...
首页> 外文期刊>Electronic Servicing & Technology >The Magnavox electronic tuner
【24h】

The Magnavox electronic tuner

机译:Magnavox电子调谐器

获取原文
获取原文并翻译 | 示例
           

摘要

The state-of -the-art TV series continues here with a look at the tuner used in the Magnavox chassis #25P506-OOAA. Before we begin, a brief review of tuner theory is in order. The purpose of the tuner is to select a single channel in the VHF or UHF band and convert it from an RF (radio frequency) to an IF (intermediate frequency) for processing in the IF section. The IF frequency remains fixed. Frequency conversion is achieved by mixing or "heterodyning" the RF signal with a suitable signal from a local oscillator. This mixing of signals, which takes place in a nonlinear device (typically a diode or transistor), generates so-called sum and difference signals. For example, mixing a 100kHz signal with a 1kHz signal results in the generation of 101kHz and 99kHz signals. By selecting a local oscillator frequency that differs from the RF frequency by the proper amount for each selected channel, the appropriate IF frequency conversion will be made.
机译:最先进的电视连续剧在这里继续看一下Magnavox底盘#25P506-OOAA中使用的调谐器。在我们开始之前,先简要回顾一下调谐器理论。调谐器的目的是选择VHF或UHF频带中的单个通道,并将其从RF(射频)转换为IF(中频)以在IF部分中进行处理。中频频率保持固定。通过将RF信号与来自本地振荡器的合适信号混合或“异质化”来实现频率转换。在非线性设备(通常是二极管或晶体管)中发生的信号混合会产生所谓的和与差信号。例如,将100kHz信号与1kHz信号混合会产生101kHz和99kHz信号。通过为每个选定通道选择与RF频率相差适当数量的本地振荡器频率,可以进行适当的IF频率转换。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱:kefu@zhangqiaokeyan.com

京公网安备:11010802029741号 ICP备案号:京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有
  • 客服微信

  • 服务号