shared Features and Uses of a Directional Antenna Phasing Cabinet

shared Features and Uses of a Directional Antenna Phasing Cabinet




One of the meaningful elements of a directional antenna system, involving a receiving or transmitting aerial device that converts electric strength into radio groups and vice versa, is the phasing equipment (aka the phasor cabinet). This system is highly used in directional AM Stations and in the medium wave (AM) frequency band, as it allows the strengthening of the signal in a particular direction and reduces the interference to stations located in other directions that are not desired. It’s possible, in fact, to set the degree of directivity of the antenna’s radiation pattern, which is controlled by the amplitude and phase weights of each individual component.

To assure maximum accuracy and stability, the phasing equipment is used. The phasor manages the strength that is sent to each antenna tower in a system. The phasor cabinet holds tuning coils, vacuum/cast mica capacitors, inductors, RF contactors and variable junctions of circuitry connected to the other elements; it is all housed in the cabinet where someone can do most of the adjustments (on the front panel’s control knobs) to increase the coverage area or unprotected to the best antenna gain (beamwidth) and path, or nullify interference.

A phasor can already help fix small transmission problems. It is not uncommon to find a slight change in directivity or performance of antennas. A simple fix, however, can be applied by controlling the cabinet’s knobs. by this radio part, the phase and strength going to each antenna can be modificated.

On the confront of the phasor cabinet, it is possible to check base current levels without the need to open the cabinet doors or remove its panels, as there are indicators showing the mode of operation. However, a tech may need to use the cabinets’ rear doors for easy parts access, to have access to all housed elements. At times, an engineer may need check the equipment inside of the cabinet, when needing to inspect the system after encountering a system fault. From the inside, the person is able to insert a measuring instrument, for example, to troubleshoot and fix what may not be working properly.

A good example of the phasor not working properly is when the owner’s antenna monitor readings changes dramatically or there is absence of the shorting bar (J-plug) which may have fallen out of its socket/jack. Every now and then the cabinet requires a radio engineer to discover the problem(s) and ensure the phasor is being fed by the transmitter(s).

Aside from shifting the phase or increasing the amplitude of the signal, for example, in order to get the needed direction from the antenna system, the phasor unit is crucial to functioning of other devices too, such as the antenna tuning unit (ATU), line-terminating unit (LTU) and antenna coupling unit (ACU), whose satisfy lines are also correlated to each tower. To get enough signal strength and the right phasing and matching of the range parameters, it is paramount to have each unit working aside the other to gain the desired directional pattern and unprotected to wanted measurements.

In sum, the phasor, its matching and strength dividing equipment for directional AM operation, housed in the cabinet, is purposely used as a phase unit controller which ensures strength is being applied to each antenna. It is commonly used as a monitoring system to check pattern changes, of which can be customized to meet the needs of the user.

shared features of a good cabinet include:

• Easy access from front and rear panel via hinged doors

• The ability to check current levels without already opening the front doors

• Digital front controls that include cranks or aluminum knobs for precise adjustments

• Dual AC receptacle in each bay

• Clear identification for each elements by engraved labels

• J-plugs positioned for ease of access, including nearby bridge grounding posts

• Interior panels that divide bays, so that RF isolation can be ensured to day and night networks

• A variety of fixed and variable capacitors

• An input current meter that allows for far away output

Fabrication and placement: Directional antenna phasing units are typically constructed in non-corrosive aluminum weatherproof housings (when placed outside) or placed in metal cabinets (when used indoor) or on sustain stands; they can also have an open panel and shelf ATU kind for wall mounting.




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