In structure of selected category of broadcast signals, one channel includes the category of program material transmitted by the station. Further installed is a control spool that is operated by the hydraulic oil fed to the forward movement hydraulic clutch and that cooperates with the check valve to hold the hydraulic oil accumulated in the accumulator. 29180,269, of the inventor, entitled Surface Configuration of a Vehicle, Toy andor Other Repilcas. The method is useful as a primary screen, and may be used in conjunction with or as a substitute for additional tests, such as a stress test, CRP assay, LDL assay, etc.