Abstract: An attachable/detachable probe point for use with an electrical measurement probe includes a base having a aperture formed therein that extends through the base. An electrically conductive probing contact having at least a partially threaded body member and a pointed contact member is disposed in the aperture with a portion of the body member extending from the top surface of the base and the pointed contact member extendable from a first position within the aperture to a second protruding position outside the aperture at the bottom surface of the base. A compliant adhesive material formed on the bottom surface of the base for securing the attachable/detachable probe point to probing contact point.

Abstract: A digital storage oscilloscope includes first and second memory modules each including a data input section for receiving an input stream of digital data words and generating a sequence of address words, an acquisition memory which is addressed utilizing the address words for storing the data words, and a trigger input section for receiving a discrete input trigger and supplying the discrete input trigger to the data input section for initiating termination of an acquisition. The data input section of the first memory module passes the stream of digital data words to the data input section of the second memory module and supplies a discrete trigger to the trigger input section of the second memory module.

Abstract: An adapter for a multi-channel signal probe has one of the mating plug or receptacle portions of the connector electrically coupled to a first array of contact pads on one surface of a substrate. A second array of contact pads corresponding to the signal contact pads on a device under test is formed on the other surface of the substrate. A removable signal contact holder supports electrically conductive elastomer signal contacts that couple the second array of contact pads to the signal contact pads of the device under test. The adapter is secured to the device under test using an adapter retention member that is positioned on the opposite of the circuit board from the signal contact pads. Screws attach the retention member to the adapter via through holes formed in the device under test.

Abstract: Cable loss correction of distance to fault (DTF) and time domain reflectometer (TDR) measurements obtains distances to impulses representing reflections from a cable under test from a time domain representation of the cable. For each impulse a plurality of frequency data are generated and amplitude corrected based upon the cable loss at the given distance to the impulse. The resulting frequency data are then converted back to the time domain to present a time domain representation of a corresponding lossless cable showing the impulses at appropriate amplitudes. The impulses representing the reflections from the cable may be obtained by a vector network analyzer that obtains amplitude and phase data for a plurality of test signal frequencies, which data is then converted to the time domain to show the impulses and the distances of the impulses from the measurement end of the cable.

Abstract: A method of measuring blockiness in a video signal generates a power spectrum for a video field of the video signal. The largest peaks of the power spectrum at the higher frequency end of the power spectrum are initially selected and a common frequency interval between peaks is determined. The contribution to the amplitude of peaks at the common frequency interval by peaks at other than the common frequency interval are subtracted from the amplitude of the peaks at the common frequency interval. The average of the corrected amplitudes of the peaks at the common frequency interval is obtained and normalized as a blockiness metric for the video signal.

Abstract: A method and apparatus for the detection of Gaussian noise in a video signal decomposes an image from the video signal to obtain best qualified blocks having a relatively uniform luminance. From the best qualified blocks an average standard deviation is calculated, and then smoothed by temporal filtering. The filtered average standard deviation is finally calibrated against a scale of corresponding input noise levels to obtain the Gaussian noise in the video signal.

Abstract: A frequency spectrum measurement apparatus sweeps a desired frequency range using multiple scan lines. A controller provides a non-contiguous sequence of input values to a frequency synthesizer operating as a local oscillator for generating a non-contiguous frequency output signal over the desired frequency range with each value offsetting a current frequency output signal from a previous frequency output signal. A mixer receives an input signal and the variable frequency synthesizer signal for generating an intermediate frequency signal that is filtered through a bandpass filter. The power of the intermediate frequency signal output of the bandpass filter is measured and displayed. The frequency spectrum measurement apparatus is usable in measuring out of channel emissions of a terrestrial RF broadcast digital television signal.

Abstract: A method of efficient and reliable detection of error blocks in a DCT-based compressed video sequence extracts edges from an image that correspond to the DCT blocks. These edges are processed to determine an edge energy value. The edge energy value is compared with a threshold to provide an alarm for an error block when the threshold is exceeded. The edge energies for each block may be summed and compared with an overall threshold value to generate the alarm, or the edge energy for each edge may be compared with an edge threshold value to determine which are good and which are suspect, with the alarm being set when at least three of the edges are suspect (two edges for corner blocks).

Abstract: A phase stable clock circuit includes a phase gate having track-and-hold (T/H) circuits with each T/H circuit receiving a phase shifted continuous sinusoidal signal of predetermined phase and a control input signal to capture and hold phase samples of the sinusoidal signals. In alternative embodiments, a phase correction circuit provides phase correction values that are added to the held phase values to generate corrected phase values and time-error phase lookup table is used to generate time position correction values. The corrected phase values are applied to the phase gate remove deterministic phase errors to generate an output signal with a predetermined startup phase relative to the control input signal transition. The phase error-to-time lookup table adjusts the time placement of waveform record samples after the acquisition of the samples.

Abstract: An electronic interconnect assembly has a high speed coaxial interconnect for a coaxial transmission line having a central signal conductor and a surrounding shield conductor. The coaxial interconnect has a male side and a female side, with the female side including a shield sleeve having a chamber that receives a male shield contact on the male side. The shield sleeve has a contact with a compliant portion that flexibly grips the male shield contact. A mechanical alignment facility includes a closely mating pocket and body, each attached to a respective male or female side of the interconnect. Additional data and power connectors may be included with the pocket and body.

Abstract: A variable spacing probe tip adapter for a differential measurement probe has a measurement probe head with first and second probe tips extending from the probe head. Ribs and grooves formed in the probe head that extend radially from around each of the probe tips. Each of first and second first probing tips have an electrically conductive shaft that has a bore formed in one end for engaging the probe tips of the measurement probe. Each shaft has ribs and grooves formed therein that extend radially from the bore for engaging the corresponding grooves and ribs in the probe head. The other end of the conductive shaft tapers to a probing point with and a portion of the shaft toward the tapered end of the shaft being angled such that the probing tips. The conductive shafts are rotatable on measurement probe tips and locked into position by the engagement of the ribs and grooves in the probe head and the probing tips.

Abstract: An interactive multimedia audio/video communications system uses a lower data rate, non-deterministic graphics/command network having a plurality of desktop viewing stations and a network server. A separate, higher data rate, deterministic audio/video network is coupled to the plurality of desktop viewing stations using appropriate resources, such as an audio/video routing switcher and a professional disk recorder. A database contains a telephone directory so that when a user at one of the plurality of stations desires to communicate with another station, the user selects a telephone number and the server from the database determines the appropriate resources required to complete the connection. The server configures the necessary hardware via the graphics/command network to route the audio/video signals over the audio/video network from one station to the other.

Abstract: An apparatus and method for determining the period of a data signal encoded using PN sequences may be implemented using software, and takes advantage of the fact that the signal is generated based upon a pseudo-random binary sequence, and of the fact that the order of the characteristic polynomial is known. The apparatus and method uses knowledge about the structure of the signal generator (i.e. the order of the characterizing polynomial of the encoding PN sequence), and recognizes the fact that short data tokens from the original signal can be used with the same success in determining the period as longer sequences having at least the length of the period.

Abstract: An adapter for an electronic interconnect assembly has a high speed coaxial interconnect for a coaxial transmission line having a central signal conductor and a surrounding shield conductor. The coaxial interconnect has a male side and a female side, with the female side including a shield sleeve having a chamber that receives a male shield contact on the male side. The shield sleeve has a contact with a compliant portion that flexibly grips the male shield contact. A mechanical alignment facility portion selected from a pair of alignment facility portions including a closely mating pocket and body has one of the male side or female side of the coaxial interconnect. An electrical signal connector is electrically coupled to the selected male or female of the coaxial interconnect.

Abstract: A probe tip adapter for a measurement probe has at least a first electrically conductive element with a bore at one end and a probing contact formed on the other end. The bore of the electrically conductive element has an electrically conductive elastomer disposed therein having sufficient tensile strength, compression set, hardness, deflection force, elongation and percent recovery for repeatably securing the electrically conductive element to the probing tip of the measurement probe. An element holder is positionable on the measurement probe and has a cavity formed in one end for receiving the measurement probe. At least a first bore is formed in the other end of the element holder extending to the cavity and aligned with the probing tip of the measurement probe. The electrically conductive element is positioned in the holder bore such that the probing tip penetrates the elastomer and the probing contact extends from the holder.

Abstract: A PALC panel is operated by increasing the voltage between the channel electrodes to a firing voltage to create a plasma in the channel, reducing the voltage between the channel electrodes to a sustaining voltage to sustain the plasma for an interval during which a selected drive voltage is applied to the data drive electrode to establish an electric field in the layer of electro-optic material, and reducing the voltage between the channel electrodes to a bias voltage, which is insufficient to sustain the plasma but provides an electric field having a component parallel to the cover sheet in the layer of electro-optic material.

Abstract: A twisting fiber depolarizer has sections of a birefringent (HiBi) fiber spliced to opposing ends of a nominally non-birefringent fiber, such as a single mode fiber, between a pair of hold points to produce a fiber assembly. Means is applied to the free portion of the fiber assembly between the hold points for twisting the free portion of the fiber assembly with a back and forth motion to depolarize an optical signal input to one end of the fiber assembly.

Abstract: A reference receiver has a biased, strobed sampling system that is tuned to provide the predominant frequency response of the reference receiver allowing for the removal of the discrete reference receiver filter. The reference receiver has a photodiode optical-to-electrical converter that is configured to effectively utilize the current output of the high impedance source in that the converter is not reverse terminated to the characteristic impedance of a transmission coupled to the electrical output of the converter. The electrical output of the converter is coupled to a sampling circuit that receives biasing voltages and gating strobe pulses for producing an approximate Bessel-Thompson filter response from the sampling circuit. The combination of the unterminated optical-to-electrical converter and the tuned sampling circuit results in a reference receiver having higher gain and narrower reference receiver tolerance limits.