Abstract: A multi-pin connector for grounding a shielded flat cable is disclosed. A first conducting element is positioned between the receptacle portion of the connector and a grounded portion of the panel through which the connector passes via an aperture therein. A flat extension of the first conducting element projects through the aperture and grounds a second conducting element which is coupled to the plug portion of the connector by means of a cable positioning slot therein through which the cable and second conducting element pass. The second conducting element is folded around the flat cable in contact with the cable shield which is effectively grounded when the connection is made.

Abstract: An oscillator is described for use in the tuner of a television receiver which is tuned to a selected channel by a variable tuning voltage. The oscillator provides a higher than conventional power output at relatively low channel numbers by virtue of circuitry which changes the oscillator's operating current in response to the tuning voltage reaching a predetermined value. That predetermined value is selected to correspond to a relatively low channel number at which the power output of a conventional oscillator begins to decline.

Abstract: A UHF television receiver tuner comprises a varactor tuned circuit coupled to an input electrode of a field effect transistor mixer through a serially connected RF coupling capacitor. A local oscillator signal is coupled to the input electrode of the field effect transistor mixer through an inductive loop whose inductance value is chosen such that proper impedance matching over the UHF band is achieved.

Abstract: A cathode ray picture has a neck terminated by a plurality of electrically conductive pins extending axially from the neck terminus. The tube is characterized by each pin having an electrically conductive wire attached thereto. A base in abutting relationship to the neck terminus comprises an insulative member filled with an electrically insulative adhesive. The base has a closed end facing away from the neck terminus. The base includes a plurality of apertures equal in number to the wires for spacedly receiving and passing the wires. The wires are electrically isolated one from the others by the spacing and the insulative adhesive, and the base is adhered to the neck terminus by the adhesive.

Abstract: An acoustic surface wave filter is described for receiving one of two electrical signals at either of a pair of input ports and for providing a filtered electrical signal at a common output port. The filter includes a pair of input electro-acoustic transducers on a substrate, each coupled to one of the input ports, for launching surface waves in response to an electrical input signal. Each of the input transducers is associated with a multistrip coupler and an output transducer for converting the surface waves to an electrical output signal. The layout and geometry of the filter components are such that all surface waves are launched in a direction which is oblique to the substrate boundaries to reduce interference due to reflected surface waves. The layout and geometry also result in a relatively small substrate and a simultaneous reduction of insertion loss.

Abstract: A line choke is disclosed for use in attenuating interfering emissions on a power line. The choke includes a ferrite core having four holes extending through it. A pair of windings are threaded through the holes and around the center of the core so that the windings crisscross to enhance the mutual coupling between them. Interfering emissions received by the choke are greatly attenuated at relatively low frequencies by the choke acting as a pi section filter, and higher frequency emissions are attenuated by the choke action as a very lossy transmission line.

Abstract: A noise processing system is described for use in protecting a television receiver's sync processing path and its video processing path from impulse noise. To protect the video processing path, a first noise canceller receives a composite video signal, detects each noise pulse therein which exceeds a video noise threshold, and replaces each such noise pulse with a selected voltage level. The resultant noise processed video may then be applied to the receiver's video processing path. To protect the sync processing path, another noise canceller receives the composite video signal, detects noise pulses therein which exceed a sync noise threshold, generates a detection pulse for each such noise pulse, and combines the detection pulses with composite video so as to cancel the noise pulses. Thus, another noise processed video signal is developed for application to the receiver's sync processing path.

Abstract: A television receiver includes a video display for producing a video display image in accordance with a received television signal and a power supply responsive to an irregular current drain for perturbating the video display image. A telephone interface circuit coupled to the power supply is responsive to a viewer initiated dialing signal for completing a telephone connection with the corresponding telephone number in a manner so as to cause an irregular current drain from the power supply. The resulting perturbations otherwise present in the video display image are eliminated by a circuit cooperating with the telephone interface circuit for effecting a substantially uniform current drain from the power supply in response to the dialing signal.

Abstract: A projection television system having three different primary color pitcure tubes in an in-line configuration, one centrally located on the projection screen axis and the other two on opposite sides of the axis. In order to compensate for the defocussing which these off-axis locations produce at the edges of the projected image, the off-axis picture tubes are rotated relative to the optical axes of their respective focussing lenses, thus rotating the corresponding projected images into coincidence with the projection screen. The off-axis positioning also produces color shading by making the square law fall-off in illumination vary across the projection screen, and also by producing a trapezoidal distortion which is compensated by pre-distortion which introduces additional color shading effects. The first effect is reduced by making the lenses tangent or nearly tangent to each other, thus minimizing the angular deviation of the projection axes.

Abstract: A surface wave acoustic filter is compensated for diffraction and other spurious effects, which distort its frequency response, by adding an auxiliary acoustic channel which is in parallel with the primary acoustic channel, is out of phase therewith, and mimics the frequency response of the primary channel to the diffracted or other spurious wave.

Abstract: Disclosed is an overvoltage protection circuit for use in a television receiver with a floating ground, high voltage, alternating or direct current power supply in which a protective network of two spark gaps in series across one of which is coupled a capristor (or a capacitor and resistor) is connected across an isolation network between high and low voltage grounds thus limiting the maximum potential difference and providing a reliable, safe means of discharging continuous or transient high voltages which may develop between the floating ground and fixed (earth) ground. Reliability is provided by the inherent characteristics of two spark gaps in series while safety is insured by the predictable breakdown of first one spark gap rapidly followed by the discharge of the second spark gap across which is connected the capristor.

Abstract: A system for controlling a channel/band selective microcomputer programmed indirect frequency synthesis tuner is disclosed. Separate groups of VHF, UHF or CATV channels are programmed by means of a key switch having various positions of engagement corresponding to individual groups of channels. Following key switch selection of a given group of channels, any number of channels within that group may be programmed for viewing by means of channel UP and DOWN selector keys. A RAM is used to store "saved" and "skipped" channels for each key switch position. A backup non-volatile MNOS memory is provided for preserving stored data in the event AC power is removed. Also provided is programmable raster blanking for audio-only channels thus eliminating unwanted video snow. Front panel LED indicators inform the programmer of the status of each channel during television receiver programming.

Abstract: In order to reduce changes in color balance which occur as a function of viewing angle, a 3-color projection TV system having one axial and two off-axis image projectors employs a lenticular image screen having a plurality of vertical lenticules for horizontal light distribution, all of which have the same unique optical profile. This profile is derived by starting with a location-dependent shape appropriate for a location directly in line with an off-axis image projector, in order to obtain an asymmetric profile. The minor portion of the asymmetric profile is then discarded, and replaced by a mirror image of the major portion, thus producing a lenticule profile which is symmetrical but of too coarse a pitch. That oversized profile is then scaled down to the proper pitch, and duplicated all across the breadth of the screen.

Abstract: A method and network are described for correcting vertical non-linearity and mis-convergence in a color television projection system. The correction method includes adjusting the height of the projected image so that proper convergence is attained at either the top or at the bottom of the image, and so that the opposite end of the image is stretched. The stretched end of the image is compressed to proper size and proper convergence by shunting current away from each of three vertical deflection yokes included in the projection system.

Abstract: A head-end facility is provided for encoding selected data into the vertical intervals of one or more received television signals in a manner so as to avoid conflicts with the simultaneous re-broadcasting of the encoded signals. The selected data is generated at the head-end facility in the form of a plurality of pairs of duplicate data packets whose corresponding portions are separated in time by one-half field of a standard television signal. A plurality of channel registers are successively updated by being loaded with one of the duplicate data packets of each pair, the loaded duplicate data packets being non-coincident in time with the vertical intervals of the received television signal intended to be re-broadcast over the respective channel. The contents of the channel registers are successively read and inserted into the vertical intervals of the television signals of the respective channels.

Abstract: Disclosed is a microcomputer-controlled frequency synthesis television tuning system utilizing variable tuning ramp speeds following channel selection. Channel tuning is expedited by means of three ramping speeds employed during the tuning process. The system initially ramps quickly toward the selected channel and then automatically and incrementally reduces tuning speed as the proper frequency is approached. Once the proper frequency has been reached, the variable ramp speed signal acquisition mode is terminated and an AFC mode is initiated. Large frequency changes are thus made possible over short periods to accomodate widely separated channels efficiently.

Abstract: A video security system with intercom activated by means of a doorbell. The video input to a remote camera is automatically presented on the video display of a television receiver upon activation of the doorbell while audio from the intercom's speaker microphone is output through the television receiver's speaker system. Following a predetermined time interval after doorbell actuation, the system automatically turns off. If the television receiver is on when the doorbell is actuated, the system automatically provides video camera and intercom information at the television, reverting to the received television signal mode of operation upon user selection.

Abstract: A stabilization network is disclosed which compensates for variable emission characteristics of a cathode in a television receiver's cathode ray tube. During the receiver's vertical interval, a variable gain video amplifier applies a black level D.C. voltage to the cathode. The resulting cathode current is sensed and compared to a low level reference current. If the cathode current does not equal the reference current, a control signal is applied to the amplifier. The amplifier responds to changing its D.C. output voltage until the cathode current is equal to the reference current. The amplifier also responds to the control signal by altering its gain so that, when a video signal is received, the cathode develops peak white currents of a given value in response to peak white portions of the video signal.

Abstract: An isolating connector is disclosed for isolating the center conductor of a shielded cable from DC and low frequency AC potentials. The connector includes a generally tubular shell which is connected to the cable's shield and within which a connector pin is located for coupling to a female plug. A capacitance inside the shell is connected in series with the pin and the cable's inner conductor. Also inside the shell are two bleeder resistances, one connected in parallel with the capacitance and another connected in series between the shell and the connector pin. With this arrangement, any DC or low frequency AC potential appearing on the cable's inner conductor is isolated from the connector pin, and a discharge path is provided for the capacitance in the shell and any capacitance serially coupled with the cable's shield.