Radio Reception Center
Radio Reception Center
a complex of buildings and equipment for the simultaneous reception of signals transmitted
from many radio stations. The first such centers were built at the same time as radio transmission centers.
A radio reception center may be a separate facility or part of a communications center that has a specific function, such as main-line or space communications or radio broadcasting. The basic equipment includes antennas and feeder devices with an amplifier-distribution system, radio receivers, and intermediate and terminal apparatus of the receiving circuit. Auxiliary facilities include the control and remote-control equipment and the apparatus for service communications and signaling. The technical equipment is usually located in permanent structures on the center’s grounds. Small radio reception centers can be located in semipermanent structures or in vehicles.
The technical design of a radio reception center depends on the type of signals to be received and on the measures taken to improve reception. Figure 1 shows a generalized structural scheme indicating the functional relationships between the principal components of a radio reception center. Antenna equipment is located in an antenna field close to the technical building; the field usually occupies an area of approximately 10–100 hectares, the greater part of the center’s grounds. At permanent centers there may be as many as 20 to 30 large directional antennas with lengths up to several hundred m or more; they may include complex systems, such as phased antenna arrays. Up to 100 or more radio receivers are connected to the antennas by feeders. The antennas are also connected to tuning and matching devices, devices that control operation of the antennas, and feeders and lightning-protection devices at the receiver inputs. During the operation of the center, it often becomes necessary to connect several radio receivers to one antenna or to switch receivers from one antenna to another. This switching is done by means of an amplifier-distribution system. Each antenna is connected to a broadband antenna amplifier that has several outputs leading to signal distributors; the signal distributors are connected to antenna-selector switches. These selector switches have switching banks featuring coordinate structures, such that the inputs of each switch are connected to the outputs of all amplifiers; however, the outputs of each switch are connected only to the switch’s own group of radio receivers.
In large radio reception centers, radio receivers are located in special rooms equipped for audio reception, for teletypewriter reception, or for other specialized functions. The outputs of radio receivers are connected to intermediate and terminal receiving apparatus. The purpose of these apparatus is to improve the quality of signal reception; in particular, two or even four antennas may be connected simultaneously to a single receiver in order to reduce signal fading. Intermediate and terminal apparatus have outputs that are connected to communication lines. These lines carry the received signals through the center’s office or traffic-control station to other equipment rooms, at the communications center. The aggregate of antennas, radio receivers, and intermediate and terminal apparatus constitutes the center’s combined reception system.
The number of subscribers to the service and the quality and quantity of technical equipment are characteristic indicators of the technical capabilities of a radio reception center. The assignment and control of technical equipment depend on the center’s purpose and the degree of automation; a center can be controlled either directly from within the center or by remote control from an office, traffic-control station, or telephone or telegraph center.
In order to improve radio reception and to reduce the influence of radio interference, radio reception centers are usually located far from industrial sources of radio interference, from radio transmission centers, and from individual, powerful broadcasting stations.
REFERENCESBaranovskii, B. K. Apparatura mnogokratnogo ispol’zovaniia priemnykh antenn korotkovolnovogo diapazona. Moscow, 1966.
Chelyshev, V. D. Priemnye radiotsentry. Moscow, 1975.
V. D. CHELYSHEV