Abstract: Apparatus for guiding tape is disclosed wherein the tape is guided over a gaseous cushion at a guiding surface mounted relative to a reference surface with means urging the tape along the guiding surface against the reference surface. In one embodiment the urging means is the provision of the guiding surface and the reference surface positioned at a slight angle, in the range of from 5' to 30' and preferably 10' from normal so that the surfaces are positioned at an acute angle. The guide member can have the outside surface of an inverted frustum of a cone. In addition the guide member may include at least one sidewall of a vacuum column. Instead of the provision of a slight angle to urge the tape against the reference surface the apparatus can be constructed to provide a gaseous cushion between the guiding surface and the tape thicker at a location remote from the reference surface than adjacent to the reference surface.

Abstract: A feed device is tuned to resonance at a selected frequency, to provide essentially infinite impedance between, for example, a system being fed and the power source. The feed device allows passage of feedline currents, which are equal in magnitude and opposite in phase, but prevents passage of any other, unbalanced currents, e.g., common mode currents, antenna radiation currents, etc. This is due to the fact that the infinite impedance of the feed device defines extremely high attenuation to currents other than feedline currents, at the selected frequency. Thus the resonant feed device acts as an isolating circuit for transmitting and receiving antenna systems and the like, since any unbalance in the antenna elements is isolated from the feedlines, and vice versa, whereby the antenna is truly ground and/or feedline independent.

Abstract: A helical scanning rotating head magnetic tape transport is provided for use with cassettes, and is arranged with vacuum means to pull a loop of tape from the cassette and helically around the rotating head scanning drum to a capstan and retracted pinch roller. The pinch roller is then automatically inserted into the bight of the loop, together with an element between the loop shanks to keep them apart during operation, and the vacuum means is then inactivated.