User manual

nient to update or write to this device - for updates, a special procedure must
be followed .
The SG-7200 is provided with a main executable code module that provides
communications support: NEWTOR.EXE. This code module is stored on the
Flash ROM disk and is ready to be loaded into memory for execution. Once
loaded, a code module remains active until terminated by the user. The code
module is a regular DOS executable file.
SG-7200 software supports operation in several digital modes, or protocols.
Some of these modes, such as Baudot, ASCII, AMTOR, and SITOR, are suit-
able for use by radio amateurs.
5.1 Communication Modes (Protocols)
The SG-7200 supports a number of popular digital communication
modes. Some are used extensively by radio amateurs while others are
designed for use in the maritime mobile service.
5.1.1 Baudot/ASCII
The commercial- or military-surplus Baudot-encoded teletype-
writer (TTY) was the mainstay of amateur RTTY operators from
1946 through around 1977 when other digital modes become pop-
ular. FCC rules in Part 97, identify the Baudot code as the ITA 2
code, which is a 5-level code. This code has 32 different code
combinations that requires the use of a “case shift” to implement a
full operator’s keyboard.
The SG-7200 Baudot implementation, fortunately takes care of
this rather confusing mode of operation by automatically doing the
case shifting during receive and transmit. In addition, a “diddle”
feature and “unshift on space” feature is provided to enhance
RTTY operations. The user also may select the data rate for either
45,75 or 110 baud RTTY.
The ASCII mode is similar to the Baudot mode, except that an 8-
level code is used that allows for the use of the full ASCII charac-
ter set. Any data rate is technically possible. However, high data
rates require special modems that occupy wider bandwidths. For
this reason, only lower speed ASCII is presently available for
ASCII operation.
5.1.2 Amtor
Peter Martinez, G3PLX, popularized AMTOR, “Amateur
Teleprinter over Radio” in the 1970’s. AMTOR is a derivative of a
commercial maritime mobile communications mode SITOR .
AMTOR was made part of the FCC regulations for amateur radio
use in 1983.
AMTOR uses a scheme to improve communications of the 5-level
© 1999 SGC Inc
SGC Inc. SGC Building, 13737 S.E. 26th St. Bellevue, WA. 98005 USA
P.O.Box 3526, 98009 Fax: [phone] or 746-7173 Tel: [phone] or 1-800-259 7331
E-mail: [e-mail] Web site: http://www.sgcworld.com
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