发明名称 |
AFC System for a synthesizer tuning system |
摘要 |
A voltage-controllable reference oscillator for a synthesized receiver. In one mode of operation the reference oscillator is injection locked to a crystal-controlled oscillator so that the receiver's local oscillator frequency is a rational multiple of the crystal oscillator frequency. In another mode of operation the reference oscillator is isolated from the crystal-controlled oscillator and its operating frequency is determined by the voltage applied at its tuning control terminal. The control voltage is selectively provided by a manually variable fine tuning circuit or by an AFC circuit. An acquisition delay circuit develops a pulse when a channel is selected or when the source of tuning voltage is changed, thereby assuring that the reference oscillator is operating in the injection-locked mode until the synthesizer phase-locked loop has achieved acquisition.
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申请公布号 |
US4208741(A) |
申请公布日期 |
1980.06.17 |
申请号 |
US19780956955 |
申请日期 |
1978.11.02 |
申请人 |
GTE PRODUCTS CORP |
发明人 |
BRUN, CRAIG W;HAND, WILFRED L |
分类号 |
H03J7/08;H03L7/24;(IPC1-7):H03B3/06;H04N5/50 |
主分类号 |
H03J7/08 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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