Presentation on theme: "Chapter 1 Welcome to Amateur Radio. What is Amateur Radio? Amateur (or Ham) Radio is a personal radio service authorized by the Federal Communications."— Presentation transcript:
Chapter 1 Welcome to Amateur Radio
What is Amateur Radio? Amateur (or Ham) Radio is a personal radio service authorized by the Federal Communications Commission (FCC). To encourage the advancement of the art and science of radio. To promote the development of an emergency communication capability to assist communities when needed. To develop a pool of trained radio operators. To promote international good will by connecting private citizens in countries around the globe. Through ham radio, you will become an ambassador for your community and your country.
What Do Hams Do? Communicate Participate Experiment Build Compete Serve their communities Life-long learning
What Makes Ham Radio Different? There are many unlicensed radio services available. Ham radio is authorized: Fewer restrictions. More frequencies (channels or bands to utilize). More power (to improve range and quality). More ways to communicate. Its free to operate your radio.
With More Privileges Comes More Responsibility Because ham radios are much more capable and have the potential of interfering with other radio services. Because ham radios have unlimited reach. They easily reach around the globe and into space. FCC authorization is required to ensure the operator is qualified to operate the ham radio safely, appropriately and within the rules and regulation – that is why you are here.
Steps to Obtaining Your Ticket Study the material in the Ham Radio License Manual. Review the questions in the back of the book Take interactive practice exams. Pass a 35-question multiple choice test. Questions pulled directly from the question pool. Need to answer 26 questions correctly. No Morse code is required
T1A01 -- For whom is the Amateur Radio Service intended? A.Persons who have messages to broadcast to the public B.Persons who need communications for the activities of their immediate family members, relatives and friends C.Persons who need two-way communications for personal reasons D.Persons who are interested in radio technique solely with a personal aim and without pecuniary interest
T1A10 -- What is the FCC Part 97 definition of an amateur station? A.A station in an Amateur Radio Service consisting of apparatus necessary for carrying out radio communications B.A building where Amateur Radio receivers, transmitters, and RF power amplifiers are installed CAn radio station operated by a non- professional D.Any radio station for hobby use
T1A02 -- What agency regulates and enforces the rules for the Amateur Radio service in the United States? A.FEMA B.The ITU C.The FCC D.Homeland Security
Chapter 2 Radio Signals & Fundamentals
The Basic Radio Station
What Happens During Radio Communication? Transmitting (sending a signal): Information (voice, data, video, commands, etc.) is converted to electronic form. The information in electronic form is attached or embedded on a radio wave (a carrier). The radio wave is sent out from the station antenna into space.
What Happens During Radio Communication? Receiving end: The radio wave (carrier) with the information is intercepted by the receiving station antenna. The receiver extracts the information from the radio wave. The information is then presented to the user in a format that can be understood (sound, picture, words on a computer screen, response to a command).
What Happens During Radio Communication? This sounds pretty simple, but it in reality is pretty complex. This complexity is one thing that makes ham radio fun…learning all about how radios work. Dont be intimidated. You will be required to only know the basics, but you can learn as much about the art and science of radio as you want.
Radio Waves are AC Radio waves (electromagnetic radiation) are AC waves. Radio waves are used to carry the information you want to convey to someone else.
Wave Vocabulary Before we study radio waves, we need to learn some wave vocabulary. Amplitude Frequency Period Wavelength Harmonics
How Radio Waves Travel Moving electrons in the antenna create a magnetic field. This changing magnetic field creates an electric field. Then back and forth between magnetic and electric fields from point A to point B.
Finding Where You are on the Radio Dial There are two ways to tell someone where to meet you on the radio dial (spectrum). Band Frequency
Radio Frequency (RF) Spectrum The RF spectrum is the range of wave frequencies which will leave an antenna and travel through space. The RF spectrum is divided into segments of frequencies that basically have unique behavior.
Radio Frequency (RF) Spectrum
Wavelength The distance a radio wave travels during one cycle. One complete change between magnetic and electric fields.
Wavelength 300 f MHz λmλm Frequency (MHz) = 300 / Wavelength (meters) Wavelength (meters) = 300 / Frequency (MHz)
T3B01 -- What is the name for the distance a radio wave travels during one complete cycle? A.Wave speed B.Waveform C.Wavelength D.Wave spread
T3B04 -- How fast does a radio wave travel through free space? A.At the speed of light B.At the speed of sound C.Its speed is inversely proportional to its wavelength D.Its speed increases as the frequency increases
T3B05 -- How does the wavelength of a radio wave relate to its frequency? A.The wavelength gets longer as the frequency increases B.The wavelength gets shorter as the frequency increases C.There is no relationship between wavelength and frequency D.The wavelength depends on the bandwidth of the signal
T3B06 -- What is the formula for converting frequency to wavelength in meters? A.Wavelength in meters equals frequency in hertz multiplied by 300 B.Wavelength in meters equals frequency in hertz divided by 300 C.Wavelength in meters equals frequency in megahertz divided by 300 D.Wavelength in meters equals 300 divided by frequency in megahertz
T3B07 -- What property of radio waves is often used to identify the different frequency bands? A.The approximate wavelength B.The magnetic intensity of waves C.The time it takes for waves to travel one mile D.The voltage standing wave ratio of waves
T3B08 -- What are the frequency limits of the VHF spectrum? A.30 to 300 kHz B.30 to 300 MHz C300 to 3000 kHz D.300 to 3000 MHz
T3B09 -- What are the frequency limits of the UHF spectrum? A.30 to 300 kHz B.30 to 300 MHz C300 to 3000 kHz D.300 to 3000 MHz
T3B10 -- What frequency range is referred to as HF? A.300 to 3000 MHz B.30 to 300 MHz C.3 to 30 MHz D.300 to 3000 kHz
T3B11 -- What is the approximate velocity of a radio wave as it travels through free space? A.3000 kilometers per second B.300,000,000 meters per second C.300,000 miles per hour D.186,000 miles per hour
T5C05 -- What is the unit of frequency? A.Hertz B.Henry C.Farad D.Tesla
T5C06 -- What is the abbreviation that refers to radio frequency signals of all types? A.AF B.HF C.RF D.VHF
So, Where Am I? Bands identify the segment of the spectrum where you will operate. Wavelength is used to identify the band. Frequencies identify specifically where you are within the band.
Another Use for Frequency and Wavelength For the station antenna to efficiently send the radio wave out into space, the antenna must be designed for the specific operating frequency. The antenna length needs to closely match the wavelength of the frequency to be used. Any mismatch between antenna length and frequency wavelength will result in radio frequency energy being reflected back to the transmitter, not radiated into space.
Adding Information - Modulation When we imprint some information on the radio wave, we modulate the wave. Turn the wave on and off Voice -- AM and FM Data Different modulation techniques are called modes.
CW - Morse Code – On and Off
Amplitude Modulation (AM) In AM, the amplitude of the carrier wave is modified in step with the waveform of the information (voice).
Characteristics of AM AM signals consist of three components: Carrier Lower sideband Upper sideband Voice bandwidth is from 300 Hz to 3 kHz. AM bandwidth is twice the voice bandwidth.
Characteristics of AM Sound waves that make up your voice are a complex mixture of multiple frequencies. When this complex mixture is embedded on a carrier, two sidebands are created that are mirror images.
Characteristics of AM 50% 25%
Single Sideband Modulation (SSB) Since voice is made up of identical mirror image sidebands: We can improve efficiency of transmission by transmitting only one sideband and then reconstruct the missing sideband at the receiver.
Frequency Modulation (FM) Instead of varying amplitude, if we vary the frequency in step with the information waveform, FM is produced. FM signals are much more resistant to the effects of noise but require more bandwidth. FM bandwidth (for voice) is between 5 and 15 kHz.
T1B09 -- Why should you not set your transmit frequency to be exactly at the edge of an amateur band or sub-band? A.To allow for calibration error in the transmitter frequency display B.So that modulation sidebands do not extend beyond the band edge C.To allow for transmitter frequency drift D.All of these choices are correct
T2B05 -- What determines the amount of deviation of an FM signal? A.Both the frequency and amplitude of the modulating signal B.The frequency of the modulating signal C.The amplitude of the modulating signal D.The relative phase of the modulating signal and the carrier
T2B06 -- What happens when the deviation of an FM transmitter is increased? A.Its signal occupies more bandwidth B.Its output power increases C.Its output power and bandwidth increases D.Asymmetric modulation occurs
T8A01 -- Which of the following is a form of amplitude modulation? A.Spread-spectrum B.Packet radio C.Single sideband D.Phase shift keying
T8A02 -- What type of modulation is most commonly used for VHF packet radio transmission? A.FM B.SSB C.AM D.Spread Spectrum
T8A03 -- Which type of voice modulation is most often used for long-distance or weak signal contacts on the VHF and UHF bands? A.FM B.AM C.SSB D.PM
T8A04 -- Which type of modulation is most commonly used for VHF and UHF voice repeaters? A.AM B.SSB C.PSK D.FM
T8A05 -- Which of the following types of emission has the narrowest bandwidth? A.FM voice B.SSB voice C.CW D.Slow-scan TV
T8A06 -- Which sideband is normally used for 10 meter HF, VHF and UHF single- sideband communications? A.Upper sideband B.Lower sideband C.Suppressed sideband D.Inverted sideband
T8A07 -- What is the primary advantage of single sideband over FM for voice transmissions? A.SSB signals are easier to tune B.SSB signals are less susceptible to interference C.SSB signals have narrower bandwidth D.All of the choices are correct
T8A08 -- What is the approximate bandwidth of a single sideband voice signal? A.1 kHz B.3 kHz C.6 kHz D.15 kHz
T8A09 -- What is the approximate bandwidth of a VHF repeater FM phone signal? A.Less than 500 Hz B.About 150 kHz C.Between 5 and 15 kHz D.Between 50 and 125 kHz
T8A10 -- What is the typical bandwidth of analog fast-scan TV transmissions on the 70 cm band? A.More than 10 MHz B.About 6 MHz C.About 3 MHz D.About 1 MHz
T8A11 -- What is the approximate maximum bandwidth required to transmit a CW signal? A.2.4 kHz B.150 Hz C.1000 Hz D.15 kHz
The Basic Radio Station
Basic Station Organization Station Equipment Receiver Transmitter Antenna Power Supply Accessory Station Equipment Repeaters
Special Stations You Will Use (Repeaters) Repeaters are automated stations located at high places that receive and then retransmit your signal simultaneously. Dramatically improves range. The basic components of a repeater are the same as your station: receiver, transmitter, antenna and power supply.
Repeaters Repeaters are transmitting and receiving at the same time often using the same antenna. This requires a very high quality and specialized filter to prevent the transmitted signal from overpowering the receiver. This filter is called a duplexer.
Basic Station Accessories Human interface accessories: Microphones Speakers Earphones Computer Morse code key TV camera etc. Station performance accessories: Antenna tuner SWR meter Amplifier Antenna rotator Filters etc.
T1F09 -- What type of amateur station simultaneously retransmits the signal of another amateur station on a different channel or channels? A.Beacon station B.Earth station C.Repeater station D.Message forwarding station
T4A02 -- What could be used in place of a regular speaker to help you copy signals in a noisy area? A.A video display B.A low pass filter C.A set of headphones D.A boom microphone
T7A07 -- If Figure T5 represents a transceiver in which block 1 is the transmitter portion and block 3 is the receiver portion, what is the function of block 2? A.A balanced modulator B.A transmit-receive switch C.A power amplifier D.A high-pass filter
Next Session Chapter 3 Electricity, Components and Circuits