Rotheta Directionfinder RT-1000

VHF Radio Direction Finder (VDF) System for ATC and VTS
  • 8.33 kHz channel spacing in the VHF air band available
  • Antenna location independent of controller workstation
  • Secound simultaneous channel optionally available
  • Compact antenna system for simple installation


Leading technology

The RT-1000 radio direction finder, which has become the benchmark in its class, is also known under the Rohde & Schwarz designation PA030. More than 150 systems are currently in use worldwide.

DF Commander

The main purpose of the “DF Commander" Software is to provide the remote control and monitoring of multiple DF-Channels and DF-Systems from a standard PC. This software allows the visualizing of the bearing data, such as bearing angle, signal level and frequency of an appropriate channel. The simple and convenient design of the “Bearing Page” and the possibility to adjust the orientation of the compass rose towards the tower window view makes the controller’s work very comfortable. Furthermore the software provides the possibility to simultaneously monitor the status of all channels connected, which is also a helpful feature for the technical monitoring and maintaining of the DF-System.

DF Commander MK2 Software

The DF Commander MK2 software enables remote control and monitoring of radio direction finding systems. Besides displaying the direction finding results on different electronic charts, the software is able to calculate cross bearings on different frequencies. Soundings, cross bearing results and status information of radio direction finding systems are made available via an integrated server. Radio direction finding systems can also be set and controlled via the same server. Thus the software is to be understood as a DF service.

Antenna Model

The antenna model simulates the radio direction antenna. If the antenna model is connected to a signal generator, it delivers a signal like a DF antenna under perfect conditions. It simulates the signal angle 0 °; 90 °; 180 ° or 270 ° at its RF output; The antenna model is a very useful device for the maintenance of the DF system.

Antenna mast with test and maintenance functions

The antenna mast is a girder mast which has been developed especially for the Doppler antenna system RTA 1300, which makes possible the turning and titling of the antenna for assembly and maintenance purposes. The mast will be delivered in disassembled condition. It has to be mounted and grounded after the assembly on a suitable base. The scope of delivery also includes a waterproof installation box, in which the receiver unit and remote data transmission can be located. All parts of the mast and the bolted connections are hot-dip galvanized or respectively made out of stainless steel.

Obstacle Light

he Obstacle Light is an optional safety accessory for the RT-1000 antenna mast. There exist two orderable variations: Single Obstacle Light and Double Obstacle Light. Both variations are intended for mounting on the top of the RT-1000 antenna mast. Single Obstacle Light is a single-light-construction, which contains a light bulb in its housing and a corresponding mounting frame. The Double Obstacle Light is a construction with two lights, which have an identical structure as the Single Obstacle Light. While the first lamp is in operation (operation lamp), the second lamp is in standby (standby lamp). In case of the failure of the operation lamp, the standby lamp will be automatically switched on. Furthermore the construction includes the IP 64 connection box and the corresponding mounting frame.

Antenna Mastflange

The antenna mast flange allows the installation of the RT-1000 antenna on any construction. CAD drawings for integration are available on request.

Additional Bearing Channel

The bearing system can be equipped with an additional receiver module and an additional controller. In this way, two workstations can work on different frequencies simultaneously with the system.

DF-Emulator Software

The "DF Emulator" is a software that emulates a bearing system on a Windows PC by playing a pre-recorded log file. In the simplest case, the DF emulator uses the serial COM port of the PC to transfer the data via RS232 to another PC or system that displays the bearing data.
This software is designed for projects like bearing data integration in radar displays or other map- and control displays and is intended to facilitate the work of integrators.

SNMP Modul

SNMP Module is an optional hardware that provides the remote error monitoring of RHOTHETA RT-1000 direction finder systems over the Simple Network Management Protocol.

Technical informations

Frequency Range: ATC: 118 to 136.975 MHz | VTS:156 to 174 MHz
Operating channels: ATC (25kHz): 760 | ATC (8,33kHz): 2278 | VTS: Channel 01 to 88 including Duplex channels
Channel spacing: 8.33 kHz / 25 kHz
Bearable modulation types: A3E, F3E, A3X (ELT-modulation)
Bearing accuracy: 2° RMS (±1° with bearing precision improvement option)
Bearing sensitivity: VHF Airband oder Marineband ≤ 5 µV/m / 2 µV/m typical at ±2° bearing fluctuation | VHF Airband or Marineband including 2nd bearing channel ≤ 5 µV/m / 3 µV/m typical
Polarisation: Vertical Polarisation error ±1° (with field vector rotation up to 45°)
Cone of silence: approx. 35° referred to the vertical
Power supply: AC: 115 / 230 V ±15%; 47 to 63 Hz | DC: 24 V -10% / +20%; automatic switch-over to DC voltage in case of AC mains failure
Power consumption: Controller unit: max. 15 VA | Receiver unit: max. 10 VA (65 VA with heater)
Temperature ranges:  Operating temperature Antenna: -40° to +80°C | Receiver unit: -40° to +60°C | Controller unit: -20° to +55°C
Storage temperature: -40° to +60°C
Interfaces: serial V.24 (RS232) | parallel
Response time Display: ≤ 400 MS | RS-232 Output: ≤ 450 ms
Variant A: Digital: 3 digits with 7-segment LED indicator | Resolution: 1° | Bearing reference: QDM, QDR, QUJ, QTE | Updating rate: approx. one indication/s
Variant B: Dual compass dial: 2 concentrical circles of LED points | Resolution: 10° | Bearing reference: QDR | Updating rate: Outer circle approx. one indication per secound | Inner circle 47 indications 
Audio: Built-in speaker | Headphone Output
Ground transmitter suppression: with external contact to ground
Lateral thrust due to wind: with constant wind speed | 150 km/h approx. 135 N | 180 km/h approx. 195 N (data including lightning rod and mast)
Dimensions and Weight Controller: 9"-desk-top model 3 UH, prepared for rack installation | Dimensions (H x W x D): 132.5 x 448 x 370 mm
Weight: 8.1kg
Dimensions and Weight Receiver unit: Non-metallic cabinet for wall mounting (IP 65) | Dimensions (H x W x D): 250 x 340 x 285 mm
Weight: 6.9kg
Dimensions and Weight Antenna:  Dimensions (Diameter x H): 400 x 1120 mm | with lightning rod and mast: 400 x 3400 mm | Weight including antenna rods: 3.8kg
Methode of Bearing: Doppler-principle (3kHz rotational frequency)