Advanced Radiotelegraph Operator's Certificate

SITOR-ARQ is a common mode of data communications in the maritime service. It is a system based ontransmission bursts and acknowledgements. What is the baud, and interval between the bursttransmissions:

Weather information is commonly sent by radio in map form by one-way facsimile transmission. Twocommon parameters which must be set by the receiving station are:

2182 kHz is the international radiotelephone distress frequency. It is also used for a calling channel. Theauthorized mode of emission is H3E (single-sideband full carrier). A3E (double-sideband full carrier) isonly authorized for equipment:

Ship's power is generated as 3-phase and is ungrounded. On a delta-wound transformer with 120 VACline-to-line secondary, what is the voltmeter reading from line to ground:

When passing through areas of static charge, high voltages can accumulate on antennas which areinsulated from ground. What protects a connected receiver from damage?

Vertical shipboard antennas for use in the MF band (410-525 kHz) are often fitted with top-hat loadingsections. What is the purpose of these structures?

Modern reserve transmitters are solid-state designs and transmit using only A2 modulation. Whenmeasuring transmitter center frequency, what precaution must be taken:

Voltage may be expressed by what other expression?

Amperage may also be known by:

Factors which determine the amplitude of the voltage induced in a conductor which is cutting magneticlines of force:

An electrical potential may be generated by:

Ohm's law is stated as:

The unit of electrical power is:

The unit of conductance is:

The unit of inductance is:

The ratio of current through a conductor to the voltage which produces it is:

The product of the number of turns and the current in amperes used to describe relative magnitude is:

The property of a conductor or coil which causes a voltage to be developed across its terminals when thenumber of magnetic lines of force in the circuit or coil is changed is:

The charge of electricity which passes a given point in one second when a current of one ampere isflowing is:

C = capacity in farads. Q = the measure of the quantity of charge of electricity in Coulombs. E = theapplied voltage. So Q = CE:

Resistance is:

The unit of AC impedance in a circuit is:

The unit of capacitance is:

Decibel is:

What factors determine the charge stored in a capacitor?

Ohm's law for AC circuits when I = amperes, E = volts, Z = impedance in volts is:

The formula for determining the power in a DC circuit when the voltage and resistance are known is:

The formula for finding power in a DC circuit when current and resistance are known:

The formula for finding power in a DC circuit when current and voltage are known:

The prefix " kilo " means:

The prefix " micro " means:

The factor by which the product of volts and amperes must be multiplied to obtain true power is:

The prefix " meg " means:

Factors which influence the resistance of a conductor:

Halving the cross-sectional area of a conductor will:

Name four conducting materials in order of their conductivity.

Good insulators at radio frequencies are:

A resistance across which a constant voltage is applied is doubled. What power dissipation will result?

The needle of a magnetic compass when placed within a coil carrying an electric current:

Electrical resistance is measured with:

The sum of all voltage drops around a simple DC circuit, including the source, is:

If a resistance to which a constant voltage is applied is halved, what power dissipation will result?

The diameter of a conductor six inches long is doubled, what will be the effect on the resistance?

A minute subdivision of matter having the smallest known unit of negative electrical charge is:

Conductors differ from nonconductors, i.e.:

Direction of flow of DC electricity in a conductor can be determined by:

The difference between electrical power and electrical energy is:

A positive temperature coefficient means:

A liquid which is capable of conducting electricity, but undergoes decomposition while doing so is:

The effective value of an RF current and the heating value of the current are:

One horsepower is:

What factors determine the heat generated in a conductor?

What is the ratio of peak to average value of a sine wave?

When the current sine wave in a circuit reaches its peak value before the voltage wave:

An "harmonic" is:

Assuming a power source to have a fixed value of internal impedance, maximum power will betransferred to the load when:

When two sine waves of the same frequency do not reach their maximum or minimum valuessimultaneously:

Which method may be used to obtain more than one value of voltage from a fixed DC source?

The conductance (G) of a circuit if 6 A flows when 12 VDC is applied is:

Two 10 W, 500 ohm resistors in parallel will dissipate how many watts?

A 20 ohm resistor with a current of 0.25 A passing through it will dissipate how many watts?

If the voltage to a circuit is doubled and the resistance is increased to three times the original value, whatwill be the final current?

If a vacuum tube with a filament rating of 0.25 A and 5 V is operated from a 6 volt battery, what value ofresistor is necessary?

The minimum power dissipation rating of a resistor of 20,000 ohms across a potential of 500 V shouldbe:

The total power dissipation capability of two 10 watt, 500 ohm resistors connected in series is:

What is the total power dissipation capability of two 10 watt 500 ohm resistors connected in parallel?

What is the maximum current carrying capacity of a resistor of 5000 ohms, 200 watts?

What is the total resistance of a parallel circuit consisting of a 10 ohm branch and a 25 ohm branch?

The current through two resistors in series is 3

An 18 ohm and a 15 ohm resistor are connected in parallel; a 36 ohm resistor is connected in series withthis combination; a 22 ohm resistor is connected in parallel with this total combination. The total currentis 5

A circuit passes 3

A relay coil has 500 ohms resistance, and operates on 125 m

Given: Input power to a receiver is 75 watts. How much power does the receiver consume in 24 hours ofcontinuous operation?

The total reactance when two capacitances of equal value are connected in series is:

A capacitor's charge is stored:

The voltage drop across an individual capacitor of a group of capacitors connected in series across an ACsource is:

What is the total capacitance of the capacitors of 3, 5, and 7 microfarad connected in series?

If capacitors of 3, 5, and 7 microfarad are connected in parallel, what is the total capacitance?

How many capacitors of 400 volts and 2 microfarad each would be necessary to obtain a combinationrated at 1600 volts and 1.5 microfarad?

If a turn in an inductor is shorted:

The relationship between the number of turns and the inductance of a coil may be expressed by:

The formula for determining the resonant frequency of a circuit when the inductance and capacitance areknown is:

The formula for determining the wavelength when the frequency is known is:

The wavelength of the period of one complete cycle of a radio wave of 0.000,001 second is:

The efficiency of a radio device is:

What is the total impedance of a parallel capacitor and inductor with equal values of reactance?

The total inductance of two coils in parallel without any mutual coupling is:

What is the total reactance of a series AC circuit, with no resistance and equal inductance and capacitivereactances?

The total inductance of two coils in series without any mutual coupling is:

One wave-length is:

In an AC circuit, a series inductance acting alone:

Shock excitation into an L-C circuit is the result of:

The term cathode ray usually applies to:

Shielding an RF inductance:

The tendency of a tank circuit to keep oscillating for a time after the excitation energy has been removedis:

Power factor is defined as:

High or low frequency oscillations occurring in circuits other than the original tank desired outputfrequencies are:

What are effects of parasitic oscillations?

The velocity of propagation of radio frequency waves in free space is:

To double the resonant frequency of a resonant circuit:

How may the Q of a parallel resonant circuit be increased?

If L and C in a parallel resonant circuit resonants at 1000 kHz are so varied that their product remainsconstant, what will be the resulting resonant frequency?

What is the resonant frequency of a tuned circuit consisting of a 500 picofarad capacitor, a 150microfarad tuning coil, and 10 ohms resistance?

What is voltage regulation as applied to power supplies?

An EMF may be generated by sound waves by what principle?

How can you correct power factor in an electrical circuit?

Permeability is:

The time in seconds for a capacitor to attain 63.2 % of the applied voltage across its terminals is:

What is the reactance of a 2-henry choke at 3000 Hz?

If there is no resistance in either leg of a circuit with an inductance of 5 henrys in parallel with acapacitance of 1 microfarad, what is the equivalent impedance of the parallel network circuit?

What is the total impedance of a series AC circuit having a resistance of 6 ohms, an inductive reactanceof 17 ohms, and zero capacitive reactance?

The total impedance of a series AC circuit with an inductive reactance of 24 ohms, a resistance of 16ohms, and a capacitive reactance of 16 ohms is:

Essentials for making a good solder connection are:

For protection of personnel handling a transmitter:

The ratio of peak-to-effective voltage values of a sign wave are:

The opposition to the creation of magnetic lines of force in a magnetic circuit is known as:

The ratio of magnetic flux density to the field strength is known as:

The magnetic force which remains in a substance after the original magnetizing force has been removedis known as:

The direction of electron flow through a coil and the manner of winding the turns:

Adding an iron core to an air-core inductance:

Electromagnets are used in:

What will be the effect of a small increase in the number of turns upon the field strength of a single layersolenoid?

Can a transformer be used with direct current?

A tube containing either a filament or cathode structure, grid, and a plate is a:

A tube similar to a triode with the addition of a spirally wound screen grid between the plate and controlgrid is a:

Theoretical gain of a tube. The ratio of a small change in plate voltage to give a certain small change inplate current to a change in grid which would cause the same current:

Effectiveness of the grid in causing changes of plate current:

The maximum negative anode voltage with respect to the cathode. It equals the DC voltage at the inputto the plus the peak AC voltage applied during the nonconducting portion of the cycle of operation of thetube:

What is the primary purpose of the control grid of the triode?

What is the primary purpose of the screen grid of the tetrode?

What is the primary purpose of the suppressor grid of a pentode?

Thoriated tungsten is usually used to make:

In what types of circuits do beam power vacuum tubes find application?

When free electrons in a conductor acquire sufficient energy to leave the conductor and pass into thesurrounding space, it is expressed as:

The emission of electrons from a material due to the impact of high-velocity electrons on its surface is:

Characteristics of a vacuum tube operating as a class A amplifier:

Characteristics of a vacuum tube operating as a class B amplifier:

Factors which determine bios voltage of a vacuum tube:

In the usual Class A amplifier:

The DC bias in a Class A amplifier:

What is the effect of incorrect grid bias in a Class A amplifier?

The approximate efficiency of a Class A vacuum tube amplifier:

The approximate efficiency of a Class B vacuum tube amplifier:

The approximate efficiency of a Class C vacuum tube amplifier:

A charge due to the accumulation of negative electrons because the plate potential cannot attract all ofthe electrons leaving the emitter:

A material flashed by the application of heat after the tube is evacuated that absorbs any gases remaininginside the tube:

What types of vacuum tube filaments are reactivated:

A tungsten filament is operated at ____ temperature than a thoriated tungsten filament:

The presence of gas within a tube is indicated:

The cathode of an indirectly heated type of vacuum tube should be maintained at nearly the samepotential as the heater circuit:

Transmitting tube filaments should be maintained at recommended voltages:

Use of an AC filament supply is desirable:

If a DC filament supply is used, it is advisable to periodically reverse the polarity of the filamentpotential:

Bias voltage on the grid of an AF amplifier tube:

The screen grid in a vacuum tube:

The suppressor grid in a multielement vacuum tube:

The gain of a triode audio amplifier is a function of:

"Load" on a vacuum tube commonly refers to:

A case in which the grid is held at an excessively negative value for a period of time thereby cutting offplate current:

The maximum power that can be safely and continuously dissipated in heat on the plate:

Occurs when plate current equals electron emission for any given filament or cathode temperature:

The most desirable factor in the choice of a vacuum tube for a voltage amplifier:

Lack of requirement for neutralizing, except at ultra high frequencies, is an advantage of a tetrode over____:

Characteristics of a vacuum tube operating as a Class C amplifier:

Plate current flows for less than 180 degrees (about 120 degrees when the grid bias is about twice cutoffvalue) in what class amplifier?

Tubes operated as Class C amplifiers are not suited for audio-frequency amplifiers:

Low plate current may be caused by:

A tuned circuit made up of inductance and capacitance is:

Some radio-frequency amplifiers must be neutralized:

Cavity resonators are:

The diode detector:

The functioning of a grid-leak detector:

Characteristic of a square law type of vacuum tube detector:

A diode detector ordinarily produces ____ overall distortion of the audio output wave than does a triodedetector:

Operating conditions for determining that a tube is being used as a power detector:

Why is a center top usually provided for vacuum tube plate and grid return circuits when and ACfilament supply is used?

How would you determine the cathode-bias resistance necessary to provide correct grid bias for anamplifier?

Given the following vacuum tube constants: Gp = 1000 V, Ip = 150 mA, Ig = 10 mA, Grid leaks = 5000ohms. What would be the grid bias voltage?

What currents will be indicated by a milliammeter connected between the center top of the filamenttransformer of a tetrode and negative high voltage?

A dynatron oscillator is a ____ which depends upon the negative resistance characteristic of a tetrodetube for its operation:

Materials which can be used as crystal detectors:

A power detector may be operated:

Used to multiply the fundamental frequency by two:

When used as an RF amplifier, a pentode vacuum tube:

A quartz crystal in a radio transmitter:

Advantage of crystal control over tuned circuit oscillators:

If the crystal will undergo very small changes in its operating frequency with relatively large temperaturevariations:

A separate source of power is sometimes desirable for crystal-oscillator units in a transmitter:

"The temperature coefficient of an x-cut crystal is negative":

If you apply DC voltage to the opposite plane surfaces of a quartz crystal:

"The temperature coefficient of a y-cut crystal is positive" means:

Two dissimilar metals joined together and producing a current between them when the junction is heatedis:

Waveguides:

Transistors may be compared to a conventional triode vacuum tube functionally:

Types of transistors:

When using and storing crystal microphones:

What effect does a change in the dielectric constant of a capacitor dielectric material have upon thecapacitance of a capacitor:

Increasing the number of plates of a capacitor:

If the dielectric constants of a capacitor dielectric material between the capacitor plates were changedfrom 1 to 1:

Contacts which slide together on opening and closing:

Permanent magnets used in head telephones:

Emergency repairs to an inductance coil having burned or charred insulation:

Indications of a defective vacuum tube in a transmitter:

The breakdown voltage rating of a capacitor are determined by:

Crystal surfaces should be free of dirt of grease to operate properly:

A purplish glow from within a tube indicates:

Given a solenoid with a resistance of 5 ohms and 0.34 through the winding when 1108 at 60 Hz isapplied. What is the impedance?

Use of a low pass filter network:

A special type of power supply filter choke whose inductance is inversely proportioned to values of DCwithin specified limits is:

The best suited material for use as an antenna strain insulator exposed to the elements:

Materials frequently used for relay contacts:

Why is rosin used as a soldering flux?

What substance is the most widely used in crystal oscillators?

Why is an oscillator crystal operated at a constant temperature?

The advantage of a single-button carbon microphone:

A carbon microphone should not be:

In connecting head telephones directly in the plate circuit of a vacuum tube one should observe theproper polarity:

What should the plate current do in the operation of a Class B audio amplifier?

What turns ratio does a transformer need to match a source impedance of 500 ohms to a load of 10 ohms?

What microphones have a high impedance output?

How may low impedance (75 ohm) head telephones be connected to the output of a vacuum tube?

Why do headphones usually have high-impedance windings?

A "choke" coil:

Why is correct grid bias necessary for audio frequency amplifier?

When a tube is used as a Class B amplifier what portion of the excitation voltage cycle does plate currentflow?

A properly operated Class A audio amplifier:

What is the main advantage obtained by using two triodes in push-pull in a Class a audio frequencyamplifier?

What is the maximum permissible RMS value of audio voltage which can be applied to the grid of aClass A audio amplifier which has a grid bias of 10 V?

Distortion in a Class A amplifier can be caused by:

Vacuum tubes operating as Class A amplifiers may be used as:

What is the DC plate voltage of a resistance-coupled amplifier state with a plate-supply voltage of 260 V,a plate current of 1 mA, and a plate load resistance of 100,000 ohms?

Why is it necessary to use two tubes in a Class B audio amplifier?

If the coupling capacitor leaked in a resistance-coupled audio frequency amplifier:

A vacuum tube operated Class C audio amplifier is not feasible, either in single or push-pull:

Even harmonics may be reduced in the output of an audio frequency amplifier:

The main advantage of a tuned audio frequency amplifier in a receiver used for the reception of CW:

Decoupling networks in the plate circuit of a multistage audio amplifier:

An audio-transformer is seldom used as the output device in the plate circuit of a tetrode audio-amplifierstage:

The chief advantage of Class A audio operation is compared to the other classes of audio-frequencyamplifiers:

Which is not the principle advantage of transformer coupling compared to resistance coupling in audio-frequency amplifiers?

Efficiency of a power transformer is determined by:

The ratios of primary and secondary currents in a power transformer:

A transformer has a primary voltage of 100, primary turns = 200, and secondary turns = 40. What is thesecondary voltage?

What factors determine the no-load voltage ratio of a power transformer?

The turns ratio of a transformer varies:

Primary cells:

Secondary cells:

The formation of hydrogen gas around the positive electrode of a primary cell is:

A dry cell may be tested:

In the usual type dry cell:

"A", "B", and "C" batteries are alike, but specifically constructed for a particular function. Explain:

The condition of a dry "B" battery may be determined:

Spare "B" batteries should be stored:

A means of comparing the weight of a volume of liquid with the same volume of distilled water:

Edison type batteries:

The electrolyte of a lead-acid storage cell:

The negative plate of a lead-acid storage cell:

The positive plate of a lead-acid storage cell:

The chemical composition of the electrolyte in an Edison-type storage cell:

The negative plate of an Edison-type storage cell is:

The positive plate of an Edison-type storage cell is:

The average fully-charged voltage of an Edison storage cell is:

Decrease in capacity of an Edison-type storage cell can be caused by:

The average fully charged voltage of a lead-acid cell is:

To increase the power output of a storage cell:

The condition of charge of an Edison cell can be determined:

The charge of a lead-acid storage cell:

Sulfation:

If the polarity is reversed when charging a storage cell:

You may measure the voltage of a battery under heavy load:

If the voltage of some cells in a battery are found to be reversed, what is indicated?

Distilled water should be added to a lead-acid storage cell:

Local action in a lead-acid storage cell:

To maintain a group of storage cells in good operating condition:

What may cause the plates of a lead-acid call to buckle?

What may cause sulfation of a lead-acid cell?

What may be used to neutralize an acid electrolyte?

To prevent corrosion of battery terminals:

Why should there be ventilation to the room housing a large group of storage cells?

Radio equipment on which electrolyte may be used:

What is the effect of low temperature on the operation of a lead-acid storage battery?

What form of energy is stored in a lead-acid storage battery?

How may polarity of a storage battery be determined?

A battery with a terminal voltage of 12.5 V is to be trickle-charged at a 0.5 A rate. What resistanceshould be connected in series with the battery to charge from a 110 V line?

A discharged storage battery of 3 cells has an open circuit voltage of 1.8 V per cell and an internalresistance of 0.1 ohm per cell. What voltage is needed to give an initial charging rate of 10 A?

What capacity in amperes of storage battery is required to operate a 50 W emergency transmitter for 6hr.? Assume a continuous transmitter load of 70% of the key-locked demand of 40 A, and an emergencylight load of 1.5

If a receiver storage A battery could not be kept charged, and maintain the required watch period, whatshould you do?

Abnormally low input power terminal voltage of a lifeboat radiotelegraph transmitter while in operationcould be caused by:

If a battery has 12.4 V on open circuit and 12.2 V when its charging circuit is closed:

The tops of lead-acid batteries should be kept dry:

When lead-acid cells are subject to low temperatures they should:

If an electrolyte in a lead-acid storage cell becomes low due to evaporation:

An Edison storage battery should not be charged at less than the manufacturer's specified rate:

Your emergency battery has a specific gravity reading of 1.120. What should be done?

What care should be taken with selecting water to add to a storage cell?

If the circuit breakers refuse to stay closed when you place the emergency batteries on charge, what is thetrouble?

Heat developed within a storage cell under charge or discharge conditions is caused by:

How would you connect a group of similar cells in a storage battery to obtain the maximum zeroresistance current?

How would you connect a group of similar cells in a storage battery to obtain the maximum no-bondoutput voltage?

What current will flow in a 6 V storage battery with an internal resistance of 0.01 ohms, when a 3 W, 6 Vlamp is connected?

The charging rate of a storage cell charged from a fixed voltage source decreases as the chargingprogresses opposition to the charging voltage?

The principal function of the filter in a power supply:

Advantages of capacitor input and choke-input filters when used with rectifiers:

A high-resistance fixed resistor is shunted across each unit of a high voltage series capacitor bank in thepower-supply filter circuit to:

Part of the secondary winding of a transmitters power transformer is accidentally shorted. What shouldbe the immediate effect?

Bleeder resistors are used in power supplies:

The ratio of the frequencies of the output and input circuits of a single-phase full-wave rectifier:

A capacitor is sometimes placed in series with the primary of a power transformer:

What is the maximum allowable secondary voltage of a transformer used as a center-tapped full-waverectifier with tubes having a peak inverse voltage rating of 10,000 V?

If a 60 Hz transformer is connected to a 120 Hz source of the same voltage:

If a 500 Hz transformer is connected to a 60 Hz source of the same voltage:

A 500 Hz AC plate supply, rectified by a full-wave, unfiltered rectifier circuit. What would the emissionbe?

The purpose of an air gap in a filter choke coil core. Which is the incorrect answer?

Loose laminations in a filter choke:

Poor regulation in a power supply may be caused by:

Why should the case of a high-voltage transformer be grounded?

When connecting electrolytic capacitors in series:

Full wave rectification has ____ than half-wave:

Voltage regulation is ____ with a high resistance choke:

Electrolyte capacitors are desirable over other types because:

The most common values of chokes range from:

The power transformer and rectifier of a radio receiver are designed to supply a plate voltage of 250 Vwhen operating from a 110 V 60 Hz supply, if the transformer is connected to 110 VDC what willhappen?

A shunt-wound DC motor:

A series DC motor has:

This partially counteracts the line voltage and so limits the armature current in a DC motor:

A compound-wound DC motor:

Laminated iron is used in armature and field construction to:

The ____ of a DC motor periodically change the armature coils to maintain one direction of rotation:

The speed of a series DC motor may increase and destroy the motor by centrifugal action:

When the field of a shunt-wound DC motor opens while the machine is operating under no load:

____ are used in a DC motor to reduce brush sparking without moving the brushes:

A short in the armature coils of a DC motor causes:

The motor-field rheostat should be ____ when starting a DC motor generator set:

If a motor generator fails to start when the start button is depressed, the trouble may be:

When increased output is desired from a motor-generator, what is the usual procedure?

A dynamotor is:

Output voltage of a dynamotor may be regulated:

What disadvantage is there to a dynamotor?

Causes of excessive sparking at the brushes of a DC motor or generator include:

By-pass capacitors are often connected across the brushes of a high-voltage DC generator:

Causes of motor-generator bearing overheating include:

RF interference may be minimized:

Emery cloth should never be used to clean the commutator of a motor or generator:

A 3 HP 100 V DC motor is 85% efficient when developing its rated output. What is the current?

The speed of a synchronous motor is determined:

The speed of an induction motor is determined:

The speed of a DC series motor is determined:

What is the line current of a 7 HP motor operating on 120 V at full load, a power factor of 0.8, and 95%efficiency?

Alternators are usually rated in:

What conditions must be met before two AC generators can be operated in parallel?

The voltage of an alternator will:

What effect will high coupling between the plate and grid circuits of a quartz-crystal oscillator have?

The operation of a dynatron oscillator depends on what?

To provide additional feedback voltage in a crystal oscillator what is sometimes needed?

What is the primary reason for the use of a crystal controlled oscillator for use as a transmitter?

What is are the advantages of self excited oscillator and master-oscillator power-amplifier transmitters?

The primary function of the power-amplifier stage of a marine radiotelegraph transmitter is:

The buffer amplifier stage of a transmitter:

Which class of amplifier is used in the final amplifier stage for maximum plate efficiency?

What class of amplifier is used as linear in order not to distort the modulation components?

If a class B linear final R-F amplifier were in saturation and no modulation what would happen whenmodulated?

A class C amplifier:

What effect would insufficient radio-frequency excitation have on Class C modulated amplifier output?

The second harmonic of a 380 kHz frequency is:

Two effects of over-excitation of a Class B amplifier grid circuit are:

Three main factors to consider about grid-leak in a vacuum tube transmitter:

How can an R-F amplifier stage be neutralized?

What is the purpose of a speech amplifier in connection with the modulator of a transmitter?

When the first speech-amplifier of a transmitter were overexcited, but the modulation capabilities werenot exceeded what would be the effect on the output?

The bias of a grid-modulated R-F stage is adjusted:

Given the following: (1) audio power for 100% modulation equals 50% of DC input power to RFmodulated amplifier, (2) load presented to the modulated tube consists of the DC plate impedance of themodulated amplifier, (3) constant grid excitation voltage, very lot distortion, what type of modulation?

Modulation occurring in an RF stage other than the final power amplifier:

The efficiency of a grid-bias modulated stage should be:

Does grid current flow in a grid-bias modulated stage under modulated conditions?

What might be the cause of a positive shift in carrier amplitude during modulation?

For 100% modulation, DC power input to the modulated RF amplifier should:

When a radiotelephone transmitter is 100% modulated by sinusoidal waveform , how much antennacurrent will be observed?

What can be done in a Heising modulation system to obtain 100% modulation?

A plate choke in a Heising modulator:

What value of sinusoidal audio power is required to insure 100% modulation when the DC plate input toa modulated Class C amplifier has an efficiency of 60 % , and is 200 W?

What would be the antenna current when a transmitter has an antenna current of 8 amp, under A -1, evenif it is 100% modulated by sinusoidal modulation?

If a transmitter is adjusted for maximum power for telegraph, what must be done to be amplitudemodulated?

A series-fed plate circuit of a vacuum tube amplifier has a short circuit of the plate bypass capacitor.What happened?

A shunt-fed plate circuit of a vacuum tube amplifier has a short circuit of the plate RF choke. Whathappens?

The total bandwidth of a transmitter using A-2 emission with a modulating frequency of 800 Hz and acarrier frequency of 500 kHz is:

Given a vacuum tube of the following characteristics: plate voltage 1000 V, plate current 127 ma,filament current 5.4 amp, mutual conductance 8000 microvolts, and amplification factor of 25. What isthe correct volume of negative grid bias for Class B amplifier?

When the relative amplitudes of the positive and negative modulation peaks are unsymmetrical:

What may be used as indicating devices in neutralizing an RF amplifier stage?

Important factors in the operation of the vacuum tube as a frequency doubler are:

If a 1500 kHz radio wave is modulated by a 2000 Hz sine wave tone, what frequencies does themodulated wave contain?

To avoid damage to components what precautions should be observed in tuning a transmitter?

A transmitter has a master-oscillator, intermediate amplifier, and final amplifier. In what order shouldthe circuit be adjusted in putting the transmitter in operation?

Excessive plate current of an RF amplifier may be caused by:

The disadvantage of using a self-excited oscillator type of transmitter for shipboard service:

The degree of coupling is varied in a pi-network used to transfer energy from a vacuum tube plate circuitto an antenna:

In order of selectivity, the best receivers are:

An RF filter in the plate circuit of a tube detector is sometimes necessary to:

In an RF amplifier with fixed bias, as the plate circuit is varied from below resonance to aboveresonance, what will the grid current do?

In a self-biased RF amplifier stage: plate voltage is 1250 V, plate current 150 ma, grid current 15 ma,grid-leak resistance of 4000 ohms, what is the operating grid bias?

How would you determine the cathode bias resistance necessary to provide correct grid bias for anamplifier?

What is a method of link coupling between two R-F amplifier stages?

Which type of amplifier circuit is used in a link coupling R-F?

An advantage of link coupling between RF amplifier stages is:

What effect does excessive coupling between the output circuit of an oscillator and an antenna have?

How is power output of a transmitter adjusted?

When is a transmitter tuned to reduced power?

What is meant by split tuning?

What is a self rectified circuit?

What would be the dB change in field intensity at a given distance if the power is doubled?

Keying can be accomplished at various points in a radiotelegraph transmitter. Some are:

What is the term used when the receiving operator may interrupt the transmitting operator at any pointduring transmission?

Which of the following best explains frequency-shift keying?

What is one of the advantages frequency-shift keying has over "on-off" keying?

Code speed or number of words per minute transmitted have what effect if any on the bandwidth ofemission of a radiotelegraph transmitter?

Keying a simple-oscillator type of emergency transmitter may be accomplished by:

The plate current of the final RF amplifier in a transmitter increases and radiation decreases, if theantenna circuit is in good order, what could be the cause?

When hoisting a shipboard antenna, to avoid damage to the wire and insulators:

If a field strength is 100 microvolts per meter at 100 miles, what is the field strength at 200 miles?

Field intensity is:

What point on a shipboard antenna system displays the maximum potential?

A defective vacuum tube in a transmitter may be indicated by:

A master-oscillator power-amplifier transmitter has been operating normally. The antenna ammetersuddenly reads zero. All filaments are burning and plate and grid meters read normal currents andvoltages. What happened?

Effects of dirty or salt-encrusted insulation are:

To reduce the sparking at the contacts of a key used in a radiotelegraph transmitter:

In a self excited oscillator, a swinging antenna:

What may be observed as the antenna circuit is brought into resonance about the plate current of the finalamplifier?

Instruments used to indicate various DC currents and voltages in a transmitter may be protected againstdamage to stray RF by:

In a radiotelegraph transmitter with a DC generator plate voltage source, an AC generator filamentsupply, and grid-bias keying, what could be wrong when the emission continues with the key contactsopen?

A station has an assigned frequency of 8000 kHz and a frequency tolerance of plus or minus 0.04%. Theoscillator operates at 1/8th of the input. What is the maximum permitted deviation of the oscillationfrequency in Hz, which will not exceed the tolerance?

A transmitter operating on 5000 kHz uses a 1000 kHz crystal with a tempered coefficient of - 4Hz/MHz/0 degrees centigrade. What is the change in the output frequency of the transmitter if thetemperature increases 6 degrees centigrade?

The correct formula for determining the surge impedance of a quarter wavelength matching line is:

What are the three factors to consider when figuring the surge impedance of a non-resonant transmissionline?

If the output frequency after passing through three doubler stages is 16,800 kHz, give the crystalfrequency of a transmitter:

Adding an inductor in series with an antenna will have what effect on the resonant frequency?

Adding a capacitor in series with an antenna will have what effect on resonant frequency?

The radiated wavelength of a Hertzian antenna is:

To operate on a lower resonant frequency on an available Marconi antenna which would be the correctprocedure?

By reducing the physical length of a Hertzian antenna what are the results?

Which antenna system has the ability to discriminate between various directions of receiving ortransmitting?

Given the current and resistance of the base of a Marconi antenna, what would be the formula fordetermining the power?

A vertical loop antenna has a:

What modulation is contained in static and lightning radio waves?

The difference between a Hertz and Marconi antenna is:

What is meant by the term polarization of a radio wave?

What are the lowest frequencies used in radio communication today?

Radio frequencies that are useful for long distance communications requiring continuous operation:

Communication at frequencies in the order of 15 kHz are usually accomplished by ground waves, andrequire generation of ____ power outputs for reliable and continuous operation:

Frequencies with substantially line propagations:

On an average yearly basis the received Trans-Atlantic signals increased in strength in proportion to thedegree of ____. Made on the basis of the 11 year cycle:

Harmonic radiation is:

Harmonic radiation from a transmitter may cause interference:

Why suppress RF harmonics in the output of a transmitter?

A wavetrap in a receiver:

The follow devices that could be used to indicate oscillation in a crystal oscillator are:

An artificial antenna sometimes used in testing a transmitter:

The system producing A-2 emission by a "chopper" may be thought of:

Advantages of high-frequency radio communication:

Transmitters that employ variometers rather than variable capacitors as tuning elements do so because of:

The relationship between the antenna current and radiated power of an antenna:

Iron compound cylinders found in inductances:

Modulation of an RF carrier produces in the plate circuit of the last radio stage of the system:

Basically, am FM receiver is a conventional superheterodyne but differs in:

A form of regenerative receiver in which the detector breaks into and out of oscillation at a rate aboveaudibility:

A tuned RF amplifier stage ahead of the mixer stage in a superheterodyne receiver:

What is the "mixer" tube in the superheterodyne receiver?

An incoming signal causing image interference is ____ the IF above or below the frequency to which thereceiver is tuned:

A superheterodyne receiver is adjusted to 2738 kHz. The IF is 475 kHz. What is the grid circuit of thesecond detector tuned to?

A superheterodyne receiver may not successfully be used for reception of frequencies very near the IFfrequency:

Some superheterodyne receives employ a crystal-controlled oscillator:

To obtain maximum response to weak CW signals with a superheterodyne receiver:

Most receiver hiss is due to:

High IF frequencies in a superheterodyne receiver:

What is the IF of a superheterodyne receiver receiving on 1000 kHz and the mixing oscillator is tuned to1500 kHz?

Image response may be minimized in a superheterodyne receiver:

In a tuned RF receiver the heterodyne method, over the autodyne reception, has:

A regenerative receiver's operation is:

Advantages of a stage of RF amplification are:

Disadvantages of a stage of RF amplification are:

The sensitivity of a 3 circuit receiver is controlled by:

A regenerative, oscillating-detector receives directly coupled to an antenna:

Low sensitivity of a 3 circuit regenerative receiver might be caused by:

Some components of a three-circuit regenerative circuit tested in troubleshooting:

Noisy operation of a regenerative, 3-circuit receiver with two stages of AF amplification may be causedby:

How could you test a regenerative receiver to determine if the detector is oscillating?

How would you adjust a regenerative receiver without RF amplifier stages to receive radiotelegraphsignals through interference?

How would you reduce or eliminate broadcast signal interference of reception on 500 kHz?

To adjust a regenerative receiver for maximum sensitivity:

What type of radio receiver do not respond to static interference?

Audio howl may be caused by:

If signals are heard with headphones in the detector plate circuit of a receiver, but none are heard withheadphones in the first AF stage plate circuit, what might be the cause?

In the case of an open secondary winding in a coupling transformer causing no signal in the first AFstage, satisfactory repair could be made by:

An oscillator in a receiver operating on a frequency near the IF of the receiver:

Generally used to prevent any undesired frequencies from appearing in the output of a receiver:

By-pass capacitors across the cathode-bias resistors of an RF amplifier:

In general, shielding between RF amplifier stages:

Minimizes transfer of harmonic frequencies between two inductively coupled circuits:

An auxiliary receiving antenna on a ship with a radio direction finder:

Feeding back into the control grids of the IF and RF amplifiers a negative DC bias which is proportionedto the average magnitude of the received carrier wave accomplished:

The center-tap connection in a filament supply transformer:

A shorted grid capacitor in a three-circuit regenerative receiver would:

The first detector in a superheterodyne receiver:

The advantage of using iron cores of special construction in RF transformers and inductance?

The auto alarm receiver is tuned to ____ but is able to respond to signals from ____ to ____ (+/- 12.5kHz)

The auto-alarm signal is:

The determining factor of the setting of the sensitivity control of an auto-alarm receiver:

With an auto alarm that uses a square-law detector and a mechanical selector what causes the bell toring?

Intermittent ringing of the bells of an auto alarm with a linear detector and an electronic selector could becaused by:

An open filament on an auto-alarm with a linear detector and an electronic selector will:

The auto-alarm bell rings and the release button stops it:

If the auto-alarm bell rings and the release button doesn't stop it:

If the vacuum tube heater in an approved auto-alarm system burns out:

Unused portions of inductances in receivers are ____ to reduce any losses that might occur in theseunused windings:

Harmonic radiation by a transmitter may be prevented:

The keying circuit of the ships transmitter is disconnected:

Normal undistorted modulation is indicated by:

If a vacuum tube in the only RF stages of your receiver burned out, make a temporary repair by:

A ____ provides a very high degree of selectivity in a receiver:

The D'Arsonval type meter consists of:

What is the purpose of multiplier resistance used with a voltmeter?

What is the purpose of a shunt as used with an ammeter?

What is indicated if a voltmeter connected between the negative side of a ship's DC line and ground readsthe full line voltage?

Why are copper oxide rectifiers, associated with DC voltmeters to measure AC, unsuitable for themeasurement of voltages at radio frequencies?

How may the power in a AC circuit be determined?

The product of the readings of an AC voltmeter and ammeter in an AC circuit is called what?

Does an AC ammeter indicate peak, average, or effective values of current?

What types of meters may be used to measure RF currents?

How may the range of a thermocouple ammeter be increased?

By what factor must the voltage of an ac circuit, as indicated on the scale of an AC voltmeter, bemultiplied to obtain the average voltage value?

By what factor must the voltage of an AC circuit, as indicated on the scale of an AC voltmeter, bemultiplied to obtain the peak value?

What is the meaning of "zero beat" as used in connection with frequency measuring equipment?

What is the directional reception pattern of a loop antenna?

What is the reception pattern of a vertical antenna?

What is the principal function of a vertical sense antenna associated with a unilateral radio directionfinder?

What figure represents the reception pattern of a properly adjusted unilateral radio direction finder?

From how many simultaneous directions is a direction finder capable of receiving signals if adjusted totake unilateral bearings through 360 degrees?

How is the unilateral effect obtained in a direction finder?

What is the function of the balancing capacitor in a direction finder?

What is indicated by the bearing obtained from the use of a bilateral radio direction finder?

On shipboard what factors may effect the accuracy of a direction finder after it has been properlyinstalled, calibrated?

What is indicated by the bearing obtained from the use of a unilateral radio direction finder?

Within what frequency band limits do all United States marine radio beacon stations operate?

In what part of the RF spectrum do marine radar systems operate?

Approximately at what speed does the antenna of a navigational radar rotate?

How should a radar set be adjusted by the operator to reduce "sea return"?

In determining a "fix" position by a marine LORAN system, what is the minimum number of landtransmitters involved?

What is the relationship between a master and a slave station in reference to LORAN navigationsystems?

How can the operator of a LORAN receiver on shipboard identify the transmitting stations that are beingreceived?

During daytime hours, approximately what is the maximum distance in nautical miles from LORANtransmitting stations from which LORAN lines of position can be determined?

What is the purpose of blinking in a loran navigational system?

What precautions should an operator or serviceman observe when working with cathode-ray tubes?

If the velocity of a radio wave is 186,000 statute miles per second, how many nautical miles does a radarpulse travel in one microsecond?

In all cases other than those in which the transmitter output must be maintained at a fixed value, whatamount of power should be employed for routine communications?

What is the definition of a "station open to public service"?

In the transmission of the international Morse code, what are the relative time lengths of dashes, dots?

Why is the clock on a compulsorily equipped ship radiotelegraph station required to have a sweep secondhand?

Between what points on a ship, compulsorily equipped with a radiotelegraph installation, is a reliableintercommunication system required?

Are there any age requirements that a person must meet before he can be issued a radiotelegraph operatorlicense?

Upon compulsorily equipped vessels which are required to have an accurate clock in the radio room, howfrequently must this clock be adjusted and be compared with standard time?

How frequently must an entry be made in a ship radiotelegraph log while a radio watch is beingmaintained?

At what time(s) are routine transmissions forbidden in the bands of 480 to 515 kHz?

What time system shell be used in making log entries with respect to the observance of the internationalsilent period?

What is the international radiotelegraph distress frequency for stations in the mobile service?

Describe how a distress call should be made:

What transmission should precede the transmission of the distress call?

What stations shall be in control of distress traffic?

During what periods must a distress message be repeated following the initial transmission?

For how long must mobile stations listen after hearing an urgency signal?

When the auto-alarm bell rings, what should the operator do?

What space of time should elapse between the transmission of the international auto-alarm signal and thedistress call?

While a vessel is at sea, how frequently must the auto-alarm be tested?

Upon hearing an SOS, what should an operator do?

What is the purpose of an auto-alarm signal keying device on a compulsorily equipped ship?

On a United States vessel equipped with an approved auto-alarm, where is the control button whichsilences the warning bells located?

With what type(s) of emission and upon what frequency should a transmitter be adjusted to transmit adistress call?

If you receive a distress call signed by a call signal composed of five letters, could you determine thetype of craft which transmitted the signal?

While the vessel is in the open sea, how frequently must the specific gravity of the emergency battery betaken?

How frequently must the quantity of fuel in the supply tank for use with an oil or gas driven emergencygenerator be checked while the vessel is in the open sea?

While a vessel is in port, how frequently should the emergency equipment be tested?

You intercept "CQ CQ WSV TFC"; what does this mean?

Explain the use and meaning of the following indicator or prefix "RP" on radiotelegrams:

Upon what band, in addition to the 350 to 515 kHz band must a main receiver on a United States ship becapable of operation?

After a distress call has been transmitted, every distress-traffic radiotelegram shall contain what symbolin the preamble?

For how long a period of continuous operation should the emergency power supply of a compulsorilyequipped ship station be capable of energizing the emergency radiotelegraph installation?

What is the principal port of the United States, on the Pacific coast, at which navigation lines terminate?

In what city is the major telecommunication center of the United States located?

Under what condition may an eligible person hold a radiotelegraph operator's license and a Marine RadioOperator permit?

How does a First Class Radiotelegraph Operator renew an unexpired license?

How does an eligible Second Class Radiotelegraph Operator upgrade his license to First Class?

What is the license term of the First Class Radiotelegraph Operator License?

What is a requirement of every commercial operator on duty and in charge of a transmitting system?

What is the experience requirement of a First Class Radiotelegrapher?

What examination requirements are necessary to obtain a Second Class Radiotelegraph Operator'sCertificate?

How does an applicant qualify for a Third Class Radiotelegraph Operator's Certificate?

What examination credit is accorded Amateur Extra Class operators?

What must every examination for the code portion of a radiotelegraph license contain?

What answer format is accepted on commercial radiotelegraph license contain?

What is a requirement of all transmitting apparatus used aboard United States vessels?

What happens to a lower grade of Commercial Radiotelegraph License when a licensee qualifies for ahigher grade?

What is an operating control requirement of a ship station using telegraphy?

How does a radiotelegraph operator transmit a routine call to another station?

What is the proper procedure to conduct a radiotelegraph equipment test?

How often must a radiotelegraph station transmit its call sign when a transmission is maintained for morethan 20 minutes in the band 405-525 kHz?

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?

Which operator is authorized to make equipment adjustments at maritime radio stations which may affecttransmitter operation?

Who may install, maintain or adjust radiotelephone transmitters which radiate less than 50 watts carrierpower?

Who may program authorized frequency channels into a transmitter or transceiver used in the maritimeservice?

What is the maximum authorized bandwidth of a high frequency radiotelegraphy signal, emission A1A,in the maritime service?

What is the maximum transmitter power that a ship station may radiate using radiotelegraphy emissionson frequencies below 27500 kHz?

Where must ship station logs be kept during a voyage?

How often must compulsory radiotelegraph installations on passenger vessels be inspected?

What is the antenna requirement aboard a survival craft equipped with a non-portable radiotelegraphinstallation?

What document is issued after a radio station inspection aboard a large ship that is not a passengervessel?

What is the minimum radio operator license requirement of a chief radio officer on U.S. passenger ships?

What is the order of priority of radiotelegraph communications in the maritime services?

What should a station operator do before making a transmission?