GB2017-1980

Covering technique of the medium-wave broadcastingnetwork

中波广播网覆盖技术

GB 2017-1980 é uma norma nacional chinesa obrigatória vigente: Covering technique of the medium-wave broadcastingnetwork. Setor: Eletrônicos. Foco: Segurança de produtos. Entrada em vigor: 1 de jan. de 1981.

A aplicabilidade depende do escopo do produto, da via de certificação, dos avisos da autoridade competente e das regras de transição. Solicite uma tradução ou verifique a fonte antes de usar este registro em uma decisão de conformidade.

Visão geral de conformidade

Esta visão geral está disponível por enquanto apenas em inglês.

Escopo e aplicabilidade

This standard applies to the planning of domestic medium wave broadcasting networks, the estimation of radio station service areas, and the estimation of interference between stations. It is essential for engineers involved in the design and regulation of AM broadcasting systems in China. It does not apply to shortwave or FM broadcasting networks.

Requisitos técnicos

GB 2017-80 defines critical terminology and technical indicators for medium wave broadcasting. It specifies the frequency range for medium wave broadcasting and establishes the standard channel spacing and nominal carrier frequencies for all designated channels. The standard also outlines the permissible emission bandwidths for different carrier frequencies to prevent adjacent channel interference. Furthermore, the standard defines the required radio frequency protection ratios for co-channel, adjacent channel, and synchronous broadcasting networks. These ratios are crucial for ensuring satisfactory listening quality. Engineers must ensure their broadcasting systems meet these protection ratios to avoid signal degradation. The standard also sets strict limits on carrier frequency deviation and allowable frequency offsets between adjacent stations in a frequency synchronization system.

Métodos de ensaio

The standard details comprehensive calculation and measurement methods for wave propagation. It includes methods for calculating ground wave propagation using diffraction theory and provides curves for various ground conductivity coefficients. It also covers the calculation of sky wave propagation and the method for calculating composite field strengths when multiple waves are present. Additionally, the standard specifies the calculation method for usable field strength, which is critical for determining the actual service area of a station, especially considering nighttime interference. Engineers must use these specific calculation methods to accurately estimate coverage and interference. It also details the field strength recording method for measuring frequency deviations between adjacent stations in a frequency synchronization system.

Perguntas frequentes

What products or systems are regulated under GB 2017-80?

GB 2017-80 regulates the planning and technical parameters of medium wave broadcasting networks in China, including AM radio transmitters and their coverage estimation.

Does GB 2017-80 specify the exact frequencies for medium wave broadcasting?

Yes, the standard provides a comprehensive table of nominal carrier frequencies for all designated channels within the 526.5 to 1606.5 kHz range, with a standard channel spacing of 9 kHz.

How is the service area of a radio station determined under this standard?

The service area is determined by the usable field strength, which is the minimum field strength required for satisfactory listening quality in the presence of natural noise, industrial interference, and co-channel or adjacent channel transmitter interference.

The summary above provides a high-level overview of GB 2017-80. To ensure complete compliance for your broadcasting systems entering the Chinese market, a precise and professional translation of the full technical specifications is essential. Purchase our high-quality English translation of GB 2017-80 today to access all detailed parameters, propagation curves, and calculation procedures.

Indicações de aplicabilidade

Tipo: Básica
CCS: M60
Órgão competente: National Radio and Television Administration
Comitê técnico: National Technical Committee on Radio, Television and Online Audiovisual of Standardization Administration of China