This standard applies to the site selection of medium wave broadcasting stations with a frequency of 526.5~1606.5kH, and short wave broadcasting stations with a frequency of 2.3~26.1MH, and is applicable to the new construction of cable carrier communication systems operating in this band. GBJ 142-1990 Standard for the protective distance between medium and short wave broadcasting stations and cable carrier communication systems GBJ142-1990 Standard download decompression password: www.bzxz.net

Engineering Construction Standard Full Text Information System
National Standard of the People's Republic of China
Standard for the protective distance between medium and short wave broadcasting transmitters and cable carrier communication systems
GBJ142—90
1991Beijing
Engineering Construction Standard Full Text Information System
W Engineering Construction Standard Full Text Information System
National Standard of the People's Republic of China
Standard for the protective distance between medium and short wave broadcasting transmitters and cable carrier communication systems
GBJ142—90
Editorial Department: People's Republic of China Radio, Film and Television Ministry of Radio, Film and Television Approval department: Ministry of Construction of the People's Republic of China Effective date: August 1, 1991
Engineering Construction Standards Full Text Information System
Engineering Construction Standards Full Text Information SystembzxZ.net
Notice on the promulgation of the national standard "Standard for the protective distance between medium and short wave broadcasting transmitters and cable carrier communication systems" (90) Jianbiaozi No. 673
According to the requirements of the former State Planning Commission's document No. Jizong [1986] 2630, the "Standard for the protective distance between medium and short wave broadcasting transmitters and cable carrier communication systems" jointly formulated by the Ministry of Radio, Film and Television and relevant departments has been reviewed by relevant departments. The "Standard for the protective distance between medium and short wave broadcasting transmitters and cable carrier communication systems" (GBJ142-90) is now approved as a national standard and will be implemented from August 1, 1991. The Ministry of Radio, Film and Television is responsible for the management of this standard. The Ministry of Radio, Film and Television is responsible for the specific interpretation and other work. The Standardization and Planning Institute of the Ministry of Radio, Film and Television is responsible for the publication and distribution. The Standardization and Quota Institute of the Ministry of Construction is responsible for organizing the publication and distribution.
Ministry of Construction
December 22, 1990
Engineering Construction Standards Full Text Information System
Engineering Construction Standards Full Text Information System
Preparation Instructions
This standard is prepared by the Standardization Planning Institute of the Ministry of Radio, Film and Television in conjunction with relevant units in accordance with the requirements of the former State Planning Commission's Document No. [1986] 2630.
During the preparation process, the preparation team collected a large amount of information, conducted on-site measurements of the broadcast electric field strength of the medium and short wave broadcast transmitters that are commonly used in China, and also tested and verified the overhead cable's resistance to broadcast signal interference. After widely soliciting opinions from relevant units across the country, it was revised several times and finally finalized by our department in conjunction with relevant departments.
This standard is divided into three chapters and one appendix. The main content is the protection distance between medium and short wave broadcast transmitters and cable carrier communication systems. In view of the fact that this standard is formulated for the first time, in the process of implementation, we hope that all units will combine engineering practice and scientific research, carefully summarize experience, and pay attention to accumulating data. If you find that there is a need for modification and supplementation, please send your opinions and relevant materials to the Standardization Planning Institute of the Ministry of Radio, Film and Television (postal code: 100866) for reference in future revisions. Ministry of Radio, Film and Television
June 1990
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W. Engineering Construction Standards Full Text Information System
Chapter 1 General
Chapter 2
Chapter 3
Protection distance between medium wave broadcasting transmitter and cable carrier communication system...
Protection distance between short wave broadcasting transmitter and cable carrier communication system
Explanation of terms used in this standard
Additional explanation
Engineering Construction Standards Full Text Information System
W. Engineering Construction Standards Full Text Information System
Chapter 1 General
Article 1.0.1 This standard is specially formulated to ensure the normal operation of medium and short wave broadcasting transmitters and cable carrier communication systems. Article 1.0.2 This standard applies to the site selection of medium wave broadcasting stations, 2.326.1MH, and short wave broadcasting stations with a frequency of 526.5~1606.5kH, and applies to the new construction of cable carrier communication systems operating in this band. Article 1.0.3 The protection distance refers to the distance from the center of the transmitting antenna of the medium and short wave broadcasting stations to the cable carrier communication line or bureau (station). Article 1.0.4 The cable carrier communication lines and equipment shall comply with the provisions of the current national standards "Indicators of the coaxial cable carrier communication system against radio broadcasting and communication interference" and "Indicators of the symmetrical cable carrier communication system against radio broadcasting and communication interference".
Engineering Construction Standard Full Text Information System
Engineering Construction Standard Full Text Information System
Chapter 2 Protection Distance between Medium Wave Broadcasting Transmitters and Cable Carrier Communication Systems
Article 2.0.1 The electric field strength of the medium wave broadcasting signal can be determined by on-site measurement or calculation.
Article 2.0.2 For the electric field strength of the built medium wave broadcasting transmitter, it is advisable to adopt on-site actual measurement to determine. During the actual measurement, a broadcasting field strength meter should be used. The distance between the receiving antenna of the field strength meter and the ground should be 1~1.5m, and the antenna orientation should be rotated to find the direction with the strongest electric field strength for measurement.
Article 2.0.3 When the earth conductivity is taken into account, the electric field strength must be measured; when the earth conductivity is not taken into account, the electric field strength of the medium wave broadcasting signal can be calculated according to the following formula: E=60+201g330VF
Wherein, E is the electric field strength of the medium wave broadcasting signal (dBuV/m); P is the effective radiated power of the medium wave broadcasting transmitter (kW); P is the distance from the transmitting antenna of the radio station (km). (2.0.3)
Article 2.0.4: When the electric field strength of the medium wave broadcast signal is greater than or equal to 120dBu/m, the protective distance between the medium wave broadcast transmitter and the cable carrier station and station with terminal and manned repeater can be calculated according to the following formula: D-300VP
Where P is the effective radiation power of the medium wave broadcast transmitter (kw); D is the protective distance (m).
Article 2.0.5: When the electric field strength of the medium wave broadcast signal is 140dBuV/m, the protective distance between the medium wave broadcast transmitter and the cable carrier unmanned repeater and underground cable can be calculated according to the following formula, but the minimum protective distance shall not be less than 20m outside the edge of the transmitter ground network
Engineering 2 Construction Standard Full Text Information System
Engineering Construction Standard Full Text Information System

D=30VP
Article 2.0.6 When the electric field strength of the medium wave broadcast signal is 125dBuV/m, the protective distance between the medium wave broadcast transmitter and the aluminum sheathed overhead symmetrical cable can be calculated according to the following formula, but the minimum protective distance shall not be less than 20m outside the edge of the transmitter ground network. D=169P
Engineering Construction Standard Full Text Information System
Engineering Construction Standard Full Text Information System
Chapter 3 The protective distance between the short wave broadcast transmitter and the cable carrier communication system
Article 3.0.1 The protective distance between the short wave broadcast transmitter and the cable carrier communication system shall comply with the following provisions:
1. The distance in the direction of the half-power angle of the main lobe of the strong directional antenna shall not be less than 300m, and the distance in the direction of the half-power angle of the non-main lobe of the strong directional antenna shall not be less than 50m; 2. The distance in all directions of the non-directional antenna shall not be less than 200m; 3. For the short wave transmission center, the distance shall not be less than 1000m. Article 3.0.2 The electric field strength of shortwave broadcast signals in cable carrier stations with terminals and manned repeaters shall not exceed 100dBuV/m. Article 3.0.3 The electric field strength of shortwave broadcast signals in cable carrier unmanned repeaters shall not exceed 110dBuV/m.
Article 3.0.4 The electric field strength of shortwave broadcast transmission signals in underground cables and overhead symmetrical cables shall not exceed 140dBuV/m. Engineering 4 Construction Standard Full Text Information System
Engineering Construction Standard Full Text Information System
Explanation of terms used in this standard
1. When implementing the provisions of this standard, the terms used to indicate the degree of strictness are explained as follows so as to distinguish them in implementation.
1. Words that indicate that it is very strict and must be done: positive words use "must";
negative words use "strictly prohibited".
2. Words that express strictness and should be done in normal circumstances: positive words use "should";
negative words use "should not" or "must not" 3.Words that indicate that a slight choice is allowed and that this should be done first when conditions permit: positive words use "should" or "may";
negative words use "should not".
2. The wording used in the article to indicate that it must be implemented in accordance with other relevant standards and specifications is "should be implemented in accordance with..." or "should comply with... requirements or regulations". Engineering Construction Standards Full-text Information System
Engineering Construction Standards Full-text Information System
Additional Notes
List of the editorial unit, participating units
and main drafters of this standard
Editorial Unit: Standardization Planning Institute of the Ministry of Radio, Film and Television Participating Unit: Design Institute of the Ministry of Posts and Telecommunications
Main drafters: Wu Lengqian Cheng Gang
Wei Sufen
Engineering Construction Standards Full-text Information System
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