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Set the system to 60 WPM RTTY operation as this is currently the
most popular speed used by amateurs. The mode and operating speed
are permanently displayed on the top line of your video screen. To
change the operating speed use the ‘CTRL X’ command to set it
directly.
If you are properly tuned, the tuning indicator will alternate be
tween a vertical and horizontal bar at the received bit rate which ap
pears as a cross. If you turn on the reference tone, it should sound clean
and be in sync with the received audio.
4.1.1 SELECTABLE OPTIONS:
RTTY reception is further enhanced by means of a number of
keyboard selectable options. For a full description of the available
RTTY commands see Chapter 7.
You can eliminate the display of most non RTTY signals such as
voice or CW by enabling the ANCW (ANTI-CW) option. This option is
commanded ON/OFF by means of ‘CTRL T’ command. When enabled,
this ANCW option will inhibit the display of voice and most CW
signals. It will also inhibit the display of inverted RTTY signals. There
will, however, be a slight delay when you first tune a new RTTY signal
before the display is presented on the screen. The letters ‘ANCW’ will
appear on the top line display when in RTTY receive mode.
The actual software (program) operation of the ‘ANCW’ is to in
hibit the video display until 10 properly timed stop bits are received in
a row. If two stop bits are missed, the “10” counter is reset and the
display is disabled until 10 more stop bits are received in order.
The mechanical teleprinter keyboards that use the Baudot code
have fewer keys than a standard typewriter. There are no “lower case”
letters in Baudot, only “upper case” caps. Actually the figures and
punctuation symbols are the shifted upper case with caps letters as the
lower case characters. Hence the terms LTR (letter) and FIG (figure)
shifts. The Unshift On Space function when enabled, will cause an
automatic shift to the LTR (lower case) mode upon the receipt of a
BAUDOT word space code. This option is useful in that it will not get
the system “hung-up” in the FIG (upper case) mode in the event of a
failure to detect a BAUDOT LTR (down shift) code. This option is
enabled and disabled by means of the ‘CTRL U’ toggle action com
mand. When receiving Weather Reports, turn the ‘UNSHIFT’ option
off, as they do not send a FIG shift after each group of numbers. When
not in “UNSHIFT” mode, the SWL will simply react like a mechanical
teleprinter. When enabled, the letter ‘U’ will appear near the right side
of the top line. It is initially on at power up, and not displayed during
text printing.
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