Ham radio for experiment oriented people
If you like building toy transmitters and seriously interested to upgrade your equipment for real long distance communication, then you should definitely go for ham radio. It is illegal to possess or build wireless transmitters and use them for short or long distance (worldwide) communication without a valid license. According to the Indian Wireless Telegraphs (Amateur Service) Rules 1978, "AMATEUR RADIO SERVICE" means "a service of self training, inter-communication and technical investigations carried on by amateurs that is, by persons duly authorized under these rules interested in radio technique solely with a personal aim and without pecuniary interest".The possibility of reassembling electromagnetic wave impulses into speech or music became practical with Lee Dee Forest's invention of triode valve (now replaced by semiconductors). Despite the availability of triode valve before World War-I, radio broadcasting for the most part remained the plaything of ham radio operators. While the World Wide Web (WWW) related to the present day INTERNET communication essentially utilizes computers connected to the telephone through a modem, these group of radio enthusiasts have been using their wireless radio stations to form a worldwide network. The concept of INTERNET has resemblence in many aspects to the global nets run by radio amateurs. Thousands of ham radio operators around the world have in-fact connected their computers to the radio sets through a kind of interface for exchanging information on the air and this facility has been available among the ham radio operators much before the INTERNET has been introduced.There are various types of digital communication techniques (The most common mode is the Radio Tele Typing or RTTY) where computers are being hooked to the radio sets.The ham radio operator enters the message to be transmitted into a computer by pounding the computer keyboard. From the computer the message goes to the wireless transmitter and other ham radio operators tuning their radio receivers (connected to the computer through an interface) to that particular frequency of transmission can read the message on the computer screen itself!
Nowadays, a more efficient mode of computer- to-computer ham radio communication system exists known as the PACKET RADIO communication. Hams got their own wireless E-Mail and Bulletine Board System (BBS) . Through Packet radio,a ham radio operator can get access to another ham's computer and exchange information through short wave radio as well as through Very High Frequency (Walkie-Talkies connected to computer!). The new innovations in the field of ham radio are the PacTOR (a combination of Packet Radio and Amateur Teleprinting Over Radio-AMTOR), CLOVER (a very fast data communiation method for error free operation in the HF band), Fast Scan Television (FSTV), Slow Scan Television (SSTV).