A Vogad for Radiotelephone Circuits

Commercial radiotelephone connections must generally be accessible to any telephone in an extensive wire system. Speech signals delivered to the radio terminals for transmission to distant points vary widely in amplitude due to the characteristics of the wire circuits and individual voices. To provide the best margin against atmospheric noise, it is usually the practice to equalize this wide range of speech amplitudes and thus drive the radiotelephone transmitter at its full capacity. Many devices have been proposed to adjust automatically the gain in a circuit to equalize speech volumes. The difficulties of providing a device which will respond properly over a wide range to the complex qualities of a speech signal have only recently been overcome to a satisfactory degree. The voice-operated gain-adjusting device, or "vogad," described in this paper is a practical design based upon more than a year's experience with one of the most promising devices made available by earlier development effort. A trial installation of this latest vogad is now under way at Norfolk in connection with a new radiotelephone system for harbor and coastal service.