A signal reader system having a processor for reconstructing a relatively high-frequency input signal to a low-pass filter from an output of the filter based on a characterization of the filter. 5 to 10% by weight of an abrasive precipitated silica having a 50 percentile of particle diameter being 5 \u03bcm or less, a 90 percentile of particle diameter being 15 \u03bcm or less and an RDA value of 120 or more, and 0. The server validates that the sender of the validation-message is a valid client-receiver of the subscriber television system using an authentication-token and a validator that is known to both the server and to at least one of the client-receivers. And it may be provided with a guide plate 28D perpendicular to the side wall 28b of the openingclosing bar 28A of the swollen portions side.