use. When you pass this Technician's test, you'll be licensed to operate primarily on VHF and UHF. These are things you should know, so I'm not going to cover them a great deal. If you don't remember, then look back through the last few lessons. Actually, look back through all of the lessons. And if you are waiting on me to lead you by the hand, page by page, then we're still going to be a while. So, I encourage you as local ARRL, find an Elmer, schedule a test, take it, pass it, and then start studying for your General test. The same manual comes free for the General test. Wherever you have been taking free or paid practice tests online, they will also offer free or paid General practice tests. Unless you are just interested in VHF and UHF, then you will need your General to utilize the HF bands. It's up to you. It's your call.
Okay. VHF and UHF are what is called line of sight communication. What this basically means, is if you can't see the other antenna with the top of your antenna, then you're not going to have communications. For the most part, that's true, but there are exceptions. If you will read a previous post on GMRS, it talks a lot about line of sight communications because
GMRS is UHF. But you knew that didn't you? Being line of sight communications means that it is local. For the most part, VHF and UHF signals are not reflected by the ionosphere, they just go through it and continue out into space. This is a great opportunity to believe in life on other planets, that someone on the other side of the Milky Way is listening to your transmission. Just for fun, check out the Voyager space craft. Now that is a fascinating story.
Okay, back to reality. Remember, you have to answer the questions that are on the test correctly. You will not see anything on the test about Voyager. So there are a couple of questions there about the curvature of the earth, try to make sense of them. But let me qualify one thing, there
are occasions where VHF will bounce off of the atmosphere and get caught in kind of a channel. It is called ducting. It is not dependable or reliable, therefore it is not used in communications. But on rare occasions, you will hear VHF transmissions from hundreds and thousands of miles away. You will cover this more when you pursue your General license. I was in the Army in South Korea and my jeep had a VHF radio. Every now and then we would pick up signals from Vietnam. This is the result of ducting. If you hang around long enough, we'll talk more about it later.
The manual talks here about reflecting of signals, remember this is all VHF and UHF. And what it's referencing here is transmitting in an area with numerous obstructions, like buildings. So if your signal is not being
received or transmitted properly, move a few feet one way or the other and you may be successful. And this also applies when trying to reach a repeater. The thing about knife edge propogations? Just learn it. Memorize it. It's the only time you will ever see it.
Next we are going to talk about antenna polarization. Most VHF and UHF antennas are vertical, which means up and down. If you are broadcasting line of sight, then the antenna you're transmitting from and the receiving antenna need to be the same polarization, which means vertical to
vertical. If you are broadcasting off of the ionosphere, then it is sharply less critical. Remember, most HF antennas are horizontal, most but not all. Most VHF/UHF antennas are vertical. But, again, not all. Since VHF and UHF are line of sight, then the transmitting and receiving antenna need to be the same polarization. So, if you're talking to your buddy on your handheld or HT (handy talky), hold your radio with your antenna where it is vertical, or up and down. Especially if you are trying to reach a repeater which is a fixed vertical antenna. That last part is important.
Next, picket fencing. It's just a term used by ham radio operators, but you will see it. So, read it and learn it. What's coming up next are signals being refracted from a sporadic E layer. This will be on your test. Few to none use this technique. But it will be on the test, or could be on the test.
The next part talks about, well, read about it. Try to get an idea what it is. It talks about rapid fluctuations of strength. And the next part talks about bouncing transmissions off of meteors on 6 meters. If your the type of guy that wants to sit around and wait for a meteor and see if you can bounce a signal off of it, then go for it. Yes, it could be or will be on the test, but I do not understand why it is even addressed, but it is. Take it with a grain of salt.
The next part talks about tropospheric scatter of VHF and UHF. And it talks about temperature inversions in the atmosphere called ducting. We talked about this earlier and in the real world of ham radio, it's not something you will use. But, as I've said before, it is on the test. After you take the test and pass it, you will never in your life need to know this again unless you're one of those kind that likes to bounce a signal off of a meteor.
Next is HF propagation. HF is what most people consider to be ham radio. You are bouncing signals off of the ionosphere and trying to reach long distance sites. When you work on your General, you will learn a great deal more about the ionosphere and it's many different layers. But at this time right now, this little section here is all you need to know.
Read these next two or three paragraphs. Know what the answers mean. There are only four of them. It talks a little bit about polarization and it gives you some ideas about when certain frequencies are open during
daylight hours. For the most part, HF is not open to the Technician. But, to me, this is ham radio. HF is also where the shortwave frequencies exist, which is not ham radio. But these guys use the same techniques of bouncing signals off of the ionsphere. I like ham radio, but I also like shortwave radio and I use my ham radio to listen to both.
Okay. Next time we're going to talk about antennas and feed lines. Most people will tell you that the antenna is the most important part of your radio package. Because you can have the world's most expensive radio, but if you have a cheap antenna, or a poorly aligned or adjusted antenna, then your radio is no better than your antenna. I would much rather have a poor radio with a good antenna, than a great radio with a poor antenna.
Please read ahead. I will try to post more often. Try to find a way to take your Technician test. Or if you want to, study up a little more and take your General at the same time. Find somebody in your neck of the woods to talk to. You don't need to be a great social creature to find somebody to help you. I did most of it by myself and I have boxes and boxes of equipment
that I have used in the growing process, including radios, coax cable, antennas. If you lived close, I could sell you a whole used set up. But you don't. That's why you need to get in touch with your local ARRL club. To the vast, vast majority of hams, ham radio is a hobby and they are always upgrading, changing, trying out new stuff. Therefore, they have practically new or used equipment for pennies on the dollar. This is where you need someone to help you. Most ham radio guys are good, solid and honorable. But every now and then a maggot will sneak into the group. If you want to sit at home and listen to ham radio or shortwave, wonderful. If you want to become a world class contester, great. Ham radio has a big playing field and there is room for everybody. Little kids, old geezers, and I say that with the highest respect, male, female, rich, poor, there is a slot for everybody. You can buy new or you can build your own.
Next time we'll also talk about some real simple ways to communicate if the power goes down. And if you believe that old sparky is going to be in the outlets everyday for the rest of your life, then good. But, if you believe that there is a chance that the power grid is going to go down, there are very simple ways to still have communication, local and worldwide. And I, for one, am a listener.
We'll talk more later. 73, Frank