Abstract: The data eye monitor includes a pair of comparators which compare the data input signal with a fixed reference voltage and a variable reference voltage with the resultant output of these two comparators being clocked into a digital comparator providing negative pulses representing the difference between the outputs of the two comparators. The negative pulses are coupled to an integrator to which a positive current source is coupled with the integrator providing the variable reference voltage for one of the comparators and also the output voltage of the monitor since the variable reference voltage is proportional to the opening of the data eye.

Abstract: Connection to a tantalum capacitor electrode (17) is effected using a conductive paint layer (15), incorporating pure silver and pure copper particles, which minimizes silver leeching by a tincontaining solder alloy (18) by which the lead wire (17) is connected to the conductive paint layer (15), and thus minimizes power factor degradation.

Abstract: An optical fibre directional coupler has first and second optical fibres clamped together by a piece of low index heat-shrunk tubing 12. The first fibre consists solely of a core 10 and cladding 11 while the second has a core 13 a primary cladding 14 whose cross-sectional area is larger than that of the core, and a secondary cladding 15. The outermost layer of each fibre is absent over a portion of its length within the tubing 12 so that the core 10 of the first is in intimate contact with the primary cladding 14 of the second. The second fibre may have a mode stripper 45 to strip modes guided by the primary/secondary cladding interface. Fibre break detection apparatus and a single-fibre two-way transmission system are described which use such directional couplers.

Abstract: A multilayer ceramic dielectric capacitor comprises a plurality of layers of dielectric arranged in a stack. Between the dielectric layers are arranged metallic electrodes. Alternate electrodes in the stack extend to opposite end faces thereof, where they are electrically connected by end terminations. The electrodes each comprise a plurality of parallel conductive elements provided between two adjacent dielectric layers. The adjacent dielectric layers are bonded together along three of their edges and at the gaps between the conductive elements, thus providing a stronger structure than when the adjacent layers are only bonded at the three of their edges. The electrode pattern comprised by a plurality of parallel elements is particularly applicable to metal-impregnated ceramic dielectric capacitors, which employ fugitive electrodes that are burnt away during firing of the ceramic to leave spaces for subsequent metal impregnation.

Abstract: A multi-mode radio receiver divides the radio frequency input into two channels and in each channel mixes it with the carrier wave frequency. A quadrature shift in the mixing carrier wave frequencies enables base band signals to be filtered from the mixer outputs. The analogue quadrature signals are converted to digital form and processed digitally to reproduce the original modulating signal for am, fm or pm transmissions. For ssb modulation the mixing frequency is the side band center frequency instead of carrier frequency.

Abstract: If a piezoelectric crystal is used in circuits containing ICs with low supply voltage, the additional capacitors required in oscillator or filter circuits cannot be implemented as junction capacitances. To eliminate the need for additional discrete capacitors, these capacitances are implemented with additional films on the crystal.

Abstract: The pump unit (2) is provided with a valve (6) at the pressure side, which is arranged to open a connection between the pump and the pump station thus obtaining a circulation. The valve is arranged at the upper side of the pump housing and the outlet of the valve is directed opposite to the flow direction (A) in the pump housing (4) thus minimizing the risk of clogging.

Abstract: A radio receiver for frequency shift keyed signals of the zero I.F. type. The quadrature outputs of mixers are low-pass filtered and a 90.degree. phase shift at the baseband frequency is introduced in one signal path. The baseband signals are then fully limited and applied to a logic network to provide a digital output indicative of the relative lead/lag condition of the two signal paths. The logic network can conveniently be an EXCLUSIVE-OR gate.

Abstract: An optical fiber submarine cable is made by extruding a metallic pressure tube by a friction extrusion technique, compressing the tube, applying tensile strength members, applying a conductive tape over the strength members and extruding plastic dielectric material over the tape. Armoring can subsequently be applied for shallow water application.

Abstract: The rate at which glass optical fiber can satisfactorily be coated with a primary plastics coating by a liquid application method is enhanced by causing the fiber to enter the liquid contained in a coating vessel via a suction tube in which a partial vacuum is maintained by an air induction device. Optionally a funnel is used to deflect the exhaust away from the incoming uncoated fiber.

Abstract: End terminations for multilayer ceramic dielectric capacitors, particularly but not exclusively metal-impregnated capacitors, are provided by bonding a coarse ceramic powder, which is lightly coated with silver, to the capacitor ceramic by means of a glass frit in order to produce a porous pseudo end termination containing insufficient silver to provide a good contact to the capacitor electrodes. The exposed silver in the pseudo end termination is then provided with a silver sulphide layer and subsequently the pseudo end termination is impregnated with lead. The end termination thus formed is comprised substantially of lead, which is held in place by the silver sulphide layer, that is wetted by the lead, on the bonded ceramic powder, and thus low cost and readily solderable.

Abstract: An arrangement for storing a coil of optical fiber prior to and during an inner peel deployment of the optical fiber from the coil comprises an outer aluminum casing, a body of solid foam material in the interior of the casing, and a barrier sheet in the interface, between the foam body and the coil of optical fiber. The foam body is formed in situ in a confining space outwardly and axially delimited by the casing and inwardly delimited by the barrier sheet and by two end lids, by introducing the material of the body into the enclosed space through openings in the casing and letting the material foam and cure in the spacing. During the formation of the body, the coil of optical fiber is supported on a mandrel which is, in turn coaxially supported on the end lids. After the foamed material has solidified, the end lids and the mandrel can be removed and the arrangement is now ready for inner peel deployment of the optical fiber therefrom.

Abstract: Conductive and porous end terminations for metal-impregnated multilayer ceramic dielectric capacitors are provided by firing a silver, or silver alloy, and glass frit onto respective end regions of a sintered capacitor stack. The exposed silver of the fired terminations is provided with a silver sulphide layer, the latter being a good electrical conductor and acting as a barrier between the silver and the impregnation metal, for example lead, during a subsequent impregnation step, whereby to prevent leaching of the silver. The termination is readily solderable by virtue of the silver sulphide layer being wetted by the lead during the impregnation step and resulting in a lead coating in the termination.

Abstract: In an assembly of a piezoelectric crystal and an IC on a substrate, additional capacitors, such as load capacitors of a crystal oscillator, are designed as blocks for mounting the crystal on the substrate at its vibration nodes.

Abstract: A plastic fiber cable has a flame retardant sheath which contains between 10-40% by weight of an inert filler, preferably titanium dioxide, which provides the sheath with thixotropic non-drip properties so that as well as possessing non-flammability properties the sheath when molten will also not drip and thus will not expose more flammable materials, such as the strands, inside the sheath.

Abstract: A tubular formation of particulate optical material is formed by a layer slurry deposition process which involves spraying layer after layer of slurry containing particles of the optical material onto a rotating rod-shaped bait. The composition of the slurry and particularly the index of refraction of the optical material may be varied from one layer to another or from one group of layers to another to obtain a graded or stepped refraction index profile in the formation, in an optical preform formed therefrom, and ultimately in the fiber drawn from the optical preform. The particles of the slurry are suspended in a liquid vehicle which evaporates in the spray stream or shortly after deposition, and are coated with an organic binder which holds them together in the layer and in the formation, so that the formation is self-supporting. Then, the organic binder is removed and the formation is sintered, followed by a collapse of the sintered tubular formation into the optical preform in the form of a solid rod.

Abstract: Hydroxyl free deposition with high efficiency and at a high deposition rate may be achieved, even with use of relatively inexpensive raw materials, by utilizing a ring-shaped plasma activated axial chemical vapor deposition obtaining 100% chemical conversion and fractional volatilization of impurities. The plasma is induced in an annular stream of a plasma-forming gaseous medium, and the reactant or reactants used in the axial chemical vapor deposition are introduced into the center of the ring-shaped plasma to be converted by the heat of the plasma flame into soot which is deposited on a bait. An annular stream of a cooling medium flows outwardly past the plasma flame and is circumferentially centered by an extension of the outer tubular element of a plasma torch in which the plasma is generated. An RF generator which induces the plasma is operated at a frequency exceeding 20 MHz to give the plasma flame the desired ring-sloped configuration.

Abstract: In order to provide a high power heat source having a very clean and invariable heat flux, a ring plasma is induced in a heating zone of a plasma torch including a plurality of coaxial tubular elements and the optical fiber is drawn through a channel passing axially through the center of the plasma torch and of the ring-shaped plasma. In this manner the preform from which the fiber is drawn can be placed in close proximity to the induced plasma without exposure to non-symmetrical temperature variations. Cooling gas passes through the heating zone either in an annular stream surrounding the plasma or in an annular stream passing through the center of the plasma around the preform and the fiber being drawn, or both. The heating zone is protected from environmental disturbances by an extension of the outer tubular element of the plasma torch which surrounds the heating zone.

Abstract: An improved high speed optical receiver provides an output that accurately corresponds to the optical input signal without the distorted signals caused by ac or dc coupled receivers when exposed to signals having varying amplitudes. Delaying and dividing circuits permit the creation of threshold signals which eliminate the drawbacks previously encountered.