Stabilisation of tuned oscillator circuit - uses ferrite bead and capacitor to compensate for drift associated with diode characteristic

摘要

A stabilised synchronisation mode for capacitance diodes in tuned oscillator circuits for transmission systems is provided by an additional capacitor and a ferrite bead. The circuit is intended to overcome difficulties associated with drift due to operation on a steep part of the diode characteristic that can cause the unit to go off tune. The anode of the diode (1) is coupled via the oscillator coil (2) to ground. The cathode of the diode is coupled to ground via a capacitor (3). A ferrite bead is located in the vicinity of the cathode connection to provide suitable attenuation.