Wednesday, June 23, 2010

About Ham Radio

I hear it every time I bring up the subject.  I can use my cell phone anytime I want. I have minutes to spare on my plan.  Why should I bother getting a ham license? 

When all else fails, ham radio gets through.  After the Haitian earthquake last winter, the first communications with the country were through ham radio.  After hurricanes, earthquakes, any sort of natural disaster, or even a terrorist attack, it's usually the same way: ham radio works first.  Cell phones are really more vulnerable than wired phones.  Anything that takes out the wired phones takes out cell phones, and anything that could take out a tower kills cell phones, too.  Cell phones are everywhere, but after your voice leaves that fancy little radio in your hand it goes almost entirely on the wired POTS (plain old telephone system) infrastructure.  It will be POTS all the way to the other end of the call, unless they're on a cell, too, and then it's just radio at the very end of the link.  In the event of a disaster, AT&T's phone line's emergency life is limited by remote boxes that have batteries designed for 6 hours backup time in case of a power fail, and you can expect the same from other providers.  Even if the system is physically working, have you ever noticed that whenever an emergency happens the phone system becomes useless?  Heck, the phone is almost unusable on Mother's Day!  That's because the system is designed so that only about 10-20% of the phones installed have physical wires to support them.  That's efficient network design and keeps the phone company rates reasonable, but it can't support the demand that comes in an emergency.  

If there is another terrorist attack, it will be like 9/11; a surprise attack when you're going through your day to day life.  How do you communicate with your family, or others that you need to communicate with?  What if a nuclear weapon smuggled into New York, or Chicago goes off while you're at work or separated from your spouse and kids?  You don't have to be in those cities to be affected by it - remember a couple of years ago when a couple of powerlines sagging in the heat caused a blackout that took out most of the NE of the US?  I think it's a safe bet that a major attack could take down the power grid.   

How do you communicate with your family or friends if something happens while you're at work?  The only answers involve radio, either FRS/CB or ham (amateur) radio.  For various reasons that I'll explain, I believe it's worth it to get the ham radio license and follow that path. 

The main reason to get your ham license is the ham service gives you many more choices of frequencies and ways to communicate.  FRS (Family Radio Service) is a UHF band (close to a ham band at 420-450 MHz), and CB is an HF band, again close to a ham band at 28 to 29.5 MHz.  Most amateur radio licenses grant privileges in bands spread across the entire shortwave spectrum, from 1.8 MHz (just above the AM broadcast band) to 30 MHz (just above the CB band), plus bands of frequencies through the VHF, UHF and microwave range.  The reason you want this is that the range of communications varies across all of these bands, allowing you to choose the frequencies most useful to you.  In other words, you may be trying to communicate with someone that is not in range to a CB or FRS radio, but you can choose a ham band that works.  In addition to the choice of frequencies, ham radio gives you more choices in how you communicate, from voice (AM, FM or SSB) to many digital and imaging modes. 

The optimum frequency to use will depend on the distance you need to communicate over, and will vary with the time of day, time of year, and the activity of the sun (the sun has activity cycles that last an average of 11 years; the next peak is predicted for 2013)  In general, during the day, the optimum frequency goes up, and during the night, the optimum frequency goes back down.  HF has the unique ability to propagate over long distances, and long time CB'ers will know that these signals can skip over large paths, being heard only in specific areas.  In the area closest to the transmitter, signals are carried by what is called "ground wave", and higher frequencies are better than lower.  For example, to communicate with a friend at the opposite end of town, it's easier for me to use 144 MHz than 3.5 MHz, with good outside antennas. 

For example, let's assume you want to communicate 500-ish miles, say from southern Florida into North Carolina, or from South Texas into Nebraska.  For this communications link, night time communications would be usually best in the amateur bands at 1.8, 3.5 and 7.0 MHz, while daytime communications would be in the amateur bands at 7.0, or 14.0 MHz, but it might be possible to communicate in any amateur band up to 50 MHz.  How about cross country, say from Florida to Washington?  During the evenings, the 7.0 or 14.0 MHz bands are probably good, and during the days, the bands at 18, 21 or 28 MHz would work well, depending mostly on solar activity.  "Evening" or "daytime" means at both ends of the path, by the way. 

In general, VHF and UHF are better for local communications and HF is better for long distance.  VHF/UHF tends to be "line of sight", although both get over the horizon to some degree.  It's why VHF FM broadcasters put their antennas on tall towers (in contrast to the AM broadcaster, where the tower is the antenna).  Hams usually try to put their HF antennas up high, and try for long distance communication, but HF can be used for local communications just out to a couple of hundred miles, too.   

Most hams own a handheld radio, or HT, that transmits somewhere in the VHF or UHF spectrum - typically the 144 to 148 MHz ("2 meter") band, and often the 440-450 MHz ("70 centimeter") band.  Hams around the country have invested tens of thousands of hours of their time, and millions of their own dollars to build an infrastructure of repeaters that extends the usefulness of these radios.  A repeater does what the name implies, it "repeats" your transmission from a higher, more powerful transmitter; you transmit on one frequency, it re-broadcasts on another, so your radio has to receive on a different frequency than what it transmits on.  Repeaters both extend the range and add capabilities such as dialing a connected landline phone.  If your only use for a radio is to contact your family or friends around town, a VHF or VHF/UHF dual-band radio could be all you need.  You may need to join a radio club to make use of the repeaters, but many of them are "open" - available to anyone who needs to use it.  The drawback to repeaters is the same as any infrastructure: when the SHTF and everyone is trying to use it to contact their family, the system won't support it.  These are radio channels that can only handle one user at a time.

So what's the alternative to a repeater?  A good antenna, outdoors, as high as you can get it.  With my HT and a good outside antenna, I easily communicate reliably over 20 mile ranges, direct, radio to radio.  This is going to be tough if there is a crisis and you're in a car, or if you're running to your car, or if you're trying to round up family.  Pre-planned meeting places is standard advice; you can call on the radio while on the way to make sure everyone's okay, and put everyone's mind at ease. 

A VHF or UHF HT is a good tool if you're living on a farm or in a rural setting, maybe with a group that's helping each other out.  You can keep touch with each other all over several acres directly with these radios.  FRS might do as well, but ham radios tend to be higher power and can reach farther. 

To use any ham radio, all of the users need to be licensed, or in the presence of a licensed operator, so if your spouse and children are going to use ham bands to stay in touch, all of them need to be licensed.  So how do you get a ham license?  The Feds gave responsibility for licensing over to the ham service itself back in the 1980s, under a Volunteer Examiners Program.  The two largest VE organizations allow you to find a local session here: ARRL or W5YI VEC

You can expect to find a local club or group that offers tests once a month or so. 

What are the requirements?  There are 3 classes of amateur license, technician, general and extra (the remnants of a system that once had 6 classes - I only say this because you may see reference to Novice licenses, or Advanced licenses or meet people that tell you to get a novice license).  All three classes have written exams, with no requirements to send or receive Morse code any more.  Morse code is still extremely valuable as a communications mode, especially in a SHTF scenario with low powered radios used with makeshift antennas, but you are not required to learn it any longer.  Both of the organizations that perform the tests will sell you study materials for the test, or you can find materials in a library, radio club or online.  If you go to a library, make sure the books are not more than a couple of years old, or they prepare you for the wrong test.  The technician class is a VHF/UHF only license that conveys privileges above 30 MHz.  The general provides the technician privileges along with some privileges on all the HF bands.  The extra class provides all amateur privileges on all amateur frequencies.  You may take one test or all of them on one day; there is no requirement for being licensed some amount of time before upgrading. 

It's important to remember that the purpose of the exams is not to make you a radio engineer.  It's simply to make sure you understand the laws that tell you the conditions of your license; the frequencies you can use, something about antennas, safety, and a bunch of topics.  The vast majority of hams are not technicians or engineers.  We are about 85% men, 15% women, and work as truck drivers, security guards, doctors, telephone workers, radio hosts, and a broad cross section of jobs. 

How much does it cost?  Like all hobbies you can spend as much or as little as you'd like.  I have seen installations that would make the military drool, and others put together by restoring old radios and spending almost nothing.  A good VHF or UHF HT, new, is somewhere between $100 and $400 depending on features.  An HF radio, again new, bare bones is around $600 and up as you add features.  Used radios are widely available, and very good, useful HF radios are $300-ish.  Figure some cost for an antenna system. 

Antennas are very important to your station.  For transmitters, antennas are a much bigger and trickier subject than for receivers; they must be certain specific lengths, designed to work on multiple bands, or you need to use something called an antenna tuner.  An automatic antenna tuner and a simple antenna are a very effective way to use many amateur bands.  Like most electronics, prices continue to come down and capabilities go up.  A very capable automatic antenna tuner for the usual power ranges at HF will set you back $150 to $200 brand new.  Figure $100 or so used.  A simple wire antenna that can be deployed in a hurry costs around $20. 

Being sure you can communicate with your family is priceless.  Ham radio is an excellent tool to add to your survival BOB.

The American Radio Relay League is the largest ham radio organization in the US, and they specialize in helping folks get started.  There are equivalent national organizations everywhere.

3 comments:

Bob said...

Roger that! I think we (hams) need to establish a radio based wireless alternative to the Internet and have it ready when Obama "turns off" the Internet.

Anonymous said...

The regulations governing ham radio are given in Part 97, here are two URLs that list these regulations. Doubtless they are also available from the FCC.
http://www.arrl.org/part-97-amateur-radio
http://www.ncvec.org/page.php?id=338

There are study guides that explain the regulations as well as the questions, answers, and in some cases further discussion of the material covered by the license examination.

The questions on the written exam for each license class are publicly available, altho they periodically change.
http://www.ncvec.org/page.php?id=338

Find a local amateur radio club
http://www.arrl.org/find-a-club

Graybeard said...

Good stuff, anon! Thanks for the links.