Abstract: A signal combining circuit for combining a tuning bias voltage and an automatic frequency control error voltage for application to a voltage controlled radio frequency tuning means for a television receiver is shown. The voltage controlled radio frequency tuning means has a non-linear frequency versus voltage characteristic and the signal combining circuit includes a resistance means for coupling the error voltage to the tuning means input in a manner that compensates for the non-linearity of the frequency versus voltage characteristic of the tuning means to provide a substantially constant automatic frequency control pull-in range throughout the frequency range of interest.

Abstract: A resonance circuit having an inductor, a capacitor and a semiconductor with a junction, and means for applying a signal to the semiconductor junction. The semiconductor junction satisfies the equation: ##EQU1## where C represents the capacitance of the semiconductor junction when a voltage V is applied thereto and the junction of the semiconductor is reverse biased, C' is a constant, and the inductor and capacitor are connected in series.

Abstract: A channel-selecting apparatus in which is designed to determine the oscillation frequencies of a local oscillator and/or the tuning frequencies of a radio-frequency amplifier for all channels by varying analogue dc voltages being applied to a frequency control element such as a variable capacitance diode included in the oscillator and/or the amplifier in accordance with channel selective operation. Digital memory devices are provided each of which previously stores digital information representing the different predetermined analogue voltages assigned to all the channels being applied to the frequency control element. Digital information stored in the memory devices is read out upon selective operation of any of channel selection switches each coupled with the corresponding one of bistable multivibrators.

Abstract: An apparatus for indicating a tuned frequency of a tuner of a radio or television receiver, said tuner comprising a tank circuit employing a voltage controlled variable capacitance diode as a circuit element, which diode is supplied in a reverse direction with a scanning control voltage from a solid state potential memory device, which control voltage is set as a result of tuning of said tuner, said indicating apparatus comprising a plurality of light emitting diodes arranged in a line, each illuminating the corresponding frequency indicating region out of a plurality of divided frequency indicating regions of a frequency band to be received by said receiver, said regions being arranged in succession to cover said frequency band, and a corresponding plurality of drivers responsive to said control voltage for energizing the corresponding light emitting diode for illuminating the corresponding frequency region to which said tuned frequency pertains.

Abstract: In a channel selector of the type having an electronic tuner in which the channel selection voltage, which is different for each channel, is applied across a voltage-variable reactance element such as a varactor diode in order to select and receive the desired channel, each channel selection voltage is converted into the digital signal, and is stored in a memory block, and in selecting the desired channel, the corresponding digital signal is read out of the memory block and is converted into the analog channel-selection signal to be applied to the tuner. A completely electronic channel selection becomes possible because any mechanical parts such as variable resistors for storing the channel selection voltages may be eliminated.

Abstract: There is disclosed a signal-seeking, scanning superheterodyne radio receiver operable on all four bands comprising the public service radio frequencies. The receiver uses a single oscillator and appropriately controlled frequency multipliers to generate the required local oscillator signals. Circuitry is included for tracking the radio frequency portions of the receiver to tune them for optimum operation as the receiver is tuned to different portions of the individual bands. The tracking circuitry is responsive to the oscillator circuit and includes two parallel resonant circuits connected in series to generate a d.c. signal varying in amplitude in response to the oscillator frequency. Circuitry is also included for altering the magnitude of the d.c. signal in accord with the band to which the receiver is tuned.

Abstract: An automatic tuning apparatus comprising a tuner having a tank circuit employing a voltage controlled variable capacitance diode as a circuit element, which diode is supplied in the reverse direction with a scanning control voltage from a solid state potential memory device, which control voltage is varied under the control of a scanning voltage control circuit to scan the frequencies in the frequency band by the tuner and is set by a scan stop signal obtained from the tuner as a result of tuning of the tuner to a certain frequency, and a pair of manual switches for upward and downward scanning, a first flip-flop to be reset by the closing of either manual switch and to be set by the scan stop signal, a second flip-flop to be set and reset by the closing of the downward and upward scanning switches, respectively, a third flip-flop to be set and reset by the closing of both manual switches and caused to be reversed in the storing state thereof when the scanning voltage reaches the maximum or minimum value ther

Abstract: An abrupt junction type varactor diode television tuner includes a source of DC tuning voltage supplying bias to the diodes for tuning the tuner to broadcast television signals. The varactor diode in the RF amplifier stage is connected to the source of tuning voltage through a very large resistance which provides automatic signal overload protection.

Abstract: A television tuning system has a ramp voltage source including an electrical current source and an electrical current sink coupled through selectively operable transmission gates for varying the voltage of a tuning capacitor to control a local oscillator for tuning independent of received signal. The local oscillator signal is mixed with a received signal to produce an intermediate frequency signal which is amplified in an IF amplifier. A frequency detector is coupled to the IF amplifier and produces an error signal dependent upon the frequency difference between a reference frequency and the IF signal. An additional current source and sink are coupled to the tuning capacitor through transmission gates controlled by the error signals. Differences greater than a predetermined amount selectively activate the latter transmission gates to provide substantially constant magnitude tuning voltage corrections irrespective of the amount of the difference.

Abstract: A fine tunable electronic channel select system for controlling the varactor tuner of a television receiver or the like and including a dual mode prescaler for dividing the local oscillator (VCO) frequency of the tuner by a first divisor and then by a second divisor to produce a selectively variable average divide during a sample period, a programmable digital divider for dividing the output of the prescaler by a predetermined divisor corresponding to a selected television channel, a channel selection mechanism for controlling the programmable divider, a signal source for generating a stable reference frequency, a frequency/phase comparator for comparing the output of the programmable divider with the reference signal to develop an error signal, an integrator/amplifier for integrating the error signal to develop a biasing signal for controlling the tuner, and a fine-tune control circuit for selectively controlling the length of time the prescaler operates in each of its two modes, thereby enabling incremental

Abstract: A television tuner features a switching voltage generator that resets the voltage across the varicap tuning diodes to about zero voltage when a new tuning range is switched on. This allows the full steepness of the capacitance-voltage characteristics of the diodes to be used in each range. This in turn allows more ranges to be tuned and reduces the effects of stray capacitances.

Abstract: A channel selector comprising a tuning circuit including a variable reactance element as a tuning element and a non-volatile memory for permanently memorizing coded signals of channel selecting voltages to be applied to said variable reactance element, and being arranged in such a manner that the channel identification numbers and the coded signals for selecting these channels can be correspondingly memorized preliminarily in said non-volatile memory, and in channel selection the coded signal of the channel selecting voltage corresponding to a desired channel can be read out from said non-volatile memory, converted into a voltage and applied to said variable reactance element to achieve channel selection. A selected channel does not change by the cutting of the power source and the device is purely electronic. The device is especially effective for use in a television receiver.

Abstract: A frequency band selection switch and variable resistor assembly for one channel of a television tuner in which tuning is performed by varying a tuning voltage. A tuning shaft is connected to the slider of the variable resistor through a harmonic drive reduction gear assembly. A tuning scale is connected to the slider through a bored tuning scale shaft through which the tuning shaft coaxially extends. A bored switch shaft through which both the tuning and tuning scale shafts coaxially extend carries a movable contact of the band selection switch and a frequency band indicator. An assembly support member has a graduated dial associated with both the tuning scale and the frequency band indicator in a unitary manner.

Abstract: An electronic tuner control system particularly adapted for television receivers employs a gated oscillator for sequentially stepping the tuner from one channel selection to the next. The system includes a counter responsive to the gated oscillator for causing the sequential scanning or stepping to take place in either the "up" or "down" direction. Separate tuning potentiometers are associated with each channel and are selected in sequence under control of the counter. Each potentiometer is set to either a first range of settings indicative of a valid tuning voltage for that channel or to a second range indicating that no tuning or channel selection is to be effected for such a second or "non-preferred" setting. All of the tuning potentiometers are coupled to an analog steering circuit comprised of isolating diodes, and only one potentiometer at a time is selected to apply a tuning voltage to the output of the steering circuit under control of the counter.

Abstract: A VHF television tuner system has four tunable circuits each including an abrupt junction varactor diode having a predictable capacitance-tuning voltage characteristic. The VHF frequency spectrum is divided into Lo and Hi bands encompassing television channels 2-6 and 7-13, respectively. A pair of voltage divider networks comprising precisely trimmed resistive material on a ceramic substrate provide tuning voltage terminals corresponding to the VHF television channels. The end terminals of each divider network are coupled to adjustable potentiometers for setting the tuning voltage at each extreme of the voltage divider. A substrate mounted switch accesses the tuning voltage points, supplies bandswitching voltages and provides AFC defeat between channels.

Abstract: A rotary wiper contact supported on a hub is housed between a substrate having a resistive element and a bracket means to form a potentiometer subassembly. The bracket and substrate are fixedly mounted to a pushbutton tuner frame with the hub of the wiper contact directly mounted on the treadle bar for integral movement therewith. Actuation of any pushbutton or the manual tuning shaft to select a predetermined frequency rotates the treadle bar and the wiper contact varying the effective resistance of the potentiometer which controls the voltage of a varactor to tune the receiver.

Abstract: A remote control receiver for a television receiver remote control system having a memory capacitor and a field-effect transistor readout to provide a direct control voltage is shown. Circuit means illustrated as a diode connected in series with the memory capacitor limits the magnitude of the charge stored by the memory capacitor to prevent the field-effect transistor from being driven beyond cut-off by an excessive amount.

Abstract: A station selector comprising a first memory for memorizing the first decimal digit of a given channel number in a form of a corresponding binary signal, a second memory for memorizing the second decimal place digit of the channel number in a form of corresponding binary signal, first and second binary-to-decimal converters for converting the contents of the first and second memories into corresponding decimal signals, a matrix circuit for combining the decimal outputs of both the first and second binary-to-decimal converters such that the resultant combination can be taken out from one of the intersections of a matrix corresponding to a given two-digit decimal channel number, and a preset voltage circuit having a plurality of preset channel selection voltage elements adapted to provide respective preset channel selection voltages and selecting one of the voltages for selecting a channel of a corresponding channel number in response to the output taken out from the afore-said intersection, the selected voltag

Abstract: An all-electronic television tuning system has a sequentially accessible multi-position two digit memory coupled to a viewer controlled channel number selection means for providing storage and recall of selected two digit channel numbers in a sequence established by loading selected channel numbers into fifteen of sixteen serial memory locations. The system has program and operate modes, corresponding respectively to storage and recall of channel number information, and the memory has a sixteenth, particular location accessible only in the operate mode for providing immediate all channel tuning control for the viewer irrespective of the pre-programmed channel number sequence.

Abstract: A TV channel selector assembly includes a keyboard having ten keys corresponding to the decimal numbers zero through nine, inclusive. The desired channel may be selected merely by activating the appropriately numbered keys, there being no other keys required to be activated to effect a channel change. After activation of the first key, which may be either a units digit channel or the tens digit of a two digit channel, a delay circuit defines a timed interval of about two seconds. Each keyboard output is encoded into a four digital word. A control device transfers the first digital word to a units channel input if a second key is not activated during the timed interval. If a second key is activated during the timed interval, the first digital word is transferred to a tens channel output, and the second digital word is transferred to the units channel output.

Abstract: An AFC circuit has a tuning circuit including a first variable capacitance element and a pair of series connected inductive elements. Switch means are connected between ground and a point between the inductive elements for alternatively operably connecting one or both of the inductive elements in parallel with the first variable capacitance element to switch the tuning circuit between a higher frequency range and a lower frequency range. The AFC portion of the circuit comprises a second variable capacitance element which is connected in parallel with the first variable capacitance element. In order to improve the sensitivity of this circuit, a means is provided for capacitively coupling the second variable capacitance element to a point between the inductive elements. As a result, substantially equal AFC ranges are obtained whether the circuit is tuned to the higher or the lower frequency range.