FCC Element 6 – Radiotelegraph Operator License (T) Practice Test

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• To operate on a lower resonant frequency on an available Marconi antenna, what would be the correct procedure?
• Instruments used to indicate various DC currents and voltages in a transmitter may be protected against damage to stray RF by?
• What effect does adding an iron core to an air-core inductance have?
• What is the correct procedure when observing another vessel in distress?
• Which devices may be used as indicating tools in neutralizing an RF amplifier stage?
• What happens when the field of a shunt-wound DC motor opens while the machine is operating under no load?
• Under what condition may a person hold both a radiotelegraph operator's license and a Marine Radio Operator Permit?
• What is the function of a plate choke in a Heising modulator?
• To switch a transmitter from maximum power for telegraph to amplitude modulation, what modification must be made?
• What determines the permissible distortion in a vacuum tube amplifier?
• How frequently must the quantity of fuel in the supply tank for use with an oil or gas driven emergency generator be checked while at sea?
• What turns ratio is required for a transformer to match a source impedance of 500 ohms to a load of 10 ohms?
• The total power dissipation capability of two 10 watt, 500 ohm resistors connected in series is:
• What value of sinusoidal audio power is needed to ensure 100% modulation with a 200 W DC plate input and 60% efficiency in a Class C amplifier?
• Which vacuum tube's characteristic is associated with high sensitivity due to output signal amplitude being proportional to voltage?
• What is the outcome of using a lower distortion output in a diode detector compared to a triode detector?
• What does a difference between open circuit voltage of 12.4 V and 12.2 V when charging indicate?
• What does the screen grid in a vacuum tube enable?
• What effect will adding an inductor in series with an antenna have on the resonant frequency?
• What is the baud rate and interval between burst transmissions in the SITOR-ARQ system?
• What effect does a high resistance choke have on voltage regulation?
• What is the ratio of peak-to-effective voltage values of a sine wave?
• What is the minimum radio operator license requirement of a chief radio officer on U.S. passenger ships?
• With what type and frequency should a transmitter be adjusted to transmit a distress call?
• Given vacuum tube constants, what grid bias voltage is obtained when Gp = 1000 V and Ig = 10 mA?
• The second harmonic of a 380 kHz frequency is:
• In a typical Class A amplifier, what occurs in relation to grid current?
• The degree of coupling is varied in a pi-network used to transfer energy from a vacuum tube plate circuit to an antenna by?
• In order of selectivity, which receivers are considered the best?
• In a self excited oscillator, what will a swinging antenna cause?
• What is a characteristic of a square law type of vacuum tube detector?
• What type of oscillator depends on the negative resistance characteristic of a tetrode tube?
• What is a significant disadvantage of using a self-excited oscillator type of transmitter for shipboard service?
• Which component in a resonant circuit is necessary to achieve resonance?
• What is the opposition to the creation of magnetic lines of force in a magnetic circuit called?
• What can be a consequence of operating a transmitter on a nearly depleted battery?
• The time in seconds for a capacitor to attain 63.2% of the applied voltage across its terminals is called:
• When a radiotelephone transmitter is 100% modulated by a sinusoidal waveform, what is the expected change in antenna current?
• How does increasing the dielectric constant of insulating material affect surge impedance?
• Upon hearing an SOS, what should an operator do?
• How often must a radiotelegraph station transmit its call sign when a transmission is maintained for more than 20 minutes in the band 405-525 kHz?
• What should the motor-field rheostat be set to when starting a DC motor generator set?
• What should not be done to a carbon microphone while it is in operation?
• What is the primary purpose of the suppressor grid in a pentode?
• If a 500 Hz transformer is connected to a 60 Hz source of the same voltage, what consequence might occur?
• Which operator is authorized to make equipment adjustments at maritime radio stations which may affect transmitter operation?
• Which frequency is designated for maritime distress calls?
• You intercept "CQ CQ WSV TFC"; what does this mean?
• What is a common consequence of connecting a transformer to a source with a different frequency?
• What should be done if a distress signal is received?
• Who may program authorized frequency channels into a transmitter or transceiver used in the maritime service?
• What action can be taken in a Heising modulation system to achieve 100% modulation?
• What is the usual procedure when increased output is desired from a motor-generator?
• If a 1500 kHz radio wave is modulated by a 2000 Hz sine wave tone, what frequencies does the modulated wave contain?
• What is the maximum authorized bandwidth of a high frequency radiotelegraphy signal, emission A1A, in the maritime service?
• When the first speech-amplifier of a transmitter was overexcited but the modulation capabilities were not exceeded, what would be the effect on the output?
• In grid-bias modulation, what is essential for achieving high modulation efficiency?
• What is the incorrect statement regarding the purpose of an air gap in a filter choke coil core?
• What is the maximum transmitter power that a ship station may radiate using radiotelegraphy emissions on frequencies below 27500 kHz?
• Compared to half-wave rectification, full wave rectification has what advantage?
• What is the antenna requirement aboard a survival craft equipped with a non-portable radiotelegraph installation?
• Amperage may also be referred to as:
• Why is it important to prevent second harmonics in telephones?
• What is the nature of the DC bias in a Class A amplifier?
• In a shunt-fed plate circuit with a short circuit of the plate RF choke, what is the likely outcome?
• What happens to the resonant frequency when inductance is increased in an antenna circuit?
• What is the common issue faced by batteries that cannot maintain a charge?
• What is a likely consequence of a short in the armature coils of a DC motor?
• What are the characteristics of a vacuum tube operating as a Class A amplifier?
• In which city is the major telecommunication center of the United States located?
• What is the authorized mode of emission for the international radiotelephone distress frequency, 2182 kHz?
• In the context of vacuum tubes, what is commonly referred to as "load"?
• What is the purpose of an auto-alarm signal keying device on a compulsorily equipped ship?
• How can you determine the condition of a dry ""B"" battery?
• What is the main role of grid excitation voltage in RF modulation?
• How frequently must the auto-alarm be tested while a vessel is at sea?
• Which of the following is NOT a recommended storage condition for batteries?
• What does the indicator or prefix "RP" signify on radiotelegrams?
• Which characteristic describes a vacuum tube functioning as a Class B amplifier?
• Which type of microphones have a high impedance output?
• What does a high output impedance indicate in audio equipment?
• For 100% modulation, how should the DC power input to the modulated RF amplifier be related to the AC power from the modulation?
• What is the primary purpose of a choke in an electrical circuit?
• What is required of a radiotelegraph operator on board a passenger vessel?
• What type of equipment may utilize electrolyte?
• What resistance is needed for trickle charging a 12.5 V battery at a 0.5 A rate from a 110 V line?
• Where must ship station logs be kept during a voyage?
• How does a First Class Radiotelegraph Operator renew an unexpired license?
• What is the effect of using a battery with a low specific gravity electrolyte?
• What currents can be measured between the center top of the filament transformer of a tetrode and negative high voltage?
• Which battery type is more suitable for grid bias voltage?
• What should the plate current do in the operation of a Class B audio amplifier?
• Which material is frequently used for relay contacts?
• What is the purpose of top-hat loading sections on vertical shipboard antennas for use in the MF band?
• What does a higher input grid resistance indicate about an amplifier's operation?
• What factors determine the bias voltage of a vacuum tube?
• Which of the following is required for operational safety in radiotelegraph operations?
• What occurs if the grid is held at an excessively negative value?
• In what condition might a transformer draw excessive current?
• A transmitter has a master-oscillator, intermediate amplifier, and final amplifier. In what order should the circuit be adjusted in putting the transmitter in operation?
• What is the main advantage of the thoriated tungsten used in vacuum tubes?
• What effect does grid-leak and capacitor have in a grid-leak detector?
• If you receive a distress call signed by a call signal composed of five letters, could you determine the type of craft which transmitted the signal?
• When measuring transmitter center frequency for modern reserve transmitters, what precaution must be taken?
• What does a higher plate circuit efficiency indicate in vacuum tubes?
• Which of the following statements is true regarding distress calls?
• What purpose does a crystal-controlled oscillator serve in some superheterodyne receivers?
• Which of the following indicates a defective vacuum tube in a transmitter?
• What characteristic of the diode detector contributes to its functionality on weak signals?
• What might cause a positive shift in carrier amplitude during modulation?
• What is a primary function of the suppressor grid in a multielement vacuum tube?
• What condition may lead to poor regulation in a power supply?
• What effect do iron compound cylinders have in inductances?
• What type of modulation occurs when the audio power for 100% modulation equals 50% of the DC input power to RF modulated amplifier?
• Why should the case of a high-voltage transformer be grounded?
• What determines the critical parameters of the operating conditions of an amplifier tube?
• What is the correct formula for determining the surge impedance of a quarter wavelength matching line?
• Who is ultimately responsible for the operational integrity of the radio equipment on a vessel?
• What operating condition indicates that a tube is functioning as a power detector?
• In which condition can a storage battery be unable to sustain the required load?
• What is the minimum capacity in ampere-hours required for a 50 W emergency transmitter operating for 6 hours with a continuous load?
• The specific gravity of a fully charged lead-acid battery electrolyte is approximately?
• What is the main purpose of connecting a suitable key-click filter in a radiotelegraph transmitter?
• What is an important factor to consider when tuning a final amplifier for modulation?
• What characteristic of a capacitor influences its voltage rating?
• A class C amplifier:
• What is the role of harmonic suppression filters in antenna systems?
• What is the chemical composition of the electrolyte in an Edison-type storage cell?
• In a self-biased RF amplifier stage, if the plate voltage is 1250 V, plate current 150 ma, grid current 15 ma, and grid-leak resistance is 4000 ohms, what is the operating grid bias?
• What is the total power dissipation capability of two 10 watt 500 ohm resistors connected in parallel?
• What phenomenon occurs when free electrons leave a conductor into surrounding space?
• If a solenoid has a resistance of 5 ohms and carries 0.34 amps when 110 volts at 60 Hz is applied, what is the impedance?
• How is the cathode-bias resistance for an amplifier determined?
• What is the order of priority of radiotelegraph communications in the maritime services?
• What type of emission would be expected from a 500 Hz AC plate supply, rectified by a full-wave, unfiltered rectifier circuit?
• What is the proper procedure to conduct a radiotelegraph equipment test?
• A 20 ohm resistor with a current of 0.25 A passing through it will dissipate how many watts?
• What effect does increasing the capacitance have in a resonant circuit?
• What type of plates do Edison type batteries typically have?
• What is the composition of the negative plate in a lead-acid storage cell?
• Why might a superheterodyne receiver struggle with frequencies near the IF frequency?
• What type of signal quality can be expected from a power detector using a tube under specific operating conditions?
• What purpose does a center top serve in a vacuum tube plate and grid return circuits?
• Which condition could indicate a potential problem in a transmitter's vacuum tube?
• When there is asymmetry in the relative amplitudes of the positive and negative modulation peaks, what does this indicate?
• What can occur when a high-voltage transformer case is not grounded?
• What factors determine the breakdown voltage rating of a capacitor?
• Which of the following is a special type of power supply filter choke?
• Who may install, maintain or adjust radiotelephone transmitters which radiate less than 50 watts carrier power?
• On a delta-wound transformer with a 120 VAC line-to-line secondary, what is the voltmeter reading from line to ground?
• How does low temperature affect a lead-acid storage battery?
• If a vacuum tube with a filament rating of 0.25 A and 5 V is operated from a 6 volt battery, what value of resistor is necessary?
• How often must compulsory radiotelegraph installations on passenger vessels be inspected?
• If there is no resistance in either leg of a circuit with an inductance of 5 henrys in parallel with a capacitance of 1 microfarad, what is the equivalent impedance of the parallel network circuit?
• Does grid current flow in a grid-bias modulated stage under modulated conditions?
• What is a dynamotor?
• What form of energy is primarily stored in a lead-acid storage battery?
• What is the total bandwidth of a transmitter using A-2 emission with a modulating frequency of 800 Hz and a carrier frequency of 500 kHz?
• If a receiver storage battery cannot maintain charge for the required watch period, what should be done?
• What symbol must be included in the preamble of every distress-traffic radiotelegram after a distress call?
• By reducing the physical length of a Hertzian antenna what will be the result?
• Which three factors should be considered when figuring the surge impedance of a non-resonant transmission line?
• What are important factors in the function of a vacuum tube as a frequency doubler?
• What result can be expected from insufficient bias voltage in an amplifier tube?
• Which type of receiver involves a detector that oscillates above audibility?
• The radiated wavelength of a Hertzian antenna is?
• What is the impact of insufficient filter capacity in a power supply?
• In what way does an FM receiver differ from a conventional superheterodyne?
• What should be the maximum plate dissipation of a vacuum tube?
• What type of equipment is essential for a vessel operating in areas subject to maritime distress?
• How may the Q of a parallel resonant circuit be increased?
• Why is an oscillator crystal operated at a constant temperature?
• What is the benefit of using permanent magnets in head telephones?
• How may the output voltage of a dynamotor be regulated?
• How does the design of a Class B amplifier differ from a Class A amplifier?
• Where should spare ""B"" batteries be stored for optimal preservation?
• What effect will adding a capacitor in series with an antenna have on resonant frequency?
• What occurs when the antenna circuit is brought into resonance?
• What potential issue could arise from using dirty or salt-encrusted insulation in an antenna?
• If a motor generator fails to start when the start button is depressed, which of the following could be the issue?
• When connecting head telephones directly to the plate circuit of a vacuum tube, proper polarity should be observed because:
• What is the primary function of a ""B"" battery?
• What is the total impedance of a series AC circuit with an inductive reactance of 24 ohms, a resistance of 16 ohms, and a capacitive reactance of 16 ohms?
• What is a common application for a low pass filter network?
• How frequently must the specific gravity of the emergency battery be taken while the vessel is in the open sea?
• If L and C in a parallel resonant circuit resonate at 1000 kHz and their product remains constant, what will be the resulting resonant frequency?
• What can be a consequence of failing to maintain proper radio communication protocols?
• What is a common application for grid-leak detectors?
• What is the total impedance of a series AC circuit having a resistance of 6 ohms, an inductive reactance of 17 ohms, and zero capacitive reactance?
• What is the characteristic of modulation occurring in an RF stage other than the final power amplifier?
• What is meant by maximum power dissipation in a tube?
• What is the resonant frequency of a tuned circuit consisting of a 500 picofarad capacitor, a 150 microfarad tuning coil, and 10 ohms resistance?
• While the vessel is in port, how frequently should the emergency equipment be tested?
• Which port is recognized as the principal port on the Pacific coast of the United States?
• Which item is typically NOT included in a radiotelegraph inspection checklist?
• In an RF amplifier with fixed bias, what happens to the grid current as the plate circuit is varied from below resonance to above resonance?
• What influences the direction of magnetic line of force generated by an electromagnet?
• What is the positive plate of a lead-acid storage cell composed of?
• What does a purplish glow from within a vacuum tube indicate?
• If the output frequency after passing through three doubler stages is 16,800 kHz, what is the crystal frequency of a transmitter?
• How does a radiotelegraph operator transmit a routine call to another station?
• What action should be taken when a distress signal is received that is unknown to the operator?
• For how long must the emergency power supply of a compulsorily equipped ship station be capable of energizing the emergency radiotelegraph installation?
• An EMF may be generated by sound waves by what principle?
• What voltage is necessary to initially charge a 3-cell battery with open circuit voltage of 1.8 V per cell at a rate of 10 A?
• What protects a connected receiver from damage when high voltages accumulate on antennas insulated from ground?
• When may a public coast station authorized to use high frequency narrow-band direct-printing (NB-DP) establish contact with a ship station using telegraphy?
• What class of amplifier is used as linear in order not to distort the modulation components?
• Two effects of over-excitation of a Class B amplifier grid circuit are:
• The current through two resistors in series is 3 A. Resistance #1 is 50 ohms, resistance #2 drops 50 V across its terminals. What is the total voltage?
• What is voltage regulation as applied to power supplies?
• To reduce the sparking at the contacts of a key used in a radiotelegraph transmitter?
• What is the primary reason for maintaining transmitting tube filaments at recommended voltages?
• What is the primary reason for using rosin as a soldering flux?
• What is the ratio of magnetic flux density to the field strength known as?
• What is the total resistance of a parallel circuit consisting of a 10 ohm branch and a 25 ohm branch?
• What may be observed as the antenna circuit is brought into resonance about the plate current of the final amplifier?
• If a transmitter with an antenna current of 8 amps is 100% modulated by sinusoidal modulation, what would be the antenna current?
• The minimum power dissipation rating of a resistor of 20,000 ohms across a potential of 500 V should be:
• In the context of electrical circuits, what does the term "impedance" refer to?
• How does the distortion level of audio output from a diode detector compare with that of a triode detector?
• What describes the emission of electrons due to the impact of high-velocity electrons on a surface?
• What must be included in the Annual Equipment Verification Report?
• Which method can be used to determine the polarity of a storage battery?
• What is the process for a Second Class Radiotelegraph Operator to upgrade to First Class?
• In a radiotelegraph transmitter with a DC generator plate voltage source, what could be wrong when the emission continues with the key contacts open?
• When connecting electrolytic capacitors in series, what must be observed?
• A transmitter operating on 5000 kHz uses a 1000 kHz crystal with a tempered coefficient of - 4 Hz/MHz/0 degrees centigrade. What is the change in the output frequency of the transmitter if the temperature increases 6 degrees centigrade?
• What advantage does a tuned RF amplifier stage provide in a superheterodyne receiver?
• What occurs if there is a short circuit of the plate bypass capacitor in a series-fed plate circuit of a vacuum tube amplifier?
• What is the typical condition for modulation in an RF amplifier?
• Which of the following can cause excessive sparking at the brushes of a DC motor or generator?
• If a class B linear final R-F amplifier were in saturation and no modulation, what would happen when modulated?
• What material is typically used for making filaments in vacuum tubes?
• What should a station operator do before making a transmission?
• To avoid damage to components, what precautions should be observed in tuning a transmitter?
• If a 60 Hz transformer is connected to a 120 Hz source of the same voltage, what is the expected outcome?
• When should the efficiency of a grid-bias modulated stage be at its maximum?
• What role does bias voltage play in an AF amplifier tube?
• What type of distortion can grid current induce in a grid-bias modulated stage?
• What is the most practical approach for emergency repairs to a burned inductance coil?
• In RF communication, what is the primary purpose of a matching network?
• In one-way facsimile transmission of weather information, which parameters must be set by the receiving station?
• What are essentials for making a good solder connection?
• What is an advantage of a single-button carbon microphone?
• Given a vacuum tube with 1000 V plate voltage and 127 ma plate current, what is the correct negative grid bias for a Class B amplifier?
• What is the best material for an antenna strain insulator exposed to the elements?
• Which function does the "mixer" tube serve in a superheterodyne receiver?
• What point on a shipboard antenna system displays the maximum potential?
• What term describes the weight of a volume of liquid compared to the same volume of distilled water?
• What is the purpose of a speech amplifier in connection with the modulator of a transmitter?
• What kind of output does an RF power amplifier provide?
• If the voltage to a circuit is doubled and the resistance is increased to three times the original value, what will be the final current?
• A master-oscillator power-amplifier transmitter has been operating normally. The antenna ammeter suddenly reads zero. What happened?
• Which of the following factors influences the gain of a triode audio amplifier?
• Three main factors to consider about grid-leak in a vacuum tube transmitter:
• For protection of personnel handling a transmitter, what is recommended?
• Excessive plate current of an RF amplifier may be caused by?
• Which of the following is used in a DC motor to reduce brush sparking without moving the brushes?
• Which component is primarily used for tuning in RF circuits?
• Which condition can lead to arcing in vacuum tubes?
• What can loose laminations in a filter choke cause?
• A defective vacuum tube in a transmitter may be indicated by?
• An 18 ohm and a 15 ohm resistor are connected in parallel; a 36 ohm resistor is connected in series with this combination; a 22 ohm resistor is connected in parallel with this total combination. The total current is 5 A. What current is flowing in the 15 ohm resistor?
• What could cause abnormally low input power terminal voltage in a lifeboat radiotelegraph transmitter?
• When using a DC filament supply, why is it advisable to periodically reverse the polarity?
• How can an R-F amplifier stage be neutralized?
• Which substance is the most widely used in crystal oscillators?
• Which type of energy storage cell is constructed with iron plates?
• Permeability is defined as:
• A station has an assigned frequency of 8000 kHz. What is the maximum permitted deviation of the oscillation frequency in Hz, which will not exceed the tolerance of plus or minus 0.04%?
• With a superheterodyne receiver set to 2738 kHz and an IF of 475 kHz, what frequency is the grid circuit of the second detector tuned to?
• When should routine safety tests of radiotelegraph equipment be performed?
• Which antenna system has the ability to discriminate between various directions of receiving or transmitting?
• What is the license term of the First Class Radiotelegraph Operator License?
• What is the maximum current carrying capacity of a resistor of 5000 ohms, 200 watts?
• Which of the following is a common effect of using too high a filament voltage?
• What is the composition of the electrolyte in a lead-acid storage cell?
• What is the reactance of a 2-henry choke at 3000 Hz?
• What document is issued after a radio station inspection aboard a large ship that is not a passenger vessel?
• How can you correct power factor in an electrical circuit?
• Why is the use of an AC filament supply generally preferred?
• An RF filter in the plate circuit of a tube detector is sometimes necessary to?
• In what types of circuits are beam power vacuum tubes commonly used?
• What is a common consequence of high-frequency operation in RF amplifiers?
• What effect would insufficient radio-frequency excitation have on Class C modulated amplifier output?
• Voltage may be expressed by which of the following terms?
• What remains in a substance after the original magnetizing force has been removed?
• Which parameter is crucial for determining the quality factor (Q) of a resonant circuit?
• How does high resistance in filter chokes affect power supply performance?
• What is a disadvantage of a dynamotor?
• What type of modulation occurs in the plate circuit of the last radio stage of the system?
• Where is the control button that silences the warning bells located on a United States vessel equipped with an approved auto-alarm?
• What factors determine the amplitude of the voltage induced in a conductor cutting magnetic lines of force?
• Effects of dirty or salt-encrusted insulation are?
• What indicates that a dry battery should be replaced under normal load conditions?
• In maritime communication, what does the term "urgency" refer to?
• What is a consequence of using a non-resonant transmission line?
• If an incoming signal causes image interference, where is it in relation to the IF?
• How is the bias of a grid-modulated R-F stage adjusted?
• What might happen if the spacing of a key used in a transmitter is increased?
• In addition to the 350 to 515 kHz band, on what other band must a main receiver on a United States ship operate?
• What is the negative electrode typically made of in a usual type dry cell?