Hams are all over the world. Although they all use transmitter-receiver, there are more than one QSO modes. Similar to swimming ways include breaststroke, butterfly, backstroke and other ways. QSO modes also have Audio, Morse code, RTTY, TV(SSTV) and Packet radio.
According to a recent research, the most used mode for hams is audio QSO. Audio QSO has rules that must be followed in order to improve the clarity of oral communication and reduce the error rate of oral expression. The equipment of audio QSO is simple, just a radio, and sending audio messages according to rules to make QSO with others. Therefore, the outstanding advantage of Audio QSO is that the operation is simple and easy to use.
Morse code QSO
Morse code is the used mode second only to audio QSO. The way breaks the difference between languages of various countries, and only depends on a stable and unmodulated radio signal, so the equipment is more simpler than other QSO ways, and we can make morse code QSO in high noise and low signal environments, so it is the most commonly used way in QRP. At present morse code is mainly used in CW mode.
RTTY is the short of Radioteletype. RTTY is also the one of the mainly used in CW mode. It needs radio and computer software to work together. The audio signal processing is all done by sound card and computer software. As long as the radio has SSB function, RTTY can be done. The computer used for RTTY does not need to be too high configuration, but need to have a sound card. The advantages of RTTY are high transmission recognition rate and fast transmission speed.
TV QSO is a main mode for amateurs to transmit pictures, including SSTV and ATV. Because the ATV needs very wide frequency band, we often use the SSTV. the advantages of SSTV are the narrow frequency band occupied, strong anti-interference ability, low cost and convenient software for fault tolerance and image post-processing. TV QSO is usually used in SW mode (or HF), VHF, and UHF band.
Packet radio QSO
Packet radio QSO uses packet switching technology to transmit data with the help of radio. The advantage of Packet radio QSO are high-speed transmission, and each packet sent contains callsign of the sender and receiver. Each packet station can be used as a repeater to communicate with our hams, which also makes packet radio particularly useful for emergency communications. Packet radios can automatically send their location and also check with the network regularly to show that they are still running.