Observations of the large–scale distrubutions of galaxies in the universe indicate the presence of very large wall–like superclusters. In their distributions there is a growing evidence that there is a characteristic scale in excess of 100h−1Mpc. This scale is rather interesting since it is too small to be well measured from fluctuations in the cosmic microwave background, but at the same time is large enough to be easily sampled in current redshift surveys. There are several physical processes in the universe at around recombination (equality of matter and radiation, the sound horizon, the recombination) which may have left an imprint on the fluctuation spectrum even in the galaxy distribution. We discuss on how ongoing large–scale redshift surveys may be optimally analysed, via the Karhunen–Loève method, to provide high–precision information on the fluctuations on these interesting scales. These large surveys are the first where the dominant source of noise is systematic errors, requiring novel techniques in their statistical analysis.