Radio TeleTYpe (RTTY) is a method of sending digital messages between radios using tones. It's a digital mode used in ham radio that can be conversational, similar to technical conversation or rag chewing.
Here are some things to know about RTTY:
- RTTY evolved from landline teleprinters in the mid-1800s. The US Navy successfully tested printing telegraphy between an airplane and ground radio station in 1922.
- RTTY can use several coding methods, such as Baudot, Amtor, and simple ASCII.
- Modulation: RTTY uses AFSK (audio frequency shift keying) or FSK (frequency shift keying) to transmit tones.
- Speeds: The most common RTTY speed is RTTY 45 (45.45 baud), but other speeds include 50 baud and 75 baud.
- The shift is usually 170 Hz, with the upper tone used for idle condition (MARK).
- Today, RTTY usually involves using a computer and modulation/demodulation software.
