RTTY

Description :
Baud rate : 45. A character is composed of a “ start ” bit (1 “ space ”), 5 bits and a “ stop ” bit (1.5 “ mark ”)
Speed : 60 wpm
Modulation : FSK two tones (“ mark ” and “ space ”, "mark" high) with a shift between tones of 170 Hz (or, sometimes, 200 Hz),
Receive mode : USB
Character set : ITA2 (32 letters and 32 figures) without error correction character (“ fixed length ” characters). Small characters are transformed in capital characters and special characters as “ é ” are transformed in standard capital (in the example: “ E ”)
Shape of pulse : rectangular
Bandwidth : about 600 Hz (due to rectangular shape),
Demodulation : non coherent,
Synchronization: on “ start ”
Correction code: no
Convolution code: no
Interleaving : no
Pmean/Ppeak : 1
Lowest S/N : -5.5 dB

For radio amateurs, the transmission speed is 45 bauds with a 170 Hz shift.

In commercial RTTY, the transmission speed may be, theoretically, 50, 75 or 100 bauds with a 85, 425 Hz, 450 or 850 Hz shift. In reality, only 50 and 75 bauds are available (in fact only 50 bauds).