Radio - Become a Ham, Part 4

Hello, Frank here.

Oh, you’re back. I know in many classes, when you get into the math portion and simple formulas, you start to lose people. I don’t mean from an educational, intellectual point of view. What I mean is, people’s feet walk out the door. That’s a shame, because there are only 36 questions on the test and I have seen the odds and probabilities of getting math or formula questions on the test. I don’t remember what they are, but they are very small. So, if you can’t get the math or you can’t get P = E x I, then just memorize those answers. Memorize the questions too. It helps to know which ones go together. I hope some of you have signed into QRZ, if not, start now. This is not difficult, but it will take a little bit of time and it will take a little bit of study. There are many adults that have not studied for a test in a long, long time. So, brush away some of the cobwebs. As Mother Superior would say, “Put on your thinking cap”, and do what you need to do.

Now, as before, and will be the case everytime, I am going to use the No-Nonsense Technician Class, Study Guide by Dan Romanchik, KB6NU. If you do not have this by now, then I hope you enjoy the pictures.

Today I’m going to be starting on page 10, Electronic Principles and Components. Many of these components you use in every day life. If you turn on a light switch in your house, which you probably do, then you use one of these components. The way this manual describes these components is the very basic level. Because that is what is on the test. In some cases you will see different symbols for the same item in different books. These symbols are not cast in concrete. There are slight variations. For the purpose of this class, these are the ones that are used on the test. So if you see a symbol that is different from one that you learned sometime in the past, it’s okay. It’s not necessarily wrong, but the one that is here is the one that is on the test. The object of this whole exercise is to pass the test.

The area we are going into, you are just going to need to learn it and figure it out. There will be a couple of diagrams coming up very shortly. These are simple diagrams with simple explanations as to what the components are. Remember, this is a simple test. It is not detailed. If you choose to study for more advanced licenses, they will become a little more detailed. But for right now we’re going to make this simple. 

On page 8, under the word resistor, which is the first component, you will see a group of numbers and letters. The one under resistor is T6A01. This is the section and number of this question in the question pool. Here is the Technician 2010 question pool. Skip the first 3 pages, these are corrections that have been made. Pages 4 – 6 explain the different sections. It also tells you how many questions on the test come from each section. Starting on page 7 are the actual questions. In section T1A, the first question is T1A01. Next to that is the letter ‘D’ in parenthesis (D), that is the answer to this question. T6A01, answer (B) is on page 41.

These are all the answers to all the questions. You will see these numbers and letters next to questions on all the free and paid practice tests. How cool. All the questions and all the answers. So here it is. Keep this document, it is invaluable. When you go to QRZ and sign in and do the practice tests, it will have this same T6A01 for this question. Wa-la! Isn’t life good?

The first electronic component is the resistor. It does exactly what is says, it resists. As you’re reading along, remember, that I am going to cover this part quickly. Resistors have values and that value is measured in ohms, which on your brand new mulitmeter, is measured in the resistance area. Remember, don’t measure resistance on a live circuit or you will be buying a new

mulitmeter. The next word in bold letters is potentiometer. This is the volume control on your radio. Resistance is controlled by your potentiometer. A potentiometer is a coil of wires that is adjustable. If you have a dimmer light switch in your house, it’s also called a rheostat, but for our purposes here it is a potentiometer. It is measured by resistance. 

Next is a capacitor. It stores energy. This is

one of those components that will get more sophisticated as we go along, but for now it stores energy. How much energy it can store is it’s capacitance. This is measured by the farad. You have probably heard talk of a Faraday Cage which people like to store their electronic gear in in case of an EMP or CME, which we’ll talk more about later. But the term farad comes from Michael Faraday. 

Next is an inductor. It also stores energy in a magnetic field and this stored energy is called inductance. It is measured by the henry. A coil of wire is an inductor. Here in just a moment you will see where you can take two inductors and make a transformer. You can also take an inductor and make a switch. More on all of this much later.

Next term is switch. When you turn your lights on in your house, it’s a switch. And, of course, switches can get very complicated. But the one here is ON/OFF (on slash off). 

Next is a fuse. A fuse protects circuits from surges of power and too much power that doesn’t come in the form of a surge. 

The next little bit is going to be about rechargeable and non-rechargeable batteries. On this test, the non-rechargeable is referred to as a carbon zinc battery. This is not on the test, but C, D, AA, AAA non-rechargeable batteries are all 1.5 volts VDC. On this test rechargeable are referred to as NiCad batteries. 

These batteries are 1.2 volts VDC. So there is a difference in the voltage that comes out of a chargeable battery and a non-rechargeable battery. For the most part, this is not on the test, most electronic pieces of equipment will accept rechargeable batteries in place of non-rechargeables. Every now and then, you will find the exception to the rule. Note: I use lots of rechargeable batteries.

Okay. We’re going to step into a different type of component now. A diode allows current to travel in one direction. Remember, this is a simple diode. Anode and cathode are the names of the two electrodes in the diode. Anode and cathode are also used a lot more. Example: the terminals of a battery are sometimes referred to as anode and cathode. But for this test purpose, it’s the name of the two electrodes of a diode. The cathode side is identified with a stripe.

Transistor is a modern day type switch, or an amplifier. It’s a cool little instrument. This little gizmo is what has allowed big jets to fly, men to go to the moon, and for you and I to carry a cell phone in our pockets that

has more storage capability than what used to take a large building to store. Of course, all that is not on the test, and maybe someday in the future, we will discuss what that means. All these little gizmos now are the size of little circuit boards, a little bit bigger than the diameter of a hair. That little transistor was invented by two men playing in their garage, in the good old United States of

America. Because without that invention, we would not be having this discussion over this medium. You’ll see the term gain used with a transistor. This term is used to discuss how well it works. A bipolar junction transistor, just read the little descriptions about it there in the book, there could be two questions on it. FET stands for field effect transistor and it has a gate electrode.

An LED is that wonderful invention that has changed the way lighting is used. It means light emitting diode. I love LED’s. All of my flashlights and some of my interior lighting are LED’s and the little gizmos appear to work forever. Your batteries will last significantly longer. They produce little to zero heat and they just work. Somebody made a better mouse trap. I wish somebody could make a good coffee pot that works as well. Sorry for the distraction.

Okay. Schematic symbols is a name for standardized representations of components. That’s what is on the test, but as I mentioned earlier, not all symbols are going to be the same in different places. Figure T-1. Here is what some of these components are that we have been talking about. Don’t get figure T-1, T-2 and T-3 mixed up.  

In figure T-1, component 1 is a resistor. Remember, it resists. Component 2 is a transistor. In this function it is a switch to control the flow of current. Component 3 is a lamp. Component 4 is a battery. It is not mentioned here in Figure 1, but component 5 is ground. And it’s not mentioned here either, but in component 4 also tells you which side is negative and positive. More on that later.

Let’s scoot down to Figure 2. Okay. Component 2 is a fuse. It actually looks like a fuse, the old type that is still used in lots of pieces of equipment. If your car is newer, it has a blade type fuse, but the symbol represents a fuse. Component 3 is a single pole, single throw switch. Component 4 is a transformer. See the two coils there together? What it is going to do here is change AC, which remember is alternating current, into DC, which is direct current. In this figure, component 1 is not mentioned, but it is your AC input. Component 5 is a rectifier. If you look, component 8 and 10 also look like a rectifier, the reason is, that they are, just a little more complicated. This is a rectifier diode. It only allows current to go in one direction. Component 10 is not discussed at this time, but for future reference it is a zener diode. And also, component 8, is an LED. In this case, it tells you that the system is on. Component 6 is a capacitor. Read the description about a capacitor, they will get much more complicated. And a capacitor can also injure you. But for now you need to know what it says on page 13. Component 9 is a variable resistor. That little arm with the arrow going across the resistor, in the future, you will see that little arrow on other components. Component 7 is also not mentioned, but it is a resistor.

Okay, moving on to Figure T3. Component 3 is a variable inductor. Remember, an inductor is normally a coil. Component 2 is a capacitor, except in this case, it is a variable capacitor. More on that later on, but for this test, this is all you need to know about a capacitor. Component 4 is an antenna. You will also see other symbols for antenna and you will see other symbols for ground. 

Okay. Stay with me. We are just about finished. I am on page 14 of this manual. A relay is a switch controlled by an electromagnet. Relays are

used in all types of equipment and they are actually magnets. A relay can be used to open a circuit or close a circuit. An example: if you have a gas stove in your house, and the electricity goes off, you might not be able to use your cook stove because when the power is on a relay holds the gas valve open. When the electrical power goes off the relay closes and shuts off your gas. It is a safety feature.

Okay. Meter. This is not the type of meter we talked about earlier, like millimeter. This is actually a physical device that you can read on a numeric scale. The temperature on your air conditioner and

heat is a meter that tells you what the temperature is or was. A regulator regulates. In this case, it’s talking about voltage. It controls the amount of power. LED, we talked about before, is a visual indicator or light that tells you something is on or off. And last, is an integrated circuit. It puts several things together. Not mentioned here, but it is commonly referred to as IC, integrated circuit. If you work in the electronics field, then you know that an IC is ancient electronics. A term you will see, that is not on the test, is SMT, surface mount technology. These are those little, bitty, teeny things that you can barely see without a magnifying glass. These are the resistors and diodes and etc. of today’s ham radios.

Okay. Play with these diagrams. You will see at least one of these on the Technician’s test. Read it over and over. Play with the questions in your head, and over time these things will start to come together. If you need more answers to questions that you can’t put together, contact your local ARRL chapter and ask for an Elmer. An Elmer is a teacher or buddy or friend that will help you. They are good people and they will be glad to help. What I’m doing right now, I’m trying to help a handful of people. So. 

We have completed page 14. A whole lot of the test coming, is just common sense stuff. We’re going to start dealing with sine waves. And to me, this is the fun part of what we’re doing. It’s actually what radio is made up of. So, if you haven’t had fun yet, now is the time to start. Have I told you about God and his sense of humor? If you don’t believe God has a sense of humor, then just go look in your bathroom mirror. And if you don’t think that is funny, then look again.

Seriously, I hope that some of you have already read this manual and made arrangements with your local ARRL to take the Technician’s test. Go to QRZ, sign up, and start taking the practice tests. When you get to about an 85% pass level, then go take the test. You should know by now that the next test is the General. It is available in the same format as the Technician Guide and you can take the practice tests free on QRZ. 
 

It’s raining at my house today. Temperatures are about to drop. Autumn is about here.

We’ll talk more later. 73, Frank

P.S. Frank told me this would be the shortest radio post yet! I just laughed.    Fern

Visit Thoughts From Frank and Fern at http://thoughtsfromfrankandfern.blogspot.com/