One of the key components of a directional antenna system is a phasing device [also known as a phasor cabinet] that involves receiving or transmitting airborne equipment that concentrates power into radio waves, and vice versa. This system is highly used to orient the AM station and the medium wave [AM] band because it allows the signal to be boosted in a particular direction and reduces interference to stations in other directions that are not desired. In fact, the degree of directivity of the antenna radiation pattern can be set, which is controlled by the amplitude and phase weight of each individual component.
To ensure maximum accuracy and stability, use a phased device. The phasor manages the power sent to each antenna tower in the system. The phasor cabinet houses the tuning coil, vacuum/cast mica capacitors, inductors, RF contactors and variable circuit connection points to other components; it is all placed in the cabinet and some people can make most adjustments [control on the front panel] Knob] to increase coverage or achieve optimal antenna gain [beamwidth] and path, or to eliminate interference.
Phasor can even help solve small transmission problems. It is not uncommon to find a slight change in the direction or performance of the antenna. However, you can apply a simple fix by controlling the knob of the speaker. The phase and power entering each antenna can be adjusted throughout the radio.
On the surface of the phasor cabinet, the basic current level can be checked without opening the door or removing its panel as there is an indicator showing the mode of operation. However, technicians may need to use a cabinet. The back door makes it easy to access parts and has access to all built-in components. Sometimes, when a system failure is required to inspect the system, the engineer may need to inspect the equipment inside the cabinet. For example, from the inside, personnel can insert measuring instruments to troubleshoot and repair faults that may not work properly.
A good example of a phasor that does not work properly is when the owner's antenna monitor readings change significantly or there is no shorting bar [J plug] that might fall out of the socket/jack. The cabinet needs a radio engineer to detect problems at regular intervals and ensure that the transmitter is feeding phasors.
In addition to moving the phase of the signal or increasing the amplitude of the signal, for example, to obtain the desired direction from the antenna system, the phasor unit is also critical to the functionality of other devices, such as the Antenna Tuning Unit [ATU] line. - Terminal Unit [LTU] and Antenna Coupling Unit [ACU], whose feeders are also associated with each tower. In order to obtain sufficient signal strength and positive phase determination and matching of the array parameters, it is of utmost importance to have each unit work as another unit to obtain the desired pattern and achieve the desired measurements.
In summary, the phasors for directional AM operation, their matching and power distribution devices, housed in the cabinet, are deliberately used as phase unit controllers, which ensure that power is applied to each antenna. It is often used as a monitoring system to check for mode changes, which can be customized to meet the needs of the user.
Common features of good cabinets include:
• Easy access to front and rear panels through hinged doors
• Check the current level of function without opening the front door
• Digital front controller, including crank or aluminum knob for precise adjustment
• Dual AC outlets in each bay
• Clearly identify each component by engraving labels
• J-type plug positioning is easy to access, including auxiliary bridge posts
• Internal panel separates the bay to ensure RF isolation for day and night networks
• Various fixed and variable capacitors
• Input ammeter to allow remote output
Manufacture and placement: Directional antenna phasing devices are typically used in non-corrosive aluminum weatherproof enclosures [when placed outdoors] or in metal cabinets [for indoor use] or on support frames; they can also be open for wall mounting Panel and shelf ATU type.
Orignal From: Common features and uses of directional antenna camera cabinets
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