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LW1DSE > RTTY 24.11.07 20:58l 63 Lines 2559 Bytes #999 (0) @ WW
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Subj: WHAT IS RTTY?
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To : RTTY@WW
* Radioteletype *
=================
Radioteletype (RTTY) is a telecommunications system consisting of
two teleprinters linked by a radio link.
Contents:
1) How it works
2) Slow by modern standards
3) Spectrum efficiency
4) Primary users
5) Pronunciation
1.- How it works:
----------------
RTTY uses a variety of different modulation methods, of which
frequency shift keying are the most common.
Coding used is typically 5-bit ITA2 code (also known as the Baudot
code, see BAUDOT.TXT), which is used asynchronously with start and stop bits.
At least one common RTTY system uses 6-bit ITA2 character codes.
More modern systems use 7-bit or 8-bit bytes.
2.- Slow by modern standards:
----------------------------
RTTY is extremely slow by modern standards; a typical baud rate for
RTTY operation was 45 baud (approximately 60 words per minute).
The combination of low baud rate with robust FSK modulation makes
RTTY highly resistant to most forms of radio interference, second only to
Morse code.
3.- Spectrum efficiency:
-----------------------
RTTY and Packet spectrum efficiency compared with respect to
{bits/second} thruput.
4.-Primary users:
----------------
Principally users that need robust shortwave communications:
* Various navies of the world
* Various armies of the world
* Diplomats, especially in Africa and parts of Asia
* RTTY systems are also fielded by radio amateurs.
5.- Pronunciation:
-----------------
The pronunciation of RTTY is disputed. In very few applications,
notably the U.S. military, radio teletype is known by the acronym RATT rather
than RTTY.
Those who are actively engaged in amateur RTTY communications
pronounce RTTY not by its initials but as "ritty".
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º Compilled from Wikipedia.com . Translatted to ASCII by LW1DSE Osvaldo º
º F. Zappacosta. Barrio Garay, Almirante Brown, Buenos Aires, Argentina. º
º Made with MSDOS 7.10's Text Editor (edit.com) in my AMD's 80486. º
º May 26, 2007 º
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