A communications engineer looks at conical scanning

The conical-scanning (con-scan) technique for automatic antenna control generates a double-side-band suppressed carrier (DSSC) signal, which must retain its absolute side-band-carrier phase and amplitude relationship for proper antenna operation. Definite passbands must be allowed in order to permit frequencies in the neighborhood of the nutation, or periodic movement, rate to pass through the system, unmodified by circuit characteristics. Signal-strength variations can cause serious deterioration of the tracking capabilities of the con-scan antenna, and total loss of track is not uncommon.