PRESERVATION OF RTTY HISTORY
TELETYPE ART & CULTURE
EST. 1998
RTTY.COM The Radio Teletype Reference & Archive
THE INTERNET'S OLDEST
RTTY RESOURCE
BAUDOT • TELETYPE • WIRE
ITTY — INTERNET TELETYPE — FOUR CHANNELS • 24 HOURS A DAY • BAUDOT RTTY • ARVADA, CO

What is ITTY?

ITTY — Internet Teletype — is a live audio stream that encodes Baudot RTTY signals just as the AP and UPI wire services did for fifty years. The audio is standard MP3, playable in any browser or media player. Point a software decoder at the audio output, or route it through a hardware terminal unit to a real teletype machine, and the news prints continuously in ALL CAPS on paper — exactly as it would have in 1965.

ITTY broadcasts four channels, 24 hours a day, seven days a week, from Arvada, Colorado. Each channel is a separate Icecast stream. There is no subscription, no login, and no cost. Connect and listen.

How to Listen

The simplest way to listen is to click one of the channel buttons below. Your browser will open the stream directly — you will hear the FSK tones of the Baudot signal. To decode the signal into readable text, route the audio to a software decoder such as MMTTY or fldigi, or to a hardware terminal unit connected to a teletype machine.
Open a channel stream by clicking one of the Listen buttons below. The stream will play in your browser or default media player. Any internet-capable media player works — browser, VLC, Winamp, RealPlayer, or any application that can open an MP3 stream URL.
Route the audio to a decoder. On Windows, use a virtual audio cable (e.g. VB-Cable) to feed the stream audio into MMTTY or fldigi. Set the decoder to RTTY mode, 170 Hz shift, at the baud rate for your chosen channel (see Technical Details below). On a Mac or Linux system, use BlackHole or Jack for audio routing.
For a real teletype machine, route the stream audio to a hardware FSK terminal unit (demodulator), then connect the TU’s current loop output to the machine. The signal chain is identical to a radio RTTY installation — the only difference is that the audio source is the internet stream rather than a radio receiver.

The Four Channels

LIVE 24/7
ITTY — 60 WPM
45.45 baud • 170 Hz shift • LSB
internet-tty.net:8000/ITTY
Wire service news articles, formatted and transmitted continuously at the North American amateur RTTY standard of 60 words per minute. Content is loaded daily.
▶  Listen http://internet-tty.net:8000/ITTY
LIVE 24/7
ITTY — 100 WPM
75 baud • 170 Hz shift • LSB
internet-tty.net:8010/ITTY100
The same wire service content as the 60 WPM channel, transmitted at 100 words per minute for machines and operators comfortable at higher speed.
▶  Listen http://internet-tty.net:8010/ITTY100
LIVE 24/7
ITTY Europe
50 baud • Mark 1275 Hz • Space 1445 Hz
internet-tty.net:8040/EUROPE
BBC news content, fetched automatically from RSS feeds and delivered at the European RTTY standard — 50 baud, matching the carrier frequencies used on European radio circuits.
▶  Listen http://internet-tty.net:8040/EUROPE
LIVE 24/7
AUTOSTART
45.45 baud • 170 Hz shift • LSB
internet-tty.net:8030/AUTOSTART
A mixed-content channel: a daily “This Day in History” bulletin, user-submitted articles, and selected messages from the GreenKeys teletype discussion list. Content is submitted via RTTYMailer.
▶  Listen http://internet-tty.net:8030/AUTOSTART

Sending Content to ITTY

Anyone can submit articles to the AUTOSTART channel using RTTYMailer, a free Windows application written specifically for ITTY. RTTYMailer handles all the formatting and transmission details — you write your article, select a channel, and click Send.

Download RTTYMailer and install it on a Windows PC.
▼  Download RTTYMailer v16
Configure RTTYMailer with the channel address for AUTOSTART. RTTYMailer includes built-in channel configuration — select AUTOSTART from the channel list and the correct server settings are applied automatically.
Write and send your article. Type or paste your content, give it a title, and click Send. RTTYMailer delivers it to the AUTOSTART queue, where it will be transmitted on the next available slot.
Note: Some documentation mentions using a standard email client to submit content by configuring a custom SMTP server. In practice this is unreliable and difficult to set up correctly. Use RTTYMailer — it works.

Technical Details

All ITTY streams use the Baudot (ITA2) character set and audio frequency-shift keying (AFSK). The audio signal in the stream is exactly what you would hear from a radio receiver tuned to an RTTY transmission. Configure your decoder with the Mark and Space tone frequencies from the table below — that is all your software needs to decode the signal.

Channel Speed Baud rate Mark Space Mode
ITTY 60 WPM 60 WPM 45.45 baud 2125 Hz 2295 Hz LSB / AFSK
ITTY 100 WPM 100 WPM 75 baud 2125 Hz 2295 Hz LSB / AFSK
ITTY Europe * 66 WPM 50 baud 1275 Hz 1445 Hz LSB / AFSK
AUTOSTART 60 WPM 45.45 baud 2125 Hz 2295 Hz LSB / AFSK

* The ITTY Europe mark tone is 1275 Hertz — or 1275 Cycles, depending on one’s upbringing. The space tone is 1445 Hertz, or 1445 Cycles, once again dependent on one’s early life. — George Hutchison W7TTY

Listeners use a wide variety of decoders — there is no single recommendation. Common software choices include MMTTY and fldigi. Hardware terminal units of all vintages work equally well, from the classic Mainline designs to commercial units. See the Equipment section for schematics and documentation on terminal units and demodulators.