Telephonics Corporation
R
A D A R
S
Y S T E M S
D
I V I S I O N
TM113806 (3/10)
1-27
1.5
SYSTEM COMPONENT DESCRIPTION
1.5.1 General
The RDR-1700A Radar System consists of six basic units: an RT-1501A Radar Receiver-Transmitter,
DA-1503B Antenna Drive Unit with an AA-1504A flat-plate array, an IN-1502R 6.4" LCD Display,
an IN-1702A 15" LCD Display, and an IU-1707A Interface Unit.
The following paragraphs provide a brief description of each flight-line replaceable unit (LRU).
1.5.2 RT-1501A
Receiver-Transmitter
The RT-1501A Receiver-Transmitter functions as a short-range pulse radar for high-resolution sea
search and terrain mapping and also as a long-range pulse radar for long-range sea search, terrain
mapping, and conventional weather avoidance. The reflected signal is received by the system 360-
degree scanning antenna, amplified and digitized by the R-T unit, and routed to the interface unit for
processing. The RT-1501A frequency-trimmable magnetron provides reliable interrogation of beacon
transponders. Transmitter frequency is 9375 MHz, accurate to within ± 5 MHz.
For easy maintenance, all circuits are contained on plug-in PC boards. These PC boards are
interconnected by ribbon cables through a main interconnect PC board, which replaces the
conventional wiring harness arrangement.
A cast housing on the front panel of the unit contains a waveguide flange, unit connector, two coaxial
connectors, and a test connector. The waveguide flange accepts a waveguide quick-disconnect
coupling.
The unit connector provides all connections to the radar system except the digital signal. The digital
signal is routed to the interface unit from the coaxial BNC connectors on the front panel.
The mounting tray for the R-T unit is designed for front loading. It provides positive positioning and
holding of the unit to the aircraft, allowing easy removal for servicing and replacement. For overall
dimensions of the R-T unit, refer to the outline drawing in the RDR-1700A Installation Manual,
TM110402.
Detailed theory of operation, assembly, list of materials, and test procedures for the RT-1501A
Receiver – Transmitter can be found in the RDR-1700A Radar System Maintenance Manuals,
TM114306
.
1.5.3
DA-1503B Antenna Drive Unit and AA-1504A Antenna Array
The antenna drive unit is a stabilized 360-degree scanning unit, which uses a 39- x 9-inch planar array.
Optional 29- x 9-inch and 33- x 9-inch arrays are also available. The array is mechanically scanned in
azimuth by means of a motor-driven gear train at the antenna drive unit. The DA-1503B Antenna
Drive Unit positions the AA-1504A Antenna Array in both the azimuth and elevation axes. These
items are shipped separately and must be assembled by the installing agency.
The antenna is used for both transmitting and receiving. It is remotely controlled in the elevation axis
by a tilt control, on the control unit, to any position of beam tilt between 15 degrees above and 15
degrees below the horizontal (zero-degree attitude). Stabilization in the pitch and roll axes depends
The document reference is online, please check the correspondence between the online documentation and the printed version.
