Hello, Frank here.
Hi everybody, I hope there are still a few people out there following along. Okay, this session we're going to talk about amateur radio practices. I'm on page 38 of Romanchik. I want to remind you of a few things before we get
started. When it comes time to take the General test, you will need to get in touch with the local ARRL club and check for when and where to take your test. There is no way around this, it's the only way. Check the price for the test. In my area, they are normally $15.00. If you plan on taking the test more than once, then bring a couple of extra $15.00 bills. Also remember that the manual I'm using here is not the only way to study. There are some free online sites, paid online sites and the ARRL manuals that now days come with a CD so you can study with your computer. For my General I used HamTestOnline and it worked well for me. I did not use the Romanchik manual for my General, it's just a common reference point for you and I to communicate, and it's free. Some of this information we are about to cover is going to appear to be a little outdated. The reason being, because it is. But this is what is on the test. So, learn the answers.
Okay, so let's talk about it some. The newer HF transceivers are pretty much plug and play. Back in the old days ham radio consisted of two different radios, one transmitter and one receiver. These were two separate beasts entirely. I don't believe these can even be bought new. So, here is where some of this information we are about to cover comes from, it's the old days. Also remember that not very long ago CW, or morse code, was a requirement for ham operators. That is not the case now days. Many still pursue CW, but that's strictly by choice.
These next few items are just ways to help you receive signals better. I seldom use these on my bottom of the line radio, but it does have them. One is a notch filter and one is an IF shift. Next we go onto RF amplifiers. You can run lots of power through a radio. This is where it's particularly important to understand the affects of RF and how to use it properly and not fry your brain. Remember, safety. If you don't know what you're doing, DON'T DO IT. And if you're going to do it anyway, do it at low power.
Skipping on down here, other things you need to know about the operation of your radio. How to set up CW. How to operate in split mode, which you notice has a lot of questions. That means a lot of answers. Split mode basically means transmitting in one frequency and receiving in another.
I'm in the middle of page 39 now, and at the bottom it briefly mentions antenna tuners. Most modern operators use an antenna tuner and most use an automatic antenna tuner. Many radios come with them built in, but the less expensive radios, if you choose to use one, will need an antenna
tuner. I would recommend an automatic one, and I would recommend LDG. If you buy a matching tuner for your radio manufactured by LDG, it is basically plug and play. A word of wisdom here. A capable tuner will tune many frequencies, but in many cases you are losing a tremendous amount of power to do so. This is where a quality antenna is important. As stated before, your antenna is the most important part of your radio system. For most operators, a dipole antenna works great, and I would check out Alpha Delta antennas, but there are many other quality antenna manufacturers.
Okay, I'm sliding over to page 40, test equipment. Do you have to have test equipment? No. Do you want to blow your radio up? No. Here's what I
would recommend. A decent mulitmeter, an antenna analyzer, and an appropriate frequency SWR meter. Let's talk about these. A multimeter measures voltage and resistance. They are relatively easy to use, just ask somebody to teach you. That's where your mentor, or Elmer, from ARRL will come in real handy. They make $10.00 multimeters and up. If you don't know how to use one, make your first one a cheap one, because if you're going to fry something, you'd rather fry $10.00 than $100.00. Okay? Okay.
Your antenna analyzer, not a piece of equipment that you have to have. Once your equipment is set up and running, you may not ever use it again. They cost $250.00 and up. An SWR meter is highly recommended. Normally it goes between your radio output and your antenna. Extremely high SWR will damage or kill a radio. Once it's set up and operating,
it'll operate for years just fine. They make meters that cover wide frequency ranges, and they make meters specific to certain frequency ranges. Some radios have built in SWR meters. Most operators still use an external meter, though. Inexpensive meters start at about $60.00. SWR is important. There are analog type meters and digital, find one that works for you. This is not a piece of equipment that you have to have, but it is highly recommended. It's very important if you're choosing to operate out of the ham bands on the VHF/UHF frequencies. Many of the commercial VHF radios are built to operate outside of the ham bands, but just because the radio will transmit on those frequencies does not mean that your antenna will. This is where an SWR meter comes in very handy. There are antennas made that will operate out of the ham bands, but you might have to have more than one antenna. If you choose to stay within the ham bands, then as a general rule your antennas will work fine. But you still need to check your SWR.
The stuff we just talked about, you need to read these pages and understand the answers. I'm heading on to page 42 now where we're going to talk about interference. I'm not going to cover all of the information on pages 42 and 43, but you need to understand some very simple concepts. If you put up a ham antenna and your
neighbor is having a problem with their TV signal, and they didn't have one before you put your antenna up, then you are probably the problem. And if you are the problem, you need to stop being the problem. It's real simple. Your transmissions can affect television, telephone, baby monitors, heart and respiratory equipment...so you don't want to be interfering with these signals. And it's real simple, under the law you have to stop transmitting until the problem is fixed. No if's, and's, are's or but's. There is no point in arguing with your neighbor that your signal is clean and pure. Any questions about that? This is one of those cases where grounding your equipment well will help solve a plethora of problems.
Okay heading on to page 44, down toward the bottom of it, it talks about single side band operation. You will see a lot of this on the test, it is important and you need to understand it. One, if you understand it, it's
a whole lot easier to figure it out. But if you are on frequency and you're
operating on LSB or USB, then your signal extends out to the edge of your operating frequency, which in most cases is 3 KHz. If you need to get a piece of paper and draw a little signal, we all know 3 + 3 = 6. So, can you go right to the edge of a band and operate on SSB? Sure you can. If it's the top of the band, then you can operate on LSB. If it's the very bottom of the band, then you can operate on USB. Let that sit in your brain for a while. Get a piece of paper and a pencil and if you need to, draw it out.
Okay, on to page 45. I do not recommend mobile HF operation for new operators. For the most part the antennas are very expensive and they don't operate particularly well. Again, if you're using a 100 watt transceiver, then you need to connect directly to your battery and make sure it is fused correctly. Your cigarette lighter plug as a general rule, will not provide enough power to operate 100 watts. Remember, P = E x I. Go ahead and read page 45 and 46 because you will see it on the test.
We should have about three more lessons, three, at the most four, for your General. I hope you're enjoying this particular teaching style. What I'm trying to do is get a few people set up for emergency communications when things shut down. If you
choose to pursue other routes, wonderful. Amateur radio has a place for just about everybody. An example. Some guys still like to build their own radios. Some of these guys have a tremendous amount of knowledge. Others like to contest and there is a large arena for these folks. My goal is to help get people in the door using the least amount of equipment possible and doing it safely. The equipment I recommend is the equipment I use, and this is just one man's opinion. But if you see a need for communications, then you need to get started. There are lots of ways to communicate in ham radio and outside of ham radio. In the section called Frank's Radio Communications there are articles about CB's, GMRS, scanners and lots of other good, solid information. You might want to skim these areas. Remember, a CB is an HF transceiver that operates between 10 meter and 12 meter, and has the ability in some cases to operate on SSB.
There's an old saying around, "I'd rather be a day early, than a minute late." and if you're reading this, then you know what I'm talking about. Today the stores are open, the internet is working and the electricity is on. No guarantees about tomorrow. If you're a fence sitter, then get it done.
We'll talk more later. 73, Frank
Hello, Frank here.
Hi everybody, anybody get any RF burns this week? If you did, hopefully it was on your hand and not inside your head. I'm going to start with safety and end with safety.
Today we're going to talk about signals and emissions and some other interesting things. Right now we're going to look at the word emissions. You want emissions to go from your radio, out your coax and ultimately out of your antenna. If you have things set up right they will. But if you have a piece of equipment that might be getting a little old and it's just wearing out, then you might get some emissions where you don't want them. Same thing can go if you have your antenna system hooked up incorrectly.
You need to have your equipment grounded. This will take these unwanted emissions that are bouncing around inside your metal radio and send them to ground, or Earth. If your piece of equipment is too hot, and it shouldn't be, this can be caused by many things. One of the causes is RF escaping from your radio at the wrong place, at the wrong time. It's kind of like if your car is running hot, and it's not a summer day and you're not pulling a trailer. So, things to think about and pay attention to. Ground your equipment and know how it works. Some pieces of equipment just operate warm all of the time, it's their basic nature. That's part of the reason that you need a good mentor from ARRL.
Okay, AM and FM. Most of you are familiar with AM and FM radio in your car, or home. These are the two primary ways that signals are sent through the air. But for listening purposes, in your car AM is amplitude
modulation and FM is frequency modulation. AM is older, FM is newer. Okay, let's say you are listening to an AM radio station on your dial, and you cross an old metal type bridge. There is a chance you will lose part of your signal because the bridge is acting like a Faraday cage. If you're on FM you probably won't notice a difference in the signal at all. Because FM is normally a higher frequency, or newer frequency. For the most part, 30 MHz and down are AM, and in most cases, but not all, 30 MHz and up are FM, which is what you're using right now if you're playing around on VHF and UHF. Why the change? Newer discoveries and newer technology.
So far we've talked about AM and FM as bands. But AM is a type of modulation, as is FM. By the way, on a side note. Most shortwave listening, SWL, is AM. Now for both of these, AM and FM, you have a carrier frequency. Let's say my voice is at a certain frequency. It is added to the carrier frequency. Remember what a sine wave looks like? The sine wave is the carrier frequency. Let's take 900 KHz and my voice at 8000 hertz, you add that to the 900. But you add it and make the amplitude of the sine wave get taller on the top side and the
same on the bottom side. The frequency really doesn't change, just the amplitude of the signal. That's why AM radio is more affected by weather. I'll explain more why in just a second.
Now with FM, which means frequency modulation, you still have a carrier frequency, which for radio purposes, let's say 100 MHz. You add my 8000 hertz voice, and it's added to the frequency. It goes through the air and the radio receiver separates the two and you hear my 8000 hertz voice again. But the reason weather, lightening and things, do not affect FM is because the top and bottom of the carrier frequencies are filtered and removed, wherein, AM is not. That's why FM has a cleaner nicer signal and less static. That's a whole lot for just the first two questions here, but that's basically how AM and FM work. Very basically.
So, skimming down page 22, you see talk about upper and lower side bands. These are used almost all the time in HF transmission. Ironically, the lower HF bands, 160, 80, and 40, use the lower side band, or LSB, and above 40, most of the time, upper side band, USB, is used. Okay.
What are side bands? If you have a regular AM signal, like you listen to on your car radio, or your SW radio, which is intermingled in between all of the ham bands, then this signal includes the carrier and upper and lower sidebands. When you are transmitting on 40 meter LSB, your radio removes the carrier frequency and the USB. This makes the bandwidth much smaller, takes less room on the bandwidth and your power can be used more efficiently. This may sound a little complicated, but if you let it soak in for a while, it will make sense. Just for knowledge purposes there is some SSB on VHF FM, but it's not used a great deal.
Okay, let's continue. Modulation is very important. If you're listening to HF and some guy sounds like a duck, then either you or he are probably off frequency just a little bit, or the sender could be over-driving the frequency. This boils down to too much power going into the microphone, often referred to as microphone gain, or he could have the microphone too close to his mouth. Okay, go ahead and read these pages and don't forget the links at the bottom of each section.
Page 24 breaks down some of the terminology of the parts inside of a radio. You will see these on the test. Go ahead and go through page 25 and we're coming up to antennas.
I need to give you a couple of formulas to start with. We're going to use the 'T' formula. It is: 300 = frequency x meter. The next one is: 468 = length in feet x frequency in MHz. So, build you a 'T', put the 300 on top, and on each side of the vertical underneath the 300, put frequency on one side and meter on the other. Now this is just used for estimations, but it will come in real handy on the test. And remember, once you start the test, ask to use scratch paper and write down these two formulas and use them all through the test.
Example: Your frequency is 150 MHz. You divide that into 300 and you get 2, which would be 2 meter. Or, if you know the meter and you want to try to find the frequency, let's say you know it's 10 meter. Take 300 divide it by 10 and you get 30. Is this exact? No. But 10 meter is 28 and 29 MHz. So, this is just for estimation, but it will get you in the ballpark. And if you have forgotten the frequency and meter relationship, this will get you real close.
The other one. Build you a 'T', put 468 on top. Put length in feet on one side of the vertical bar, and right beside it, on the other side of the bar, put frequency in MHz. This is to find the length of an antenna for 1/2 wave. This is also an approximation, but it's very close.
Example: You want to find 1/2 wavelength for 10 meter. So, you know that the frequency is, let's say 28.7 MHz. You take 468 divided by 28.7 and you get 16.3. So for a half wavelength antenna at 28.7 MHz, you need approximately a 16 foot antenna. Okay? Now, let's say you want a 160 meter antenna, which is 3.9 MHz. You take 468 divided by 3.9 and you get 120 feet for a half wave signal. Now at this stage you can tell that this is not going to be a vertical antenna. This will obviously be a horizontal antenna.
Let's try one more for fun. Your 2 meter VHF radio, which is, let's say 147 MHz. Take 468 divided by 147 and you get about 3.2 feet. Remember, the higher the frequency, the shorter the antenna. It's a whole lot easier to have a mobile VHF radio, than a mobile HF radio. Want to know why your cell phone has such a small antenna? Remember, this if for half wave. You can use a quarter wave or a one eighth wave antenna. Back to your cell phone. Take 468 divided by 900 MHz equals 0.5 foot. Which is about 6 inches. So a quarter wave antenna would be about 3 inches, and a one eighth wave antenna would be about an inch and a half.
So, obviously the higher the frequency, the easier it is for mobile communications. And, remember, almost all VHF and UHF are line of sight communications. And for all practical purposes, they're all vertical antennas. And for all practical purposes, all HF frequencies use a horizontal antenna. There are some exceptions for 10 meter and 12 meter, and there are still some 10 meter repeaters around the country. And don't forget 11 meter. You say, "What is 11 meter?" It is where the CB frequencies are located, which an HF radio. CB also has single side band, SSB, but they operate on LSB instead of USB. Don't forget the humble CB, it is a great radio. And some CB antennas are also good for 10 meter and 12 meter.
Go ahead and read along about impedance matching. But you have to understand that SWR is critical. You may have a tuner for your HF radio and it may tell you that you're tuned, but that doesn't mean that your SWR has decreased. It means that through the miracle of electronics your
radio is matched with your antenna, but your SWR will still be high and your power will be reduced significantly. An antenna tuner may allow you to transmit safely, but if your SWR is high, your power will be sharply reduced. You hear people talk about 1:1 SWR ratio. Well, that is in a perfect world and we do not live in a perfect world. Now, for test purposes you will see 1:1, 4:1, 6:1. You will notice that the larger number is always first. But on the test, you will find that sometimes the largest number is second. You can eliminate those as wrong answers. You're going to need SWR meters for HF and VHF/UHF radios. If you are mobile, you can check your SWR, get it set right and remove your meter. And if you want to, you can do the same thing for HF, but many leave the meter attached permanently.
Next time. Read ahead about antennas, starting on page 28, and please read through page 32. Most people will agree that your antenna is the most important part of your radio system. Always remember safety. If you don't know what you're doing, check with your mentor, or more commonly called, your Elmer. I hope this helps just a little bit.
We'll talk more later. 73, Frank
