RT-300 Dual-Band Direction Finder System of RHOTHETA

Special Features

• Universal dual-band direction finder system for the VHF marine and aviation bands and the VHF/UHF aviation bands
• SAR direction finder, communication direction finder and navigation aid
• Automatic monitoring of emergency frequency 121.500 MHz during work on marine radio band
• Unsurpassed reception sensitivity in this class to permit detection of extremely weak or distant signals
• Selective Squelch to avoid false Alarms
• Display of bearing with reference direction as true north, magnetic north or relative
• Completely illuminated control unit
• Optimized signal processing for fast, stable direction finding
• Excellent localization precision
• NMEA, RS-485 and RS-232 interfaces for system integration and remote control capability
• Correction of lag error after changes in direction by attaching a Compass modul
• Optimized for use at sea: robust, compact design, waterproof (IP67)

Technical Data

Method of bearing	Doppler-principle (3 kHz rotational frequency)
Bearing accuracy	≤ 5° (RMS)
Bearing reference	Relative to antenna orientation, magnetic or geographic north (with optional Compass modul or external Compass Information)
Resolution	LED Display: 10° LCD Display: 1° Data Interface: 1°
Bearing Sensitivity Airband	0,7 µV/m (typical) at ±5° bearing fluctuation
Frequency range RT-300 VS:	VHF air band: 118.800 to 124.000 MHz VHF marine band: 156.000 to 162.300 MHz (maritime, channel 01 - 88)
Frequency steps	25 kHz
Bearable modulation types	A3E, F3E, A3X (Distress signal-modulation); bearing largely independent of modulation
Polarisation	vertical
Error of polarisation	≤ 5° at 60° field vector rotation
Time of response	≤ 300 ms typ. (with sufficient receiving field strength)
Display	LC-graphic display 98x32 dots with backlight 13 buttons with legend illumination 36 LED circle for bearing display Free adjustable dimming of LCD backlight, legend illumination and LED circle illumination
Supply voltage range	12 V to 28 V DC
Current consumption	supply voltage of 12V = stand by 350mA (4.2 W) supply voltage of 28V = stand by 250mA (7.0 W) typ. without ext. speaker 400mA (4.8 W) 300mA (8.4 W) typ. with ext. speaker 600mA (7.2 W) 400mA (11.2 W) max. without ext. speaker 450mA (5.4 W) 350mA (9.8 W) max. with ext. speaker 800mA (9.6 W) 600 mA (16,8 W)
External audio	max. 1.5 W at 4 Ohm (U_pp-max = 10 V)
Data Interface	Remote Control: RS232, RS485 Self-bearing Suppression: Discrete PTT Input Alarm Output: Discret/optional
Weight	DCU: app. 700 g AU: app. 1400 g
Temperature range	DCU: - 20°C to + 60°C AU: - 40°C to + 60°C
Protective systems	DCU: IP 67 AU: IP 67
Bearing Sensitivity Marineband	2 µV/m (typical) at ±5° bearing fluctuation
Frequency range RT-300 VU	VHF air band:118.800 to 124.000 MHz UHF air band: 241.000 to 245.000 MHz
Dimensions	Display (length x width x height): 220 mm x 113 mm x 27,8 mm Antenna (Diameter x height): 260 mm x 600 mm
Windload	Constant wind speed, without ice load 150 km/h ca. 115 N 180 km/h ca. 165 N Constant wind speed, with ice load 150 km/h ca. 150 N 180 km/h ca. 215 N

Accessories

Kompass Modul

The compass module allows a direction indication with a northbound reference direction. By using the compass module, the so-called drag error is negated and the direction finding system responds without delay to a change of heading of the vessel.

DC/DC Converter

The DC / DC converter prevents damage to the direction finding system due to compensation current which flows across the System Ground to minus voltage supply e.g. generated when starting the engines. Mandatory for vessles with metal hull.