SD6-400 TETRA Stacked Dipole Array | 380-420 MHz 6/9 dBd
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SD6-400

UHF High Gain Stacked Dipole Array

ModelProduct DescriptionFrequencyGainDownloadPDFEnquiry
SD6-400UHF High Gain Stacked Dipole Array380 - 420 MHz6 dBd.Download DatasheetDownload ManualPost Enquiry

Overview: SD6-400 High-Gain TETRA Band Stacked Dipole Array

The SD6-400 is an ultra-high-performance Stacked Dipole Array engineered for the 380–420 MHz TETRA band. Designed for high-density radio sites and mission-critical repeater systems, this heavy-duty array offers exceptional versatility, allowing for either long-haul 6 dBd omni-directional coverage or a high-intensity 9 dBd offset pattern. Constructed from 6063T6 architectural anodized aluminum, the SD6-400 maintains constant gain and a low VSWR across its entire 40 MHz bandwidth, making it the premier choice for TETRA base stations, paging, and multi-channel communication hubs.

Tactical Construction & Weatherproofing

Precision engineering for zero-failure performance in extreme theaters. The SD6-400 is fabricated from 6063T6 ultra-corrosion-resistant aluminum alloy and features four folded dipoles stacked vertically. To ensure absolute reliability, the center-fed dipole ends and cable connections are sealed in high-strength epoxy, providing a moisture-proof barrier while imparting mechanical rigidity to the structure. All fasteners are made of marine-grade stainless steel, ensuring the array remains rust-free in corrosive or coastal environments.

Pattern Versatility & Operational Efficiency

Field-adjustable radiation patterns for tactical flexibility. The SD6-400 offers unique field-configurability without the need for specialized tools:

  • Omni-Directional Mode (6 dBd): Arrange the four dipoles 90 degrees apart around the central mast for uniform 360-degree saturation.
  • Offset/Directional Mode (9 dBd): Align all four dipoles collinearly (facing one direction) to achieve a higher-gain offset pattern for targeted long-haul coverage.

The array features a narrow 18-degree vertical beamwidth, focusing energy toward the horizon for maximum range, and includes null-filling technology to ensure consistent signal strength for ground-level units near the tower.

Advanced Phasing & Lightning Protection

Low-loss signal distribution with integrated safety. The system utilizes a specially designed center-fed phasing harness that ensures equal and in-phase signal distribution to all four dipoles. To minimize signal loss and maximize waterproofing, all power splitter joints are molded, eliminating the need for internal connectors or adapters. The antenna operates at Direct DC Ground, utilizing the high-strength aluminum tubular boom as a low-resistance path to discharge lightning strikes safely during stormy weather.

Detailed Technical Features

  • TETRA Optimized: Full coverage of the 380–420 MHz band, ideal for public safety and emergency response networks.
  • High Power Handling: Engineered for a sustained 500-Watt RF power capacity, facilitating robust multi-channel broadcasting.
  • Molded Harness Technology: Waterproofed phasing harness with molded joints and a molded N-Female termination for maximum durability.
  • Constant Gain Architecture: Maintains stable electrical characteristics across the entire 40 MHz bandwidth.
  • Elite VSWR Performance: Better than 1.5:1 across the band, ensuring high efficiency and protection for connected transmitters.
  • Modular Logistics: The 3-meter central mast is shipped in two 1.6-meter sections, allowing for cost-effective transport and easier field handling.
  • Vertical Polarization: Standard orientation for tactical voice and data VHF/UHF mobile radio systems.

Environmental Specifications (MIL-STD-810G Hardened)

The SD6-400 is built to survive the world's most punishing mission parameters:

  • Operating Temperature: Certified for mission-critical use from -30°C to +70°C.
  • High-Velocity Wind Rating: Aerodynamically stable in constant winds up to 200 Km/Hr.
  • Humidity Defense: Fully functional in 0 to 95% Relative Humidity, designed for tropical and coastal theaters.
  • Structural Integrity: Heavy-duty 51 mm support pipe and 12.7 mm dipole elements maintain boresight stability in extreme weather.

Key Advantages, Benefits & Applications

Key Advantages:

  • Dual-Pattern Flexibility: Switch between Omni and Offset patterns in the field to adapt to changing mission requirements.
  • Maintenance-Free Life: Epoxy-sealed junctions and molded splitters eliminate the primary points of failure in traditional antennas.
  • Inter-Modulation Free: High-class materials and specialized construction techniques prevent the formation of "Signal Cells."

Key Applications:

  • TETRA Base Stations: Primary aperture for critical public safety and emergency services communication.
  • Repeater & Paging Sites: Reliable long-haul signal dissemination for wide-area coverage.
  • Multi-Channel Systems: Stable performance for high-traffic sites where multiple frequencies are co-located.
  • Remote Outposts: Ruggedized construction and lightning protection make it ideal for unmanned or hard-to-access sites.

 

Design Features: The SD6-400 high performance TETRA band stacked dipole array is designed for use with highly populated radio sites requiring long haul omni directional coverage. The SD6-400 is heavy duty stacked dipole array features, wide bandwidth, high gain, high power handling capacity, low VSWR, low noise performance and null filling coverage with omni-directional characteristics. This stacked dipole array maintains constant gain and VSWR over its entire 40 MHz bandwidth, making it highly suitable as base station antennas for TETRA systems, repeater, paging and any other multi-channel communication systems.

Constructions: The SD6-400 stacked dipole array uses 6063T6 ultra corrosion resistant architectural anodized aluminum, consists of Four folded dipoles stacked vertically, fed in phase. The center fed dipole ends and cable connections to the dipoles are sealed in epoxy at the end of the boom for protection against weather and imparting rigidity and strength to the dipole structure. All fasteners are made of stainless steel. This Stacked Dipole Antenna operates at D.C. ground for protection against lightning. The 3 Meters long central mast for mounting the dipoles, shipped in two sections of 1.6 Meters each.

Radiation Pattern: When the FOUR dipoles are arranged 90 degrees apart around the central mast, 6dBd. omni directional radiation pattern results. Aligning the Four dipoles collinearly (facing in one direction) a 9dBd. offset radiation pattern is obtained. The radiation pattern can be changed in the field by use of common hand tools. Vertical stacking distance is factory adjusted for highest efficiency.

Electrical Specifications:
Frequency Range380 - 420 MHz
Gain6 dBd.
Bandwidth40 MHz.
PolarizationVertical
Input Impedance50 Ohms
Radiation PatternOmni-directional
Horizontal Beamwidth -Half Power Points360 Degrees
Vertical Beamwidth -Half Power Points18 Degees
VSWR - Equal To or Better Then1:1.5
RF Power Handling Capacity300 Watts
Input TerminationN-Female
Lightning ProtectionDirect Ground

 

Mechanical Specifications:
Antenna Materials                                       All Aluminum
Mounting Hardware -MaterialsStainless Steel
Wind Rating200 Km/Hr.
Overall Length3 Meters
Shipping Length1.6 Meters
Support Pipe O.D.51 mm
Support Pipe MaterialAluminum
Maximum Mount Pipe Diameter51 mm ( 2 Inches)
Gross Weight10 Kgs.

 

Environmental Specifications:
Operating Temperature                                                                   (-)30 to +70 Degrees Celsius
Storage Temperature(-)40 to +80 Degrees Celsius
Humidity0 to 95% RH