كتاب البداية في الهواية
What is Amateur Radio?
Amateur radio is a community of people that use radio transmitters and receivers to communicate with other Amateur radio operators. If you were to ask a dozen different amateurs what ham radio meant to them chances are you would get 12 different answers. Amateur radio operators are often called ham radio operators or simply "hams" and frequently the public is more familiar with this term than with the legal term Radio Amateur. The source of this nickname is for all practical purposes lost from the beginning.
Amateur (HAM) Radio is truly a hobby and often one that makes a difference especially in emergency or disaster situations. It is an activity of Self Learning, Inter-Communication & Technical Investigation carried on between Amateur Radio Operators. Amateurs talk to local friends over the radio waves using a hand-held transceiver, communicating digitally with packet radio to exchange personal messages or vital information in an emergency, talking to other hams anywhere in the world, or engaging in contests with other Radio Amateurs over the airwaves there is something for everyone. An estimated six million people all over the world pursue this activity in their free time. Popular Amateur Radio Activities
- QRP – Communicating with "very low power" is a challenge that many hams enjoy. QRP is usually practiced on the HF bands
- HF radio – Hams can talk to other hams in literally any part of the globe using HF radios
- VHF (2 meters) or UHF (70 cm.) – Hams enjoy extremely reliable communications within their local community. You can extend your VHF range up to 50 miles or more by transmitting through a local repeater.
- DXing – DX means distance communication and with the right equipment worldwide communication on the HF bands (10 through 160 meters) is a regular possibility.
- Emergency and other volunteer services – Floods, landslides, earthquakes, Cyclones, Accidents (Rail / Road / Air). when ever normal communications go out, hams are ready to use their radios to provide emergency communication services to their communities
- Technical experimenting – Hams come from all walks of life ranging from technicians to engineers, teachers to scientists, and students to retirees. For many of them the attraction to the hobby is to build their own equipment whether it is just a simple antenna, something as complex as a transmitter, or an interface between their radio and a computer.
- Contesting – Contesting is often called the "sport" of ham radio. Almost all the time there is some form of amateur radio contest. Hams get on the air and compete to see who can make the most contacts in a limited period of time.
- Space Communication – Yes, it is really possible. Space stations do have ham radio equipment and licensed ham astronauts take the time to make contacts with amateurs on earth. Hams also have satellites where you can bounce a signal to communicate with other hams on earth.
- Digital communication – Connect a computer to your radio and install some software and you can communicate digitally over the air. Some of these digital modes can be more effective in marginal transmission conditions and some even sport error free transmission.
- Internet communication – Using some of the latest technologies, hams can supplement a modest station with Internet connections. Using features such as URL or IRLP on a local repeater, a ham in Europe can talk to one in Asia or even Australia using a simple hand-held transceiver.
- Fast Scan TV or Amateur television (ATV) – Transmit or receive broadcast-quality video and audio.
- Slow Scan TV – Transmit and receive pictures to and from around the world.
- Morse Code -Communication using the Morse Code system originally designed by Samuel F. B. Morse.
- IOTA Chasing – IOTAs (Islands on the Air) are Island based stations. Hams usually compete by making contact to large numbers of IOTA stations or to IOTA stations with rare amateur radio activity.
These are just a few of the many different activities that radio amateurs participate in and enjoy on a daily basis.
The Beginning of Radio During the 1860s, Scottish physicist, James Clerk Maxwell predicted the existence of radio waves; and in 1886, German physicist, Heinrich Rudolph Hertz demonstrated that rapid variations of electric current could be projected into space in the form of radio waves similar to those of light and heat. In 1866, Mahlon Loomis, an American dentist, successfully demonstrated "wireless telegraphy."
Loomis was able to make a meter connected to one kite cause another one to move, marking the first known instance of wireless aerial communication. Guglielmo Marconi, an Italian inventor, proved the feasibility of radio communication.
He sent and received his first radio signal in Italy in 1895. By 1899 he flashed the first wireless signal across the English Channel and two years later received the letter "S", telegraphed from England to Newfoundland.
This was the first successful transatlantic radiotelegraph message in 1902. In addition to Marconi, two of his contemporaries Nikola Tesla and Nathan Stufflefield took out patents for wireless radio transmitters. Nikola Tesla is now credited with being the first person to patent radio technology; the Supreme Court overturned Marconi's patent in 1943 in favor of Tesla. In 1901, radiotelegraph service was instituted between five Hawaiian Islands.
By 1903, a Marconi station located in Wellfleet, Massachusetts, carried an exchange or greetings between President Theodore Roosevelt and King Edward VII.
In 1905 the naval battle of Port Arthur in the Russo-Japanese war was reported by wireless, and in 1906 the U.S. Weather Bureau experimented with radiotelegraphy to speed notice of weather conditions.
In 1909, Robert E. Peary, arctic explorer, radio-telegraphed: "I found the Pole".
In 1910 Marconi opened regular American-European radiotelegraph service, which several months later, enabled an escaped British murderer to be apprehended on the high seas.
When the United States entered the first world war in 1917, all radio development was controlled by the U.S. Navy to prevent its possible use by enemy spies. The U.S. government took over control of all patents related to radio technology.
In 1919, after the government released its control of all patents, the Radio Corporation of America (RCA) was established with the purpose of distributing control of the radio patents that had been restricted during the war.
In 1915, speech was first transmitted across the continent from New York City to San Francisco and across the Atlantic Ocean from Naval radio station NAA at Arlington, Virginia, to the Eiffel Tower in Paris.
Edwin Howard Armstrong invented frequency-modulated or FM radio in 1933. FM improved the audio signal of radio by controlling the noise static caused by electrical equipment and the earth's atmosphe.
Until 1936, all American transatlantic telephone communication had to be routed through England. In that year, a direct radiotelephone circuit was opened to Paris In 1947, Bell Labs scientists invented the transistor.
In 1954, a then small Japanese company called Sony introduced the transistor radio.
In 1965, the first Master FM Antenna system in the world designed to allow individual FM stations to broadcast simultaneously from one source was erected on the Empire State Building in NYC.