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

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