Figure 1-25.Comparator-Converter group AN/URA-17(C).
called diversity. When the URA-17 is operating in
diversity mode, the signal comparator circuits in the
equipment compare the signal strength and clarity of
each received signal, and allow only the better signal to
be routed to a printer.
A properly tuned signal should appear as an "X"
pattern centered on the middle lines inscribed on the
CRT window (fig. 1-27, view A). If the pattern is
shifted above the bottom inscribed line (view B), the
radio frequency needs to be lowered slightly. If the
pattern is shifted below the top inscribed line (view C),
the radio frequency needs to be raised slightly.
Each converter may also be used independently.
When you operate a CV-483 in the single mode, the
comparator circuits are not used. Separate radio-
teletype broadcasts may be routed through each
converter and sent out to separate printers. Operation of
When the "X" pattern is centered, but the top and
bottom pattern lines do not touch the top and bottom
lines inscribed on the CRT (view D), the CV-483
"level" control must be increased. If the "X" pattern
extends both above and below the top and bottom
inscribed lines (view E), the "level" must be decreased.
each individual CV-483 is not difficult. Operator
controls are all on the front of the unit (fig. 1-26).
In order to successfully copy RATT data, you must
complete the following steps:
1. Using switchboards and antenna patch panels,
connect an appropriate antenna to your receiver(s), and
then connect your receiver(s) to the CV-483(s).
Optionally, you may also patch radio output to an audio
speaker. A RATT signal has a distinctive sound. With
experience, you may be able to properly tune a RATT
signal by sound alone.
2. Turn the power on with the power switch, and
then place the function switch to the "tune" position.
3. Then tune a radio receiver to a listed
radioteletype frequency. You may have to tune to 1.5 to
1.9 kHz above or below the actual listed frequency if
copying sideband transmissions. The wave pattern in
the cathode-ray tube window is used to properly adjust
Figure 1-26.Frequency Shift Converter CV-483/URA-17 front panel controls.