Telephonics Corporation
R
A D A R
S
Y S T E M S
D
I V I S I O N
1-2
TM113806 (3/10)
display techniques to achieve a high-contrast TV-type display of the operational modes at the color
indicator. Digital techniques permit a full-time presentation to the pilot without distracting sweep
decay as the antenna scans. A display-offset feature allows moving the origin of the display to any
point on the screen using an optional joystick. The radar displays can present alphanumeric on-screen
readout of the selected display and functional modes and beacon, NAV, and NAV LOG information.
The radar indicators have the capability to display either the normal radar/NAV information or
externally supplied RS-170 (525-line, 60-Hz) or CCIR (625-line, 50-Hz) “TV” video information.
Built-in test circuits provide rapid checkout of system performance in the air or on the ground. The
built-in test function is selectable at the control unit to validate system operation. If the system is
operating normally, selecting the test function can produce a test pattern on the indicator. In the event
of a failure of a system LRU (R-T unit, antenna, or interface unit), a fault display on the indicator can
provide a visual warning.
1.1.2 Operational
Modes
For complete description of the RDR-1700A Radar System see the RDR-1700A Pilot’s Guide (P/N:
TM114106).
1.1.2.1 Search (SRCH) Mode
The prime functions of the RDR-1700A in the search mode are to provide for maritime sea search
operations and low-altitude terrain mapping. In sea search operations, the radar system can detect and
display surface targets down to a minimum range of 500 feet. Even under adverse conditions, targets
such as a small boat can be detected.
The radar system control unit has numerous controls to use in the search mode for optimizing the
desired radar returns displayed in both sea search and terrain mapping operations. Proper use of these
controls allows the operator to build the desired radar presentation.
The radar system has three pulse widths that are selectable by the operator on any range in the search
mode. An auto-search mode is also available in which the pulse widths are controlled automatically
depending upon the range selected. RDR-1700A pulse widths and associated pulse repetition
frequencies (PRF) are as follows:
PULSE WIDTH
PRF
RATE
PRF AVG
0.1
μ
s
1600 Hz
1200 Hz
0.5
μ
s
800 Hz
600 Hz
2.35
μ
s
200 Hz
200 Hz
The document reference is online, please check the correspondence between the online documentation and the printed version.
