Phasor cabinets in directional antenna systems
Directional antenna systems are widely used in the medium wave (AM) frequency band for the dual purpose of increasing signal strength in desired directions and reducing interference with other stations in undesired directions. Typically, these systems include 2 to 12 towers, antenna coupling units on each tower, transmission lines, power splitting and bypass center sections, and control and monitoring equipment.
The heart of the directional system, the power division, the pairing and the phasor cabinet. Phasor cabinets give you precise coverage patterns that require minimal adjustment and provide maximum stability. The phasor cabinet divides and controls the power that is sent to each tower in a system.
Directional antenna systems must be computer designed to ensure the highest accuracy and most efficient circuitry. A wide network range for ease of tuning is a design goal. Components are chosen for conservative ratings to maximize reliability. All circuits must have a large number of pin and socket test points, and toroidal meters and phase samplers are standard.
High power antenna systems are built with special care to prevent arcing and overheating. Generous diameter connecting tubing is used, with crown rings and ball gaps where necessary for electrical gradient relief and component protection. Adequate coil gaps are maintained to reduce wall currents and minimize setting interaction. Insulators are specifically selected for the appropriate dissipation factor and dielectric strength for the circuit sector. Particular attention should be paid to internal and external grounding and protection of personnel.
Front panel access to all components is a design goal, which also minimizes floor space requirements for cabinets. Control systems feature full interlocks for safety and to prevent inadvertent application of power during switching sequences. Cabinet lighting and work plugs are available.
Outdoor phasor cabinets are typically constructed in a non-corrosive aluminum weatherproof metal cabinet or as a panel and shelf type for wall mounting in a tuning house. Internal equipment cabinets can be built to your specifications and can become an integral planning factor in coordinating design and style to reflect overall system compatibility and appearance.
