Automatic volume control for aircraft radio receivers
Wilbur S. Hinman · Bureau of Standards Journal of Research · 1931
An automatic volume-control device is described for use primarily in the recep- tion of visual type radio range-beacon signals, the device being easily applied to existing aircraft radio receiving sets.This device operates on the output voltage of the radio receiver, and is provided with a filter unit to prevent operation of the automatic volume control by signals other than those from the range beacon.The controlling voltage is derived from the output of the radio receiver, part of which is rectified and then applied as negative bias to the radio-frequency ampli- fier.The automatic volume control maintains a substantially constant output voltage for input voltage variations of the order of 5,000 to 1.A distance indicator, operating in conjunction with the automatic volume-control device, is provided to serve as a gage of distance from the transmitting station.A variation of the automatic volume-control device is given which is intermediate between completely automatic and manual volume control.This semi- automatic volume-control arrangement serves the purpose of simplifying the use of the range beacon on the part of the pilot, and at the same time permits the retention of sense of approach to the beacon station without requiring the addition of a distance indicator.CONTENTS Page I. Introduction 37 II.The filter unit 38 III.The automatic volume-control device 40 lv General description 40 2. Control grid method 40 3. Semiautomatic control using control-grid method 44 4. Semiautomatic control using screen-grid method 45 IV.