Technician Licensing Class Chapter 5 Valid dates: July 1, 2010 – June 30, 2014 Amateur Radio Equipment

Technician Licensing ClassTechnician Licensing Class“Chapter 5”“Chapter 5”

Valid dates:

July 1, 2010 – June 30, 2014

Amateur Radio EquipmentAmateur Radio Equipment

22

Chapter 5 ContentsChapter 5 Contents

Transmitters and ReceiversTransmitters and Receivers

Digital CommunicationsDigital Communications

Power Supplies and BatteriesPower Supplies and Batteries

Radio Frequency Interference (RFI)Radio Frequency Interference (RFI)

RF GroundingRF Grounding

33


Used to be separate unitsUsed to be separate units Still can beStill can be Transceivers (containing both Transceivers (containing both

transmitter and receiver more transmitter and receiver more common place now)common place now)

AbbreviationsAbbreviations• Tx Rx or Rcvr XCVRTx Rx or Rcvr XCVR

44


Selecting Band, Frequency and ModeSelecting Band, Frequency and Mode

Amateur radio has bands rather than Amateur radio has bands rather than channels other than on 60 meters)channels other than on 60 meters)

AM and SSB can be more than speech (CW AM and SSB can be more than speech (CW datadata

FM can be voice or dataFM can be voice or data

55

Amateur Radio BandsAmateur Radio Bands

HFHF• 160160 1.8 MHz1.8 MHz• 8080 3.5 MHz3.5 MHz• 60*60* 5 Mhz5 Mhz• 4040 7 MHz7 MHz• 3030 10 Mhz10 Mhz• 2020 14 Mhz14 Mhz• 1717 18 Mhz18 Mhz• 1515 21 Mhz21 Mhz• 1212 24 Mhz24 Mhz• 1010 28 Mhz28 Mhz

VHFVHF• 66 50 Mhz50 Mhz• 22 144 Mhz144 Mhz• 1¼1¼ 222 Mhz222 Mhz

UHFUHF• 70 cm70 cm 440 Mhz440 Mhz• 33 cm33 cm 902 Mhz902 Mhz• 23 cm23 cm 1240 1240

MhzMhz• 13 cm13 cm 2300 2300

MhzMhz

66

Control and Function KeysControl and Function Keys

Can be separate or same keyCan be separate or same key Control keys typically directly control Control keys typically directly control

the radiothe radio Function keys are more like menu Function keys are more like menu

and are used to select and set and are used to select and set functions and parameters for the functions and parameters for the radio’s operationradio’s operation

77


Transmitter FunctionsTransmitter Functions

88


RF Power Control RF Power Control Microphone GainMicrophone Gain Speech Compressor/ProcessorSpeech Compressor/Processor PEP (Peak Envelope Power) SSB & AMPEP (Peak Envelope Power) SSB & AM ALCALC Band and frequency tuningBand and frequency tuning

99


Spurious SignalsSpurious Signals• Turn down microphone gainTurn down microphone gain• Turn down compressor/speech Turn down compressor/speech

processorprocessor• Back away from microphoneBack away from microphone• ALCALC• Proper Tuning if not solid state Proper Tuning if not solid state

equipmentequipment

1010


MicrophonesMicrophones• HandHand• DeskDesk• BoomBoom• HeadsetHeadset• ThroatThroat

VOX vs ManualVOX vs Manual

1111


KeysKeys• ManualManual

Straight KeyStraight Key

• Semi-AutomaticSemi-Automatic Bug Dits automatic Dahs automaticBug Dits automatic Dahs automatic

• Automatic/ElectronicAutomatic/Electronic Dits and Dahs both automatic and self Dits and Dahs both automatic and self

completingcompleting Single and double lever typesSingle and double lever types Iambic and non iambicIambic and non iambic

1212

Receiver FunctionsReceiver Functions

AF and RF GainAF and RF Gain Bandwidth (filters)Bandwidth (filters) Band and frequency tuningBand and frequency tuning AttenuatorAttenuator DSPDSP Automatic Gain Control (AGC)Automatic Gain Control (AGC) RIT Receiver Incremental Tuning RIT Receiver Incremental Tuning

(Clarifier)(Clarifier)• Allows rx tuning off of tx frequency in xcvrAllows rx tuning off of tx frequency in xcvr

1313

Modern TransceiverModern Transceiver

1414

Digital Signal Processing (DSP)Digital Signal Processing (DSP)

Noise ReductionNoise Reduction Variable signal filteringVariable signal filtering Automatic notching filteringAutomatic notching filtering Audio contouring on tx and rxAudio contouring on tx and rx ShiftShift WidthWidth

1515

Handheld TranceiversHandheld Tranceivers

Single Band, Dual, Tri, and quad Single Band, Dual, Tri, and quad bandband

Built in microphone and speakers but Built in microphone and speakers but jacks for externaljacks for external

MemoriesMemories Push to Talk PTTPush to Talk PTT Rubber Duck antennaRubber Duck antenna Better antennasBetter antennas Connect to outside antennasConnect to outside antennas

1616

DIGITAL COMMUNICATIONSDIGITAL COMMUNICATIONS

Need Modem / TNCNeed Modem / TNC

Advantages Digital Signal ProcessingAdvantages Digital Signal Processing

RedundancyRedundancy

Error CorrectionError Correction

Allow easy reception of very weak signalsAllow easy reception of very weak signals

1717

Amateur Digital ModesAmateur Digital Modes

RTTYRTTY PACTOR & WINMORPACTOR & WINMOR PSK31 & MFSKPSK31 & MFSK OliviaOlivia DominoDomino VHF & UHF Packet and Winlink 2000VHF & UHF Packet and Winlink 2000

1818

Errors in Digital DataErrors in Digital Data

Errors measured in Bit Error Rate Errors measured in Bit Error Rate (BER)(BER)

Parity bitsParity bits Forward Error CorrectionForward Error Correction

1919

Packet & Packet NetworksPacket & Packet Networks

Use FSK (Frequency Shift Keying)Use FSK (Frequency Shift Keying) Can run automaticallyCan run automatically ARQ Automatic Repeat RequestARQ Automatic Repeat Request AX.25 protocolAX.25 protocol Bulletin BoardsBulletin Boards MessagesMessages Or direct hands on communicationsOr direct hands on communications Think long lists of data to be Think long lists of data to be

transmittedtransmitted

202020

T8D:T8D: Non-voice communications; image data, digital modes CW, Non-voice communications; image data, digital modes CW,

packet,PSK31packet,PSK31

• T8D8T8D8 Packet transmissions may include: Packet transmissions may include: A check sum which permits error detection;A check sum which permits error detection; A header which contains the call sign of the station to A header which contains the call sign of the station to

which the information is being sent;which the information is being sent; Automatic repeat request in case of error.Automatic repeat request in case of error.

Laptop, TNC, and Handheld comprise

Packet Station.

2121

Keyboard-to-KeyboardKeyboard-to-Keyboard

Most Digital Modes including RTTY Most Digital Modes including RTTY and CWand CW

CW faster than you can send or CW faster than you can send or receivereceive

PSK31, Olivia, Domino, Many othersPSK31, Olivia, Domino, Many others

2222

T8D:T8D: Non-voice communications; image data, digital modes CW, packet, Non-voice communications; image data, digital modes CW, packet,

PSK31PSK31

• T8D7T8D7 PSK31 is a low-rate data transmission mode. PSK31 is a low-rate data transmission mode. PSK-31 transmission rate is about normal typing speed.PSK-31 transmission rate is about normal typing speed. PSK is a remarkable digital mode that slices through interference and PSK is a remarkable digital mode that slices through interference and

gets message across sometimes to the moon and back.gets message across sometimes to the moon and back.

You can connect a PSK-31 and RTTY data reader to your radio to decode

messages

2323

APRSAPRS

Automatic Position Reporting SystemAutomatic Position Reporting System

/www.ui-view.org/findu.htm/www.ui-view.org/findu.htm

2424

APRSAPRS

2525

APRS – www.findu.comAPRS – www.findu.com

2626

WinlinkWinlink

Permits sending email over the air on Permits sending email over the air on HF, VHF or UHFHF, VHF or UHF

2727

Setting up for digital modesSetting up for digital modes

Page 5-12 of ManualPage 5-12 of Manual Transceiver connects to Transceiver connects to

• PC, audio interface, and TNCPC, audio interface, and TNC

2828

GatewaysGateways

PAGE 5-12PAGE 5-12 Usually forward messagesUsually forward messages Some provide Internet ConnectivitySome provide Internet Connectivity

2929

T4A06T4A06 Which of the following would be Which of the following would be connected between a connected between a

transceiver and transceiver and computer in a computer in a packet radio station?packet radio station?

A.A. TransmatchTransmatch

B.B. MixerMixer

C.C. Terminal node controllerTerminal node controller

D.D. AntennaAntenna

3030

T4A07T4A07 How is the computer’s sound card How is the computer’s sound card used used when conducting digital when conducting digital communications communications using a computer?using a computer?

A.A. The sound card communicates between The sound card communicates between the computer CPU and the video displaythe computer CPU and the video display

B.B. The sound card records the audio The sound card records the audio frequency for video displayfrequency for video display

C.C. The sound card provides audio to the The sound card provides audio to the microphone input and converts received microphone input and converts received audio to digital formaudio to digital form

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

3131

T8C11T8C11 What name is given to an amateur What name is given to an amateur radio radio station that is used to connect station that is used to connect other other amateur stations to the amateur stations to the Internet?Internet?

A.A. A gatewayA gateway

B.B. A repeaterA repeater

C.C. A digipeaterA digipeater

D.D. A beaconA beacon

3232

T8D02T8D02 What does the term APRS mean?What does the term APRS mean?

A.A. Automatic Position Reporting Automatic Position Reporting SystemSystem

B.B. Associated Public Radio StationAssociated Public Radio Station

C.C. Auto Planning Radio Set-upAuto Planning Radio Set-up

D.D. Advanced Polar Radio SystemAdvanced Polar Radio System

3333

T8D03T8D03 Which of the following is normally Which of the following is normally used used when sending automatic location when sending automatic location reports reports via amateur radio?via amateur radio?

A.A. A connection to the vehicle A connection to the vehicle speedometerspeedometer

B.B. A WWV receiverA WWV receiver

C.C. A connection to a broadcast FM A connection to a broadcast FM sub-carrier receiversub-carrier receiver

D.D. A Global Positioning System A Global Positioning System receiverreceiver

3434

T8D06T8D06 What does the abbreviation What does the abbreviation PSK PSK mean?mean?

A.A. Pulse Shift KeyingPulse Shift Keying

B.B. Phase Shift KeyingPhase Shift Keying

C.C. Packet Short KeyingPacket Short Keying

D.D. Phased Slide KeyingPhased Slide Keying

3535

T8D07T8D07 What is PSK31?What is PSK31?

A.A. A high-rate data transmission modeA high-rate data transmission mode

B.B. A method of reducing noise A method of reducing noise interference to FM signalsinterference to FM signals

C.C. A method of compressing digital A method of compressing digital television signaltelevision signal

D.D. A low-rate data transmission mode A low-rate data transmission mode

3636

T8D08T8D08 Which of the following may be Which of the following may be included in included in packet transmissions?packet transmissions?

A.A. A check sum which permits error A check sum which permits error detectiondetection

B.B. A header which contains the call sign A header which contains the call sign of the station to which the information of the station to which the information is being sentis being sent

C.C. Automatic repeat request in case of Automatic repeat request in case of errorerror

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

3737

POWER SUPPLIES & POWER SUPPLIES & BATTERIESBATTERIES

3838

Power SuppliesPower Supplies

Convert AC current to voltages needed by Convert AC current to voltages needed by equipmentequipment

Can be internal or externalCan be internal or external Wall wartsWall warts Power SuppliesPower Supplies

• Analog or LinearAnalog or Linear• SwitchingSwitching• Regulated to keep voltage constant with and Regulated to keep voltage constant with and

without loadwithout loadRating must be at least as much as required by Rating must be at least as much as required by

the equipmentthe equipment

3939

Mobile Power WiringMobile Power Wiring

Fuse both Positive and Negative LeadsFuse both Positive and Negative Leads Connect negative lead to battery Connect negative lead to battery

terminalterminal Use grommets when wire passes Use grommets when wire passes

through bulkhead or firewallthrough bulkhead or firewall Do not assume all metal is grounded. Do not assume all metal is grounded.

Lots are connected with plasticLots are connected with plastic Keep leads short and use heavy cableKeep leads short and use heavy cable Alternator whine can be removed with Alternator whine can be removed with

DC power filter at your radioDC power filter at your radio

4040

T0A: T0A: AC power circuits; hazardous voltages, fuses and AC power circuits; hazardous voltages, fuses and circuit breakers, circuit breakers, grounding, lightning protection, battery grounding, lightning protection, battery

safety, electrical code compliance.safety, electrical code compliance.

• T0A4T0A4 The purpose of a fuse in an electrical circuit is to interrupt The purpose of a fuse in an electrical circuit is to interrupt power in case of overload.power in case of overload.

Place the fuses as close to the battery as possible

Fuses

Slow-Blow fuseAutomobile fuse

4141

Generators & InvertersGenerators & Inverters

Generate power – usually 120 0r 240 Generate power – usually 120 0r 240 VACVAC

Inverters – Turn DC power into AC Inverters – Turn DC power into AC powerpower

Voltage regulation very important to Voltage regulation very important to protect equipment from surgesprotect equipment from surges

4242

T4A03T4A03 Which is a good reason to use a Which is a good reason to use a regulated regulated power supply for power supply for communications communications equipment?equipment?

A.A. It prevents voltage fluctuations It prevents voltage fluctuations from reaching sensitive circuitsfrom reaching sensitive circuits

B.B. A regulated power supply has FCC A regulated power supply has FCC approvalapproval

C.C. A fuse or circuit breaker regulates A fuse or circuit breaker regulates the powerthe power

D.D. Power consumption is Power consumption is independent of loadindependent of load

4343

T4A10T4A10 What is the source of a high-What is the source of a high-pitched whine pitched whine that varies with that varies with engine speed in a mobile engine speed in a mobile transceiver’s receive audio?transceiver’s receive audio?

A.A. The ignition systemThe ignition system

B.B. The alternatorThe alternator

C.C. The electric fuel pumpThe electric fuel pump

D.D. Anti-lock braking system Anti-lock braking system controllerscontrollers

4444

T4A11T4A11 Where should a mobile Where should a mobile transceiver’s transceiver’s power negative power negative connection be made?connection be made?

A.A. At the battery or engine block At the battery or engine block ground strapground strap

B.B. At the antenna mountAt the antenna mount

C.C. To any metal part of the vehicleTo any metal part of the vehicle

D.D. Through the transceiver’s Through the transceiver’s mounting bracketmounting bracket

4545

T5A06T5A06 How much voltage does a mobile How much voltage does a mobile transceiver usually require?transceiver usually require?

A.A. About 12 voltsAbout 12 volts

B.B. About 30 voltsAbout 30 volts

C.C. About 120 voltsAbout 120 volts

D.D. About 240 voltsAbout 240 volts

4646

T6D05T6D05 What type of circuit controls the What type of circuit controls the amount of amount of voltage from a power voltage from a power supply?supply?

A.A. RegulatorRegulator

B.B. OscillatorOscillator

C.C. FilterFilter

D.D. Phase inverterPhase inverter

4747

T7B09T7B09 What could be happening if another What could be happening if another operator reports a variable operator reports a variable

high-pitched high-pitched whine on the audio from whine on the audio from your mobile transmitter?your mobile transmitter?

A.A. Your microphone is picking up noise Your microphone is picking up noise from an open windowfrom an open window

B.B. You have the volume on your receiver You have the volume on your receiver set too highset too high

C.C. You need to adjust your squelch You need to adjust your squelch controlcontrol

D.D. Noise on the vehicle’s electrical Noise on the vehicle’s electrical system is being transmitted along system is being transmitted along with your speech audiowith your speech audio

4848

BatteriesBatteries

DisposableDisposable• Used once and disposed of cannot be Used once and disposed of cannot be

rechargedrecharged

Rechargeable or SecondaryRechargeable or Secondary• Chemical reaction reversed to chargeChemical reaction reversed to charge

StorageStorage• Also rechargeable used for long-term energy Also rechargeable used for long-term energy

storagestorage

4949

Handheld Radio BatteriesHandheld Radio Batteries

Some radios can use disposable Some radios can use disposable batteriesbatteries

Most use custom packs of rechargeablesMost use custom packs of rechargeables• NiCad (Nickel Cadmium)NiCad (Nickel Cadmium)• NiMH (Nickel-metal hydride)NiMH (Nickel-metal hydride)• Li-ion (Lithium Ion)Li-ion (Lithium Ion)

Li-ion highest energy capacity NiMH and Li-ion highest energy capacity NiMH and NiCad next.NiCad next.

Most HTs come with chargers to charge Most HTs come with chargers to charge batteriesbatteries

Memory in NiCad batteriesMemory in NiCad batteries

5050

T6A10T6A10 What is the nominal voltage of a What is the nominal voltage of a fully fully charged nickel-cadmium cell?charged nickel-cadmium cell?

A.A. 1.0 volts1.0 volts

B.B. 1.2 volts1.2 volts

C.C. 1.5 volts1.5 volts

D.D. 2.2 volts2.2 volts

5151

T6A11T6A11 Which battery type is not Which battery type is not

rechargeable?rechargeable? A.A. Nickel-cadmiumNickel-cadmium

B.B. Carbon-zincCarbon-zinc

C.C. Lead-acidLead-acid

D.D. Lithium-ionLithium-ion

5252

T0A08T0A08 What is one way to recharge a 12-What is one way to recharge a 12-volt lead-volt lead- acid station battery if the acid station battery if the commercial commercial power is out?power is out?

A.A. Cool the battery in ice for several Cool the battery in ice for several hourshours

B.B. Add acid to the batteryAdd acid to the battery

C.C. Connect the battery to a car's battery Connect the battery to a car's battery and run the engineand run the engine


5353

T0A09T0A09 What kind of hazard is presented What kind of hazard is presented by a by a conventional 12-volt storage conventional 12-volt storage battery?battery?

A.A. It emits ozone which can be It emits ozone which can be harmful to the atmosphereharmful to the atmosphere

B.B. Shock hazard due to high voltageShock hazard due to high voltage

C.C. Explosive gas can collect if not Explosive gas can collect if not properly ventedproperly vented


5454

T0A10T0A10 What can happen if a lead-acid What can happen if a lead-acid storage battery is charged storage battery is charged

or or discharged too quickly?discharged too quickly?

A.A. The battery could overheat and The battery could overheat and give off flammable gas or explodegive off flammable gas or explode

B.B. The voltage can become reversedThe voltage can become reversed

C.C. The “memory effect” will reduce The “memory effect” will reduce the capacity of the batterythe capacity of the battery


5555

RADIO FREQUENCY RADIO FREQUENCY INTERFERENCE (RFI)INTERFERENCE (RFI)

Getting more common placeGetting more common place Can be amateur radio interfering Can be amateur radio interfering

with other deviceswith other devices OROR Other devices interfering with Other devices interfering with

amateur radio operationamateur radio operation

5656

FiltersFilters

Very important and useful in Very important and useful in resolving Radio Frequency resolving Radio Frequency InterferenceInterference

AC power line filtersAC power line filters

RF choke/common-mode ferrite RF choke/common-mode ferrite filtersfilters

5757

Direct DetectionDirect Detection

RF gets into devices and is turned RF gets into devices and is turned into voltages that cause interferenceinto voltages that cause interference

Common with phonesCommon with phones Low pass filter at wired phone’s Low pass filter at wired phone’s

modular jackmodular jack Chokes and ferrite on speaker cordsChokes and ferrite on speaker cords

5858

OverloadOverload

““Fundamental OverloadFundamental Overload• Strong signal just gets in and interferes Strong signal just gets in and interferes

with electronics because of its strengthwith electronics because of its strength High Pass Filter at ReceiverHigh Pass Filter at Receiver Ferrite on device’s power cordFerrite on device’s power cord Shielding at ReceiverShielding at Receiver If tx & rx frequencies close – notch If tx & rx frequencies close – notch

filter or resolution not possiblefilter or resolution not possible

5959

Harmonics & Spurious EmissionsHarmonics & Spurious Emissions

Low Pass Filters on TransmitterLow Pass Filters on Transmitter Can be in-band interference and Can be in-band interference and

cannot be filtered out at receivercannot be filtered out at receiver

6060

Noise SourcesNoise Sources

Electrical equipment, lights, switchesElectrical equipment, lights, switches Cracked or dirty insulatorsCracked or dirty insulators Ignition noise from enginesIgnition noise from engines Alternator whineAlternator whine Switching Power SuppliesSwitching Power Supplies Computer, peripheral & network Computer, peripheral & network

equipmentequipment

6161

Unknown SignalsUnknown Signals

Track with a radio when possibleTrack with a radio when possible Radio Direction Finding (RDF)Radio Direction Finding (RDF)

• TriangulationTriangulation• Get azimuth bearing from three or more Get azimuth bearing from three or more

locationslocations• Plot on mapPlot on map• Interference where lines crossInterference where lines cross

6262

GuidelinesGuidelines

Make sure your station is in good Make sure your station is in good working orderworking order

Make sure you do not interfere with Make sure you do not interfere with anything in your homeanything in your home

Take care of any devices in your Take care of any devices in your home that cause interferencehome that cause interference

6363

GuidelinesGuidelines

Be diplomatic and good neighborBe diplomatic and good neighbor

Put yourself in the other person’s Put yourself in the other person’s positionposition

Demonstrate where possibleDemonstrate where possible

Get help from other hamsGet help from other hams

6464

FCC Part 15 RulesFCC Part 15 Rules

FCC sanctioned unlicensed operation FCC sanctioned unlicensed operation of certain low powered devicesof certain low powered devices

NIB to licensed servicesNIB to licensed services Must accept interference from Must accept interference from

licensed services and other Part 15 licensed services and other Part 15 devicesdevices

656565

T7B: T7B: Common transmitter and receiver problems; Common transmitter and receiver problems; symptoms of overload and symptoms of overload and overdrive, distortion, interference, overdrive, distortion, interference,

over and under modulation, RF feedback, over and under modulation, RF feedback, off frequency signals; off frequency signals; fading and noise; problems with digital fading and noise; problems with digital communications communications

interfacesinterfaces

• T7B8T7B8 If a "Part 15" device in your neighbor’s home is causing If a "Part 15" device in your neighbor’s home is causing harmful interference to your amateur station:harmful interference to your amateur station:

Work with your neighbor to identify the offending device; Work with your neighbor to identify the offending device; Politely inform your neighbor about the rules that require Politely inform your neighbor about the rules that require

him to stop using the device if it causes interference; him to stop using the device if it causes interference; Check your station and make sure it meets the standards Check your station and make sure it meets the standards

of good amateur practice.of good amateur practice.

A simple snap-on choke filter like this

one can help resolve harmful

interference problems on Part

15 devices.

6666

T4A04T4A04 Where must a filter be installed to Where must a filter be installed to reduce reduce harmonic emissions?harmonic emissions?

A.A. Between the transmitter and the antennaBetween the transmitter and the antenna

B.B. Between the receiver and the transmitterBetween the receiver and the transmitter

C.C. At the station power supplyAt the station power supply

D.D. At the microphoneAt the microphone

6767

T4A05T4A05 What type of filter should be connected What type of filter should be connected to a TV to a TV receiver as the first step in trying to receiver as the first step in trying to prevent RF prevent RF overload from a nearby 2 overload from a nearby 2 meter transmitter?meter transmitter?

A.A. Low-pass filterLow-pass filter

B.B. High-pass filterHigh-pass filter

C.C. Band-pass filterBand-pass filter

D.D. Band-reject filterBand-reject filter

6868

T4A09T4A09 Which would you use to reduce RF Which would you use to reduce RF current current flowing on the shield of an flowing on the shield of an

audio cable?audio cable? A.A. Band-pass filterBand-pass filter

B.B. Low-pass filterLow-pass filter

C.C. PreamplifierPreamplifier

D.D. Ferrite chokeFerrite choke

6969

T7B02T7B02 What is meant by fundamental What is meant by fundamental overload in overload in reference to a receiver?reference to a receiver?

A.A. Too much voltage from the power Too much voltage from the power supplysupply

B.B. Too much current from the power Too much current from the power supplysupply

C.C. Interference caused by very strong Interference caused by very strong signalssignals

D.D. Interference caused by turning the Interference caused by turning the volume up too highvolume up too high

7070

T7B03T7B03 Which of the following may be a Which of the following may be a cause of cause of radio frequency radio frequency interference?interference?

A.A. Fundamental overloadFundamental overload

B.B. HarmonicsHarmonics

C.C. Spurious emissionsSpurious emissions


7171

T7B04T7B04 What is the most likely cause of What is the most likely cause of interference to a non-interference to a non-

cordless telephone cordless telephone from a nearby from a nearby transmitter?transmitter?

A.A. Harmonics from the transmitterHarmonics from the transmitter

B.B. The telephone is inadvertently The telephone is inadvertently acting as a radio receiveracting as a radio receiver

C.C. Poor station groundingPoor station grounding

D.D. Improper transmitter adjustmentImproper transmitter adjustment

7272

T7B05T7B05 What is a logical first step when What is a logical first step when attempting attempting to cure a radio frequency to cure a radio frequency interference interference problem in a nearby problem in a nearby telephone?telephone?

A.A. Install a low-pass filter at the transmitterInstall a low-pass filter at the transmitter

B.B. Install a high-pass filter at the transmitterInstall a high-pass filter at the transmitter

C.C. Install an RF filter at the telephoneInstall an RF filter at the telephone

D.D. Improve station groundingImprove station grounding

7373

T7B06T7B06 What should you do first if someone What should you do first if someone tells tells you that your station’s you that your station’s transmissions are transmissions are interfering interfering with their radio or TV reception?with their radio or TV reception?

A.A. Make sure that your station is functioning properly and Make sure that your station is functioning properly and that it does not cause interference to your own that it does not cause interference to your own televisiontelevision

B.B. Immediately turn off your transmitter and contact the Immediately turn off your transmitter and contact the nearest FCC office for assistancenearest FCC office for assistance

C.C. Tell them that your license gives you the right to Tell them that your license gives you the right to transmit and nothing can be done to reduce the transmit and nothing can be done to reduce the interferenceinterference

D.D. Continue operating normally because your equipment Continue operating normally because your equipment cannot possibly cause any interferencecannot possibly cause any interference

7474

T7B07T7B07 Which of the following may be Which of the following may be useful useful in correcting a radio in correcting a radio frequency frequency interference interference problem?problem?

A.A. Snap-on ferrite chokesSnap-on ferrite chokes

B.B. Low-pass and high-pass filtersLow-pass and high-pass filters

C.C. band-reject and band-pass filtersband-reject and band-pass filters


7575

T7B08T7B08 What should you do if a "Part 15" What should you do if a "Part 15" device in device in your neighbor’s home is your neighbor’s home is causing harmful causing harmful interference to your interference to your amateur station?amateur station?

A.A. Work with your neighbor to identify the Work with your neighbor to identify the offending deviceoffending device

B.B. Politely inform your neighbor about the Politely inform your neighbor about the rules that require him to stop using the rules that require him to stop using the device if it causes interferencedevice if it causes interference

C.C. Check your station and make sure it Check your station and make sure it meets the standards of good amateur meets the standards of good amateur practicepractice


7676

RF GROUNDINGRF GROUNDING

Electrical and RF ground not always Electrical and RF ground not always samesame

Use short lengths of heavy cable or flat Use short lengths of heavy cable or flat strap to ground all equipment to strap to ground all equipment to ground rodground rod

Flat Strap Is BestFlat Strap Is Best

7777


Bad RF ground can result in RF current Bad RF ground can result in RF current affecting sensitive audio or other affecting sensitive audio or other equipmentequipment

Can cause shock or RF burnsCan cause shock or RF burns

RF feedback via microphone cable can RF feedback via microphone cable can distort your signaldistort your signal

7878


7979

T4A08T4A08 Which type of conductor is best to Which type of conductor is best to use for use for RF grounding?RF grounding?

A.A. Round stranded wire Round stranded wire

B.B. Round copper-clad steel wireRound copper-clad steel wire

C.C. Twisted-pair cableTwisted-pair cable

D.D. Flat strapFlat strap

8080

T7B11T7B11 What is a symptom of RF feedback What is a symptom of RF feedback in ain a transmitter or transceiver? transmitter or transceiver?

A.A. Excessive SWR at the antenna Excessive SWR at the antenna connectionconnection

B.B. The transmitter will not stay on the The transmitter will not stay on the desired frequencydesired frequency

C.C. Reports of garbled, distorted, or Reports of garbled, distorted, or unintelligible transmissionsunintelligible transmissions

D.D. Frequent blowing of power supply Frequent blowing of power supply fusesfuses

Documents

Technician Licensing Class Chapter 5 Valid dates: July 1, 2010 – June 30, 2014 Amateur Radio Equipment