GB11410-1989

Technical bases of HFBC coverage

短波广播网覆盖技术规定

GB 11410-1989 — действующий обязательный национальный стандарт Китая: Technical bases of HFBC coverage. Отрасль: Электроника. Тема: Безопасность продукции. Дата вступления в силу: 1 февр. 1990 г..

Применимость зависит от продукции, схемы сертификации, уведомлений компетентных органов и переходных правил. Закажите перевод или проверьте источник, прежде чем использовать эту запись в решениях по соответствию.

Обзор требований

Этот обзор пока доступен только на английском языке.

Область применения

This standard specifies the main technical indicators and calculation methods for shortwave double-sideband amplitude modulation (DSB-AM) broadcasting networks. It is strictly applicable to the planning of shortwave broadcasting networks, the estimation of transmitter service areas, and the calculation of interference between stations. It does not apply to FM or television broadcasting systems. Engineers involved in international HF broadcast coordination and CIRAF zone planning should refer to this standard.

Технические требования

The standard defines critical operational parameters for shortwave broadcasting frequencies, including channel spacing, nominal carrier frequencies, and emission bandwidth. It establishes strict limits for RF signal-to-noise ratio (SNR) and various protection ratios, such as co-channel, adjacent-channel, and synchronous broadcasting protection rates, to ensure satisfactory listening quality. Engineers must ensure these protection ratios are met to mitigate interference between transmitters. Furthermore, the standard outlines the requirements for frequency tolerance and fading characteristics (both short-term and long-term). It introduces the concept of basic broadcasting reliability (BBR), which mandates that at least 80% of test points in a required service area must achieve the specified SNR. This reliability metric is fundamental for evaluating network coverage adequacy. The standard also classifies available frequency bands into different categories (A, B, C, D) based on their field strength performance relative to the minimum usable field strength.

Методы испытаний

The standard details comprehensive calculation and prediction methods rather than physical laboratory testing. It heavily references the HFBC86G program for shortwave propagation prediction, which calculates ionospheric parameters, field strength medians, and basic circuit reliability (BCR). Key evaluation procedures include predicting the basic maximum usable frequency (MUF) for E and F2 layers, calculating long-path and short-path field strength, and determining atmospheric noise factors. Engineers must use these computational methods to generate interference matrices and evaluate protection margins between broadcasting requirements. The calculation of minimum usable field strength incorporates atmospheric noise, man-made noise, and receiver internal noise.

Частые вопросы

What products and systems are regulated under GB 11410-1989?

This standard regulates the planning, service area estimation, and interference calculation for shortwave double-sideband amplitude modulation (HFBC) broadcasting networks. It is applicable to network planning rather than individual receiver manufacturing.

Does GB 11410-1989 align with international broadcasting standards?

The standard adopts the shortwave propagation prediction method approved by WARC-HFBC-1984/1987. It specifically references the HFBC86G software package for calculating ionospheric parameters, field strength, and circuit reliability.

What are the core technical indicators specified for shortwave broadcasting?

It defines key metrics including RF signal-to-noise ratio (SNR), co-channel and adjacent-channel protection ratios, frequency tolerance, and basic broadcasting reliability (BBR), which must meet a minimum of 80% for service areas.

The summary above provides a high-level overview of GB 11410-1989. To ensure complete compliance for your broadcasting projects and network planning in the Chinese market, a precise and professional translation of the full technical specifications is essential. Purchase our high-quality English translation of GB 11410-1989 today to access all detailed parameters, mathematical formulas, data tables, and software calculation procedures.

Подсказки по применимости

Тип: Продукция
CCS: M60
Компетентное ведомство: National Radio and Television Administration
Технический комитет: National Technical Committee on Radio, Television and Online Audiovisual of Standardization Administration of China