Amateur radio

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Amateur radio, often called "Ham radio," consists of a set of high-frequency short wave bands that licensed individuals can broadcast and receive communications in virtually any country, with the exception of North Korea. Hams (the name given to amateur radio operators) volunteer their radio skills during emergencies to provide communications when regular communications fail such as in the aftermath of Katrina or a terrorist attack. Ham radio is also a hobby and a source of entertainment for operators who use it to broadcast information, educational, music, two-way communication, and many other types of broadcasts.

Amateur Radio Base Station.jpg

Contents

Common Ham Uses

Two-Way Communication

  • Chat with other people
  • DX - try to talk to as many different countries as you can
  • Morse code
  • Radioteletype - broadcast what you type on a special keyboard
  • Use small handheld radios to communicate locally
  • National Traffic System - Still used to shuttle messages back and forth across the country.

Organized Programs

ARES (Amateur Radio Emergency Service)
Help keep communication up during emergencies.
RACES (Radio Amateur Civil Emergency Service)
A group much like ARES but tied to local civil defense agencies.
SKYWARN
A weather spotting and reporting program of the National Weather Service (NWS). (You do not need to be an amateur radio operator to participate in this program, but you do need NWS certification and training.)
MARS (Military Affiliate Radio System)
Help overseas soldiers keep in touch with home.
Public Service Communications
Volunteer to help with marathons, parades, and other public functions where they need trained communicators.

Technical Pursuits

  • Bounce your signal off of the Moon
  • Build your own radio or collect antique radios
  • Experiment (new antennas, laser or microwave communications, etc.)
  • Go on foxhunts (finding hidden radio transmitters)
  • Send and receive TV
  • Send and receive data using packet radio
  • Use ham radio satellites (several in orbit)
  • Talk to astronauts on the International Space Station
  • Use a repeater (powerful stations that retransmit your weak signal)

Digital Communications

Digital communications over ham is becoming increasingly popular.

PSK31
A digital mode requiring a computer, PSK31 (Phase Shift Keying) requires little bandwidth (around 100 Hz) and can be heard easily over long distances
WSPR
A digital mode requiring a computer which can tolerate high amounts of noise. In fact you can receive a data transmission even when the signal is below the noise floor.
RTTY
A digital mode requiring a computer which only supports a limited character set, and is used both in net operation and 1:1 chats
SSTV
A digital mode that transmits pictures. Frame rate is about 2 frames per minute. The space shuttle and International Space Station (NA1SS) transmit images from space via this mode.
Packet
A digital mode requiring a computer, allowing for transmission of text as well as small computer files. Uses the AX.25 protocol (Amateur x.25). Developed in the 1970s.
Pactor
A digital mode requiring a computer, allowing for transmission of text as well as small computer files. Released to the public in 1991. Improved reception of digital signals as it includes error correction (CRC). Allows for internet access to remote locations (as well as at sea using Marine Radio).

Nets

A net is an on-the-air meeting of hams who have a particular interest. There are nets for hams who are pilots, RV travelers, high school students, WWII veterans, hams who are gay, hams who collect Civil War memorabilia, and many more. There are “traffic nets” that are used to pass information worldwide; for example, for missionaries to communicate with their families.

Licensing

This following applies to licensing in the USA; other countries have their own (usually similar) requirements.

A license is required to transmit with ham radio, anyone can listen, but it is a felony to transmit without a license. Ham is actively patrolled for offenders who are prosecuted, which is why ham radio is far more organized and orderly than CB radio.

It should be noted that in a real emergency where no other means of communication is available that anybody can use any mode or frequency, regardless of licensing. While this is the case licensing is still strongly recommended as it allows for usage of the radios and its various modes to ensure familiarity when an emergency does arise.

License Classes

In the USA, there are three classes of ham radio license and all of them require that you pass tests. These tests are published to make preparation easier and not considered to be difficult by most people. Licenses in the USA are valid for 10 years from date of registration, and are renewable.

Technician Class (prerequisites - None)
The first license is the Technician class which requires you to pass a 35 question test with 70% correct or better. There is a “pool” of 350 possible questions, divided into 35 sections of ten questions each. On the test, one question is taken from each section. The questions are on the rules and regulations governing ham radio, operating procedures, safety, and very basic electronics. Many of the questions are common sense (Q: When is it legal to use obscenities on the air? A: never), and the rest are relatively easy to learn. Once you have your technician class license you will have the following privileges:
  • Transmit on VHF and UHF and Microwave frequencies up to 1500w
  • Transmit on part of the 80, 40, and 15 Meter Bands in Morse Code up to 200w
  • Transmit on part of the 10 Meter Band in SSB voice up to 200w
General Class (prerequisites - Technician Class license)
A general class license will allow you to broadcast on a greater range or high-frequency bands and requires another written test. The test will consist of more about in depth information about the rules, operating procedures, and electronics. While it does require a more preparation than the technician class, anyone can get a general class license with a little work. With a general class license you gain the following privileges:
Amateur Extra Class (prerequisites - General Class license)
The highest class license is the Amateur Extra class, which requires a 50 question written test on more advanced operating procedures and electronics. With an amateur extra class, you will be able to broadcast on all amateur radio frequencies. Amateur Extra class also enjoys full reciprocal operating privileges in many foreign countries when traveling, though you will need to properly apply for such privileges from the governing authority of that country.

Preparing For Tests

To prepare, you need a copy of the questions that can download them from the American Radio Relay League, or you can buy one of the study manuals from the ARRL:

  • The Technician’s Q&A Book - the questions with short explanations of the answers)
  • Now You’re Talking - a more detailed guide to ham radio

Or you can download a free study guide from KB6NU:

  • No-Nonsense Technician Study Guide (pdf) this guide will explain the theory using the same words that the test uses. This makes it a snap to learn the material and pass the test.
  • No-nonsense General Study Guide (pdf) This guide will use the exact wording that appears on the test to explain the theory that the test covers. It makes it much easier to pass the test.
  • AD7FO's extra class study material This will give you the questions and answers along with some information why those are the answers for the Extra exam. Its similar to the no-nonsense guides by KB6NU.

The ARRL also sells manuals for the higher licenses, helpful materials for learning code, and other educational materials. You can als buy DVDs that will prepare you for the test. There are also web sites where you can take practice tests using the actual questions, such as W8MHB.com.

Taking The Tests

When you’re ready to take the test, you have to find a local radio club. The tests are given by Volunteer Examiners (VE) who are ham radio operators trained and certified to administer examinations. They will administer and grade the test and send your info to the FCC if you pass. The FCC will issue your license. If you pass an examination for one level you may also take the examination for the next level at that same session for no additional cost. So, if you pass your Technician's exam, you can immediately take your General exam as well. Some hams have passed all three tests at the same session. The test may cost anywhere up to $15.00 to cover the volunteer’s expenses, though it is sometimes given for free at special events or through amateur radio clubs. You can get a list of clubs and test dates from the ARRL web site. Once you pass your test, you have a license for life (it must be renewed once every 10 years; renewal is free). You will be assigned a set of call letters that uniquely identifies your station.

Equipment

Once you have a license, you will need equipment to make use of it; namely a radio transceiver that is capable of broadcasting and receiving the frequencies you are interested in and licensed to use.

Types of Radios

There are many different types or radios with a wide variety of features, capabilities, and price ranges.

Handheld Radios
These are excellent for portability and local communication. Also known as HT radios (short for handy-talkie).
Mobile Radios
These are excellent all-around radios with the power of a base station and the mobility of a portable. Typically near the size of a car stereo for easy mounting in a vehicle.
Station Radios
These are used from a base location and have more power, features, and range

Radio Features

Radio transceivers have many different features and capabilities to consider when choosing which radio is right for you.

  • Band/Frequency Capabilities - some radio only broadcast/receive 1 band, others cover the entire amateur spectrum
  • Power - radios can very greatly in power output, which is a major factor in range capability
  • Digital
  • Modes - voice (called Phone), Morse code, RTTY
  • Modulation type - AM, FM, SSB, CW
  • Antenna Analyzers
  • Computer Control
  • Digital Signal Processors

Antennas

For inexpensive but effective portable antennas you may want to visit homebrew antennas.

Amplifiers

Most HF rigs put out somewhere between 100 and 400 watts. With use of a linear amplifier, you can go up to a full legal limit of 1500 Watts! There are some rules concerning what bands you can do this on, and how much power you can put out in terms of PEP (Peak Envelope Power) but by the time you get into all of that, all of that will make sense.

Repeaters

A repeater is a machine that typically exists in a fairly high place that listens on one frequency, amplifies the signal, and outputs it on another frequency. In the 2 meter band, the frequency offset is typically 600khz. The direction of the offset is dictated by the band plan.

Some Dual-band/Dual-VFO mobile radios have a feature called "cross band repeating." This acts as a repeater that crosses bands. Handy if you're prone to hiking just outside of your HT's range, but well within your mobile's range. Here, you can use your HT to "hit" your mobile rig in your vehicle, which can then hit the repeater.

Often repeaters can be interconnected so what one repeater transmits gets repeated across multiple repeaters, giving a much longer range. It is not unusual on some frequencies to be able to reach from Portland to Puget Sound on a frequency that is typically line-of-sight due to interconnected repeaters.

While there are no laws governing who can make a repeater and where, there is a general agreement that when setting up a new repeater the repeater owner will work with a registering organization to identify available frequencies on which they can operate without causing conflict with other established repeaters.

Where to Get a Radio

There are a lot of places to buy ham radios and accessories, Hamfests are gatherings of ham radio operators where they buy, sell, and swap equipment, win radios as prizes in drawings, take ham radio tests, and talk. At hamfests you can get both new and used equipment. Many hams operate with used rigs, and a well-cared for radio lasts all but forever. Here are some sources:

See Also


References


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