This page is all about RTTY, or “Radio Teletype“. Radio Teletype is the evolution of the old “telegram” services from the late 1800s, but instead using “teleprinters” (aka Typewriters) that work over radio waves. It was first pioneered by the Navy, and later amateur radio operators formed groups such as the “South California Radio Teletype Society” that literally took in cheap and free equipment from companies such as Western Union, and got them in the hands of amateur radio operators who started figuring out how to get them to talk over the air on the amateur bands.
There’s a bit of crossover here, as Teletypes were not only used for amateur radio use, but often used for computing as well (now vintage computing), so this page is dedicated to the radio side of things, while I may have another page dedicated to the computer use of Teletypes.
Equipment
The interesting part of RTTY, is that it’s not only still a fairly popular digital mode amongst many newer, better digital modes, but it’s historically significant that this particular mode can work with equipment that literally dates back to the 1920’s.
RTTY usually involves 3 major pieces of equipment; your radio receiver/transceiver (most standard ham radios today work with RTTY), a “terminal unit”, and a teleprinter/Teletype. In most modern cases, a USB audio interface now replaces the “terminal unit”, and software like FLDIGI replace the teleprinter, but as the RTTY protocol uses the old Baudot character set at 45.5bps baud, most older gear still works fine! For example a Model 15 teletype can be used for RTTY, and it first came out in 1930!
My Equipment: My RTTY equipment has grown a bit, but generally now has:
HAL-ST6 Terminal Unit
Dovetron MPC-1000 Terminal Unit
Heathkit Terminal Unit
(2) Teletype Model 32s, which although similar to the infamous Model 33, is a 5-bit “Baudot” machine, originally used for the “Telex” Network. One stays at home, the other, missing a base, goes on field trips like Field day any wherever else I feel like dragging a 50lb typewriter to. Click here to read about when I acquired the ST-6 and first Model 32.
Tips and Tricks
Enabling CR/LF in your RTTY Software for working “real” Teletypes
Links
Ratt Rigs – See how the Army used Teletypes in the field
SMECC – More info about Teletypes and RTTY than you ever cared to know
rttycontesting.com – Info about RTTY and other Digital Contesting