMARSAT-B terminal, what techniques are used?
3-96P5Which of the following statements concerning INMARSAT geostationary satellites is true?
3-96P6Which of the following conditions can render INMARSAT -B communications impossible?
Topic 97: INMARSAT Communications Systems-2
What is the best description for the INMARSAT-C system?
3-97P2The INMARSAT mini-M system is a:
3-97P3What statement best describes the INMARSAT-B services?
3-97P4Which INMARSAT systems offer High Speed Data at 64/54 kbps?
3-97P5When INMARSAT-B and INMARSAT-C terminals are compared:
3-97P6What services are provided by the INMARSAT-M service?
Topic 98: GPS
Global Positioning Service (GPS) satellite orbiting altitude is:
3-98P2The GPS transmitted frequencies are:
3-98P3How many GPS satellites are normally in operation?
3-98P4What best describes the GPS Satellites orbits?
3-98P5How many satellites must be received to provide complete position and time?
3-98P6What is DGPS?