Automatic adjustment of wobbulator centre frequency - compares instantaneous wobbling voltage with nominal voltage, and corrections are made accordingly

摘要

The wobbulator is a part of a spectrum ananlyser, and its centre frequency is adjusted to the centre of the frequency coordinate of the indicator. The device has a highly constant auxiliary oscillator connected periodically, esp. during return sweep of the wobbling voltage, to the analyser input. The oscillator frequency ocrresponds to the specified frequency. A voltage comparator and controller is allocated to the wobbling oscillator. It is controlled by the analyser demodulator (5) output and compares the wobbling voltage instantaneous amplitude with a nominal voltage corresponding to the specified point of the indicator. The wobbling oscillator frequency or the deflection voltage of the indicator frequency coordinate are readjusted in accordance with the above difference.