| 摘要 |
PURPOSE:To enable to cover wide tuning range with one varactor diode, by connecting the load capacity to the auto-transformer having taps and providing varactor diode at other ends. CONSTITUTION:The transformer Ra is the tapped auto-transformer of winiding ratio of T1:T2, and the capacity viewed from the secondary side to which the varactor diode C is connected is small. Accordingly, with the varactor diode C having the capacity variable ratio of about 15, the frequency band of AM broadcast in Japan can be covered. Further, the capacitor Cg connected to the tap provided for the transformer TAa compensates the minimum capacity required for the varactor diode C and produces the primary current of the transformer TRa, allowing to stabilize the output voltage. |
