What is "AA6E"?
AA6E is an amateur radio station callsign, assigned by the U.S. Federal Communications Commission. "AA" is one of the prefixes assigned to every licensed radio (and television) station. You are probably more familiar with other U.S. prefixes, such as "W" or "K".
The numeral "6" indicates the FCC district -- in this case, California, where I originally got my license. (A native Connecticut license would have a "1", meaning New England.)
An FCC amateur radio ("ham") license nowadays requires a formal application and passing a written examination covering a certain level of electronics and radio theory along with knowledge of relevant government regulations. Up to 2007, hams also had to pass a Morse code test, but that is no longer required.
For more details on ham radio, check What is Ham Radio?
This article is for readers who are new to the idea of Amateur Radio, but who have heard that there might just be something interesting to learn.
Amateur radio (or "ham" radio) is a non-commercial hobby that encourages radio communications and experimentation. Ham operators are licensed by the U.S. Federal Communications Commission (FCC Amateur Radio Service) or the equivalent authorities in other countries. Historically, amateur radio has attracted technically-inclined people who are interested in building and operating radio receivers, transmitters, and antennas. Today, excellent commercial equipment is available at attractive prices, so hams less often build their own basic receivers and transmitters. Many interesting technical frontiers remain to be explored, including for example, computer-based radio signaling methods, satellite communications, and new antenna designs.
Ham radio operations is the most interesting aspect for many. You can compete to work the most geographical areas ("DX" - long distance), you can help out in emergency and public-service communications, you can operate "mobile" from your car, boat, or airplane. There are many other special operating niches.
Amateur radio has a grand tradition from the 1910's onward, but the proliferation of computers, internet technology, cheap long-distance, and the cell phone have fundamentally changed the environment for the hobby. Still, there are over 600,000 licensed ham radio operators in the U.S., and active organizations like the American Radio Relay League (ARRL), supporting everything from old-fashioned "rag-chewing", to data transmission, to moon-bounce and satellite based communication, and beyond.
Amateur Radio began in the early 1900's using the technology of the day: Morse Code and "spark" radio transmitters. Operators would exchange non-commercial radio messages very similar to the wire-line telegrams of the day, which were sent across the continent by Morse.
The ARRL (aka "The National Association for Amateur Radio") is the major US organization supporting Amateur Radio. It was formed in 1914 specifically to support the passing of messages. Over time, radio connections supported more and more unstructured conversations between operators. While general conversations ("ragchews") are common today, there is still a hardy subset of ham operators who pass non-commercial messages.
As technology developed in the 1920's, hams added voice communications to their repertoire. In the 1940's the new radioteletype mode became possible. At first, this required large and troublesome electromechanical typewriters, but as personal computing technology came in in the 1970s, the big machines went away in favor of computer keyboards and displays.
Many other new communications methods become available. You can communicate through special amateur earth satellites and even bounce your signal off the Moon. You can operate from your car or boat. You can use FM voice modes mostly in the VHF and UHF bands using handheld ("walkie talkie") radios. You can send computer-to-computer messages using advanced processing methods. There are video (image) transmissions, too.
The FCC license supports innovations in radio
How we communicate today
Ham communications cover a wide range of operating styles. Here are a few of the more common ones:
- "Rag chewing" Informal contacts between one ham and another, or among a group of hams. The subject can be most anything, but we traditionally avoid touchy areas like politics and religion. Often we are talking to someone for the first time, and we can't take much for granted except a shared interest in the hobby.
- "Nets" Groups of amateurs get together on nets, usually at a scheduled time and frequency. It may be a group who are members of a single radio club, or it could be organized on a topic like public service (e.g. emergency service) or about any other particular interest. The earliest nets were organized for traffic handling, exchanging "radiograms" for the public. These are similar to telegrams, except they have to be non-commercial in nature. Traffic nets are still active today.
- "DXing" Hams like to "work" stations in exotic locations. Depending on operating conditions, "long distance" (DX) may be a few hundred miles, or it might be a connection with a station on the other side of the planet. Contacts ("QSOs") can be had with the International Space Station or some day with interplanetary probes. DXers often seek certification of their work by qualifying for special awards, like "Worked All States" or DXCC (contacts with 100+ countries).
- "Contesting" Many special contests are designed to test operating skill and endurance. They are typically scored according to the number of stations contacted, with emphasis on working as many countries or other regions as possible, using as many frequency bands as possible, etc. over a prescribed period of 24 - 48 hours.
A delightful tradition is the exchange of "QSL cards" confirming an on-air contact. Originally QSLs were The FCC license supports innovations in radio printed cards that were sent by post, or through special QSL bureaus. In recent years, several on-line QSL equivalents have developed, such as ARRL's Logbook of the World and e-QSL. QSL confirmations are important when hams are seeking awards such as DXCC (for working 100 countries or more).
How we communicate today: technology
There are so many technical options available today, it's hard to make a good list of all the ways you can communicate. Here is a list of some of the more popular activities:
- Morse Code (usually called "CW" - continuous wave). The original operating mode. You tap your message out in code using a telegraph key. The receiving amateur decodes the "dits" and "dahs" in his or her head. Nowadays, there are faster sending options ("bugs" or electronic keyers) and there is also computer decoding that can work in some situations. You can operate CW with relatively simple and inexpensive equipment. The FCC license supports innovations in radio
- Voice communication. Many modes are possible with voice:
- Amplitude Modulation (AM). The original voice mode uses the voice waveform to control the power level of a carrier signal. AM radio receivers can be quite inexpensive and are easy to tune.
- Single Sideband (SSB). A more advanced form of AM where redundant or unnecessary parts of the signal (i.e. one sideband and the carrier) are suppressed and not transmitted. This results in double the spectral efficiency (halving the bandwidth) and much higher power efficiency. SSB is the most common voice mode today for the HF bands (1.8 - 30 MHz).
- Frequency Modulation (FM). FM was introduced to minimize background noise that can be a problem with AM or SSB. It is the most common voice mode in the VHF/UHF (50 - 450 MHz) bands, but is mostly used for local or regional communications. FM does not work well with weaker signals.
- Digital Voice (DV). A number of methods of transmitting voice as streams of digital data have been developed. Some of them (D-STAR, DMR, Fusion) are mainly aimed at VHF/UHF use, while others (e.g. FreeDV) are also aimed at HF operation.
- Data Modes. There are many operating modes that have been developed to transmit digital data (text, image, voice, etc.) Most of these are aimed at the HF spectrum:
- FSK (RTTY) Radio teletype by frequency shift keying is the oldest digital radio mode, if you don't count Morse.
- FT8 (and other WSJT modes)
- Various others (MFSK, Olivia, ......)
- Other modes. Amateur Radio is a service that appeals to experimenters, and the FCC license supports many possible modes. Often this means trying new and exotic technical modes: adaptation of WiFi for ham use, many forms of digital operation, pulse (radar) operation, etc.
This chart (pdf) shows the most commonly used bands in the U.S.