Chelton Df 935 2 Pdf Install Instant
The Chelton DF 935 series is a high-performance tactical direction-finding system designed primarily for Search and Rescue (SAR) and Combat SAR (CSAR) operations. It is widely used on helicopters and fixed-wing aircraft to accurately locate personnel and emergency beacons. Core Capabilities
Wide Frequency Coverage: Features an integral synthesized receiver covering 30 MHz to 470 MHz.
Simultaneous Monitoring: Includes five dedicated Guard Receivers, allowing the system to monitor distress frequencies while taking bearings on all six receivers at once.
Advanced Decoding: Fully supports COSPAS-SARSAT message decoding and marine DSC (Digital Selective Calling) messages.
High Accuracy: Offers directional accuracy better than 5° rms, though this is highly dependent on proper installation and airframe interference. Installation & Integration Review
Installing a 935 series system is a specialized modification, often requiring a two-stage approach: structural provisions and the actual equipment installation. Standard Installation Location DF Antenna
Typically installed on the belly of the aircraft for unobstructed signal reception. Control Panel Installed in the center console or cockpit dashboard. Mounting
Must be rigid and aligned exactly with the airframe (normal or inverted). Technical Specifications for Installers:
Electrical: Operates on 16.0 to 31.5 V d.c. with a 1.6 A maximum draw.
Physical: The antenna unit has dimensions of roughly 286 x 286 x 90 mm and weighs approximately 3.8 kg. chelton df 935 2 pdf install
Interface Options: Compatible with various data buses including RS 422, ARINC 429, and MIL-STD-1553B, allowing it to integrate with modern flight management systems.
Environmental Resilience: Compliant with RTCA DO-160C for vibration and temperature, and rated for altitudes up to 25,000 feet. Manufacturer & Industry Perspective
“The design of Chelton's 935 DF Antenna has been proven in a customer trial to have had 3x the range detection when compared to other competitor systems.” Chelton
“It can interface with Personnel Survival Radios (PSR) like AN/PRC-112 and PRC-434, providing range and bearing information.” AeroExpo Summary Review
The DF 935 is a "Gold Standard" for tactical rescue. Its primary strength lies in its parallel processing, which ensures that the crew never misses a distress alert on a guard frequency even while actively tracking a different signal. However, because it is an airborne system, its performance is heavily tied to the quality of the installation and the electronic noise environment of the specific aircraft.
For civilian use where military-specific features (CSAR) are not required, Chelton offers the ITAR-free 938-series. 935 Series Tactical DF Antenna | Chelton
The Chelton DF 935-2 is a tactical direction-finding system typically installed on aircraft for Search and Rescue (SAR) or Combat SAR (CSAR) missions. Installation Guide Summary
The installation follows a two-stage approach: provisioning the aircraft and the actual hardware mounting.
Antenna Mounting: The 935 Series antenna is typically installed on the belly of the aircraft (normal) or inverted, depending on the mission profile. It requires a rigid mounting method in line with the airframe. The Chelton DF 935 series is a high-performance
Cockpit Controls: The corresponding control panel or Control Display Unit (CDU) is typically installed in the center console of the cockpit. Dimensions & Clearance: Antenna Diameter: 286 mm. Antenna Height (External): 90 mm. Internal Penetration: 75 mm.
Interfacing: The system can be controlled via RS 422 using a Chelton CDU or through customer-provided interfaces such as MIL-STD-1553B, ARINC 407, or ARINC 429. Technical Specifications for Installation Requirement / Specification Primary Power 16.0 to 31.5 V DC, 1.6 A max Weight 3.8 kg (Antenna) Connector Type MS3114-16-26P, GB711 5009-1, or GB711 5009-2 Compliance
RTCA DO-160C / EUROCAE ED-14C (Vibration, Shock, Waterproofness) Operational Accuracy
Better than 5° rms (highly dependent on correct installation)
For full wiring diagrams and specific airframe mounting plinth options, refer to the official 935 Series Datasheet or contact Chelton Support. AI responses may include mistakes. Learn more 935 Series Tactical DF Antenna | Chelton
The Chelton (now Cobham) DF 935 is a tactical Direction Finding (DF) system used primarily for Search and Rescue (SAR) and Combat SAR (CSAR) missions. Detailed installation and technical data are typically provided in its official Technical Data Sheet and specific Installation Manuals, which are often controlled documents due to their military and aerospace applications. Technical Overview for Installation
Based on official specifications, the following parameters are critical for a standard installation:
Frequency Range: 30 MHz to 470 MHz, covering standard international distress frequencies. Physical Dimensions: Maximum footprint of approximately Mass: Approximately 3.8 kg maximum.
Power Requirements: Primary power must be between 16.0 to 31.5 V d.c., with a maximum current draw of 1.6 A. Maintenance and Best Practices
Interfacing: The unit is compatible with the Chelton 715-40 DF Controller and supports bus-controlled (1553B) or stand-alone RS422 configurations.
Connectors: Standard installations utilize MS3114-16-26P connectors. Installation Guidelines
Mounting Attitude: The antenna should be mounted in line with the airframe, either in a normal or inverted position depending on the aircraft type.
Environmental Compliance: The system is designed to meet EUROCAE ED-14C / RTCA DO-160C standards for vibration (Cat L for fixed-wing, Cat Y for helicopters) and shock.
Interrogator Interface: For CSAR missions, ensure the system is correctly interfaced with beacon interrogators such as the PRC-112G, PRC-434, or URX3000 to facilitate covert rescue. Official Documentation & Support
Because these systems involve specialized avionics, it is highly recommended to obtain the latest version-specific PDF manuals directly from the manufacturer:
Datasheets: Can be downloaded from the Chelton 935 Series product page.
Technical Support: For full installation manuals (PDF), visit the Chelton Support portal to request specific documentation. 935 Series Tactical DF Antenna | Chelton
Maintenance and Best Practices
- Regular Cleaning: Wipe the transducer and display unit with a mild detergent to remove salt deposits.
- Firmware Updates: Check the manufacturer’s website for software updates to enhance device performance.
- Annual Inspection: Ensure all seals, wiring, and mounting hardware are secure and corrosion-free.
Step 1 – Mechanical Mounting of the Antenna Array
- Location: Top of fuselage or tailboom, centerline, with clear view of the sky (no shadowing by rotor mast or wing).
- Ground Plane: The DF 935-2 requires a conductive ground plane of at least 30 cm radius around each element. Use an aluminum doubler if the skin is composite.
- Orientation: Arrow on the array base must align with the aircraft longitudinal axis (pointing forward). Tolerance: ±0.5 degrees.
- Drilling: Use the included drill template (Figure 3-12 in the PDF). Deburr and seal with corrosion inhibitor.
3. Electrical Wiring & "2 PDF" Configuration
- RF Cabling: Use low-loss coaxial cable (RG-142 or RG-393 usually recommended for airborne use). The "2" designation implies dual connections; ensure both ports (Port A and Port B) are connected to the DF receiver using phase-matched cables to ensure accurate bearing calculations.
- Bonding: The antenna base must be electrically bonded to the airframe. Verify resistance between the antenna base and the airframe skin is less than 0.1 ohms.
- Lightning Protection: If the antenna is the highest point on the platform, ensure it is integrated into the vehicle's lightning protection circuit.
How to Locate the Official Chelton DF-935-2 Installation PDF
While manufacturers frequently change their document portals, Chelton (now operating under the Cobham Aerospace Communications or Collins Aerospace umbrella, depending on the region) typically restricts direct public downloads due to ITAR and proprietary concerns. However, here are the three most reliable methods to obtain the installation PDF:
