Welcome to my self-made study guide for the Canadian amateur radio license exam, Basic qualification level. Questions and answers from the pool are here reformatted into statements. Future re-edits are likely. Download latest and greatest version from KY8D.NET/CA. I made this for me, and you get it free. Be aware that it comes with no guarantee. This version is dated July 30, 2022. No rights reserved. {{pause}} Topic: Regulations The Radiocommunication Act grants authority to make both regulations and standards. It also defines offenses and penalties. The Department that is responsible for the Radiocommunication Act is Innovation, Science and Economic Development, Canada (hereafter abbreviated I.S.E.D.) The "amateur radio service" is defined in radiocommunication regulations. Input power of 2 watts or more requires a certificate and call sign. The fee for taking examinations at an I.S.E.D. office is $20 per qualification. The fee for taking examinations with an accredited volunteer examiner is to be negotiated. No candidate may be accompanied by an interpreter. A candidate with disabilities, while not granted any exemptions, will be instead accommodated by way of oral (versus written) examination. There is no age limit to hold a Certificate. Nor any on nationality. The Basic examination must be passed before a Certificate is issued. Holders of a maritime certificate may be issued an Amateur Radio Operator Certificate. After Basic qualifications, Certificate holders may be examined for additional qualifications in any order. 5 word-per-minute Morse code qualification is available. The Basic Qualification is authorized to operate stations in the amateur service. Candidates must have a valid address in Canada. There is no fee for a Certificate. The Certificate itself is free and valid for life. Certificates must be retained at the station at the address provided. Notify "I.S.E.D." of an address change. Produce your certificate, or a copy thereof, to the inspector within 48 hours after the request Out of amateur band transmissions are prohibited. Transmitting "Mayday" to pretend an emergency is called false or deceptive signals. A person found guilty confronts a fine, not exceeding $5,000, or a prison term of one year, or both. The Minister will not suspend a Certificate without prior notice. A radio inspector may not enter a dwelling without the owner's consent and without a warrant. You may communicate with stations operated under similar authorizations. An amateur may not amplify a license-exempt transmitter outside of allocations. An operator transmitting unnecessary or offensive signals does violate accepted practice. Amateurs are authorized to operate only on amatuer bands, not on aeronautical, marine or land mobile frequencies. VHF and UHF FM radios may be programmed to the land mobile service if the radio is certified. An amateur may never broadcast to the general public. Never may false or deceptive signals be transmitted. New digital encoding techniques must be in the public domain. Secret transmissions are forbidden. Disallowed are all secret codes, encodings, ciphers, and procedural signals. Q signals, being non-secret, are allowed. Transmissions from the amateur service (the same as those of broadcasting stations) are public. All other transmissions are private and may not be either divulged or used. Providing information to a journalist is not an exception. Business-related communication is forbidden. Ensure that communications are limited to messages of a technical or personal nature. and when transmitting to a foreign country, kept to those of a technical nature or personal remarks of relative unimportance. Amateurs must also comply with the regulations of the ITU. Canada is in ITU Region 2. Australia, Japan, and Southeast Asia are in ITU Region 3. I.S.E.D. does not require amateurs to keep a logbook. An unmodulated carrier may be transmitted only for brief tests on frequencies below 30 MHz. Topic: Privileges Certificate holders may operate anywhere in Canada. One-way transmission allowed for beacon stations. Operators may install or operate at any location in Canada. Station owners may permit any person to operate under supervision of a Certificate holder. When two amateurs want to use the same frequency, both operators have an equal right. You need Basic plus Advanced qualifications for any of the following: to install a club station; install a repeater; install or operate equipment which is not professionally designed and commercially manufactured. You need Basic plus Advanced, or else Basic plus Morse qualifications to install equipment for other Certificate holders. Communication is permitted only with other amateur stations. Not even during relief operations following a disaster may an amateur operate outside amateur bands. An amateur station shall not demand or accept remuneration in any form. When a guest amateur operates another amateur's station, the lesser set of privileges are in force. In addition to passing the BASIC exam, you need the Morse code exam to use frequencies below 30 MHz. Certificate holders may operate radio controlled models on all frequencies above 30 MHz. A person having only Basic Qualification, despite having VHF privileges, still may not transmit into the VHF input of a repeater whose output is below 29.5 MHz. Topic: Responsibilities As a station owner you are responsible for proper operation in accordance with regulations. Stations must have a control operator, present in person at the control point, whenever the station is transmitting. Any qualified amateur chosen by the station owner may be the control operator. The station owner and control operator are jointly responsible for the proper operation. You may never deliberately interfere with another station's communications. Transmission that disturbs other communications, seriously degradeing, obstructing or repeatedly interrupting them, is called harmful interference. Where the amateur service is a secondary user of a frequency band, operators may not cause interference to primary users. 430 to 450 MHz (70 centimeters) is such a band. 902 to 928 MHz (33 centimeters) is another. The 902 to 928 MHz amateur band is heavily occupied by license-exempt devices. Amateurs are not protected from interference on this band. The 2300 to 2450 MHz Industrial Scientific Medical (ISM) band is heavily used by license exempt devices. Topic: Distress, Emergencies, and Disasters Transmit "SOS" or "MAYDAY" when in distress. By "distress" is meant a situation both life-threatening and immediate. Although not a test question, all should still know the emergency signal "Pan Pan". Life might still hang in the balance, but time is not yet of the essence. If adrift without power due to a fire in the engine room, a captain at sea will authorize calling just only "Pan Pan". Not until the fire is clearly out of control, the ship in immanent danger of sinking, will "SOS" then be transmitted. An airline captian will signal "Pan Pan" for one of two engines having gone out and failing to restart. "Mayday" will be held in reserve while the second engine still holds. Stations in distress may employ any means of radio-communication with no limitation on power. Distress messages have higher priority than emergency traffic. It is permissible to interfere with the working of another station if your station is directly involved with a distress situation. Hearing an unanswered distress signal on an amateur band where you do not have privileges, you should nevertheless offer assistance. If you hear distress traffic and are unable to render direct assistance, you should contact authorities and then maintain watch until you are certain that assistance will be forthcoming. While communicating with another amateur station and hearing a station in distress break in, acknowledge the station in distress and determine its location and what assistance may be needed. The proper way to interrupt a repeater conversation to signal a distress call is to break-in immediately following the transmission of the active party and state your situation and call sign. It is permissible to broadcast communications required for the immediate safety of life of individuals or the immediate protection of property. During a disaster, an amateur station may make transmissions necessary to meet essential communication needs and assist relief operations when normal communication systems are overloaded, damaged or disrupted. During a disaster most communications are handled by nets using predetermined frequencies. avoid transmission on or near those frequencies. Messages from recognized public service agencies may be handled by amateur radio stations during peace time and civil emergencies and exercises. It is a good idea to have a way to operate your amateur station without using commercial AC power line so you may provide communications in an emergency. The most important accessory to have for a hand-held radio in an emergency is several sets of charged batteries. Topic: Operating Practices Before transmitting, the first thing you should do is listen carefully. Stations must identify in English or French at least every thirty minutes, also at the beginning and at the end of a contact. Make your call sign better understood use the Standard International Phonetic Alphabet. When calling CQ, use a 3 by 3 format. Answer in CW, using 2 by 2 format. Answer in voice by saying their call sign then yours spelled phonetically. Local amateur communications should use VHF and UHF frequencies instead of HF frequencies to minimize interference on hf. Minimum separation for single sideband is approximately 3 kHz. A band plan is a guideline for using different operating modes. Example signal reports in voice mode: "5 by 7" means "the signal is "perfectly readable and moderately strong"; "3 3" means "readable with considerable difficulty and weak in strength"; "1 1" means "unreadable, and barely perceptible". If you get a signal report saying your signal is extremely strong and perfectly readable, turn down your power output to the minimum necessary. To keep from re-transmitting music, turn down the volume of background audio. On frequencies below 30 MHz, an unmodulated carrier may be transmitted only for brief tests. When operating on frequencies below 148 MHz, frequency stability must be comparable to crystal control. To tell if a band is "open", listen for signals from that area from an amateur beacon station or a foreign broadcast or television station on a nearby frequency. Before transmitting on any frequency, listen to make sure others are not using it. Use a dummy load during transmitter tune-up (especially any lengthy testing) to cut down on interference. If you are the net control station of a daily HF net, and the frequency on which you normally meet is in use just before the net begins you should call and ask occupants to relinquish it, but if they are not agreeable conduct the net 3 to 5 kHz away. If a net is about to begin on a frequency which you and another station are using, you should as a courtesy to the net, QSY elsewhere. If propagation changes and you notice increasing interference, you should move to another frequency. A "QSL card" is written proof of communication between two amateurs. An azimuthal map is a projection centered on a particular location. Azimuthal maps are the most useful type to use when orienting a directional HF antenna because it shows the compass bearing to any place on earth. 180 degrees is the long-path direction away from its short-path heading. When hearing other local stations talking to New Zealand but not New Zealand when pointed along the short path, point your beam 180 degrees away from that bearing and listen for the stations arriving on the "long-path". UTC means universal time coordinated. Set your clock to UTC from CHU, WWV or WWVH. Topic: Power Limitations Verify output power at the antenna connector of the transmitter or amplifier. Verify DC input power at the anode or collector circuit of the final RF stage. Power at the crest of the modulation envelope is peak envelope power, hereafter abbreviated P.E.P. Power limitations for Basic Qualification are 250 Watts DC input, 560 Watts P.E.P. for single sideband, or 190 Watts carrier power for other modes. Power limitations for Advanced Qualification are 1,000 Watts DC input, 2,250 Watts P.E.P. for single sideband, or 750 Watts carrier power for other modes. The maximum level of modulation permitted in radiotelephony is 100%. Increasing power output by four times, affords one S unit on the S-meter. Topic: Safety Health Canada has published safety guidelines for the maximum limits of RF energy near the human body. These are found in Safety Code 6. Info: Safety Code 6 protects against adverse health effects from exposure to all forms of radiofrequency EMF, no matter the source. It specifies exposure limits within, and reference limits outside of, the human body. Said limits are defined in terms of field strength, frequency, and proximity to living tissue. The code is not device specific. Nor are there any exclusions. The human body absorbs RF energy the most in the frequency range of 30 MHz to 300 MHz. The maximum safe power output to the antenna of a hand-held VHF or UHF radio is not specified. Permissible exposure levels to RF fields do not decrease below 10 MHz. The permissible exposure levels of RF fields increases, as frequency is increased from 300 MHz to 1.5 GHz. For safety, configure any antenna such that no one can come in contact with it. Before removing the shielding on a UHF power amplifier make sure the amplifier cannot accidentally be turned on. Exposure to a large amount of RF energy affects the body by heating tissue. Most likely to be damaged from the heating effects of RF radiation are the eyes. Depending on wavelength and energy density, RF energy heats body tissue. Directional high-gain antennas should be mounted higher than nearby structures so they will not direct RF energy toward people. For best RF safety, the ends and center of a dipole should be located as high as possible. As little as 20 milliamperes flowing through the human body can be fatal. The heart can be fatally affected by a very small amount of current. 30 volts is the minimum voltage usually dangerous to humans. Before checking a fault in a mains operated power supply unit, turn off the power and remove power plug. For best protection from electrical shock, all station equipment should be grounded. If you ground your station equipment to a ground rod, the shortest length used should conform to electrical code requirements. To avoid stray RF energy in your amateur station keep the ground wire as short as possible. The purpose of using a three-wire power cord and plug prevent the chassis from becoming live. Ground all antenna and rotator cables when your amateur station is not in use to help protect from lightning damage. Install a lightning arrestor on your antenna transmission line outside, as close to earth grounding as possible. To protect from lightning damage disconnect all equipment from the power lines and antenna cables. RF hot spots can occur above the ground floor when grounded by a long ground wire. Topic: Third Party Traffic No payment of any kind is allowed for third-party messages. Third party traffic is allowed only when authorized by both countries. It is therefor forbidden to communicate with another country when that country has notified the ITU that it objects to the communication. When allowing a non-amatuer to use your station, they constitute a third party. You must continuously monitor and supervise. Suppose that your non-amateur freind is talking to someone in Canada, and a foreign station breaks in to talk to your friend. You must have your friend wait until you determine from the foreign station whether their administration permits third-party traffic. International third party amateur radio communication in case of emergencies or disaster relief is expressly permitted unless specifically prohibited by the foreign administration. Traffic from C.F.A.R.S. or M.A.R.S. is not considered third-party. Topic: Antennas The Minister OF I.S.E.D. has authority over antenna installations. Amateurs planning to install or modify an antenna system must fulfill the public consultation requirements set out in i.s.e.d.c.'s default public consultation process unless the land use authority excludes their type of proposal from consultation or it is excluded by i.s.e.d.c.'s process. You may not be required to contact land use authorities when there is an exclusion criterion defined By I.S.E.D. The Default Public Consultation Process for antenna systems requires proponents to address reasonable and relevant concerns provided in writing within the 30 day public comment period. Participating in public meetings on the project is not an element of the I.S.E.D. public consultation process for antenna systems. Where a municipality has developed a public consultation process, public consultation may not be required when exclusions are listed in both CPC-2-0-03 and the local land use authority process. Where the proponent and a stakeholder other than the general public reach an impasse over a proposed antenna system the final decision will be made By I.S.E.D.. The municipality or local land use authority determines how public consultation should take place. In general, the tallest amateur radio antenna system excluded from the requirement to consult with the land use authority and the public is the taller of the height exclusion in the land use authority public consultation process and I.S.E.D.'s antenna siting procedures. A dipole antenna is a good choice for portable HF in case of an emergency. An SWR bridge is the most useful component for determining the effectiveness of the antenna system. An antenna is the component normally connected closest to the antenna, antenna tuner and dummy load. An antenna tuner is the component used to match impedances between the transceiver and antenna. Antenna tuners are usually used below 14 MHz. Topic: Bandwidths Maximum bandwidths on HF bands is 6 kHz with these exceptions: 60 meters 2.8 kHz, 30 meters 1 kHz, and 10 meters 20 kHz. Maximum bandwidth on the 6 and 2 meter bands is 30 kHz. As the bandwidth of fast-scan television (ATV) is 6 MHz, that is too wide for any band below 70 centimeters. Likewise forbidden due to bandwidth are voice modes on the 30 meter band, and voice modes other than single sideband on the 60 meter band. When transmitting near band edges ensure that the bandwidth required on either side of the carrier frequency does not fall out of band. The usual bandwidth of single sideband is between 2 and 3 kHz. The order of narrowest to widest bandwidth are the modes CW, RTTY, single sideband, double sideband and AM, lastly FM. The usual bandwidth of a FM signal for plus-or-minus 5 kHz deviation is between 10 and 20 kHz. FM phone isn't used below 28 MHz because bandwidth would exceed limits. Topic: Repeaters Be careful in choosing a simplex frequency when operating VHF or UHF FM so as to avoid repeater input frequencies. Consider switching to simplex when you can clearly receive the station on the input frequency. If operating simplex on a repeater frequency, it is good amateur practice to change to another frequency because changing the repeater is not practical. The main purpose of a repeater to increase the range of portable and mobile stations. To make contact on a repeater say their call sign, then your call sign. Frequency coordination on VHF and UHF bands is a process which seeks to carefully assign frequencies so as to minimize interference with neighbouring repeaters. The purpose of a repeater time-out timer is to interrupt lengthy transmissions without pauses. A CTCSS tone is a sub-audible tone that activates a receiver audio output. You should pause briefly between transmissions when using a repeater to listen for anyone else wanting to use the repeater. Keep transmissions short when using a repeater because someone with an emergency might need it. The proper way to join into a conversation on a repeater is to say your call sign during a break between transmissions. The accepted way to ask someone their location on a repeater is to say "Where are you?" The duplex split on 2-meter repeaters is 600 kHz. You should consider using simplex operation instead of a repeater when signals are reliable without using a repeater. Requests for a signal report on a local repeater means the other operator needs to know how well he is received by the repeater. Topic: CW Morse code is usually transmitted by radio as an interrupted carrier. An electronic key-er helps form good Morse code characters. Initiate Morse code CQ calls in 3x3 format at any speed which you can reliably receive. Answer CQ calls in 2x2 format. Minimum separation for CW is 150 to 500 Hz. "RST 5 7 9" in CW means perfectly readable, moderately strong, and perfect tone. "RST 4 5 9" in CW means quite readable, fair strength, and perfect tone. QRX means "I will call you again". Use 100 to 1100 Hz audio filters to copy CW, a 250 Hz filter for instance. Keep the power supply voltages very steady under transmit to avoid chirp. Topic: Single Sideband Use a 2.4 kHz filter for single sideband. Microphone gain control should be adjusted on single sideband for slight movement of the alc meter on modulation peaks. The purpose of a balanced modulator in single sideband is to suppress the carrier and pass on the two sidebands. In a single sideband transmission, the carrier is reinserted at the receiver. ALC in an single sideband transmitter controls the peak audio input so that the power amplifier is not over-driven. On single sideband, a properly adjusted speech processor improves signal intelligibility. If a single-sideband phone transmitter is 100% modulated, a speech processor will add nothing to the output peak. When operating single sideband, 10 MHz (30 meters) is frequency below which "lower" sideband is chosen; above which "upper" sideband is instead preferred. Topic: FM Voice FM voice is best for local VHF/UHF radio communications because it provides good signal plus noise to noise ratio at low RF signal levels. On FM with the microphone gain or deviation control set too high it may cause interference near its frequency. If you shout into your FM hand-held's microphone and the deviation adjustment is set too high it may cause interference to other stations operating near its frequency. If told your FM transceiver is over-deviating let the transceiver cool off. If the microphone fails on your FM transmitter, you emit an unmodulated carrier. Over-deviation in an FM transmitter produces out-of-channel emissions. Phase modulation is produced by a reactance modulator connected to an RF power amplifier. On 2 meters FM, if your transmission is loud and distorted the frequency deviation is set too high. With FM receivers, capture effect causes only the strongest signal to be heard. Topic: Digital Modes A digipeater is a station that re-transmits only data that is marked to be re-transmitted. In packet radio, "network" means a way of connecting packet-radio stations so data can be sent over long distances. In AX.25 packet-radio operation, the equipment that connects to a terminal-node controller is a transceiver, a computer and possibly a GPS receiver. In an AX.25 packet-radio link, "connected" means that a transmitting station is sending data to only one receiving station, it replies that the data is being received correctly. To modulate a 2 meter FM transceiver to produce packet-radio emissions you would connect a terminal-node controller to the transceiver's microphone input. For RTTY select a frequency 250 to 500 Hz away from any contacts in progress. Digital transmissions use signals called MARK AND SPACE to transmit the states 1 and 0. The term bow-doh does not apply to packet radio. In AMTOR there are two modes. Mode A uses Automatic Repeat Request (ARQ) protocol and is normally used for communications after contact has been established. With a digital communication mode based on a computer sound card, the result of feeding too much audio is splatter or out-of-channel emissions. Topic: Radio Wave Propagation Selective fading is caused by phase differences between portions of the same transmission as received. Selective fading is more pronounced at wide bandwidths. Reflection of a single-sideband transmission from the ionosphere causes a high-pitch squeal at the receiver. The ability of the ionosphere to reflect high frequency radio signals depends on the amount of solar radiation. All communication frequencies throughout the spectrum are affected in varying degrees By the sun. Solar radiation influences all radiocommunication beyond ground-wave or line-of-sight ranges. The more sunspots there are, the greater the ionization. When sunspot numbers are high, frequencies up to 40 MHz or even higher become usable for long-distance communication. The two types of radiation from the sun which influence propagation are electromagnetic and particle emissions. Solar flux results from radio energy emitted by the sun. The solar-flux index is a measure of solar activity that is taken at a specific frequency. Maximum usable frequency (MUF) means the highest frequency signal that will reach its intended destination. Signals above the critical frequency pass through the ionosphere. Below the MUF, radio waves are usually bent back to the earth by the ionosphere. The MUF varies because of the amount of radiation received from the sun, mainly ultraviolet. A transmitted signal higher than the MUF in frequency will not be received as a reflection from the ionosphere. Compared with the MUF, the optimum working frequency for longest range is usually slightly lower. One way to determine if the MUF supports 28 MHz propagation is to listen for 10-meter beacon stations. The 20 meter band usually supports worldwide propagation during daylight hours at any point in the solar cycle. The E region most affects skywave propagation on the 6 meter band. A sporadic-E condition is patches of dense ionization at E-region height. Extended propagation from sporadic-E is most often observed on the 6 meter band. 2000 km is the maximum distance covered in one hop via the E region. That portion of radiation kept close to the Earth's surface due to bending in the atmosphere is called the "tropospheric" wave. Tropospheric bending extends the range of VHF. Tropospheric ducting of radio waves is caused by a temperature inversion. Info: A term you'll hear next, "enhanced propagation mode", is an umbrella, which in relation to VHF, includes these four: "Sporadic E", "Aurora", "Ducting" and "Trans-Equitorial". So then... Excluding enhanced propagation modes, the approximate range of normal VHF tropospheric propagation is 800 KM. If given a list and asked to choose which effect is responsible for propagating a VHF signal beyond 800 km, choose "Tropospheric Ducting", it alone being one of the four. Also occurring at E-region height is "auroral" propagation. Point an antenna toward the nearest of Earth's axial poles to take maximum advantage of auroral propagation, choosing CW as the best emission mode. The unusual HF propagation allowing weak signals from the skip zone to be occasionally heard is scatter-mode. If hearing a weak, distorted signal from far away, at a frequency close to the MUF, that is scatter propagation. A characteristic of HF scatter signals is rapid flutter or hollow sounding distortion. What makes HF scatter signals often sound distorted is energy scattered into the skip zone through several radio-wave paths, with only a small part of the signal energy being scattered into the skip zone. Scatter propagation at HF is most likely involved when weak and distorted signals near or above the MUF can be heard over unusual paths. Plural modes of scatter propagation exist. Be alert to recognize "absorption scatter" and/or "inverted scatter" as non-existant, made-up fiction. Meteor scatter is most effective for extended-range communication from 30 to 100 MHz, the lower portion of VHF. VHF signals propagated within the range of the visible horizon by direct wave. The distance travelled by ground waves is less at higher frequencies The radio wave which follows a path from the transmitter to the ionosphere and back to Earth is known correctly as the ionospheric wave. Reception of high frequency (HF) radio waves beyond 4000 km is generally made possible by ionospheric wave. What causes the ionosphere to form is solar radiation ionizing the outer atmosphere. Ultraviolet radiation is most responsible for ionization in the outer atmosphere. The ionosphere is most ionized at midday and least ionized shortly before dawn. The D ionospheric region is closest to the Earth, and not at all useful for long distance propagation. The 160, 80 and 40 meter amateur bands tend to be useful only for short-distance communications during daylight hours because of D-region absorption. In daylight hours, signal absorption by the D region is what causes AM broadcast and 160 meter amateur stations to not be heard. During daytime in summer, the 160 and 80 meter bands are difficult beyond ground wave-distance, as any reflection from F2 will have passed through the D region twice. The F1 AND F2 sub-regions of the ionosphere exist only in the daytime. At night these two merge into one, called simply F. The F2 region is mainly responsible for the longest distance propagation because it is the highest ionospheric region. The maximum distance covered by a single hop via the F2 region is 4000 km. For a distance of 5000 km, multihop propagation is the most likely. A skip zone is an area which is too far away for groundwave, but too close for skywave. It is that zone between the end of the ground wave and the point where the first refracted wave returns to earth. Skip distance is the distance to where the sky wave returns to the Earth, the minimum distance reached by a signal after one reflection by the ionosphere. Skip distance is determined by the height of the ionosphere and the angle of radiation. It will be greatest when the angle between the ground and the radiation is smallest. Skip effects are due to reflection and refraction from the ionosphere. If the height of the ionosphere's reflecting layer increases, skip distance becomes greater. When a signal arrives by a one-hop and a two-hop skip path, small changes in the ionosphere can cause variations in signal strength. Parts of the radio wave may follow different paths resulting in phase differences at the receiver. This "change" at the receiver is called fading. This change or variation in signal strength at the antenna is caused by differences in path lengths. Ionospheric storms cause a fade-out of HF skywave signals. To continue HF communications during a sudden ionospheric disturbance try a higher band. Topic: Radio Frequency Interference Amateurs may not make trials or tests when there is a possibility of interfering.. Where interference is caused by an amateur station the Minister may require steps to prevent it. Splatter interference is caused by overmodulating a transmitter. A reliable means to prevent or indicate over-modulation must be employed if radiotelephony is used. A station using radiotelephony must install a device for indicating or preventing over-modulation On single sideband, splatter occurs when microphone gain is set too high, also when there is too much speech processing. Receiver overload is interference caused by strong signals from a nearby transmitter. One way to tell if RFI to a receiver is caused by front-end overload is when the interference is about the same no matter what frequency is used for the transmitter. Suppose a neighbour reports television interference whenever you transmit, no matter what band you use, the cause is probably receiver overload. A high-pass filter should be connected to a TV receiver as the first step in trying to prevent RF overload. During a club outing, if reception on the 20 meter single sideband station is compromised every time the 20 meter CW station is on the air, the cause is receiver desensitization. Intermodulation in a broadcast receiver by a nearby transmitter would be noticed in the receiver as the undesired signal in the background of the desired signal. Imagine you have connected your hand-held VHF transceiver to an outside gain antenna. You now hear a mixture of signals together with different modulation on your desired frequency. The nature of this interference is audio stage intermodulation. When two or more strong out-of-band signals mix in your receiver to produce interference on a desired frequency, this is called intermodulation interference. Two mobile stations are traveling along the same road in close proximity to each other and having trouble communicating through a local repeater. It will be necessary to use simplex operation to communicate between these because the strong signal of one mobile transmitter may desensitize the receiver of the other mobile receiver. A television receiver suffers interference on channel 5 at 76 to 82 MHz only when you transmit on 14 MHz. From your home you see the tower of a commercial FM station known to broadcast on 92.5 MHz. The solution to try first is insert a high pass filter at the antenna connector of the television. Intermodulation can be reduced by installing a suitable filter at the receiver. The devices would you install to reduce or eliminate audio-frequency interference to home entertainment systems are coils or ferrite cores. If a properly operating amateur station is the cause of interference to a nearby telephone, you should install a modular plug-in telephone RFI filter close to the telephone device. The sound heard from a public-address system if audio rectification of a nearby single-sideband phone transmission occurs is distorted speech from the transmitter's signals. The sound heard from a public-address system if audio rectification of a nearby CW transmission occurs is on-and-off humming or clicking. To minimize the possibility of audio rectification of your transmitter's signals, ensure that all station equipment is properly grounded. An amateur transmitter is being heard across the entire dial of a broadcast receiver. the receiver is most probably suffering from audio rectification in the receiver. Your single sideband hf transmissions are heard muffled on a sound system in the living room regardless of its volume setting. this is caused by audio rectification of strong signals. To minimize the effect of RF pickup by audio wires connected to stereo speakers, intercom amplifiers, telephones, etc, use a ferrite core. Stereo speaker leads often act as antennas to pick up RF signals. To minimize this effect shorten the leads. Wrap each of the speaker leads through a ferrite core. Stereo amplifiers often have long leads which pick up transmitted signals because they act as receiving antennas. If your transmitter sends signals outside the band where it is transmitting, this is called spurious emissions. If someone tells you that signals from your hand-held transceiver are interfering with other signals on a frequency near yours, it could be that your hand-held is transmitting spurious emissions. If your transmitter is operated without the cover and other shielding in place it may radiate spurious emissions. Key-clicks heard as broad band RF interference by a distant receiver are the result of poor wave shaping (overly sharp rise and decay times) of the keyed carrier. Key clicks can be heard also as local RFI produced by the making and breaking of the circuit at the Morse key. If you learn your transmitter is producing key clicks, you should check the keying filter and the functioning of later stages. Try installing an external key-click filter. A parasitic oscillation is an unwanted signal developed in a transmitter, often generated in its RF amplifiers at frequencies above or below the transmitter frequency. By "harmonic radiation" is meant unwanted signals at frequencies which are multiples of the fundamental (chosen) frequency. Harmonic radiation is unwanted because it may cause interference and may result in out-of-band signals. Multi-band antennas radiate harmonics more readily than do single-band antennas. If you are told your station was heard on 21,375 kHz, but at the time you were operating on 7125 kHz, one reason this could happen is your transmitter was radiating harmonic signals. In a transmitter, excessive harmonics are produced by overdriven stages. Excessively driving an RF power amplfier might be the cause. Likewise a single sideband transmitter whose microphone gain is too high. This is called "flat topping" since the sine waves are clipped flat at their tops. Remedy this by reducing microphone gain and/or the output of the transmitter feeding into the power amplifier. A 2nd harmonic from any part of the 10 meter band interferes with TV Channel 2 at 54 to 60MHz. A 3rd harmonic from any part of the 15 meter band interferes with TV Channel 3 at 60 to 66MHz. To reduce harmonic radiation connect a low pass filter. Modern HF transmitters have one built-in. An external low pass filter will be most effective when located as close as possible to the transmitter or amplifier output. In designing an HF station, include a low pass filter to reduce harmonic output. It should frequencies above 30 MHz. A low pass filter should have about the same impedance as that of the transmission line into which it is inserted. To keep HF frequencies out of a TV set, place a high pass filter as close to the TV input as possible. Not a question itself, but important to know with respect to actual questions is that the acronym EMCAB stands for "Electromagnetic Compatibility Advisory Bulletins". In particular, EMCAB-2 is titled "Criteria for Resolution of Immunity Complaints Involving Fundamental Emissions of Radio Communications Transmitters". EMCAB 2 defines "radio-sensitive equipment" as, "any device, machinery or equipment, other than radio apparatus, the use or functioning of which is, or can be, adversely affected by radio-communication emissions". According to EMCAB 2, in the case of a neighbour's equipment malfunctioning due to an amateur's transmitted signal the question as to which side of the complaint is at faut will hinge upon field strength on the premises. It will be either above or below the I.S.E.D.s specified immunity level. According to EMCAB 2, broadcast transmitters are not included in the list of field strength criteria for resolution of immunity complaints. Topic: Frequency Bands To correlate frequency to wavelength in meters, divide 300 by MHz. Going the other way, to find MHz, divide 300 by the wavelength in meters. A tidy example is 10 MHz, which works out quite neatly to a wavelength of 30 meters. In general, though, bands are named for the nearest convenient round number. Which might be quite close, but only at one end of the band, but the other end not so much. Thus 160 meters ranges from 1.8 to 2 MHz 80 slash 75 meters 3.5 to 4 40 meters 7 to 7.3 30 meters 10.1 to 10.15 20 meters 14 to 14.35 15 meters 21 to 21.45 10 meters 28 to 29.7 6 meters 50 to 54 2 meters 144 to 148 MHz, and so on. Topic: Equipment Transmitting equipment must have a reliable means of determining the operating frequency Below I list the order of sub-components for various equipment: In a CW transmitter: master oscillator, driver/buffer, power amplifier, antenna. In a single sideband transmitter: microphone, speech amplifier, balanced modulator with local oscillator, filter, mixer with VFO, linear amplifier, antenna. In single sideband and CW receivers: antenna, RF amplifier, mixer with local oscillator, filter, I F amplifier, product detector with BFO, AF amplifier, speaker. In an FM transmitter: microphone, speech amplifier, modulator, oscillator, frequency multiplier, power amplifier, antenna. In an FM receiver: antenna, RF amplifier, mixer with local oscillator, filter, I F amplifier, limiter, discriminator, AF amplifier, speaker. In a digital system: transceiver, modem, computer, sound card, back to transceiver. In a regulated power supply: input, transformer, rectifier, filter, regulator, output. In a receiver's specifications which indicates its sensitivity is RF input signal needed to achieve a given signal plus noise to noise ratio. A less sensitive receiver will produce less signal or more noise. The mode of transmission usually detected with a product detector is single sideband with suppressed carrier. A receiver designed for single sideband reception must have a BFO (beat frequency oscillator) because the suppressed carrier must be replaced for detection. To attenuate an interfering carrier signal while receiving an single sideband transmission employ a notch filter. The three main parameters qualifying a receiver are: sensitivity, selectivity and stability. A VFO-controlled CW transmitter has a variable-frequency oscillator connected to a buffer/driver and a power amplifier. A voltmeter usually connected to a circuit under test in phase with the circuit. Use a DC ammeter to measure the power supply current drawn by a small hand-held transistorized receiver. When measuring current drawn from a DC power supply, it is true to say that the meter will act in circuit as a low value resistance. An RF oscillator should be electrically and mechanically stable to ensure that the oscillator does not drift in frequency. The input power to the final stage is higher than output power, a portion has been dissipated as heat loss. The difference between DC input power and RF output power appears as heat dissipation. In single sideband, the filter circuit processes signals from the balanced modulator and sends to the mixer. One advantage of carrier suppression in a double-sideband phone transmission is more power can be put into the sidebands for a given power amplifier capacity. An overmodulated single or double sideband transmitter becomes distorted and occupies more bandwidth. When switching from receive to transmit the receiver should be muted. A switching system to enable the use of one antenna for a transmitter and receiver should also disable the unit not being used. An antenna changeover switch in a transmitter-receiver combination is necessary so that one antenna can be used for transmitter and receiver. A loudspeaker could be used as a dynamic microphone.. A storage cell can be repeatedly recharged. If your mobile transceiver works in your car but not in your home, first check the power supply. Power-line voltages supplied to homes are approximately 120 and 240 volts. Your mobile HF transceiver draws 22 amperes on transmit. The manufacturer suggests limiting voltage drop to 0.5 volt and the vehicle battery is 3 meters away. Given the losses listed at that current, use number 10, having only 0.07 Volts per meter. Use a key-operated on-and-off switch in the main power line to best keep unauthorized persons from using your station at home. Disconnect the microphone to best keep unauthorized persons from using a mobile amateur station. When working on an antenna tower, wear approved equipment in accordance with applicable standards concerning fall protection. If an amplifier becomes non-linear, the output signal would become distorted. The range of a speech amplifier is typically 300 to 3000 Hz. One important application for diodes is recovering information from transmitted signals. This is called "demodulation". Comparing a bipolar transistor to a triode: emitter, base, and collector correspond to cathode, grid, and plate. Comparing an FET to a bipolar transtor: source, gate, and drain correspond to emitter, base, and collector. In a field effect transistor (FET) source is where the charge carriers enter the channel gate controls channel conductance drain is where the charge carriers leave the channel The source and drain of an FET exhibit fairly similar characteristics. To reduce the current flowing in an FET, increase the reverse bias voltage. A triode vacuum tube might be used instead of a transistor when it may be able to handle higher power. A vacuum tube can amplify a small signal but must use high voltages. In a vacuum tube, the element that is furthest away from the plate is the filament. If a carbon resistor's temperature is increased, what happens will depend on the resistor's temperature coefficient. A resistor's wattage rating is by physical size and tolerance. Topic: Antennas and Transmission Line A mismatched antenna or transmission line presenting an incorrect load to the transmitter results in full power not transferred to the antenna. At the end of suspended antenna wire, insulators are used to limit the electrical length of the antenna A parasitic beam antenna is where some elements obtain their radio energy by induction or radiation from a driven element. The bandwidth of a parasitic beam antenna may be increased by use of larger diameter elements. A halfwave dipole has 2.1 dB gain over an isotropic radiator. By "antenna gain" is meant the numerical ratio relating the radiated signal strength of an antenna to that of another antenna. By "antenna bandwidth" is meant the frequency range over which the antenna may be expected to perform well. The gain of an antenna, especially on VHF and above, is quoted in dB eye. The "i" in this expression stands for isotropic. If you made a quarter-wavelength vertical antenna for 21.125 MHz, it would measure 3.36 meters. If you made a half-wavelength vertical antenna for 223 MHz, it would measure 67 centimeters. A 5/8-wavelength vertical antenna is better than a 1/4-wavelength vertical antenna for VHF or UHF because it has more gain. Downward sloping radials on a ground plane antenna bring the feed point impedance closer to 50 ohms. The feed point impedance of a ground-plane antenna increases when its radials are changed from horizontal to downward sloping. A loading is coil often used with an HF mobile vertical antenna to tune out capacitive reactance. The main reason why so many VHF base and mobile antennas are 5/8 of a wavelength is that the angle of radiation is low. In calculating the elements of a Yagi antenna, the driven element is one half wavelength, the reflector is 5% longer and the director 5% shorter. One effect of increasing the boom length and adding directors to a Yagi antenna is that gain increases. Some advantages of a Yagi with wide element spacing are high gain, less critical tuning and wider bandwidth. A Yagi antenna is often used for radiocommunications on the 20 meter band because it helps reduce interference from other stations off to the side or behind. The spacing between the elements on a three-element Yagi antenna, representing the best overall choice, is 0.2 wavelength. Stacking two Yagi antennas affords a further 3 dB. For the length of a dipole antennas, divide 143 by MHz. One disadvantage of a random wire antenna you may experience RF feedback in your station. The low angle radiation pattern of an ideal half-wavelength dipole HF antenna in free space installed parallel to the earth is a figure-eight, perpendicular to the antenna. A disadvantage of using an antenna equipped with traps is that it may radiate harmonics more readily. For the total length of the driven element for a cubical quad or delta loop, divide 303 by MHz. Two-element delta loop and quad antennas compare favourably with a three-element yagi. Compared to a dipole antenna the quad has more directivity in both horizontal and vertical planes. Polarization of the receiving antenna on HF bands is relatively unimportant because the ionosphere can change the polarization of the signal from moment to moment. A resonant antenna having a feed point impedance of 200 ohms is connected to a transmission line which has an impedance of 50 ohms will have an SWR of 4 to 1. Horizontal polarization refers to the electric lines of force being parallel to the earth's surface. Vertical polarization means they are perpendicular. The wavelength corresponding to 2 MHz is 150 meters. Note that the term "parabolic interaction" has nothing whatsoever to do with changes in polarization.The characteristic impedance of a coaxial line can be the same for different diameter line. The characteristic impedance of a transmission line is equal to the pure resistance which, if connected to the end of the line, will absorb all the power arriving along it. A transmission line differs from an ordinary circuit or network owing to propagation delay. The characteristic impedance of a parallel wire transmission line does not depend on the velocity of energy on the line. If the impedance terminating a transmission line differs significantly from the characteristic impedance of the line, the input will have some value of impedance influenced by line length. Factors determining the characteristic impedance of a parallel-conductor antenna transmission line are the distance between the centres of the conductors and the radius of the conductors. A factor determining the characteristic impedance of a coaxial antenna transmission line is the ratio of the of the inner conductor's diameter to that of the outer shield. Coaxial cable makes a good antenna transmission line because it is weatherproof, and its impedance matches most amateur antennas. Reasons not to use parallel conductor transmission line are that it does not work well when tied down to metal objects, and you should use a balun and may have to use an impedance-matching device with your transceiver. A PL-259 connector usually joins RG-213 coaxial cable to an HF transceiver. An SMA connector usually joins a hand-held transceiver to its antenna. A type N connector has the lowest loss at UHF. You should regularly clean and tighten all antenna connectors to help keep their contact resistance at a minimum. An SWR reading of less than 1.5 to 1 means a fairly good impedance match. A jumpy SWR reading may mean poor electrical contact between parts of an antenna system. SWR means the ratio of maximum to minimum voltages on a transmission line. Hot transmission line might this mean the SWR may be too high, or the transmission line loss may be high. Standing waves on a transmission line reduce transfer of RF energy to the antenna. A slight mismatch between the power amplifier and the antenna reduces radiation. Topic: General Theory The unit "decibel" is used to indicate a mathematical ratio. Said ratio is geometric, not linear. Conveniently, though, 10 dB signifies a ten-fold change in power: either ten times more, or one tenth as much. So, if given a signal report of 20 dB or 10 dB above S9, and told power is then reduced to one tenth, the signal report then would be 10 dB over S9 or just S9. The same thing in reverse would be if power went up from 5 Watts to 50 WattF15s, that would be a change of exactly 10 dB. Or they might ask the same thing backwards, tasking you to reduce the signal report of a 100 Watt transmission from 30 dB above S9 down to just only S9. To lose those excess 30 dB you simply perform a 10 dB (or ten-fold) reduction three times in succession. Starting out at 100 Watts, you pull it down to 10 Watts, then to 1 Watt, and finally to 100 mW, which is the answer. But as decibels are geometric instead of linear, a change of only 3 dB is not 30% of 10 dB. Rather it is very near (but not quite exactly) the same as double or half the original power. Call it a factor of two. So if asked to calculate the output of an amplifier having 9 dB gain, that is 3 dB three times in succession. So, whatever might be the input, double it three times in succession. Given 2 Watts as input, you go from there to 4 Watts, then to 8 Watts, and finally to 16 watts as the output. Here too they might ask the same thing backwards. If told your amplifier takes those same 2 Watts as input, giving 8 Watts of output, it got there by doubling twice in succession. The same as saying 3 dB twice in succession, or 6 dB total. The inductance of a coil is determined by the core material, diameter, length and number of turns. Capacitance is determined by material between the plates, surface area, number of plates, and the spacing between. You have three series wired 15 uF capacitors. Since they are equal, you can simply divide by three with the result of 5 uF. Whether equal or not, you can calculate like so. Invert the value of each, sum those inversions together, then invert the sum. In like manner, to replace a faulty 10uF capacitor, you could wire a pair of 20uF capacitors in series. When wired in series, total capacitance is always less than that of the smallest capacitor. if instead wired in parallel, simply sum the values together. An RF choke coil blocks RF while passing AF owing to reactance that's high for one, low for the other. A coil wound on a ferrite core is effectively an RF choke. An RF bypass capacitor to divert RFI with little effecton AF owing to reactance that's low for one, high for the other frequencies. If no load is attached to the secondary winding of a transformer, the current in the primary winding is called magnetizing current. Suppose a transformer operates a 6.3 volt light bulb drawing 2 amperes from its secondary winding. The input power to the primary winding works out to 6.3 * 2 = 12.6 Watts. The test rounds that up to 13 Watts. At a guess I assume they are writing off 400 milliwatts wasted as heat in warming the iron laminants, maybe? A transformer has a 240 volt primary that draws a current of 250 milliamperes. Assuming no losses and only one secondary, calculate current available from the 12 volt secondary. Start with 250 divided by 12, which equals 20. A ratio then, of 20 to 1. As voltage went down by 1 in 20, current goes up by a factor of 20. Thus, 250 mA into the primary gives 5 amperes out of the secondary. The primary winding has 250 turns, and the secondary has 500. If the input voltage is 120 volts, the likely secondary voltage is 240V since 500 over 250 = 2. The strength of the magnetic field around a conductor in air is directly proportional to the current in the conductor. Maximum induced voltage in a coil occurs when current is going through its greatest rate of change. The voltage induced in a conductor moving in a magnetic field is at a maximum when the movement is perpendicular to the lines of force. A 100% efficient transformer has a turns ratio of 1 to 5. If the secondary current is 50 milliamperes, the primary current is 0.25A. The fact that energy transfer from primary to secondary windings in a power transformer is not perfect is indicated by warm iron laminations. Resonance is the condition that exists when inductive reactance and capacitive reactance are equal. Parallel tuned circuits offer high impedance at resonance. Resonance is an electrical property used to describe the frequency characteristic of a coil and capacitor circuit. When a series LCR circuit is tuned to the frequency of the source, line current reaches maximum. This study guide was compiled ad-hoc by yours truly, KY8D. I made this for me, and you got it free. Remember it came with no guarantee. No rights reserved. So do with it whatever you please.