| 摘要 |
A preset tuning system has a search tuning system with varactor tuning means coupled to its output. Switch means, when closed, connects the input of the search tuning means to a voltage source so as to apply to the input a voltage sufficient to hold the search tuning circuit in a state of equilibrium. The switch means, when closed, also connects a control voltage source to the varactor tuning means and to the output of the search tuning circuit which serves to coincidentally control the voltage on the output of the search tuning circuit and the varactor tuning means while the switch means is closed. When the switch means is then opened, the search tuning circuit will immediately lock on the center of the incoming signal, whereby the voltage on its output is maintained.
|
