This invention relates to a method of preparing a mixed manganese ferrite coated catalyst, and a method of preparing 1,3-butadiene using the same, and more particularly, to a method of preparing a catalyst by coating a support with mixed manganese ferrite obtained by co-precipitation at 10\u02dc40\xb0 C. A stationary retaining strip running over a length of all separating sections is attached on the transport path on a side opposite the transport belt and operates on the mail items with friction force. An eccentric unit comprising two spaced-apart cams rotated counter to one another, with the individual piston pumps being located in a number of sectional planes through the pump housing corresponding to the number of cams and locate the connecting conduits for hydraulically coupling the pump units are located in a region of the pump housing defined by the sectional planes. Sliding portions of the base extend horizontally yet continue to transfer all load weight onto the casters.