The Chelton 935 Series Tactical Direction Finder is a rugged and versatile system designed for rapid detection and location of distress signals in military and search-and-rescue (SAR) operations. Engineered to function reliably across diverse environments and platforms, it delivers accurate direction-finding over a wide frequency range, supporting multiple distress protocols and simultaneous signal monitoring. This makes it an essential tool for enhancing situational awareness and enabling faster rescues.
Chelton DF-935
Integrated Multichannel Signal Detection and Decoding
The DF-935 system features a synthesized receiver covering 30 MHz to 470 MHz, along with five dedicated Guard Receivers for continuous monitoring of predefined distress frequencies. These receivers can simultaneously acquire bearings, and are capable of decoding COSPAS-SARSAT and marine DSC messages. Notably, each guard receiver—spanning VHF, Maritime, UHF, and GMDSS bands—has main and auxiliary channels, allowing users to monitor live distress alerts while also supporting training activities. The COSPAS-SARSAT receiver offers seamless decoding across all standard 406 MHz channels without operator intervention, reporting beacon HEX ID and GPS data directly via ARINC429 interface
Rugged Performance and SAR System Compatibility
Built for tactical missions, the DF-935 integrates smoothly with Personnel Locator Systems (PLS) and survival radios such as the AN/PRC-112 and URX3000, delivering both range and bearing data. It supports Search and Rescue (SAR) and Combat SAR (CSAR) modes, providing high situational flexibility. With discrete outputs for OTPI (on-top position indication) and distress alerts, the system ensures rapid and precise reporting under pressure. Designed to military environmental standards (DO-160C and DEF-STAN), it offers waterproofing, vibration/shock resistance, and EMI protection. Housed in a compact form factor, the antenna uses a modified annular slot design with a cardioid pattern, providing accurate DF readings—better than 5° RMS depending on installation conditions.