COGWHEEL Antenna Support Structure
Ten years of intensive research and development has resulted in the ERI COGWHEEL™ FM antenna system. Capable of operating across the FM band, it combines high power handling capabilities, outstanding radiation characteristics and mounting flexibility.
The COGWHEEL™ can be used as a single or multi- station antenna. The COGWHEEL™ antenna system allows several high powered stations to benefit from its cost efficiency, superior radiation qualities and state-of-the-art technology.
Radiating elements are made of brass and copper. Masts and screens are hotdip galvanized. Stainless steel hardware is used throughout. These outstanding features provide performance and durability. The unique design of the COGWHEEL™ eliminates the need for electrical deicing. Its feed points, baluns and feed couplers are enclosed in a pressurized environment. Optional element radomes or deicing heaters are available for use in remote areas where severe icing is expected.
The COGWHEEL™ is designed with three or four ERI Type 1180 radiating elements at each level. Screening is provided to isolate the support structure and control adjacent element coupling. Pole mounted systems incorporate the mounting pole in the system design.
The COGWHEEL™ produces a horizontal plane relative field pattern of ± 1.5 dB circularity (when pole mounted) over the FM band. Even on square structures with 8 foot face dimensions, the “Cogwheel” produces a pattern of ± 2 dB. Beam tilt and null fill are available. Vertical plane relative field patterns are available upon request to determine individual station gain. At one wavelength element spacing, gain is approximately one-half the number of element levels.
The COGWHEEL™ uses single or dual transmission line in-puts. With the use of a dual line system, the COGWHEEL™ can continue to operate on one half of the antenna in the unlikely event of a failure in the other half.
Features and Benefits
- Configurations available to allow multiplexing simulcast FM IBOC signals.
- Existing installations can be retrofit for dual input operation.
- 20 Megahertz operating bandwidth
- Power Ratings up to 280 Kilowatts.
- ± 0.5 dB Typical Horizontal Plane Pattern Circularities (Pole Mounted)
- Excellent Axial Ratio
- Electrical Deicers not required
- Split Feed System, allows partial antenna use in an emergency
- All elements are at DC Ground Potential for Lightning Protection
- The 1180 design simplifies the antenna feed system requiring only one semi-flexible coaxial feeder be used to supply power to each bay element
Specialty Structures Brochure