Hi everyone. I hope the world it treating you good. Okay, we have covered electrical principals, Ohm's Law and calculating power. The time frames I'm using comes from the No Nonsense Study Guide, Technician Class by Dan Romanchik, KB6NU.
One more area that some people have a little difficulty with is the metric system. Some people ask, "Why do we use the metric system?" Because radio was developed in Europe and Europe uses the metric system. It's that simple. Using metric is not my first choice, and it may not be yours either, but this is the system that is used in multiple professions and it is used in amateur radio. So when I sit around and whine to my wife about why does it have to be this way, she tells me to suck it up and put on my big girl panties and deal with it. God how I love being married!
Okay. We are going to be talking about the terms milli, micro, pico, kilo and mega. The last two you are already familiar with because if you get an electric bill and you look at the power consumed it will be in kilowatts. If you've ever adjusted the dial on a commercial radio station, that's the FM radio in your car, you have also used the term mega.
Okay. If you have a meter stick in your house, great. Or if you have a tape measure that also has metric on it, please get it. If you don't, then use your imagination. A meter is about three inches longer than a yard stick. A yard is 36 inches, or 3 feet, so a meter is about, about 3 inches longer than a yard stick. Now you have an approximate idea of how long a meter is. A meter is divided into centimeters and millimeters. For the benefit of teaching here, how much is one cent in relationship to one dollar? It takes 100 pennies, or cents, to make a dollar. A cent is 1/100 of a dollar. Therefore, you have 100 centimeters in a meter. For those of us stuck in a different mind frame, a centimeter is a little bigger than 1/4 inch and smaller than 1/2 inch. Okay. So.
One centimeter = one hundredth of a meter
A milli = one thousandth of a meter
Okay, now follow me closely here.
100 centimeters = 1 meter
Since a millimeter = 1/1000 of a meter
then, 1000 millimeters = 1 meter
Now, remember when we are talking about meters, we are talking about length. You can also have a millisecond, a milliamp and a millivolt, these are all 1/1000 of whatever you are dealing with. So -
1 milliamp = 1/1000 of an amp or .001 amps.
500 milliamps = .500 amps OR 1/2 amp
If you have 1000 milliamps, you have 1 amp
If you are still reading, then let's go to micro. Micro means one millionth of an item or quantity. I know it's hard to think in terms like, one millionth of a second, which is time. But we will use those when dealing with voltage. So.
A centi is 100th or .01
A milli is 1/1000 or .001
A micro is 1/1000000 or .000001
I'm not going to discuss pico because it deals with one trillionth of a quantity and it's not something you really need to know.
The milli and the micro, remember, are smaller than one, and kilo and mega are larger than one. Ok. Here goes.
Kilo = 1000
Example: one kilowatt = 1000 watts
A kilometer = 1000 meters
Your electric bill comes in kilowatts. The radio stations on the AM dial in your car radio come in kilohertz.
Example: 1000 kilohertz on your AM dial, means
1000 x 1000 = 1,000,000
That is 1000 kilohertz or 1,000,000 hertz
Mega = 1,000,000 of a quantity
You say well, I tune in my FM radio to 100 megahertz and listen to Willie Nelson sing. Well, maybe not Willie Nelson, but 100 megahertz is
100 x 1,000,000 which will give you 100,000,000 hertz. Okay. Forget your AM and FM radio, and let's go back to 1000 kilohertz. We did the math up above, and we got 1,000,000 hertz.
1,000,000 hertz is also = to 1 megahertz
Because mega = one million
therefore, 1000 kilohertz = one megahertz
Okay. Let's go back a little bit. The wall outlet in your house is approximately 120 volts AC 60 cycles per second. What that means
is one sine wave going from zero up to positive, back down to zero, continues going downward, then comes back up to zero. That is one sine wave. That is also one cycle, or one hertz. Now, I've said your wall socket has 60 cycles/second. That is also 60 hertz per second. Okay. AM radio, on your car radio dial, operates between about 670 and 1500 kilohertz, or KHZ. The FM radio stations in your car operate somewhere between 88 and 1.7 megahertz, or MHZ.
So, yes, the radio station on the FM dial has about 100,000,000 hertz per second. Okee-dokee? And, yes, it is measurable. But that's not our concern right now.
Go back to your manual on page 9 and you will see a description of what I just tried to explain. These are the question that are on the Technician's test and what you need to know is the correct answer that goes with the correct question. Hopefully you have gone to one of the previously mentioned websites and started completing the free practice tests. If you are reading this, then you are probably aware that this is not a free government program and you
are going to have to take the test and match the questions and the answers. It's helpful if you know what this information means, but it is not required. All that is required, is that you match the right answer to the right question. As I told you earlier, my wife, or YL, scored better on both tests than I did and she doesn't know and doesn't care what any of this means. If you want to know what the information means the ARRL website has books for sale that will teach you what the information actually means. If that is not your path, then just memorize the answers.
An example of this is on the bottom of page 9 where it deals with decibels (dB). It gives you three ratios - 3dB, 6dB, and 10dB. Look at each one. 3dB is a ratio of 2 to 1. 6 dB is a ratio of 4 to 1. 10 dB is a ratio of 10 to 1. You don't need to know what it means. Most people that talk dB's have no clue what they're talking about. They know that the bigger the dB, the better. But for test purposes, there are only three choices. Memorize the answers. However your mind works, find a way to relate 3, 6, and 10 to the ratio.
Okay. We are finished for today. I hope this has helped somebody on the planet. In the near future, we are going to talk about electronic principles
and components. A whole lot of this you will find to be common sense, and the rest you will just memorize. Please read ahead, take the Technician practice tests and when you are consistently scoring 85% or better, arrange to take the test. A buddy of mine took the Technician and General test on the same day and passed both of them. So don't wait for me. If you're one of those that has the ability to learn on your own, do so. If you have a question, send it to me. If you want to talk to a
human, contact your local ham radio club. But remember, safety overrides everything. Where I live it is raining right now, with occasional claps of thunder. All of my antennas are disconnected and I am not sitting in a bubble bath of hot water during an electrical storm. Think safe. Don't be stupid. Always follow the safety rules. I mentioned a long time ago, you don't want to fry your little girl's brain by doing something stupid. No joke. If you have questions let me know.
My wife just reminded me that our world is looking a little iffy as we go along. This might be one of the only means of communication when the electricity goes off. You might ask, "If the electricity goes off, it goes off everywhere." That's true. And your car may not run because of no
gasoline, but if you will pop the hood, clean off your 12 volt battery, top it off with distilled water, connect a 10 watt solar panel that you can find at thousands of stores, then you have a car battery that will stay charged and you can listen to radio, whether it's AM or FM. Now put the vehicle very close to your house. The antennas on your car will work great, connect them to the radios inside your house, run a small cord from your battery to your 12
volt radio in your house. Whether it be CB, GMRS, VHF/UHF, MURS, HF, scanner, weather radio, SW - you can have world wide communications off of that little 12 volt battery, a small 10 watt solar panel, a tad bit of creativity and a little gumption. You can now listen to radio broadcasts from around the world. And if you need to, you can talk to people in your local community and with the right radio and the right antenna you can talk to people around the world. Now if you find this inspiring, great. Then refer back to the beginning of this article, get up, put on your big girl panties, and get it done. Time is short. That little girl I mentioned earlier? It may save her life, her mommy's life and her daddy's life.
We'll talk more later. 73, Frank