What is Radio Teletype (RTTY)

Radio Teletype (RTTY)

Frequencies	147.3 kHz,3.57 MHz,4.583 MHz,5.3305 MHz,5.3465 MHz,5.357 MHz,5.3715 MHz,5.4035 MHz,7.04 MHz,7.08 MHz,7.125 MHz,7.646 MHz,11.039 MHz,14.07 MHz,14.4673 MHz,28.15 MHz,10.1008 MHz,10.13 MHz
Frequency Range	147.3 kHz - 28.15 MHz
Mode	USB
Modulation	FSK
ACF	—
Emission Designator	—
Bandwidth	85 Hz,170 Hz,450 Hz,850 Hz
Location	Worldwide
Short Description	RTTY (Also known as Baudot or ITA2) uses the Baudot 5-bit alphabet with FSK to send text messages over the shortwave. This mode is gradually dying out in favor of more robust modes like PSK31 in the amateur service.
I/Q Raw Recording	—
Audio Sample

RTTY (Also known as Baudot or ITA2) uses the Baudot 5-bit alphabet with FSK to send text messages over the shortwave.

This mode is gradually dying out in favor of more robust modes like PSK31 in the amateur service. Uses the ITA-2 alphabet (Commonly known as Baudot, derived from the Murray code).

Apart from occasional ham use, the only other known user is the Deutscher Wetterdienst (German Meteorological Service).

There are many modes that sound like Baudot, but in fact aren't. For example, the Russians use a 50 baud /200 Hz system that to the ear, sounds like Baudot.

Closer examination with tools for viewing waveforms and other data will show this clearly.

Among amateur radio, the most common default mode of RTTY is 170 Hz with 45.45Bd.