| 摘要 |
PURPOSE:To correct the tuning shift automatically, by detecting the tracking error through fine change of resonance frequency periodically. CONSTITUTION:When low frequency is superimposed on the tuning voltage given to the voltage controlled tuning circuit, the tuning frequency is slightly changed periodically. As a result, the detected outut voltage of the desired reception signal is periodically changed. If the resonant frequency fc slightly changes in the range of fc'-fc'', and if the reception signal frequency is in agreement with fc, the detected output voltage is not changed within one period, but variation is caused if the tracking error DELTAf is present. Then, the error voltage in response to the tracking error can be caused by giving the detected output voltage to the phase comparator. |
