Abstract: A security seal fastener system includes a fastener, and an enclosure around a head of the fastener that provides visual evidence of access to the head after installation of the fastener. The enclosure may include a washer that is around a shaft of the fastener, and a cap that closes off an access opening in the washer. The cap has a spring that engages a groove in an inner surface of the washer, to lock the cap in place. A flange of the cap and a ridge of the washer prevent access to the spring. The washer has an anti-rotation feature to prevent rotation of the fastening system while the enclosure is intact. The cap has a knockout that can be perforated or removed to allow access to the head of the fastener, for removal of the fastener. The cap may have an identifier, such as a serial number.

Abstract: A chassis having a unique configuration is provided along with card guide assemblies having predefined configuration types for selective installation in the chassis. The guide assemblies, when installed within the chassis, enable circuit cards having varying standard dimensions to be mounted and secured within the chassis regardless of slot location. A first type of card guide assembly is mounted at the end of a plurality of slot locations a predetermined first standard distance apart to enable cards having a first length and one of a number of depths to be installed. A second type card guide assembly is mounted between the opposed first card guide assemblies at any slot location a second predetermined standard distance from one of the first guide assemblies to form a slot partition and enable the installation of cards having a second length shorter than the first length and one of the number of depths.

Abstract: A sensitive circuit area on a circuit board is isolated from an adjacent located non-sensitive circuit area by surrounding the sensitive circuit area with electrically interconnected ground planes positioned on the opposite sides of the circuit board. The isolation system further includes a "clam shell" RF/IF tight shield attached to each side of the circuit board enclosing the sensitive circuit area. A partially conductive gasket is placed between the clam shell and the top and bottom circuit board surfaces to enhance isolation performance.

Abstract: An adaptable card mounting system includes a number of card guides having predefined configurations selectively mounted at slot locations within a chassis to enable cards of varying dimensions to be installed. A first type of card guide is mounted to opposed walls of the chassis at each slot location. This first card guide is required for installation of cards of a first length and first depth. A second card guide is mounted to the walls of the chassis in conjunction with the first card guide at slot locations requiring installation of circuit cards having a second depth different than that of the first depth. A third type of card guide is mounted between the opposed first or second card guides at selected slot locations requiring installation of cards of a second length shorter than the first length. Use of the three card guides at selected slot locations permits installation of circuit cards of varying dimensions independent of slot location.