Thomson Consumer Electronics Inc.

Other

Rca Inc.

Leroy S Wignot

Dal Frank Griepentrog

Kevin E Nortrup

Robert Preston Parker

Gene K Sendelweck

Michael Anthony Pugel

Thomas D Gurley

Daniel Mark Hutchinson

William L Lehmann

Gary Dean Grubbs

Lawrence D Smith

A television receiver having an electronically controlled tuner is presented. A controlled local oscillator provides a local oscillator signal for the mixer. The controlled local oscillator includes an first input terminal for receiving a control signal for controlling its frequency and a first output terminal for providing an output local oscillator signal. A phase-locked loop includes a second input terminal for receiving the local oscillator signal and a second output terminal for providing a signal back to the first input terminal of the controlled local oscillator for controlling its frequency. At least a portion of the coupling between the first output terminal and the second input terminal, and the second output terminal and the first input terminal, have a common line.

Negative feedback control circuit having a common line for input and

A cable converter includes a first signal path from an RF input terminal to an RF output terminal including a tuner portion, a decoder portion, and a remodulator portion for remodulating a selected channel to an unused cable channel in the upper UHF band of cable channels in the range of cable channels 84 through 125. The subject cable converter also includes a direct parallel, second signal path from the RF input terminal to the RF output terminal. The second signal path passing all of the cable channels received at the RF input terminal to the RF output terminal substantially unimpeded.

Remodulation of a cable box output signal to a UHF channel

A television receiver includes a single tuner for tuning both television channels and broadcast FM stations. The tuner serves as the first conversion stage of a double conversion FM receiver, wherein the mixer of an FM radio integrated circuit serves as the second conversion stage. A single discriminator circuit is employed for tuning FM radio signals having a first deviation, such as broadcast FM radio signals, and FM radio signals having a second deviation, such as signals of the National Weather Service. Circuitry for amplifying the output signal of the discriminator circuit exhibits a first gain when amplifying FM signals having the first deviation, and exhibiting a second gain when amplifying FM signals having the second deviation.

Audio level equalization of broadcast and national weather service FM

Conversion of an RF signal amplifier from an unbalanced signal configuration to a balanced signal configuration is provided while including an image trap for both sides of the balanced circuit. The grounded side of the secondary of a double tuned circuit is lifted from ground to provide a balanced circuit configuration. A trap filter is provided in the balanced circuit configuration by a pair of small capacitors coupled between the balanced secondary leads to appropriate signal nodes.

Double tuned circuit with balanced output and image trap

A television receiver includes a single tuner for tuning both television channels and broadcast FM stations. The tuner is operated at a fixed gain setting in FM reception mode. The tuner serves as the first conversion stage of a double conversion FM receiver, wherein the mixer of an FM radio integrated circuit serves as the second conversion stage. The arrangement operates at a specific and non-arbitrary first IF frequency. The FM receiver is also capable of automatically receiving National Weather Service broadcasts on that one of NWS's seven allocated frequencies which is operating in a listener's area. The receiver provides an on-screen display of the currently tuned FM channel number.

Stereo FM radio in a television receiver

Fixed RF AGC of a television tuner for FM reception in a television

A television receiver includes a single tuner for tuning both television channels and broadcast FM stations. The tuner is operated at a fixed gain setting in FM reception mode. The tuner serves as the first conversion stage of a double conversion FM receiver, wherein a self-oscillating mixer circuit serves as the second conversion stage. The arrangement operates at a specific and non-arbitrary first IF frequency. The second IF frequency is the television intercarrier sound IF frequency. The FM receiver is also capable of automatically receiving National Weather Service broadcasts on that one of NWS's seven allocated frequencies which is operating in a listener's area. The receiver provides an on-screen display of the currently tuned FM channel number.

Mono FM radio in a television receiver

National weather radio reception by synthesizing only center frequency

First IF filter with fixed second half-IF trap for use in an FM radio in

A television receiver includes a single tuner for tuning both television channels and broadcast FM stations. The tuner serves as the first conversion stage of a double conversion FM receiver, wherein the mixer of an FM radio integrated circuit serves as the second conversion stage. The receiver provides an on-screen display of the currently tuned FM channel number. Circuitry is provided for interrupting the path of signals from the tuner to the IF amplifier stage of the television receiver when the receiver is in FM radio signal reception mode, to prevent the FM radio signals from adversely affecting the television synchronizing signals during the display of the FM channel number.

Interrupting the video if signal path during FM radio mode in a

The present invention concerns a high impedance signal source driving a relatively low input impedance mechanical resonating device such as a ceramic filter having an input impedance which varies with frequency. The high impedance source is further loaded by a resonant circuit tuned to the center frequency of the mechanical resonating device. The skirts of the resonant tuned circuit decrease in impedance on both sides of the center frequency of interest substantially compensating for the change of circuit gain with frequency due to the change of input impedance with frequency of the ceramic filter.

Apparatus for driving a mechanical resonator from a high impedance source

A television receiver includes a kinescope spot burn protection circuit comprising a capacitor coupled between a source of blanking signal and a control grid of the kinescope for applying negative grid cut-off bias to the kinescope in response to the blanking signal. The amplifier is of the cascode type having a minimum output voltage for peak white levels of a video signal applied to the cathode. The protection circuit includes a potential divider for biasing the kinescope at a positive voltage level related to the minimum output voltage of the amplifier during normal operation of the receiver to maximize the brightness of displayed images. The protection circuit also includes a breakdown device in the potential divider for limiting the maximum grid bias voltage to a level less than the minimum output level of the amplifier but greater than the positive voltage level provided by the potential divider to thereby avoid forward biasing the grid of the kinescope upon termination of the blanking signal which otherwise could occur during recharging of the capacitor.

Video display apparatus with kinescope spot burn protection circuit

Three vertical deflection windings of corresponding three deflection yokes that are mounted on three cathode ray tubes of a projection video are coupled in series through corresponding three connector pairs. Three horizontal deflection windings of the corresponding three deflection yokes are coupled in parallel through the corresponding three connector pairs. When any of the three connector pairs is left disengaged, a disabling signal that is indicative of a loss of a vertical deflection current in the series coupled vertical deflection windings is generated. The disabling signal is coupled to a corresponding video driver of each of the cathode ray tubes for providing beam current blanking to protect the screens of the tubes against a screen burn damage.

Deflection loss protection arrangement for a CRT

Apparatus for adjusting capacitance between an electronic component and external circuitry. The electronic component is unitarily provided with a plurality of conductive leads for connection to external circuitry with at least one of the leads being configured to provide integral means for adjustment of capacitance. The configured lead is bent for a turnabout of about 180 degree change of direction such that when the component is mounted on a printed circuit board the portion of the lead distal of the component extends above the board and is positionally adjustable providing adjustable capactive coupling to other circuit components.

Unitary capacitance trimmer

A multiband local oscillator of a television tuner comprises a common collector transistor amplifier, a capacitive feedback circuit for conditioning the amplifier to oscillate in the wide range of frequencies for VHF broadcast and cable channels and a multiband tuning circuit coupled to the base electrode of the transistor. Bandswitching signals are applied to the multiband tuning circuit to produce tuned circuit configurations for the various frequency bands. When one band is selected, the corresponding bandswitching signal is coupled to the capacitive feedback network to modify it so as to inhibit out-of-band oscillations due to parasitic elements of the tuning circuit.

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Indianapolis, IN, United States of America

Leroy S Wignot