RHOTHETA Elektronik
RT-500-M
WIDE-BAND Radio Direction Finder
The RT-500-M operates between 118 and 470 MHz, including COSPAS/SARSAT (CP-SS) and all other V-UHF international distress frequencies. MOB-functionality for crew safety is a standard feature. Extended V-UHF air bands support cooperation with civil and military airborne forces, and the extended UHF FM band covers LMR, PMR and LPD radio frequencies, often used by smugglers and pirates. Scan functions allow creating a scan list, scan all 19 CP-SS channels, or scan multiple SAR frequencies sequentially (CP-SS…121.5…243.0). Additionally it decodes CP-SS data from an emergency beacon and thereby displays the beacon’s ID, its latitude-longitude location, as well as direction and distance to the beacon.
The RT-500-M calculates the bearing to an incoming radio signal with an accuracy of 5° RMS. Standard serial, NMEA, and Ethernet interfaces allow integration with ECDIS systems, sharing DF bearing and location data in real time. The installation of the light weight compact antenna (AU) system requires no RF cables. A distance of 100 m between AU and Display Control Unit (DCU) is no problem.
The RT-500-M direction finding system is ideal for SAR, Coast Guard and Law Enforcement organizations, easy to install on any size of vessel and practically maintenance free.
| Method of bearing | Doppler |
|---|---|
| Bearing reference | Relative bearing | True/magnetic bearing1 |
| Bearing indication | Digital and by a pointer in a wind rose |
| Bearing accuracy2 | ≤ 5° RMS |
| Display resolution | 1° |
| Available frequency range | 118 – 470 MHz |
| Reception frequency | VHF Air Band 118.000 – 124.000 MHz (Basic) 118.000 – 136.992 MHz (Option F1) VHF Marine Band 154.000 – 163.000 MHz (Basic) 137.000 – 224.995 MHz (Option F2) UHF Air Band 240.000 – 246.000 MHz (Basic) 225.000 – 399.975 MHz (Option F3) COSPAS/SARSAT 400.000 – 406.092 MHz (Basic) UHF FM-Band 406.100 – 410.000 MHz (Basic) 406.100 – 470.000 MHz (Option F4) |
| Bearing sensitivity Continuous signal ±5° bearing fluctuation |
VHF Air Band ≤ 4 μV/m / 2,5 μV/m typical VHF Marine Band ≤ 3 μV/m / 2 μV/m typical VHF Marine Band above 174 MHz ≤ 5 μV/m / 3 μV/m typical UHF Air Band ≤ 6 μV/m / 4 μV/m typical COSPAS/SARSAT ≤ 6 μV/m / 4 μV/m typical UHF FM-Band ≤ 6 μV/m / 4 μV/m typical |
| Bearable kinds of modulation | A3E, F3E, A3X (distress signal modulation), Bearing largely independent of modulation |
| Min. signal duration | ≤ 100 ms |
| Polarisation | Vertical |
| Scanning | Multiple scanning and monitoring functions available |
| COSPAS/SARSAT functionality | Decoding of COSPAS/SARSAT message: shows beacon ID, GPS position and whole message string (short and long) Displays direction and distance to beacon3 All 19 COSPAS/SARSAT channels available Scanning of all 19 COSPAS/SARSAT channels |
| TFT graphic display | 5“ (127 mm), 24 bit RGB 800 × 480 × 3 dots Max. brightness: >500 cd/m²; 800 cd/m² typical Dimming: manual and automatic |
| Audio | Internal speaker: 1 W; 8 Ohm External speaker: 1 W; 8 Ohm Line out: adjustable from 200 mVpp to 2 Vpp |
| Operating voltage | 12 V to 30 V DC |
| Power consumption | Max. 15 W; typical 8 W; standby 7 W |
| Current consumption | Max. 1.5 A |
| Interfaces | 3× NMEA 0183 (RS422) | 3× RS232 Ethernet LAN (NMEA over LAN) Alarm relay output (1 A, 30 V DC | 0,3 A, 125 V AC) PTT input for self-bearing suppression Squelch output for external audio controlling 2× programmable I/O ports |
| Standards | EN 60945; EN 60950-1; EN 60950-22; FCC Part154 |
RT-500-M
Accessories
Optional Frequency extensions
F1 VHF-Airband: 118,000 – 136,992 MHz; F2 VHF-Marineband: 137,000 – 224,995 MHz; F3 UHF-Airband: 225,000 – 399,975 MHz; F4 UHF-FM Band: 406,100 – 470,000 MHz
The Optional Frequency extensions can be ordered seperatly to extend the frequency range of each system individually.
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.
RT-500-M
References
RT-500-M


