Presentation on theme: "Technician License Class"— Presentation transcript:
1Technician License Class Chapter 5Amateur Radio Equipment
2Generalized Transceiver Categories Single Band VHF or UHF FMDual Band VHF/UHF FMMultimode VHF/UHFMultiband HF and VHF/UHFHandheld (HT) FM (VHF, UHF, or Both)
3Single Band FM Transceiver Probably the most common starter rig.Operates from 12 volts dc, requires external power supply.Requires an external antenna.Can be operated mobile or as a base station.Usually either 2 meters or 70 cm bands.Up to approximately 65 watts output.
4Dual Band FM Transceiver Same as the single band transceiver but includes additional band(s).Most common are 2 meter and 70 cm bands.Could add 6 meters, 222 MHz or 1.2 GHz.Depending on antenna connectors, might require separate coax for each band or a duplexer for single coax.
5Multimode Transceiver Can be single or multiband.Main difference is that these rigs can operate on all major modes SSB/AM/FM, CW, Data, RTTY etc.More features add complexity and cost.Most flexible type of rig. It will allow you to explore new modes as you gain experience.Best for weak-signal communications.
6Multiband HF Transceiver Covers many bands – can be limited to HF or can be HF/VHF/UHF.Also covers all modes.Frequently 100 watts on HF, some power limitations on high bands (50 watts).Larger units may have internal power supplies, smaller units need external power supply (13.8 V).
7Handheld (HT) Transceiver Small handheld FM units.Can be single band or dual band.Limited power (usually 5 watts or less).External RF power amplifier.Includes power (battery) and antenna in one package.An attractive first starter rig – but make sure it is what you want.
8Rig VocabularyWe will now go through some jargon and vocabulary specific to the functions and controls of a transmitter and receiver.This is a way to discuss how to operate a transceiver.These controls, though separate, are combined in a transceiver.
9Transmitter Controls & Functions Main tuning dial (both TX and RX):Controls the frequency selection via the variable frequency oscillator (VFO).Could be an actual dial or key pad or programmed channels.Variable frequency step size (tuning rate, resolution).Could have more than one VFO (control more that one frequency at a time).
10Transmitter Controls & Functions Mode selector (both TX and RX for multimode rigs).Multimode rigs only.AM/FM/SSB (LSB or USB)CWData (RTTY)Could be automatic.Based on recognized band plan.
11Transmitter Controls & Functions Microphone controlsGainHow loudly you need to talk to be heard.Speech Compressor or Speech ProcessorCompacting your speech into a narrow amplitude range to enhance “punch.”
12Transmitter Controls & Functions Microphone controlsToo much gain or compression can cause problems.Over-deviationOver-modulationSplatter
13Transmitter Controls & Functions Automatic Level Control (ALC).Automatically limits transmitter drive (output level) to prevent problems associated with too much gain or compression.Also can control external power amplifier operation.
15Transmitter Controls & Functions Microphones (Mic).Hand microphones.Desk microphones.Pre-amplified desk microphones.Speaker-microphones.Headsets or boom-sets.Internal microphones.Some microphones include PTT & power.Not all microphones use same connector.If same connector, not all wired the same.
16Transmitter Controls & Functions Morse Keys.Straight key.Semi-automatic (Bug).Electronic keyer and paddle.Electronic keyer often built into transceiver.Computer keyboard.
19Receiver Controls & Functions AF Gain or VolumeControls the audio level to the speaker or headphones.RF GainControls the strength of radio signal entering the receiver.Used to limit (attenuate) very strong local signals.Usually operated in the full-open position.Not always best practice.
20Receiver Controls & Functions Automatic Gain Control (AGC)Automatically limits the incoming signals during signal (voice) peaks.Prevents peaks from capturing the receiver and limiting reception of lower level portions of the incoming signal.Fast setting for CW.Slow settings for SSB and AM.Not used for FM.
21Receiver Controls & Functions Squelch.Turns off audio to speaker when signal is not present.Open – allows very weak signals to pass through (along with noise).Tight – allows only the strongest signals to pass through.Advance the squelch control until the noise just disappears.Used primarily for FM.
22Receiver Controls & Functions FiltersBandwidth filterUsed to narrow the width of signal that is passed.Can attenuate adjacent interference.Notch filterVery narrow filter that can be moved over an interfering signal to attenuate it.Noise blanker or limiterLimits signal spikes that are frequently associated with random naturally generated noise.
23Receiver Controls & Functions Receiver Incremental Tuning (RIT).a.k.a. – Clarifier.Used to adjust receiver frequency a small amount without changing the transmit frequency.A single-sideband signal sounds “funny” if slightly off frequency.
24Receiver Controls & Functions Receive Meter.Signal strength.Measured in “S” units.S1 to S9, dB over S9.S9 = 1 mV at antenna terminals.S9 = -73 dBm.0 dBm = 1 mW into 50Ω load.Increase of 1 S-unit = Increase of 6 dB.
25Receiver Controls & Functions Receivers can be limited to ham bands or can cover other parts of the spectrum.General coverage receivers cover a wide area of the spectrum and can be used for shortwave listening (SWL).
26Handheld Transceivers Single, dual and multiband versions (with increasing cost and complexity).Some have expanded receiver coverage (wide-band receive).Very portable and self-contained.Internal microphone and speaker.Rubber duck antenna.Battery powered.
27Handheld Transceivers Nice to have handheld accessories:Extra battery packs.Drop-in, fast charger.Extended antenna.External microphone and speaker.Headset.
28T2B03 - Which of the following describes the muting of receiver audio controlled solely by the presence or absence of an RF signal?A. Tone squelchB. Carrier squelchC. CTCSSD. Modulated carrier
29T4A01 - Which of the following is true concerning the microphone connectors on amateur transceivers? A. All transceivers use the same microphone connector typeB. Some connectors include push-to-talk and voltages for powering the microphoneC. All transceivers using the same connector type are wired identicallyD. Un-keyed connectors allow any microphone to be connected
30T4B01 - What may happen if a transmitter is operated with the microphone gain set too high? A. The output power might be too highB. The output signal might become distortedC. The frequency might varyD. The SWR might increase
31T4B02 - Which of the following can be used to enter the operating frequency on a modern transceiver? A. The keypad or VFO knobB. The CTCSS or DTMF encoderC. The Automatic Frequency ControlD. All of these choices are correct
32T4B03 - What is the purpose of a squelch control on a transceiver? A. To set the highest level of volume desiredB. To set the transmitter power levelC. To adjust the automatic gain controlD. To mute receiver output noise when no signal is being received
33T4B04 - What is a way to enable quick access to a favorite frequency on your transceiver? A. Enable the CTCSS tonesB. Store the frequency in a memory channelC. Disable the CTCSS tonesD. Use the scan mode to select the desired frequency
34T4B05 - Which of the following would reduce ignition interference to a receiver? A. Change frequency slightlyB. Decrease the squelch settingC. Turn on the noise blankerD. Use the RIT control
35T4B07 - What does the term “RIT” mean? A. Receiver Input ToneB. Receiver Incremental TuningC. Receiver Inverter TestD. Remote Input Transmitter
36T4B08 - What is the advantage of having multiple receive bandwidth choices on a multimode transceiver?A. Permits monitoring several modes at onceB. Permits noise or interference reduction by selecting a bandwidth matching the modeC. Increases the number of frequencies that can be stored in memoryD. Increases the amount of offset between receive and transmit frequencies
37T4B09 - Which of the following is an appropriate receive filter to select in order to minimize noise and interference for SSB reception?A. 500 HzB HzC HzD Hz
38T4B10 - Which of the following is an appropriate receive filter to select in order to minimize noise and interference for CW reception?A. 500 HzB HzC HzD Hz
39T7A09 - Which of the following devices is most useful for VHF weak-signal communication? A. A quarter-wave vertical antennaB. A multi-mode VHF transceiverC. An omni-directional antennaD. A mobile VHF FM transceiver
40T7A10 - What device increases the low-power output from a handheld transceiver? A. A voltage dividerB. An RF power amplifierC. An impedance networkD. A voltage regulator
41T7B01 - What can you do if you are told your FM handheld or mobile transceiver is over deviating? A. Talk louder into the microphoneB. Let the transceiver cool offC. Change to a higher power levelD. Talk farther away from the microphone
42T8D10 - Which of the following can be used to transmit CW in the amateur bands? A. Straight KeyB. Electronic KeyerC. Computer KeyboardD. All of these choices are correct
43Data Modes a.k.a. – Digital modes. Connecting computers via ham radio. Some systems use radio to connect to internet gateways.The bulk of the work is done by specialized modems or computer software/sound card.Terminal Node Controller (TNC).Multiple Protocol Controller (MPC).
44Digital Modes Error Correction. Bit Error Rate (BER). BER = number of bit errors / total number of bits.Forward Error Correction (FEC).Adds extra information so that data can be reconstructed. (e.g. - MFSK-16)Automatic Repeat Request (ARQ).If error detected, asks sending station to retransmit data. (e.g. - packet radio)
45Popular Digital Modes Radioteletype (RTTY) PSK31. Packet Radio. Automatic Packet Reporting System (APRS).Winlink.And many, many more….
49T4A06 - Which of the following would be connected between a transceiver and computer in a packet radio station?A. TransmatchB. MixerC. Terminal node controllerD. Antenna
50T4A07 - How is the computer’s sound card used when conducting digital communications using a computer?A. The sound card communicates between the computer CPU and the video displayB. The sound card records the audio frequency for video displayC. The sound card provides audio to the microphone input and converts received audio to digital formD. All of these choices are correct
51T7B12 - What does the acronym “BER” mean when applied to digital communications systems? A. Baud Enhancement RecoveryB. Baud Error RemovalC. Bit Error RateD. Bit Exponent Resource
52T8C11 - What name is given to an amateur radio station that is used to connect other amateur stations to the Internet?A. A gatewayB. A repeaterC. A digipeaterD. A beacon
53T8D01 - Which of the following is an example of a digital communications method? A. PacketB. PSK31C. MFSKD. All of these choices are correct
54T8D02 - What does the term APRS mean? A. Automatic Position Reporting SystemB. Associated Public Radio SystemC. Auto Planning Radio Set-upD. Advanced Polar Radio SystemNOTE: This is an error in the question pool. The correct answer should read:“Automatic Packet Reporting System”.
55T8D03 - Which of the following is normally used when sending automatic location reports via amateur radio?A. A connection to the vehicle speedometerB. A WWV receiverC. A connection to a broadcast FM sub-carrier receiverD. A Global Positioning System receiver
56T8D06 - What does the abbreviation PSK mean? A. Pulse Shift KeyingB. Phase Shift KeyingC. Packet Short KeyingD. Phased Slide Keying
57T8D07 - What is PSK31?A. A high-rate data transmission modeB. A method of reducing noise interference to FM signalsC. A method of compressing digital television signalD. A low-rate data transmission mode
58T8D08 - Which of the following may be included in packet transmissions? A. A check sum which permits error correctionsB. A header which contains the call sign of the station to which the information is being sentC. Automatic repeat request in case of errorD. All of these choices are correct
59T8D09 - What code is used when sending CW in the amateur bands? A. BaudotB. HammingC. International MorseD. Gray
60T8D11 - What is a “parity” bit? A. A control code required for automatic position reportingB. A timing bit used to ensure equal sharing of a frequencyC. An extra code element used to detect errors in received dataD. A “triple width” bit used to signal the end of a character
62Power Supplies House power is ~120 VAC, 60 Hz. Most modern radios require ~12 VDC.Actually 13.8 VDC.A power supply is a device that converts 120 VAC power to the desired DC voltage or voltages.
63Power Supplies Unregulated supply. Regulated supply. Simple circuit.Voltage can vary over a wide range with changing load current.Regulated supply.More complex circuit.Voltage is nearly constant with changing load.Modern rigs work best with a regulated power supply.
64Power Supplies Regulated Power Supplies. Linear. Large & heavy. Inefficient.Generate heat.Easy to repair.Less expensive.
65Power Supplies Regulated Power Supplies. Switching. Small & lightweight.Very efficient.More difficult to repair.More expensive.
66Power Supplies Ratings: Continuous current. Intermittent current. How much current can be supplied over the long term.Intermittent current.How much surge current can be supplied over the short term.Voltage regulation.How well the power supply can handle rapid current changes.
67Mobile Power WiringFuse BOTH positive & negative leads close to the power connection.Connect negative lead to battery or to battery ground connection.Use grommets or sleeves to protect wires where they pass through firewall.Do NOT assume that all metal body parts are grounded.
68Mobile Power WiringMobile installations can suffer from noise from the vehicle electrical system.Receive Interference.Ignition noise.Regular noise pulses when spark plugs fire.Alternator whine.High-pitched whine that varies in frequency with engine speed.Transmit Interference.
69Generators & Inverters For emergency & portable operations, commercial AC power may not be available.Generator.Converts mechanical energy to electrical energy.Inverter.Converts DC voltage to AC voltage.
70Generators & Inverters For emergency & portable operations, commercial AC power may not be available.Generator.Converts mechanical energy to AC or DC electrical energy.Inverter.Converts DC voltage to AC voltage.
71Generators & Inverters Motor-Generator Sets.AC generator connected to small gasoline engine.Old technology.Less Expensive.Typically very noisy.Output voltage not pure sine wave.Distorted output may damage sensitive electronic equipment.
72Generators & Inverters Motor-Generator-Inverter Sets.DC generator connected to small gasoline engine & DC voltage fed to an inverter.New technology.More expensive.Relatively quiet.Output voltage is pure sine wave.Safe for sensitive electronic equipment.
74T4A03 - Which is a good reason to use a regulated power supply for communications equipment? A. It prevents voltage fluctuations from reaching sensitive circuitsB. A regulated power supply has FCC approvalC. A fuse or circuit breaker regulates the powerD. Power consumption is independent of load
75T4A10 - What is the source of a high-pitched whine that varies with engine speed in a mobile transceiver’s receive audio?A. The ignition systemB. The alternatorC. The electric fuel pumpD. Anti-lock braking system controllers
76T4A11 - Where should a mobile transceiver’s power negative connection be made? A. At the battery or engine block ground strapB. At the antenna mountC. To any metal part of the vehicleD. Through the transceiver’s mounting bracket
77T5A06 - How much voltage does a mobile transceiver usually require? A. About 12 voltsB. About 30 voltsC. About 120 voltsD. About 240 volts
78T6D05 - What type of circuit controls the amount of voltage from a power supply? A. RegulatorB. OscillatorC. FilterD. Phase inverter
79T7B09 - What could be happening if another operator reports a variable high-pitched whine on the audio from your mobile transmitter?A. Your microphone is picking up noise from an open windowB. You have the volume on your receiver set too highC. You need to adjust your squelch controlD. Noise on the vehicle’s electrical system is being transmitted along with your speech audio
80Batteries Create electrical energy through a chemical reaction. Primary cell.Chemical reaction is not reversible.Cannot be recharged.Secondary cell.Chemical reaction is reversible.Can be recharged.
81Batteries Cell voltage depends on chemicals used. Capacity rated in Ampere-hours (AH) or milliampere hours (mAH).500 mAH battery will provide:500 mA for 1 hour.50 mA for 10 hours.25 mA for 20 hours.5 mA for 100 hours.etc.
82Batteries Lead-Acid. Secondary cell. Approximately 2.12 Volts per cell.“12V” battery = 6 cells in series.Open-Circuit at full charge: 12.6 V to 12.8 VOpen-circuit at full discharge: V to 12.0 VLoaded at full discharge: VFloat Charge: VDaily Charge: V to 14.5 V
83Batteries Lead-Acid. If overcharged will release hydrogen gas. Remember the Hindenberg!ALWAYS use in well-ventilated area!Gassing threshold ~14.4 V.
84Batteries Gel-Cell. a.k.a. – Sealed lead-acid (SLA). Electrolyte is in a gel form rather then liquid.Sealed so does not vent hydrogen gas.Avoid over charging to prevent build up of internal pressure.
85Other Types of Batteries ChemistryCell VoltageTypeCarbon-Zinc(obsolete)1.5VDisposableAlkalineDisposable*Nickel-Cadmium(NiCad)1.2VRechargeableNickel-Metal-Hydride(NiMH)Lithium Ion(LI-Ion)3.6V
86Battery Charging Some batteries can be recharged, some cannot. Use the proper charger for the battery being charged.Batteries will wear out over time.Best if batteries are maintained fully charged.Over-charging will cause heating and could damage the battery.
87Handheld Transceiver Batteries Battery packs – packages of several individual rechargeable batteries connected together.NiCd (nickel-cadmium).NiMH (nickel-metal hydride).Li-ion (lithium-ion).For emergencies, have a battery pack that can use disposable batteries (usually AA size).
88T6A10 - What is the nominal voltage of a fully charged nickel-cadmium cell? A. 1.0 voltsB. 1.2 voltsC. 1.5 voltsD. 2.2 volts
89T6A11 - Which battery type is not rechargeable? A. Nickel-cadmiumB. Carbon-zincC. Lead-acidD. Lithium-ion
90T0A08 - What is one way to recharge a 12-volt lead-acid station battery if the commercial power is out?A. Cool the battery in ice for several hoursB. Add acid to the batteryC. Connect the battery to a car’s battery and run the engineD. All of these choices are correct
91T0A09 - What kind of hazard is presented by a conventional 12-volt storage battery? A. It emits ozone which can be harmful to the atmosphereB. Shock hazard due to high voltageC. Explosive gas can collect if not properly ventedD. All of these choices are correct
92T0A10 - What can happen if a lead-acid storage battery is charged or discharged too quickly? A. The battery could overheat and give off flammable gas or explodeB. The voltage can become reversedC. The “memory effect” will reduce the capacity of the batteryD. All of these choices are correct
93Radio Frequency Interference (RFI) Radio frequency signals (RF) causing interference with the proper operation of an electronic device.Your transmitted signal can interfere with electronic devices, even if it is operating properly.Radio frequency signals generated by electrical devices can interfere with your receiver.
94Radio Frequency Interference (RFI) Filters.Used to prevent interfering signals from entering a piece of equipment.High-Pass -- Passes frequencies above a frequency.Low-Pass -- Passes frequencies below a frequency.Band-Pass -- Passes frequencies within a frequency range.Band-Reject -- Passes frequencies outside of a frequency range.
95Radio Frequency Interference (RFI) RF choke.a.k.a. – Common-mode choke.a.k.a. – Ferrite choke.Special type magnetic material (ferrite) placed around a conductor or cable.The “lump” in computer cables.Prevents RF from entering or leaving a piece of electronic equipment via the cable.
96Radio Frequency Interference (RFI) Ferrite choke.
97Types of RFI Direct detection. The presence of a strong RF signal can interference with an electronic device even if the transmitter is operating properly.Often caused by the device acting as a receiver even when it is not designed to.Semiconductors in the device can act as diode detectors.This is called direct detection.
98Types of RFI Direct detection. Telephones. Stereos. Direct detection is most common type of RFI.Low-pass filter at telephone wall jack.Ferrite choke on telephone cord.Stereos.Touch-activated lamps.Electronic doorbells.
99Types of RFIOverload.Very strong off-frequency signals can overwhelm the input stages of a receiver.Interfering signal may be heard regardless of frequency (channel) receiver is tuned to.Problem lies within the receiver.Add filters to receiver input.e.g. – Add band-reject (notch) filter to prevent a 2-meter signal from interfering with broadcast TV.Adding filters to transmitter will not help.
100Types of RFI Harmonics & Spurious Emissions. All transmitted signals contain harmonics and other spurious emissions (spurs).Goal is to reduce strength of harmonics & spurs as much as possible.Good transmitter design.Proper operation.
101Types of RFI Harmonics & Spurious Emissions. Problem lies within the transmitter.Install low-pass filter or band-pass filter between transmitter and antenna to reduce harmonics.Filtering may not reduce strength of spurious emissions (non-harmonic) if close to transmitter frequency.Adding filters to receiver input will not help.
102Types of RFI Cable TV Interference Usually the result of broken shielding somewhere in the cable.Loose connections.Broken connections.Corroded connections.Usually solved by proper cable maintenance by cable supplier.
103Types of RFI Noise Sources. Most interference to amateur radio receivers is not from transmitters, but from “unintentional radiators”.Electrical arcs (motors, thermostats, electric fences, neon signs, etc.).Power lines.Motor vehicle ignitions or alternators.Switching power supplies.Computers, networks, and TV sets.
104Types of RFI Intermodulation. Two signals combine (mix) to produce an interfering signal.Find circuit where mixing is occurring.Add filter(s) to eliminate one or both of the signals being mixed.
105Dealing with RFI Make sure you operate your equipment properly. Eliminate interference in your own home first.
106Dealing with RFI Take interference complaints seriously. Make sure that you’re really not the cause.Demonstrate that you don’t interfere within your own home.Offer to help eliminate the RFI, even if you are not at fault.Consult ARRL RFI Resources for help and assistance.
107What the Rules SayRFI from and to unlicensed devices is the responsibility of the users of such devices.Bottom line – If your station is operating properly, you are protected against interference complaints.BUT – Be a good neighbor because they may (probably) not be familiar with Part 15 rules and regulations.
108T4A04 - Where must a filter be installed to reduce harmonic emissions? A. Between the transmitter and the antennaB. Between the receiver and the transmitterC. At the station power supplyD. At the microphone
109T4A05 - What type of filter should be connected to a TV receiver as the first step in trying to prevent RF overload from a nearby 2 meter transmitter?A. Low-pass filterB. High-pass filterC. Band-pass filterD. Band-reject filter
110T4A09 - Which would you use to reduce RF current flowing on the shield of an audio cable? A. Band-pass filterB. Low-pass filterC. PreamplifierD. Ferrite choke
111T7B04 - What is the most likely cause of interference to a non-cordless telephone from a nearby transmitter?A. Harmonics from the transmitterB. The telephone is inadvertently acting as a radio receiverC. Poor station groundingD. Improper transmitter adjustment
112T7B05 - What is a logical first step when attempting to cure a radio frequency interference problem in a nearby telephone?A. Install a low-pass filter at the transmitterB. Install a high-pass filter at the transmitterC. Install an RF filter at the telephoneD. Improve station grounding
113T7B06 - What should you do first if someone tells you that your station’s transmissions are interfering with their radio or TV reception?A. Make sure that your station is functioning properly and that it does not cause interference to your own televisionB. Immediately turn off your transmitter and contact the nearest FCC office for assistanceC. Tell them that your license gives you the right to transmit and nothing can be done to reduce the interferenceD. Continue operating normally because your equipment cannot possibly cause any interference
114T7B07 - Which of the following may be useful in correcting a radio frequency interference problem? A. Snap-on ferrite chokesB. Low-pass and high-pass filtersC. Band-reject and band-pass filtersD. All of these choices are correct
115T7B08 - What should you do if a “Part 15” device in your neighbor’s home is causing harmful interference to your amateur station?A. Work with you neighbor to identify the offending deviceB. Politely inform your neighbor about the rules that require him to stop using the device if it causes interferenceC. Check your station and make sure it meets the standards of good amateur practiceD. All of these choices are correct
116Electrical Grounding Make sure your home is “up to code.” Most ham equipment does not require special wiring or circuits.Use 3-wire power cords.Use circuit breakers, circuit breaker outlets, or Ground Fault Interrupter (GFI) circuit breakers.Use proper fuse or circuit breaker size.Don’t overload single outlets.
117RF Grounding Amateur radio stations require a separate “RF” ground. Lack of a proper RF ground can result in:RF burns when touching equipment while transmitting.RF feedback resulting in distorted audio on transmitted signal.Erratic operation of computer equipment.
118RF Grounding All equipment should be connected to a common ground. Ground should be as short as possible.Use wide, flat copper strap or braid.
119Lightning ProtectionInstall a separate ground rod by each leg of your tower.Do NOT run ground rods through concrete base.Ground rods should be bonded to the tower leg & to each other.Connect to station ground.
120T7B11 - What is a symptom of RF feedback in a transmitter or transceiver? A. Excessive SWR at the antenna connectionB. The transmitter will not stay on the desired frequencyC. Reports of garbled, distorted, or unintelligible transmissionsD. Frequent blowing of power supply fuses
121T4A08 - What type of conductor is best to use for RF grounding? A. Round stranded wireB. Round copper-clad steel wireC. Twisted-pair cableD. Flat strap