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Technician Licensing Class “Chapter 5”

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

2 Chapter 5 Contents Transmitters and Receivers Digital Communications
Power Supplies and Batteries Radio Frequency Interference (RFI) RF Grounding

3 Transmitters and Receivers
Used to be separate units Still can be Transceivers (containing both transmitter and receiver more common place now) Abbreviations Tx Rx or Rcvr XCVR

4 Transmitters and Receivers
Selecting Band, Frequency and Mode Amateur radio has bands rather than channels other than on 60 meters) AM and SSB can be more than speech (CW data FM can be voice or data

5 Amateur Radio Bands HF VHF UHF 160 1.8 MHz 6 50 Mhz 80 3.5 MHz
70 cm 440 Mhz 33 cm 902 Mhz 23 cm 1240 Mhz 13 cm 2300 Mhz

6 Control and Function Keys
Can be separate or same key Control keys typically directly control the radio Function keys are more like menu and are used to select and set functions and parameters for the radio’s operation

7 Transmitters and Receivers
Transmitter Functions

8 Transmitter Functions
RF Power Control Microphone Gain Speech Compressor/Processor PEP (Peak Envelope Power) SSB & AM ALC Band and frequency tuning

9 Transmitter Functions
Spurious Signals Turn down microphone gain Turn down compressor/speech processor Back away from microphone ALC Proper Tuning if not solid state equipment

10 Transmitter Functions
Microphones Hand Desk Boom Headset Throat VOX vs Manual

11 Transmitter Functions
Keys Manual Straight Key Semi-Automatic Bug Dits automatic Dahs automatic Automatic/Electronic Dits and Dahs both automatic and self completing Single and double lever types Iambic and non iambic

12 Receiver Functions AF and RF Gain Bandwidth (filters)
Band and frequency tuning Attenuator DSP Automatic Gain Control (AGC) RIT Receiver Incremental Tuning (Clarifier) Allows rx tuning off of tx frequency in xcvr

13 Modern Transceiver

14 Digital Signal Processing (DSP)
Noise Reduction Variable signal filtering Automatic notching filtering Audio contouring on tx and rx Shift Width

15 Handheld Tranceivers Single Band, Dual, Tri, and quad band
Built in microphone and speakers but jacks for external Memories Push to Talk PTT Rubber Duck antenna Better antennas Connect to outside antennas

16 DIGITAL COMMUNICATIONS
Need Modem / TNC Advantages Digital Signal Processing Redundancy Error Correction Allow easy reception of very weak signals

17 Amateur Digital Modes RTTY PACTOR & WINMOR PSK31 & MFSK Olivia Domino
VHF & UHF Packet and Winlink 2000

18 Errors in Digital Data Errors measured in Bit Error Rate (BER)
Parity bits Forward Error Correction

19 Packet & Packet Networks
Use FSK (Frequency Shift Keying) Can run automatically ARQ Automatic Repeat Request AX.25 protocol Bulletin Boards Messages Or direct hands on communications Think long lists of data to be transmitted

20 T8D:. Non-voice communications; image data, digital modes CW,
T8D: Non-voice communications; image data, digital modes CW, packet,PSK31 T8D8 Packet transmissions may include: A check sum which permits error detection; A header which contains the call sign of the station to which the information is being sent; Automatic repeat request in case of error. Laptop, TNC, and Handheld comprise Packet Station. 20

21 Keyboard-to-Keyboard
Most Digital Modes including RTTY and CW CW faster than you can send or receive PSK31, Olivia, Domino, Many others

22 T8D:. Non-voice communications; image data, digital modes CW, packet,
T8D: Non-voice communications; image data, digital modes CW, packet, PSK31 T8D7 PSK31 is a low-rate data transmission mode. PSK-31 transmission rate is about normal typing speed. PSK is a remarkable digital mode that slices through interference and 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

23 APRS Automatic Position Reporting System /www.ui-view.org/findu.htm

24 APRS

25 APRS –

26 Winlink Permits sending over the air on HF, VHF or UHF

27 Setting up for digital modes
Page 5-12 of Manual Transceiver connects to PC, audio interface, and TNC

28 Gateways PAGE 5-12 Usually forward messages
Some provide Internet Connectivity

29 T4A06. Which of the following would be
T4A06 Which of the following would be connected between a transceiver and computer in a packet radio station? Transmatch Mixer Terminal node controller Antenna

30 T4A07. How is the computer’s sound card used
T4A07 How is the computer’s sound card used when conducting digital communications using a computer? The sound card communicates between the computer CPU and the video display The sound card records the audio frequency for video display The sound card provides audio to the microphone input and converts received audio to digital form All of these choices are correct

31 T8C11. What name is given to an amateur radio
T8C11 What name is given to an amateur radio station that is used to connect other amateur stations to the Internet? A gateway A repeater A digipeater A beacon

32 T8D02 What does the term APRS mean?
Automatic Position Reporting System Associated Public Radio Station Auto Planning Radio Set-up Advanced Polar Radio System

33 T8D03. Which of the following is normally used
T8D03 Which of the following is normally used when sending automatic location reports via amateur radio? A connection to the vehicle speedometer A WWV receiver A connection to a broadcast FM sub-carrier receiver A Global Positioning System receiver

34 T8D06 What does the abbreviation PSK mean?
Pulse Shift Keying Phase Shift Keying Packet Short Keying Phased Slide Keying

35 T8D07 What is PSK31? A high-rate data transmission mode
A method of reducing noise interference to FM signals A method of compressing digital television signal A low-rate data transmission mode

36 T8D08 Which of the following may be included in packet transmissions?
A check sum which permits error detection A header which contains the call sign of the station to which the information is being sent Automatic repeat request in case of error All of these choices are correct

37 POWER SUPPLIES & BATTERIES

38 Power Supplies Convert AC current to voltages needed by equipment
Can be internal or external Wall warts Power Supplies Analog or Linear Switching Regulated to keep voltage constant with and without load Rating must be at least as much as required by the equipment

39 Mobile Power Wiring Fuse both Positive and Negative Leads
Connect negative lead to battery terminal Use grommets when wire passes through bulkhead or firewall Do not assume all metal is grounded. Lots are connected with plastic Keep leads short and use heavy cable Alternator whine can be removed with DC power filter at your radio

40 T0A: AC power circuits; hazardous voltages, fuses and circuit breakers, grounding, lightning protection, battery safety, electrical code compliance. T0A4 The purpose of a fuse in an electrical circuit is to interrupt power in case of overload. Slow-Blow fuse Automobile fuse Fuses Place the fuses as close to the battery as possible

41 Generators & Inverters
Generate power – usually 120 0r 240 VAC Inverters – Turn DC power into AC power Voltage regulation very important to protect equipment from surges

42 T4A03. Which is a good reason to use a regulated
T4A03 Which is a good reason to use a regulated power supply for communications equipment? It prevents voltage fluctuations from reaching sensitive circuits A regulated power supply has FCC approval A fuse or circuit breaker regulates the power Power consumption is independent of load

43 T4A10. What is the source of a high-pitched whine
T4A10 What is the source of a high-pitched whine that varies with engine speed in a mobile transceiver’s receive audio? The ignition system The alternator The electric fuel pump Anti-lock braking system controllers

44 T4A11. Where should a mobile transceiver’s
T4A11 Where should a mobile transceiver’s power negative connection be made? At the battery or engine block ground strap At the antenna mount To any metal part of the vehicle Through the transceiver’s mounting bracket

45 T5A06 How much voltage does a mobile transceiver usually require?
About 12 volts About 30 volts About 120 volts About 240 volts

46 T6D05. What type of circuit controls the amount of
T6D05 What type of circuit controls the amount of voltage from a power supply? Regulator Oscillator Filter Phase inverter

47 T7B09. What could be happening if another
T7B09 What could be happening if another operator reports a variable high-pitched whine on the audio from your mobile transmitter? Your microphone is picking up noise from an open window You have the volume on your receiver set too high You need to adjust your squelch control Noise on the vehicle’s electrical system is being transmitted along with your speech audio

48 Batteries Disposable Rechargeable or Secondary Storage
Used once and disposed of cannot be recharged Rechargeable or Secondary Chemical reaction reversed to charge Storage Also rechargeable used for long-term energy storage

49 Handheld Radio Batteries
Some radios can use disposable batteries Most use custom packs of rechargeables NiCad (Nickel Cadmium) NiMH (Nickel-metal hydride) Li-ion (Lithium Ion) Li-ion highest energy capacity NiMH and NiCad next. Most HTs come with chargers to charge batteries Memory in NiCad batteries

50 T6A10. What is the nominal voltage of a fully
T6A10 What is the nominal voltage of a fully charged nickel-cadmium cell? 1.0 volts 1.2 volts 1.5 volts 2.2 volts

51 T6A11 Which battery type is not rechargeable?
Nickel-cadmium Carbon-zinc Lead-acid Lithium-ion

52 T0A08. What is one way to recharge a 12-volt lead-
T0A08 What is one way to recharge a 12-volt lead- acid station battery if the commercial power is out? Cool the battery in ice for several hours Add acid to the battery Connect the battery to a car's battery and run the engine All of these choices are correct

53 T0A09. What kind of hazard is presented by a
T0A09 What kind of hazard is presented by a conventional 12-volt storage battery? It emits ozone which can be harmful to the atmosphere Shock hazard due to high voltage Explosive gas can collect if not properly vented All of these choices are correct

54 T0A10. What can happen if a lead-acid. storage battery is charged or
T0A10 What can happen if a lead-acid storage battery is charged or discharged too quickly? The battery could overheat and give off flammable gas or explode The voltage can become reversed The “memory effect” will reduce the capacity of the battery All of these choices are correct

55 RADIO FREQUENCY INTERFERENCE (RFI)
Getting more common place Can be amateur radio interfering with other devices OR Other devices interfering with amateur radio operation

56 Filters Very important and useful in resolving Radio Frequency Interference AC power line filters RF choke/common-mode ferrite filters

57 Direct Detection RF gets into devices and is turned into voltages that cause interference Common with phones Low pass filter at wired phone’s modular jack Chokes and ferrite on speaker cords

58 Overload “Fundamental Overload High Pass Filter at Receiver
Strong signal just gets in and interferes with electronics because of its strength High Pass Filter at Receiver Ferrite on device’s power cord Shielding at Receiver If tx & rx frequencies close – notch filter or resolution not possible

59 Harmonics & Spurious Emissions
Low Pass Filters on Transmitter Can be in-band interference and cannot be filtered out at receiver

60 Noise Sources Electrical equipment, lights, switches
Cracked or dirty insulators Ignition noise from engines Alternator whine Switching Power Supplies Computer, peripheral & network equipment

61 Unknown Signals Track with a radio when possible
Radio Direction Finding (RDF) Triangulation Get azimuth bearing from three or more locations Plot on map Interference where lines cross

62 Guidelines Make sure your station is in good working order
Make sure you do not interfere with anything in your home Take care of any devices in your home that cause interference

63 Guidelines Be diplomatic and good neighbor
Put yourself in the other person’s position Demonstrate where possible Get help from other hams

64 FCC Part 15 Rules FCC sanctioned unlicensed operation of certain low powered devices NIB to licensed services Must accept interference from licensed services and other Part 15 devices

65 T7B: Common transmitter and receiver problems; symptoms of overload and overdrive, distortion, interference, over and under modulation, RF feedback, off frequency signals; fading and noise; problems with digital communications interfaces T7B8 If a "Part 15" device in your neighbor’s home is causing harmful interference to your amateur station: Work with your neighbor to identify the offending device; Politely inform your neighbor about the rules that require him to stop using the device if it causes interference; Check your station and make sure it meets the standards of good amateur practice. A simple snap-on choke filter like this one can help resolve harmful interference problems on Part 15 devices. 65

66 T4A04 Where must a filter be installed to reduce harmonic emissions?
Between the transmitter and the antenna Between the receiver and the transmitter At the station power supply At the microphone

67 T4A05. What type of filter should be connected to a TV
T4A05 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? Low-pass filter High-pass filter Band-pass filter Band-reject filter

68 T4A09. Which would you use to reduce RF current
T4A09 Which would you use to reduce RF current flowing on the shield of an audio cable? Band-pass filter Low-pass filter Preamplifier Ferrite choke

69 T7B02. What is meant by fundamental overload in
T7B02 What is meant by fundamental overload in reference to a receiver? Too much voltage from the power supply Too much current from the power supply Interference caused by very strong signals Interference caused by turning the volume up too high

70 T7B03. Which of the following may be a cause of
T7B03 Which of the following may be a cause of radio frequency interference? Fundamental overload Harmonics Spurious emissions All of these choices are correct

71 T7B04. What is the most likely cause of
T7B04 What is the most likely cause of interference to a non-cordless telephone from a nearby transmitter? Harmonics from the transmitter The telephone is inadvertently acting as a radio receiver Poor station grounding Improper transmitter adjustment

72 T7B05. What is a logical first step when attempting
T7B05 What is a logical first step when attempting to cure a radio frequency interference problem in a nearby telephone? Install a low-pass filter at the transmitter Install a high-pass filter at the transmitter Install an RF filter at the telephone Improve station grounding

73 T7B06. What should you do first if someone tells
T7B06 What should you do first if someone tells you that your station’s transmissions are interfering with their radio or TV reception? Make sure that your station is functioning properly and that it does not cause interference to your own television Immediately turn off your transmitter and contact the nearest FCC office for assistance Tell them that your license gives you the right to transmit and nothing can be done to reduce the interference Continue operating normally because your equipment cannot possibly cause any interference

74 T7B07. Which of the following may be useful
T7B07 Which of the following may be useful in correcting a radio frequency interference problem? Snap-on ferrite chokes Low-pass and high-pass filters band-reject and band-pass filters All of these choices are correct

75 T7B08. What should you do if a "Part 15" device in
T7B08 What should you do if a "Part 15" device in your neighbor’s home is causing harmful interference to your amateur station? Work with your neighbor to identify the offending device Politely inform your neighbor about the rules that require him to stop using the device if it causes interference Check your station and make sure it meets the standards of good amateur practice All of these choices are correct

76 RF GROUNDING Electrical and RF ground not always same
Use short lengths of heavy cable or flat strap to ground all equipment to ground rod Flat Strap Is Best

77 RF GROUNDING Bad RF ground can result in RF current affecting sensitive audio or other equipment Can cause shock or RF burns RF feedback via microphone cable can distort your signal

78 RF GROUNDING

79 T4A08 Which type of conductor is best to use for RF grounding?
Round stranded wire Round copper-clad steel wire Twisted-pair cable Flat strap

80 T7B11. What is a symptom of RF feedback in a
T7B11 What is a symptom of RF feedback in a transmitter or transceiver? Excessive SWR at the antenna connection The transmitter will not stay on the desired frequency Reports of garbled, distorted, or unintelligible transmissions Frequent blowing of power supply fuses


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