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

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