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General Licensing ClassGeneral Licensing Class

Subelement G6

Circuit ComponentsCircuit Components

3 Exam Questions, 3 Groups

General Class Element 3 Course P t tiPresentation

ELEMENT 3 SUB ELEMENTSELEMENT 3 SUB‐ELEMENTS

G1 – Commission’s RulesG2 – Operating ProceduresG2 Operating ProceduresG3 – Radio Wave PropagationG4 – Amateur Radio PracticesG5 – Electrical PrinciplesG6 – Circuit ComponentsG7 – Practical CircuitsG8 – Signals and EmissionsG9 A tG9 – AntennasG0 – Electrical and RF Safety

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Circuit ComponentsCircuit Components

Low equivalent series resistance is an important characteristic for q pcapacitors used to filter the DC output of a switching power supply. (G6A01)

Modern switching power supplies g p ppincorporate “crowbar protection” to

provide overvoltage protection.

Electrolytic capacitors are often used in power‐supply circuits to filter the rectified AC. (G6A02)

An advantage of ceramic capacitors as compared to other types of i i i l lcapacitors is comparatively low cost. (G6A03)

Circuit Circuit ComponentsonentsCircuit Circuit Componentsonents

High capacitance for given volume is an advantage of an electrolytic capacitor. (G6A04)

The effect of lead inductance in a capacitor used at VHF

Electrolytic Capacitors

pfrequencies and above is that effective capacitance may be reduced because of the lead inductance. (G6A05)

The resistance of a carbon resistor will change depending on the resistor's temperature coefficient rating if the ambient temperature is increased. (G6A06)ambient temperature is increased. (G6A06)

Circuit CoCircuit ComponentsmponentsCircuit CoCircuit Componentsmponents

A reason not to use wire‐wound resistors in an RF circuit isA reason not to use wire wound resistors in an RF circuit is that the resistor's inductance could make circuit performance unpredictable. (G6A07)

A thermistor is a device having a controlled change in

Wire wound resistors can act like an inductor at certain frequencies.

A thermistor is a device having a controlled change in resistance with temperature variations. (G6A08)

Circuit CoCircuit Componentsmponents

The advantages of using a ferrite core with a toroidali d tinductor (G6A09):

Large values of inductance may be obtained Th i i f h b i i d f ifi f f iThe magnetic properties of the core may be optimized for a specific range of frequencies Most of the magnetic field is contained in the core

All of these choices are correct.

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The winding axes of solenoid inductors should be placed at right anglesg p g gto minimize their mutual inductance. (G6A10)

It is important to minimize the mutual inductance between two inductors to reduce unwanted coupling between circuits. (G6A11)p g


Filter choke is a common name for an inductor used to help smooth the DC output from theused to help smooth the DC output from the rectifier in a conventional power supply. (G6A12)

An effect of inter‐turn capacitance in an inductor i th t th i d t b lf tis that the inductor may become self resonant at some frequencies.(G6A13)

The peak‐inverse‐voltage rating of a rectifier is

Capacitor: consists of metal separated by a layer(s) of a non conductor.

The peak inverse voltage rating of a rectifier is the maximum voltage the rectifier will handle in the non‐conducting direction. (G6B01)

Non-conducting region

Notice Waveforms


The two major ratings that must not be exceeded for silicon‐diode rectifiers are peak inverse voltage; average forwarddiode rectifiers are peak inverse voltage; average forward current. (G6B02)

The approximate junction threshold voltage of a germaniumThe approximate junction threshold voltage of a germanium diode is 0.3 volts. (G6B03)

• This is the voltage drop across the diode junction when it is conducting in the forward direction.

When two or more diodes are connected in parallel to increase current handling capacity, the purpose of the resistor connected in series with each diode is to ensure that one diode doesn't carry most of the current. (G6B04)


The approximate junction threshold voltage of a silicon di d i 0 7 ldiode is 0.7 volts. (G6B05)

• This is the voltage drop across the diode junction when it is conducting in the forward direction

Lower capacitance is an advantage of using a SchottkyLower capacitance is an advantage of using a Schottky diode in an RF switching circuit as compared to a standard silicon diode. (G6B06)

• It is desirable to have low capacity across the diode junction in higher frequencies where the capacitive reactance forms a significant path around the diode when reverse (Back) biased in the non conductive state.

The stable operating points for a bipolar transistor usedThe stable operating points for a bipolar transistor used as a switch in a logic circuit are its saturation and cut‐off regions. (G6B07)

• Saturation is where the transistor is Base biased for maximum emitter to collector current flow • Cut‐off is where the transistor base is biased for minimum emitter to collector current flow


The cases of some large power transistors must be insulated from ground to avoid shorting the collector or drain voltagefrom ground to avoid shorting the collector or drain voltage to ground. (G6B08) Power Transistors

I MOSFET th t i t d f th h l ith

Insulating wafer

In a MOSFET, the gate is separated from the channel with a thin insulating layer. (G6B09)

Circuit Components

The control grid is the element of a triode vacuumThe control grid is the element of a triode vacuum tube used to regulate the flow of electrons between cathode and plate. (G6B10)

H=Heater/Filament; C=Cathode; S=Screen Grid; P=Plate

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A Field Effect Transistor is the solid state device most like a vacuum tube in its general operating characteristics. (G6B11)

• In the construction of a MOSFET the gate is separated from the channel with a thin insulating layer.

• The Gate is similar to the grid of a tube, it controls current flow.


The primary purpose of a screen grid in a vacuum tube is to reduce grid‐to‐plate capacitance. (G6B12)

High discharge current is an advantage of the low internal resistance of Nickel Cadmium batteries. (G6B13)

10 5 volts is the minimum allowable discharge voltage for10.5 volts is the minimum allowable discharge voltage for maximum life of a standard 12 volt lead acid battery. (G6B14)

It is never acceptable to recharge a carbon‐zinc primary cell. (G6B15)


A linear voltage regulator is an example of anA linear voltage regulator, is an example of an analog integrated circuit.(G6C01)

Schematic symbols and actual linear voltage regulators


The term MMIC means Monolithic Microwave Integrated Circuit. (G6C02)

MMIC devices Signal connections

Low power consumption is an advantage of CMOS integrated circuits compared to TTL integrated circuits. (G6C03)

• CMOS is the most commonly used digital logic family of integrated circuits.

The term ROM means Read Only Memory. (G6C04)y y


ROM is characterized as “non‐volatile,” meaning the stored information is maintained even if power is removedinformation is maintained even if power is removed. (G6C05)

Analog is also the term that describes an integrated circuit operational amplifier ( )operational amplifier. (G6C06)

Schematic symbol Integrated circuit

• High power consumption is one disadvantage of anHigh power consumption is one disadvantage of an incandescent indicator compared to a LED. (G6C07)


An LED is forward biased when emitting light. (G6C08)g g

Array of LEDs and resistors

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LCDs do not emit light. Therefore, a liquid crystal display requires ambient or back lighting (G6C09)display requires ambient or back lighting. (G6C09)

A computer and transceiver are two devices in anA computer and transceiver are two devices in an amateur radio station that might be connected using a USB interface. (G6C10)g

The universal serial busThe universal serial bus (USB) has made it simple

to connect your ham radio to your computer.


A microprocessor is a computer on a single integrated circuit. (G6C11)g

• A DE‐9 connector would be a good choice for a serial

Basic microprocessor

A DE‐9 connector would be a good choice for a serial data port. (G6C12)

Usually called a DB‐9, but DE‐9 is the original name. (and for the exam)


A PL‐259 connector is commonly used for RF service at frequencies up to 150 MHz.(G6C13)

Male PL-259 PL-259 T-Connector

An RCA Phono connector is commonly used for audio signals in Amateur Radio stations. (G6C14)

RCA Connectors


The main reason to use keyed connectors instead yof non‐keyed types is reduced chance of incorrect mating.(G6C15)g


The type‐N connector is a moisture‐resistant RF connector useful to 10 GHzconnector useful to 10 GHz. (G6C16)

Type-N

Type-N


• The general description of a DIN type connectorThe general description of a DIN type connector is a family of multiple circuit connectors suitable for audio and control signals. (G6C17)suitable for audio and control signals. (G6C17)

CDIN Connectors

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The SMA connector is a small threaded connector suitable for signals up to several GHz. (G6C18)

A high quality SMA connector is useable to 18 GHz and beyond

G6A01 Which of the following is an important characteristic for capacitors used to filter

the DC output of a switching power supply?

A Low equivalent series resistanceA. Low equivalent series resistance

B. High equivalent series resistance

C. Low Temperature coefficient

D. High Temperature coefficient

G6A02 Which of the following types of capacitors are often used in power supply circuits to filter rectified AC?

A Disc ceramicA. Disc ceramic

B. Vacuum variable

C. Mica

D. Electrolytic

G6A03 Which of the following is an advantage of ceramic capacitors as

d t th t f it ?compared to other types of capacitors?

A Tight toleranceA. Tight tolerance

B. High stability

C. High capacitance for given volume

D. Comparatively low cost

G6A04 Which of the following is an d t f l t l ti it ?advantage of an electrolytic capacitor?

A Tight toleranceA. Tight tolerance

B. Non‐polarizedp

C. High capacitance for given volume

D. Inexpensive RF capacitor

G6A05 Which of the following is one effect of lead inductance in a capacitor

sed at VHF and abo e?used at VHF and above?

A Effective capacitance may be reducedA. Effective capacitance may be reduced

B. Voltage rating may be reducedg g y

C. ESR may be reduced

D. The polarity of the capacitor might become reversed

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G6A06 What will happen to the resistance if the temperature of a resistor is increased?

A It will change depending on the resistor’s reactance coefficientA. It will change depending on the resistor s reactance coefficient.

B. It will stay the same y

C. It will change depending on the resistor's temperature coefficient

D. It will become time dependent

G6A07 Which of the following is a reason not to use a wire‐wound resistor in an RF circuit?use a wire wound resistor in an RF circuit?

A. The resistor's tolerance value would not be adequate for such a circuit

B. The resistor's inductance could make circuit performance punpredictable.

C. The resistor could overheat

D. The resistor's internal capacitance would detune the circuit

G6A08 Which if the following describes a thermistor?

A. A resistor that is resistant to changes in value with temperature variations

B. A device having a specific change in resistance with g p gtemperature variations.

C. A special type of transistor for use at very cold temperaturesp yp y p

D. A capacitor that changes value with temperature

G6A09 What is an advantage of using a ferrite core toroidal inductor?ferrite core toroidal inductor?

A. Large values of inductance may be obtained g y

B. The magnetic properties of the core may be optimized for a specific range of frequencies

C Most of the magnetic field is contained in the coreC. Most of the magnetic field is contained in the core

D. All of these choices are correctD. All of these choices are correct

G6A10 How should the winding axes of solenoid inductors be placed to minimize their mutual inductance?p

A In lineA. In line

B. Parallel to each other

C. At right angles

D. Interleaved

G6A11 Why would it be important to minimize the mutual inductance between two inductors?

A To increase the energy transfer between circuitsA. To increase the energy transfer between circuits

B. To reduce unwanted coupling between circuitsp g

C. To reduce conducted emissions

D. To increase the self‐resonant frequency of the inductors

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G6A12 What is a common name for an inductor used to help smooth the DC output from the rectifier in a conventional power supply?

A Back EMF chokeA. Back EMF choke

B. Repulsion coilp

C. Charging inductor

D. Filter choke

G6A13 What is an effect of inter‐turn capacitance in an inductor?

A. The magnetic field may become invertedg y

B. The inductor may become self resonant at some frequencies

C. The permeability will increase

D. The voltage rating may be exceeded

G6B01 What is the peak‐inverse‐voltage rating of a rectifier?voltage rating of a rectifier?

A. The maximum voltage the rectifier will handle in the gconducting direction

B. 1.4 times the AC frequency

C The maximum voltage the rectifier will handle in the nonC. The maximum voltage the rectifier will handle in the non‐conducting direction

D. 2.8 times the AC frequency

G6B02 What are the two major ratings that must not be exceeded for silicon‐diode rectifiers?exceeded for silicon diode rectifiers?

A. Peak inverse voltage; average forward current g ; g

B. Average power; average voltage

C. Capacitive reactance; avalanche voltage

D. Peak load impedance; peak voltage

G6B03 What is the approximate junction h h ld l f i di d ?threshold voltage of a germanium diode?

A 0 1 voltA. 0.1 volt

B. 0.3 volts

C. 0.7 volts

D. 1.0 volts

G6B04 When two or more diodes are connected in parallel to increase current handling capacity, what is the purpose of

the resistor connected in series with each diode?the resistor connected in series with each diode?

A To ensure the thermal stability of the power supplyA. To ensure the thermal stability of the power supply

B. To regulate the power supply output voltageB. To regulate the power supply output voltage

C. The ensure that one diode doesn't carry most of the current

D T t i d tD. To act as an inductor

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G6B05 What is the approximate junction threshold voltage of a conventional silicon diode?g

A 0 1 voltA. 0.1 volt

B. 0.3 volts

C. 0.7 volts

D. 1.0 volts

G6B06 Which of the following is an advantage of using a Schottkydiode in an RF switching circuit as compared to a standard silicon diode?

A Lower capacitanceA. Lower capacitance

B. Lower inductance

C. Longer switching times

D. Higher breakdown voltage

G6B07 What are the stable operating points for a bipolar transistor that is

d it h i l i i it?used as a switch in a logic circuit? A. Its saturation and cut‐off regions g

B. Its active region (between the cut‐off and saturation regions)

C. Between its peak and valley current points

D. Between its enhancement and deletion modes

G6B08 Why must the cases of some large i b i l d f d?power transistors be insulated from ground?

A To increase the beta of the transistorA. To increase the beta of the transistor

B. To improve the power dissipation capabilityp p p p y

C. To reduce stray capacitance

D. To avoid shorting the collector or drain voltage to ground

G6B09 Which of the following describes the construction of a MOSFET?the construction of a MOSFET?

A. The gate is formed by a back‐biased junction g y j

B. The gate is separated from the channel with a thin insulating layer

C The source is separated from the drain by a thin insulatingC. The source is separated from the drain by a thin insulating layer

D. The source is formed by depositing metal on silicon

G6B10 Which element of a triode vacuum tube is used to regulate the flow

f l t b t th d d l t ?of electrons between cathode and plate?

A Control gridA. Control grid

B. HeaterB. Heater

C. Screen Grid

D. Trigger electrode

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G6B11 Which of the following solid state devices is most like a vacuum tube

i it l h t i ti ?in its general characteristics?

A A bipolar transistorA. A bipolar transistor

B. A Field Effect Transistor

C. A tunnel diode

D. A varistor

G6B12 What is the primary purpose of a id i t b ?screen grid in a vacuum tube?

A To reduce grid‐to‐plate capacitanceA. To reduce grid‐to‐plate capacitance

B. To increase efficiencyy

C. To increase the high frequency response

D. To decrease plate resistance

G6B13 What is an advantage of the low internal resistance of Nickel Cadmium batteries?

A Long lifeA. Long life

B. High discharge currentB. High discharge current

C. High voltage

D. Rapid recharge

G6B14 What is the minimum allowable discharge voltage for maximum life of a standard 12 volt

lead acid battery?

A. 6 voltsA. 6 volts

B. 8.5 volts

C. 10.5 volts

D. 12 volts

G6B15 When is it acceptable to h b i i ll?recharge a carbon‐zinc primary cell?

A As long as the voltage has not been allowed to drop belowA. As long as the voltage has not been allowed to drop below 1.0 volt

B. When the cell is kept warm during the recharging period

C. When a constant current charger is used

D NeverD. Never

G6C01 Which of the following is an l i d i i ?analog integrated circuit?

A NAND GateA. NAND Gate

B. Microprocessor.p

C. Frequency Counter

D. Linear voltage regulator

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G6C02 What is meant by the term MMIC?

A Multi Megabyte Integrated CircuitA. Multi Megabyte Integrated Circuit.

B. Monolithic Microwave Integrated Circuit.g

C. Military‐specification Manufactured Integrated Circuit.

D Mode Modulated Integrated CircuitD. Mode Modulated Integrated Circuit.

G6C03 Which of the following is an advantage of CMOS integrated circuits

compared to TTL integrated circ its?compared to TTL integrated circuits?

A Low power consumptionA. Low power consumption

B. High power handling capabilityg p g p y

C. Better suited for RF amplification

D. Better suited for power supply regulation

G6C04 What is meant by the term ROM?

A Resistor Operated MemoryA. Resistor Operated Memory

B. Read Only Memory

C. Random Operational Memory

D. Resistant to Overload Memory

G6C05 What is meant when memory is h t i d “ l til ”?characterized as “non‐volatile”?

A. It is resistant to radiation damageg

B. It is resistant to high temperatures

C. The stored information is maintained even if power is removedremoved

D. The stored information cannot be changed once writtenD. The stored information cannot be changed once written

G6C06 Which of the following describes an integrated circuit operational amplifier?

A DigitalA. Digital

B. MMICB. MMIC

C. Programmable Logic

D. Analog

G6C07 What is one disadvantage of an i d t i di t d t LED?incandescent indicator compared to an LED?

A Low power consumptionA. Low power consumption

B. High speedg p

C. Long life

D. High power consumption

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G6C08 How is an LED biased when emitting light?

A Beyond cutoffA. Beyond cutoff

B. At the Zener voltage

C. Reverse Biased

D. Forward Biased

G6C09 Which of the following is a h i i f li id l di l ?characteristic of a liquid crystal display?

A It requires ambient or back lightingA. It requires ambient or back lighting

B. It offers a wide dynamic rangeB. It offers a wide dynamic range

C. It has a wide viewing angle

D. All of these choices are correct

G6C10 What two devices in an amateur radio station might be connected using a USB interface?station might be connected using a USB interface?

A Computer and transceiverA. Computer and transceiver

B. Microphone and transceiverp

C. Amplifier and antenna

D. Power supply and amplifier

G6C11 What is a microprocessor?

A A low powered analog signal processor used as a microwaveA. A low powered analog signal processor used as a microwave detector

B. A computer on a single integrated circuit

C. A microwave detector, amplifier, and local oscillator on a single integrated circuit.

D. A low voltage amplifier used in a microwave transmitter modulator stage

G6C12 Which of the following connectors would be a good choice for a g

serial data port?

A. PL‐259

B T NB. Type N

C Type SMAC. Type SMA

D. DE‐9

G6C13 Which of these connector types is commonly used for RF service at

f i t 150 MH ?frequencies up to 150 MHz?

A. Octal

B RJ‐11B. RJ 11

C. PL‐259

D. DB‐25

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G6C14 Which of these connector types is commonly used for audio

i l i A t R di t ti ?y

signals in Amateur Radio stations?

A PL 259A. PL‐259

B BNCB. BNC

C. RCA Phono

D. Type N

G6C15 What is the main reason to use keyed connectors instead of non‐use keyed connectors instead of non

keyed types? A Prevention of use by unauthorized personsA. Prevention of use by unauthorized persons

B. Reduced chance of damage due to incorrect matingB. Reduced chance of damage due to incorrect mating

C. Higher current carrying capacity

D. All of these choices are correct

G6C16 Which of the following describes a Type N connector?Type‐N connector?

A. A moisture‐resistant RF connector useful to 10 GHz

B A small bayonet connector used for data circuitsB. A small bayonet connector used for data circuits

C. A threaded connector used for hydraulic systemsC. A threaded connector used for hydraulic systems

D. An audio connector used in surround‐sound installations

G6C17 What is the general description of a DIN type connector?yp

A A special connector for microwave interfacingA. A special connector for microwave interfacing.

B. A DC power connector rated for currents between 30 and 50 amperes.

f il f l i l i i i bl f di dC. A family of multiple circuit connectors suitable for audio and control signals.

D. A special watertight connector for use in marine applications.

G6C18 What is a type of SMA connector?

A. A large bayonet‐type connector usable at power levels in excess of 1 KW.

B. A small threaded connector suitable for signals up to several GHz.

C. A connector designed for serial multiple access signals.

D A type of push on connector intended for high voltage applicationsD. A type of push‐on connector intended for high‐voltage applications.

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