The application of digital inverse filter deconvolution techniques to seismic data has been routine for many years. More recently these techniques have been extended to natural gamma-ray logging in order to improve the spatial resolution of the recorded logs (Czubek, 1971; Conaway and Killeen, 1978a,b). Early work in this field (Scott, 1963) involved an iterative procedure which required repeated processing of an entire log data set. Such a technique does not lend itself to continuous on-line deconvolution of a log while the logging operation is in progress. The inverse digital filter approach, by contrast, is particularly well suited for implementation in a computer-based borehole logging data acquisition system. Such a system had been developed at the Geological Survey of Canada (G.S.C.) by 1978 and was described by Bristow and Killeen (1978) and Bristow (1977, 1979).