Amateur Radio 101: What, Why, and How

Or, why you should get a ‘ham radio’ license.

[Update 2/18/16 – Part two of the series is now available here: Amateur Radio 102: Basic Usage]

What is Amateur Radio?

First, the definition from the great and all-knowing Wikipedia:

Amateur radio (also called ham radio) describes the use of radio frequency spectra for purposes of non-commercial exchange of messages, wireless experimentation, self-training, private recreation and emergency communication. The term “amateur” is used to specify “a duly authorised person interested in radioelectric practice with a purely personal aim and without pecuniary interest;”[1] (either direct monetary or other similar reward) and to differentiate it from commercial broadcasting, public safety (such as police and fire), or professional two-way radio services (such as maritime, aviation, taxis, etc.).

That’s really sounds quite complicated, doesn’t it? Forget all that for now and read on. I’m going to break it down, start simple, and walk through what you really need to know about ham radio.

I’m definitely going to be tossing around a lot of new and unfamiliar terms, but I’ll do my best to explain them as I go.

A much simpler definition of amateur radio is this: It allows licensed hobbyists to experiment with radio technology and to communicate with one another.

Why is a license needed? The radio spectrum consists of a finite range of frequencies that are practical to use for communication. The FCC has divided this spectrum up into various assigned uses. These are just a small handful of the things using various radio frequencies:

  • FM radio broadcasts
  • Broadcast television channels
  • Air traffic control
  • Police/fire departments and other public safety users
  • Business radios
  • Military and weather radar
  • WiFi networks
  • Mobile phone networks

The FCC’s job is to keep track of all these different radio users, and keep them from interfering with each other by assigning them different ranges of frequencies to use. For example, FM radio stations broadcast between 87.5 and 108 MHz. Right above that range, from 108 to 136 MHz, is the aviation band, used for air traffic control and navigation. Clearly, if an FM radio station were to broadcast above the top of the FM broadcast ‘slot’, that would be a Bad Thing for any airplanes in the area. So it is with amateur radio, as well.

Amateur radio is assigned a handful of slots in various frequency ranges, because different ranges of frequencies can have vastly different characteristics, making them useful for different purposes. For instance, signals in the amateur radio VHF range of 144-148 MHz are line-of-sight, meaning they are blocked by hills, buildings, etc. On the other hand, down in part of the HF range around 14 MHz, signals tend to ‘bounce’ off the Earth’s atmosphere, making it possible to communicate over very long distances. Worldwide, even, when conditions are right. More on this later, though.

Your license is essentially a contract between you and the FCC. They promise that certain pieces of the radio spectrum are available for you to use. You promise to stay within those frequencies and follow the rules for using them responsibly.

What can you do with it?

VHF and UHF Communication

This is where most people begin, as the equipment to get started is fairly inexpensive. And with only a Technician class license, these are pretty very nearly the only frequency bands you are permitted to use.

The VHF or 2-meter band covers the range of 144-148 MHz, as mentioned above. The UHF or 70-centimeter band goes from 420-450 MHz

Simplex
VHF Simplex
Simplex Communication

Simplex communication is pretty much the same as what you would do with a set of typical FRS radios, or any other set of “walkie-talkies”. Two (or more) people talk back and forth on the same frequency.

The advantage here is that no infrastructure is required, you simply need a couple of VHF or UHF radios, and a clear line-of-site. The disadvantage comes in if you don’t have that required line-of-sight. If there is any terrain or buildings between you and the person you’re talking to, the signal will be blocked partially or completely. As an aside, this is why the “35 Mile Range!” claim on consumer FRS radios is just typical marketing garbage. The 35-mile range might be possible, if you happen to be at a high elevation, over a wide open valley or plain. Perhaps it might work over open water as well. But in normal everyday circumstances, you’ll never get that kind of range.

Blocked by terrain
Terrain blocking LoS

 

So, how do we get around this problem, and get some real range out of our VHF and UHF radios? Repeaters.

Repeaters
Repeater operation
Repeater operation

Repeaters are basically a powerful transmitter and receiver with an antenna situated at a high elevation. They are often placed on hilltops, water towers, tall buildings, and of course, radio towers.

Input and output frequencies

A repeater has one simple job: It listens on a particular frequency known as the input frequency. Any signal it receives is immediately transmitted, usually at higher power, on the output frequency. This can allow even a handheld radio to communicate over a larger distance. Sometimes a very large distance, if the repeater is linked to others, but that’s a topic for later.

So, why do repeaters need to use two separate frequencies? Have you ever heard what happens when you hold a microphone too close to the speakers it’s connected to? You get an obnoxious loud squeal (feedback) because the sound from the speakers is being picked up by the microphone, fed back into the speakers, to be picked up by the microphone, and so on.

The same would apply to a repeater that transmitted and received on the same frequency: The transmitted signal would be picked up by the receiver, re-transmitted, received, ad nauseam.

So to prevent this, the output frequency and input frequency are far enough apart to keep the transmitter from interfering with the receiver. Here in the USA, the input frequency for a VHF repeater is almost always 600 KHz (0.6 MHz) away from the output frequency. Sometimes the input is above the output, sometimes below. This is called the offset, and it is written as “+600” or “-600”. UHF Repeaters, on the other hand, always have their input frequency 5 MHz above the output frequency.

Typical VHF/UHF radios made specifically for the ham radio market will usually set the repeater offset automatically if you tune to a frequency within the range designated for repeater outputs. You’ll have to look at the documentation for your specific radio to see if it has this feature.

Your radio will listen to the repeater output frequency, and when you hit the push-to-talk button, it automatically switches to the repeaters input frequency to transmit.

Repeaters are usually listed by their output frequency and offset, so you might see ‘146.85 -600’, or even just ‘146.85-‘.

Aside from being a means to extend your range of communication, repeaters tend to be the ‘social hubs’ of amateur radio. On a popular repeater, you can pretty much always find a few people to talk to.

The HF bands

This is where a lot of the fun stuff happens. The HF bands exist between about 1.8 MHz and 29 MHz, broken up into a few distinct bands. The advantage to these lower frequencies is that they can work over very long distances. In fact, when conditions are right, your transmissions might wrap all the way around the planet and echo back to you. This is because the HF frequencies, unlike VHF and UHF, tend to bounce off the ionosphere, one of the layers of the Earth’s atmosphere.

HF Propagation
HF Propagation

This is in contrast to VHF propagation, which typically requires line-of-sight, as discussed above.

VHF Propagation
VHF Propagation

As you can see in that image above, the signal from the station on the left can’t reach the station on the top. The direct line-of-sight is blocked by the curvature of the earth, and the portion of the signal going over the horizon passes straight through the ionosphere without bouncing back down.

I’ll talk more about HF communication in a later post, but HF operation is definitely a popular (but expensive!) part of the hobby. Many hams spend a lot of their time trying to make contact with other countries, and consider it a point of pride to have contacted as many countries as possible.

Getting your license

Your first license is likely to be a Technician Class license. This is the most limited type of license, and the easiest to pass the test for. The technician license grants you the ability to use the VHF and UHF bands, but just tiny portions of the HF bands. The General and Extra class licenses have more difficult tests, and offer greater privileges.

The General class license test is just a bit harder than the Technician license, but grants you permission to use most of the HF bands. The Extra class license lets you use the entire range of designated ham radio frequencies, and requires passing a substantially more difficult test.

Studying

It doesn’t take a lot of time to study for the Technician license. The American Radio Relay League publishes a few books, including the ARRL Ham Radio License Manual and many other ham radio books. The also offer some links to various study material on the web. You may also be able to find some ham radio classes being taught in your area, usually run by a local radio club.

Another incredibly valuable study tool is the set of practice tests available on QRZ.com. These practice tests have questions pulled from the same collection of questions that are used to create the real licensing tests.

Taking the test

Testing sessions are held by groups of volunteers nationwide, and you can usually get information about upcoming sessions from the ARRL. You will pay a small exam fee, and take a 35 question multiple choice test. If you successfully pass the Technician exam, you can take the General class test while you’re there without paying an extra fee. If you pass that one as well, you can try the Extra exam, which is a much more difficult 50-question test.

On successful completion of the Technician exam, your information will be sent to the FCC, and you’ll be assigned a callsign and get a license mailed to you. That process takes a couple of weeks. Usually, though, your license will show up in the FCC’s database after only a week or so. If you run a search for yourself in the FCC’s ULS database and find a callsign assigned to you, you’re free to start using the privileges of your license while waiting for the paper copy to arrive in the mail.

For much more information on licensing, and information on upcoming exam sessions in your area, have a look at the ARRL’s licensing page.

Your first radio

All you really need to get started with your new hobby is a fairly inexpensive VHF or dual-band (VHF & UHF) handheld radio, or perhaps a ‘mobile’ radio to mount in your vehicle, or keep on your desk at home. There’s a lot of options out there, but I suggest starting with a basic model. More advanced radios have more features, but they can just be confusing at first.

If you’re on a budget like me, you can get a cheap Chinese handheld radio for less than $50 these days, like the Baofeng/Pofung UV-5R.

These Baofeng/Pofung handhelds are perfectly fine for the most part, but they come with terrible documentation and can be difficult to program. I’ll do a post on programming them at some point, but for now you can find a lot of good information here.

If you’ve got the money, you might consider a more reputable radio made by Kenwood, Yaesu, or Icom. This Yaesu FT-60R is a pretty great value, and one of my personal favorites.

If you live near the Twin Cities metro area, we’re lucky enough to have one of the very few amateur radio stores left in the country, Radio City in Mounds View. Stopping in there to ask some questions and get a hands-on look at your options is great. They also teach licensing classes there on occasion.

So, why?

Why should you get a license and use amateur radio? Well, it’s fun. It’s a very social hobby, since the main purpose is to talk to other hams, after all. Just talking on a local repeater for a while, you’re likely to meet all kinds of new people with a shared interest. You might even think about joining a local club and meeting up with some folks in person.

Also, it’s a great tool to have in the box in case of emergency. The saying is “When all else fails, there’s amateur radio.” Even if phone service fails, or the mobile phone network is overloaded during a disaster, you’ll still be able to communicate. Once you have a General class license and an HF radio, you can talk to anywhere in the country, or even across the world, running on battery/solar power with an improvised antenna. I’ve done it, while camping, and it was great fun.

And of course, we need a steady flow of new licensed hams to keep things interesting, and keep the hobby alive.

Conclusion

I guess that about wraps it up for this post. We’ve gone over some basic concepts, talked about licensing, and a bit about choosing your first radio. I might have rambled on for longer than I intended, but I’ve tried to keep things organized enough to skim through and jump back and forth through the different topics covered. I hope you’ll consider getting your license, and maybe I’ll hear you on the air someday.

Stay tuned for my next ham radio post; Amateur Radio 102: Basic Usage. I’ll be talking about the practical aspects of operating a radio, generally accepted procedures, courtesy and etiquette.

Ready for part 2? Here it is: Amateur Radio 102: Basic Usage

Thanks for reading!

-Steve, K0MCG

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