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Technician Licensing Class These Power Point presentations are available to individuals who register with The W5YI Group’s HamInstructor.com program. The presentations are provided by Master Publishing and The W5YI Group and include material that is covered by U.S. and International copyrights. They are intended solely for the use of Registered Instructors using the Gordon West, WB6NOA, Technician Class, General Class, and Extra Class study manuals to teach FCC Amateur Radio Licensing Classes. Registration through HamInstructor.com constitutes a Licensing Agreement between The W5YI Group and the registered instructor under which the instructor agrees not to copy or distribute the Power Point presentations to unauthorized users. 1 Technician Licensing Class Picture This! Valid July 1, 2014 Through June 30, 2018 2 Amateur Radio Technician Class Element 2 Course Presentation ELEMENT 2 SUB-ELEMENTS (Groupings) • • • • • • • • • • About Ham Radio Call Signs Control Mind the Rules Tech Frequencies Your First Radio Going On The Air! Repeaters Emergency! Weak Signal Propagation 3 Amateur Radio Technician Class Element 2 Course Presentation ELEMENT 2 SUB-ELEMENTS (Groupings) • Talk to Outer Space! • Your Computer Goes Ham Digital! • Multi-Mode Radio Excitement • Run Some Interference Protection • Electrons – Go With the Flow! • It’s the Law, per Mr. Ohm! Picture This! • Antennas • Feed Me With Some Good Coax! • Safety First! 4 Picture This! • T6C01 As a new Technician Class operator, you should be familiar with the identification of simple schematic diagram illustrations. In the next few questions, we’ll take a look at some schematic diagrams with symbols that you should know. We will home in on identifying individual symbols in the schematic diagrams for your exam. Don’t panic! It’s easy. • T6C12 Now, let’s check ourselves. The symbols on an electrical circuit schematic diagram represent electrical components. 5 Picture This! • T6C13 Schematic diagrams allow us to see exactly how components are interconnected, right down to each and every lead. • T6C10 Oh good, another figure – component #3 doesn’t have a squiggly line like a resistor, but rather a coil type line, so it is a variable inductor. It is variable because we see tap points on the hump lines and a line with an arrow indicating the inductor can be adjusted to any one of the taps. 6 Picture This! • T6C11 Component #4 looks like it – an antenna! That antenna is tuned by some of the preceding circuit components. 7 Picture This! • T6D08 We use series and parallel coils and capacitors to develop a tuned circuit inside your new radio. Another name for a coil is an inductor, and when used with a capacitor you now have a tuned circuit. 8 Picture This! 9 Picture This! • T6D11 A resonant circuit must contain at least one inductor and one capacitor. It also may have other components. The resonant frequency of the tuned circuit is the frequency at which the inductive reactance and the capacitive reactance are equal. It is one of the most crucial circuits in all of radio. Resonant circuits of one form or another determine the frequency of operation of all radio devices. 10 Picture This! • T6C02 This figure will be found on your actual Technician Class exam sheet – either with the question or on the last page of your examination materials. Component #1, that squiggly line, is a resistor. Can you imagine current flowing through all the squiggles offering resistance? 3 2 1 4 5 Figure T1 11 Picture This! • T6C03 Component #2 is our friendly transistor. The arrow is NOT pointing in, so it is an NPN transistor. 3 2 1 4 5 • T6D10 Component #2 is a NPN transistor, and this one controls the flow of current, much like a valve. 12 Picture This! • T6C04 Component #3 looks just like what it is – a small indicator lamp. Looks like a lamp, doesn’t it? 3 2 1 5 4 Figure T1 • T6C05 It takes voltage to make this circuit work, and we get the voltage from the battery, component #4. 13 Picture This! • T6D03 Your handheld may have one of these – a single-pole, single-throw switch. It is single in both senses because you see only one wire going to the switch, and only one single contact point. Single pole-single throw. 2 3 9 5 4 7 1 6 10 8 14 Picture This! T6C09 Component #4 takes in everything around it, and is a transformer. Voltage is passed from the windings on the left, to the windings on the right, with the two vertical lines representing an iron core. This transformer looks to have about the same number of turns on the primary and secondary, so the amount of voltage going in will be about the same as the amount of voltage coming out the other side! 15 Picture This! • T6C06 Ok, you’re doing so well, let’s turn you into a master engineer, and look at figure T2. Component #6 has 2 parallel (sort of) plates, separated by an insulation, so it must be a capacitor. 2 3 9 5 4 7 1 6 10 8 16 Picture This! • T6C07 See the little arrow symbols on component #8 showing the effects of light? Component # 8 is a light emitting diode – an LED. Easy • T6C08 Component #9 is indeed a resistor, but it has a variable tap point on it, so it is a variable resistor. We’ll formally call it a potentiometer, and this could be the volume control on your 17 handheld. Picture This! • T6D04 Your larger, high-frequency transceivers may have a mechanical meter movement to illustrate incoming signal strength. Even if it is an LED or LCD readout, we still call it a signal strength meter. 18 Picture This! • T6D02 Most of your handhelds don’t have one, but a mobile radio that puts out 50 watts will likely contain a relay. The relay is a mechanical switch, opened and closed by current passing through a coil, creating an electromagnet. As soon as the coil is energized, the switch goes from one state to another. 19 Picture This! • T6D05 If you want to run your handheld on house power, you’ll need a power supply that will provide regulated 12 volts to your handheld input circuit. This power supply must have a good regulator built in so that it does not exceed the 12 volts DC input that your handheld works with. Never transmit from your handheld when plugged in to an AC “wall wart” because there is not enough filtering within that “wall wart” for a good signal. It is okay for listening, but unplug before transmitting. 20 Picture This! • T6D06 When you purchase your new dual-band handheld it will come with a wall charger that plugs into the side of your radio. The wall charger contains a small transformer that takes 120 volts AC on the primary and steps it down to a lower AC voltage on the secondary. Diodes and capacitors then filter this lowered AC and convert it to 12 volts DC. The common “wall wart” contains all of this circuitry, and newer “switcher” wall warts are much lighter in weight and the transformer is extremely small in size! 21 Picture This! • T6D09 If you ever look inside the modern ham radio, you’ll see rectangular “chips” that are large scale integrated circuits. These chips contain thousands of semiconductors in one nice neat package – abbreviated “ICs.” 22 Picture This! • T5B09 Doubling your power will lead to a power increase of 3 dB. Halving your power will lead to a 3 dB decrease. But since we are going from 5 watts to 10 watts, we are doubling our power, and that is a 3 dB increase. 23 Picture This! • T5B10 Now we go from 12 watts down to 3 watts by pushing the low power button on our small mobile radio. This is a 4 times decrease (4 x 3 = 12). A 4 times decrease is a power decrease of 6 dB. • T5B11 Now we add a linear amplifier. Normally, I don’t recommend any linear amplifiers as you are getting started as a Technician Class operator. Going from 20 watts to 200 watts is a bit dangerous, and that is a 10 times increase in power (20 x 10 = 200). Ten times increase equals 10 dB. 24 Picture This! • T6B07 LED stands for Light Emitting Diode, and this is that green, red, or amber indicator that comes up on your handheld when you are transmitting. The LED draws almost no amount of current and will last for hundreds of thousands of hours without burnout. This is a big improvement over our older radios with grain-of-wheat light bulbs. LED = Light Emitting Diode. 25 Picture This! 26 Picture This! • T6D07 A good visual indicator on a handheld radio is the LED – the light emitting diode that is often used as a transmit indicator. • T5B02 To keep you from running out of pencil lead, we can abbreviate 1,500,000 Hz as either 1,500 kHz, or 1.5 MHz. From Hz to kHz, move the decimal 3 places to the left. From kHz to MHz, move it 3 more places to the left. • T5B13 There are 1,000 MHz in one GHz, so we can simply divide by 1000 to get the final answer, 2.425 GHz. 27 Picture This! • T5B03 Remember kilo? Kilo means one thousand. One kilovolt equals 1,000 volts. Watch out for Answer A. • T5B06 One milliampere equals one one-thousandth of an ampere (1 x 10-3); therefore, one ampere equal 1000 milliamperes. Divide milliamperes by 1000 to convert to amperes. Or move the decimal point 3 places to the left. Calculator keystrokes are: CLEAR 3000 ÷ 1000 = and the answer is 3. 28 Picture This! • T5B12 It’s a good idea, and a fun exercise (for some of us, anyway) to memorize all the Metric prefixes. They’re used a lot in radio electronics. There are a thousand Kilohertz in one Megahertz, so 28,400 KHz is equal to 28.400 MHz. Always remember that if the unit is smaller, you need more of them! Here’s another trick. If working with metric prefixes is not second nature to you, always convert the units to the fundamental units while working out a problem. For example, if a question asks you to do calculations involving subtracting XXX Kilohertz from YYY Megahertz, convert each number in the question to Hertz, and then work out the problem. Then convert it back to the unit they want as the last step. This can save you endless confusion, especially in the heat of an exam! Watch out for answer D – it says kHz, not MHz! 29 Picture This! • T5B05 Your handheld transceiver can also be dialed down to minimum power output, dramatically conserving battery life. Five hundred milliwatts can be converted to watts by moving the decimal point 3 places to the left. So a handheld at 500 milliwatts output is transmitting 0.5 watts of power, the same as a half watt of power. Believe it or not, you can make many contacts through local repeaters at a half-watt of power, and your batteries will love you for it. 30 Picture This! • T5B01 Your new dual-band handheld might offer as much as 5 to 7 watts of output power. Depending on the battery pack voltage, the transmitter could actually draw as much as 1,500 milliamperes. But don’t panic with all those numbers – move the decimal point 3 places to the left to go from milliamps to amps. In this question, to convert 1.5 amps to 1500 milliamperes, move the decimal point 3 places to the right. Three places. • T5B08 A picofarad is one millionth (1 x 10-6) of a microfarad or one million millionth (1 x 10-6 x 1 x 10-6 = 1 x 10-12) of a farad. Move the decimal point 6 places to the left to convert to microfarads or 12 places to the left to convert to farads. If you do the math, you’ll find the answer is 1 microfarad. 31 Picture This! • T5B04 We measure the receiver capabilities on a handheld in microvolts. The word “micro” means one-millionth. Mega means million, kilo means thousand, and milli means thousandth. Micro means one one-millionth. 32 Picture This! • T7D08 Rosin-core solder is commonly available at the same place you purchase your soldering iron or gun. A little soldering pen is fine for working on tiny circuits, but you’re going to need a massive soldering iron or a big 200 watt soldering gun if you plan to install coax connectors properly. Always use rosin-core solder. Wear protective glasses, too. “Eutectic” solder is a special alloy of lead and tin designed to melt at the lowest possible temperature, and this is recommended if you do any surface mount soldering, an increasingly more valuable skill! 33 Picture This! • T7D09 It’s easy to tell if you’ve made a good solder connection – the solder looks shiny. However, a “cold,” poorly-soldered joint looks grainy and dull. 34 Picture This! • T7D07 Every amateur operator should own a multimeter. The multiple function meter can measure voltage, current, and resistance, and check continuity. Even an inexpensive multimeter is better than no meter when you’re trying to check out a circuit in the field. You can buy an excellent multimeter for less than $25.00. The only real difference between a $25 meter and a $300 one is not the accuracy, but how many times you can run over it with a HumVee or drop it from the top of a tower and have it still work. Most experienced electronics technicians eventually end up doing the above and more to their meters, so they prefer to get the best meters they can afford! 35 Picture This! • T7D011 Any time you are checking a circuit with an ohmmeter, make sure the circuit is not energized! If you check any circuit with voltage on it, you will probably toast the ohmmeter for life. • T7D06 You’re likely to damage your brand new needle multimeter by measuring voltage if you accidentally leave it in the ohms reading setting. 36 Picture This! • T7D010 If you have a big old capacitor hanging around the shack, keep it handy! That big old capacitor has a telltale signature when you check it with an ohmmeter. On a high ohms reading scale, the discharged capacitor will first look like an almost short circuit, and then show increasing resistance as the capacitor begins to charge up from your ohm meter test. OK, that’s nice, but how can we use this principle in the real world of ham radio? Let’s say you brought in 5 lines of coaxial cable from your roof to the shack and you forgot to tag which one goes where. Use a couple of alligator clip cables to take the big electrolytic capacitor, and connect it across one coaxial cable end. Now head for the roof. Put your ohmmeter on an intermediate scale, and start testing each cable. All but one will look like an open connection, other than the one terminated with the capacitor, which first looks like low resistance, and then you see the needle meter show an increase in resistance with time. You’re so 37 smart! Element 2 Technician Class Question Pool Picture This! Valid July 1, 2014 Through June 30, 2018 38 T6C01 What is the name for standardized representations of components in an electrical wiring diagram? A. B. C. D. Electrical depictions Grey sketch Schematic symbols Component callouts 39 T6C12 What do the symbols on an electrical circuit schematic diagram represent? A. B. C. D. Electrical components Logic states Digital codes Traffic nodes 40 T6C13 Which of the following is accurately represented in electrical circuit schematic diagrams? A. Wire lengths B. Physical appearance of components C. The way components are interconnected D. All of these choices 41 T6C10 What is component 3 in figure T3? A. B. C. D. Connector Meter Variable capacitor Variable inductor 42 T6C11 A. B. C. D. What is component 4 in figure T3? Antenna Transmitter Dummy load Ground 43 T6D08 Which of the following is used together with an inductor to make a tuned circuit? A. B. C. D. Resistor Zener diode Potentiometer Capacitor 44 T6D11 What is a simple resonant or tuned circuit? A. An inductor and a capacitor connected in series or parallel to form a filter B. A type of voltage regulator C. A resistor circuit used for reducing standing wave ratio D. A circuit designed to provide high fidelity audio 45 T6C02 What is component 1 in figure T1? A. B. C. D. Resistor Transistor Battery connector 46 T6C03 What is component 2 in figure T1? A. B. C. D. Resistor Transistor Indicator lamp Connector 47 T6D10 What is the function of component 2 in Figure T1? A. Give off light when current flows through it B. Supply electrical energy C. Control the flow of current D. Convert electrical energy into radio waves 48 T6C04 What is component 3 in figure T1? A. B. C. D. Resistor Transistor Lamp Ground symbol 49 T6C05 What is component 4 in figure T1? A. B. C. D. Resistor Transistor Battery Ground symbol 50 T6D03 A. B. C. D. What type of switch is represented by item 3 in figure T2? Single-pole single-throw Single-pole double-throw Double-pole single-throw Double-pole double-throw 51 T6C09 A. B. C. D. What is component 4 in figure T2? Variable inductor Double-pole switch Potentiometer Transformer 52 T6C06 A. B. C. D. What is component 6 in figure T2? Resistor Capacitor Regulator IC Transistor 53 T6C07 What is component 8 in figure T2? A. B. C. D. Resistor Inductor Regulator IC Light emitting diode 54 T6C08 A. B. C. D. What is component 9 in figure T2? Variable capacitor Variable inductor Variable resistor Variable transformer 55 T6D04 Which of the following can be used to display signal strength on a numeric scale? A. B. C. D. Potentiometer Transistor Meter Relay 56 T6D02 What best describes a relay? A. A switch controlled by an electromagnet B. A current controlled amplifier C. An optical sensor D. A pass transistor 57 T6D05 What type of circuit controls the amount of voltage from a power supply? A. B. C. D. Regulator Oscillator Filter Phase inverter 58 T6D06 What component is commonly used to change 120V AC house current to a lower AC voltage for other uses? A. B. C. D. Variable capacitor Transformer Transistor Diode 59 T6D09 What is the name of a device that combines several semiconductors and other components into one package? A. B. C. D. Transducer Multi-pole relay Integrated circuit Transformer 60 T5B09 What is the approximate amount of change, measured in decibels (dB), of a power increase from 5 watts to 10 watts? A. B. C. D. 2 dB 3 dB 5 dB 10 dB 61 T5B10 What is the approximate amount of change, measured in decibels (dB), of a power decrease from 12 watts to 3 watts? A. B. C. D. -1 dB -3 dB -6 dB -9 dB 62 T5B11 What is the approximate amount of change, measured in decibels (dB), of a power increase from 20 watts to 200 watts? * A. B. C. D. 10 dB 12 dB 18 dB 28 dB 63 T6B07 What does the abbreviation "LED" stand for? A. B. C. D. Low Emission Diode Light Emitting Diode Liquid Emission Detector Long Echo Delay 64 T6D07 Which of the following is commonly used as a visual indicator? A. B. C. D. LED FET Zener diode Bipolar transistor 65 T5B02 What is another way to specify a radio signal frequency of 1,500,000 hertz? A. B. C. D. 1500 kHz 1500 MHz 15 GHz 150 kHz 66 T5B13 If a frequency readout shows a reading of 2425 MHz, what frequency is that in GHz? A. B. C. D. 0.002425 GHz 24.25 GHz 2.425 GHz 2425 GHz 67 T5B03 How many volts are equal to one kilovolt? A. One one-thousandth of a volt B. One hundred volts C. One thousand volts D. One million volts 68 T5B06 If an ammeter calibrated in amperes is used to measure a 3000-milliampere current, what reading would it show? A. B. C. D. 0.003 amperes 0.3 amperes 3 amperes 3,000,000 amperes 69 T5B12 Which of the following frequencies is equal to 28,400 kHz? A. B. C. D. 28.400 MHz 2.800 MHz 284.00 MHz 28.400 kHz 70 T5B05 Which of the following is equivalent to 500 milliwatts? A. B. C. D. 0.02 watts 0.5 watts 5 watts 50 watts 71 T5B01 How many milliamperes is 1.5 amperes? A. B. C. D. 15 milliamperes 150 milliamperes 1,500 milliamperes 15,000 milliamperes 72 T5B08 How many microfarads are 1,000,000 picofarads? A. B. C. D. 0.001 microfarads 1 microfarad 1000 microfarads 1,000,000,000 microfarads 73 T5B04 How many volts are equal to one microvolt? A. B. C. D. One one-millionth of a volt One million volts One thousand kilovolts One one-thousandth of a volt 74 T7D08 Which of the following types of solder is best for radio and electronic use? A. B. C. D. Acid-core solder Silver solder Rosin-core solder Aluminum solder 75 T7D09 What is the characteristic appearance of a "cold" solder joint? A. B. C. D. Dark black spots A bright or shiny surface A grainy or dull surface A greenish tint 76 T7D07 Which of the following measurements are commonly made using a multimeter? A. B. C. D. SWR and RF power Signal strength and noise Impedance and reactance Voltage and resistance 77 T7D11 Which of the following precautions should be taken when measuring circuit resistance with an ohmmeter? A. B. C. D. Ensure that the applied voltages are correct Ensure that the circuit is not powered Ensure that the circuit is grounded Ensure that the circuit is operating at the correct frequency 78 T7D06 Which of the following might damage a multimeter? A. Measuring a voltage too small for the chosen scale B. Leaving the meter in the milliamps position overnight C. Attempting to measure voltage when using the resistance setting D. Not allowing it to warm up properly 79 T7D10 What is probably happening when an ohmmeter, connected across an unpowered circuit, initially indicates a low resistance and then shows increasing resistance with time? A. B. C. D. The ohmmeter is defective The circuit contains a large capacitor The circuit contains a large inductor The circuit is a relaxation oscillator 80