Ham's Pictures
Amateur radio activities and practices
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An amateur radio operator
Radio amateurs use various modes of transmission to communicate. Voice transmissions are most common, with some such as frequency modulation (FM) offering high quality audio, and others such as single sideband (SSB) offering more reliable communications when signals are marginal and bandwidth is restricted.
Radiotelegraphy using Morse code remains popular, particularly on the shortwave bands and for experimental work, with its inherent signal-to-noise ratio advantages. Morse, using internationally agreed code groups, also facilitates communications between amateurs who speak different languages.[2] It is also popular with home constructors as CW-only transmitters are simpler to construct. For many years a knowledge of morse code was necessary to obtain amateur licences for the high frequency bands but following changes in international regulations in 2003 many countries have now dropped this requirement (the USA did so in 2007).
Modern personal computers have led to a boom in digital modes such as radioteletype, which previously required cumbersome mechanical equipment.[3] Hams led the development of packet radio, which has since been augmented by more specialized modes such as PSK31 to facilitate real-time, low-power communications on the shortwave bands. Other modes, such as WSJT, are used for weak signal modes including meteor scatter and moonbounce communications.
Similarly, fast scan amateur television, once considered rather esoteric, has exploded in popularity thanks to cheap camcorders and video cards in home computers. Because of the wide bandwidth and stable signals required, fast scan amateur television is normally limited to 100 km (about 60 miles) range. However, with ham TV repeaters linked together the video may travel across several states.
Amateur radio station with vintage vacuum tube gear featuring separate transmitter, receiver and power supply
On VHF and higher frequencies, automated relay stations, or repeaters, are used to increase range. Repeaters are usually located on the top of a mountain, hill, or tall building. A repeater allows the operator to communicate over hundreds of square miles using a low power hand-held transceiver. Repeaters can also be linked together by use of other amateur radio bands, wireline, or the Internet. Repeater stations are either owned, maintained and operated by clubs or individuals.
Specialized Interests of Ham Radio
While many hams just enjoy talking to friends, others pursue specialized interests such as:
*Emergency communications for community emergency response teams
*Designing new antennas
*Communicating via amateur satellites
*Severe weather spotting
*DX communication to far away countries
*Using the Internet Radio Linking Project (IRLP) to connect radio repeaters via the Internet
*Tracking vehicles using the Automatic Position Reporting System (APRS), which integrates with the GPS
*Engaging in the sports of contesting
*Amateur Radio Direction Finding
*High Speed Telegraphy
*Low-power operation.
Some enthusiasts collect vintage amateur radios, such as those using vacuum tube technology. Some hams also assist in the restoration and operation of antique radio equipment at museums and museum ships.
Many hams enjoy meeting each other in person as well through local clubs or at Hamfests. These annual events are popular, with the largest being held in Dayton Ohio, where more than 20,000 hams gather each May.
