This report is concerned with the nature of the mean output of a single correlator receiving system when the input is a narrow frequency band signal arising from a localized source in space. The signal is received by two uniform, collinear arrays having an equal number of omnidirectional receivers. The mean output as a function of steering is bounded by the product of the space factors of the two arrays, so that the gross nature of the mean can be determined by investigating the main lobe width and side lobe level of the space factor product. These two quantities are studied as functions of the number of receivers, the receiver spacing in wavelengths, and source direction.