Model SD3-75 66 - 88 MHz 3 dBd. Gain 
 

STACKED DIPOLE ARRAY

Design Features: The SD3-75 high performance VHF stacked dipole array is designed for use with highly populated radio sites requiring long haul omni-directional coverage. The SD3-75 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 is highly suitable as base station antennas for Repeater and Paging sites.
Constructions: The SD3-75 Stacked Dipole Array consists of two folded dipoles stacked vertically, fed in phase. This Stacked Dipole Antenna operates at D.C. ground for protection against lightning. Termination of phasing harness cable sealed by heat shrinking tube making stacked dipole antenna waterproofing. The 6 Meters long central mast for mounting the dipoles is shipped in two sections of 3 Meters each for easy of shipping. The stacked dipole antenna is suitable for side mounting on the tower and is supplied with mounting hardware of 1.35 Meters (4.5 feet) long two horizontal arms to hold the antenna on the side of the antenna tower.
Radiation Pattern: When the TWO dipoles are arranged 180 degrees apart around the central mast, 3dBd. omni directional radiation pattern results. Aligning the TWO dipoles collinearly (facing in one direction) a 6dBd. offset radiation pattern is obtained. The radiation pattern can be changed in the field by use of common hand tools..

Electrical Specifications:
Frequency Range66 - 88 MHz
Gain3 dBd.
Bandwidth6 MHz.
PolarizationVertical
Input Impedance50 Ohms
Radiation PatternOmni-directional
VSWR1:1.5
RF Power Handling Capacity500 Watts
Input TerminationN-Female
Lightning ProtectionDirect Ground

Mechanical Specifications:
MaterialsAll Aluminum
Mounting Hardware -MaterialsStainless Steel
Wind Rating200 Km/Hr
Overall Length6 Meters
Shipping Length3 Meters
Maximum Mount Pipe Diameter 51 mm (2 Inches)
Support Pipe (Mast) - MaterialAluminum 51 mm OD
Gross Weight20 Kgs.

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