公开(公告)号：US4081771A

公开(公告)日：1978-03-28

申请号：US747580

申请日：1976-12-06

申请人： Melvin Carlyle Hendrickson

发明人： Melvin Carlyle Hendrickson

IPC分类号： H03J5/02 ,  H03J7/12 ,  H03J5/06 ,  H04N5/52

CPC分类号： H03J5/0209 ,  H03J7/12

摘要： A television tuner system includes a varactor diode as the frequency determining element and means lacking a fine tuning control for addressing the varactor. In the addressing means, a plurality of DC potentials, each defining the band edges of one of the 82 standard broadcast television channels, are selectively accessible for deriving a nominal tuning voltage defining a frequency near the center of a selected channel and a pair of control voltages defining a restricted range of frequencies about the channel center frequency. The nominal tuning voltage is initially supplied to the varactor for tuning to the channel center frequency and is subsequently decoupled therefrom wherein tuning is maintained within the restricted range of frequencies by confining the voltage supplied to the varactor between the pair of control voltages. Automatic frequency control means are used to tune the varactor to a received signal within the restricted range of frequencies.

摘要翻译： 电视调谐器系统包括作为频率确定元件的变容二极管和缺少用于寻址变容二极管的微调控制的装置。 在寻址装置中，可以选择性地访问定义82个标准广播电视频道中的一个的频带边缘的多个DC电位，用于导出限定所选频道中心附近的频率的标称调谐电压和一对控制 定义关于频道中心频率的限制频率范围的电压。 标称调谐电压最初被提供给变容二极管，用于调谐到通道中心频率，并随后与其分离，其中通过限制在一对控制电压之间提供给变容二极管的电压，将调谐保持在受限频率范围内。 自动频率控制装置用于将变容二极管调谐到受限频率范围内的接收信号。