IEEE Std 1260 pdf free download

IEEE Std 1260 pdf free download.Prediction, Measurement, and Analysis of AM Broadcast Reradiation by Power Lines.
For the purposes of this document, the following terms and definitions apply. The IEEE Standards Dictionary Online should be consulted for terms not defined in this clause.1 Additionally, IEEE Std 539 TM [B5] contains definitions related to corona and field effects aspects.2
AM broadcast array: One or more towers fed the same broadcast signal but at different current levels and with different delays. By carefully choosing the height, location, current level, and delay for each tower, a far- field pattern can be constructed to broadcast strongly in some directions and weakly in others.
amplitude modulation (AM): Modulation in which the amplitude of a carrier is changed by an amount proportional to the instantaneous value of the modulating wave.
azimuth: The angle between a horizontal reference direction (usually true north) and the horizontal projection of the direction of interest, measured clockwise.
coverage area: The area surrounding the broadcast array that is within the signal strength contour that provides adequate reception.
detuners: Devices attached to a structure that alter the impedance at the connection point such that a minimum of current at the design frequency flows in the structure. They are used to minimize reradiation of the AM signal, thus correcting distortion of the AM station’s antenna pattern. Syn: detuning apparatus; detuning stub; tuning stub.
far-field radiation pattern: Any radiation pattern obtained in the far field of an antenna array.
far-field region: That region of the field of an antenna array where the angular field distribution is essentially independent of the distance from the center of the array. A general far-field approximation is 2d2IA, where d is the largest separation between elements in the array.
FCC (Federal Communications Commission): The FCC regulates interstate and international communications by radio, television, wire, satellite, and cable in all 50 states, the District of Columbia, and U.S. territories.
field strength: The magnitude of the electric field vector.
field strength meter: A calibrated radio receiver for measuring field strength. These meters employ a shielded loop antenna, which measures the magnetic component of the electromagnetic field and then converts it to an electric field by multiplying the magnetic field strength by the impedance of free space for a plane wave.
ground conductivity: A property of the ground, expressed as the ratio of electric current density to electric field strength.
interference: Field strength produced by a radio disturbance, such as signals from other stations. major lobe: The radiation lobe containing the direction of maximum radiation. Syn: main lobe. minor lobe: Any radiation lobe except a major lobe.
An AM broadcast array is carefully constructed to radiate strongly towards local listening areas and weakly in directions where interference to other stations could result. The strong signals are contained in a major lobe directed toward the local listening area. Other smaller listening areas can be serviced with minor lobes. The directions of weak signals, called nulls, generally are towards areas without listeners, or towards other stations operating at the same frequency (co-channel), at the next highest or lowest frequency (adjacent channel), or at frequencies two channels away (second adjacent channel). The signal shall be weak towards these stations so as to limit the interference to acceptable levels.IEEE Std 1260 pdf download.