Lesson 2/Learning Event 6
Learning Event 6: DATA TRANSMITTER, MODEL 7413
a. Functions. This section (figure 2-2) of the DAS10 furnishes test
signals for either teletypewriter or data communication, but not both at
the same time.
Figure 2-2.
Data Transmitter, Model 7413, Front Panel View.
(1) Teletypewriter. The data transmitter furnishes three types of test
signals for teletypewriter communication testing, including: Miscellaneous
signals ("fox" message), repeated character, and reversals. The test set
generates signals in the start-stop Barudot (7.42 unit) code, at keying
rates from 45.5 to 150 baud.
(2) Data.
This test set generates characters in the synchronous
American Standard Code for Information Interchange (ASCII 8-digit) code at
keying rates from 300 to 9,600 bauds.
The test signals can be only a
repeated letter or reversals; a test message is not provided.
Further,
the 8-digit code contains all pulses of the same length; there is no long
marking pulse as in the Baudot teletypewriter code.
(3) Distortion.
Signals may be biased marking or spacing, or the
distortion can be alternately switched between characters. Distortion is
selectable from 0 to 49 percent in steps of 1 percent.
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