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1.0 RX-103 Introduction
ORCA®(Overboard Recovery Communications Apparatus) is a personal water-activated man
overboard (MOB) alarm system developed by BriarTek Incorporated and utilized by the US
Navy and other mariners. The alarm system includes a transmitter, receiver and direction finder.
The receiver is a single channel VHF (121.5 MHz) receiver with an embedded microprocessor,
GPS and touchscreen LCD interface. The RX-103 is designed to receive a signal from any
ORCA®transmitter. When an ORCA® transmitter is activated, the transmitter emits a radio
frequency (RF) signal. A visual and audible (95 dB) alarm on the receiver sounds upon receipt
of this signal indicating the identity of the MOB as well as GPS coordinates and time (GMT) of
the MOB event.
2.0 Parts Overview
A- Liquid Crystal Display (LCD)
B– Piezoelectric Buzzer
C– Power Connector
D– RX Antenna Jack
E– GPS Antenna Jack
F – Power On/Off
G– Helical antenna
H – GPS antenna
3.0 Operating Instructions
3.1 Activation (see figure 1)
a. When a transmitter from own ship is
activated, an alarm signal (continuous
warble) is activated at the receiver buzzer
(B). The ship type, hull number, and the
serial number of the transmitter are
displayed on the LCD (A).
b. When a transmitter from another vessel is
activated and within range, an alarm signal
(chirp) is sounded and the ship type and
hull number, as well as the serial number
of the transmitter, is displayed on the LCD.
c. When an alarm signal is received, whether
own ship or other, the display will indicate
the transmitter’s battery strength, either
“Good” or “Weak.”
d. Received Signal Strength Indication (RSSI) - RSSI is displayed on the LCD. RSSI is a
measure of the field strength (radio waves at 121.5MHz) at the antenna input.
G
A
B
C
F
E
D
Figure 1
H
