Tuning control for multiple electronically tuned circuits

Claim 2

A circuit for simultaneously tuning a plurality of resonant circuits, each including as a part thereof a voltage variable capacitance means, said circuit including in combination: a source of direct current potential; tuning control voltage means connected to the source of direct current potential for providing a variable DC tuning potential from said source; reference voltage means connected to the source of direct current potential for providing different DC reference voltage outputs; means for connecting different outputs of the reference voltage means to different ones of the resonant circuits including the voltage variable capacitors; and means for connecting the variable DC tuning potential obtained from the tuning control voltage means to all of the resonant circuits to simultaneously tune the circuits, with the tuning of the circuits having predetermined offsets established by the different reference voltage outputs provided by said reference voltage means.

Claim 3

The combination according to claim 1 further including a bridge circuit having first, second, third, and fourth arms, with said first, second and third arms comprising resistors and said fourth arm including a constant voltage means providing a predetermined voltage drop thereacross for currents in a predetermined range flowing therethrough, and wherein the tuning control voltage means is connected in a diagonal between the junction of the first and second resistors and the junction of the third resistor and the constant voltage means, and the source of direct current potential is connected between the junction of the first and third resistors and the junction of the second resistor and the constant voltage means.

Claim 4

The combination according to claim 2 wherein the constant voltage means includes a Zener diode and the tuning control voltage means is a potentiometer, the tap of which is connected to a similar point in all of the resonant circuits.

Claim 5

The combination according to claim 3 wherein the DC reference voltage means for at least one of the resonant circuits is obtained from a tap on said diagonal and the DC reference voltage means for at least one other resonant circuit is obtained from one of the junctions to which the source of direct current potential is connected.

Claim 6

The combination according to claim 1 further including a bridge circuit having four arms interconnected At first and second input junctions and first and second output junctions, with the first and second input junctions being connected between said direct current source and a point of reference potential; and wherein said tuning control voltage means includes, a potentiometer connected across the first and second output junctions of said bridge, said potentiometer having a tap for providing said variable DC tuning potential, and the relative impedances of said arms being such as to cause said bridge to be unbalanced to provide a potential difference across said potentiometer.

Claim 7

The combination according to claim 5 further wherein the means for providing different DC reference voltage outputs includes means for obtaining the voltages present on at least two different junctions on said bridge circuit, said junctions being at different voltage levels.

Claim 8

The combination according to claim 6 wherein one of said reference voltage outputs is obtained from the point of reference potential and the other of said reference voltage outputs is obtained from one of said output junctions of said bridge.

Claim 9

A continuous wave signal translation device including at least an RF tuned circuit and a variable frequency oscillator, the RF tuned circuit and said oscillator each including a tunable resonant circuit having a voltage responsive variable capacitance device therein for selecting the frequency of said tuned circuits to accomplish tuning of said wave signal translation device, said device including in combination: a source of direct current potential; a bridge circuit having first and second input terminals and first and second output terminals, with said first and second input terminals connected between said source of direct current potential and a point of reference potential; control means connected across said first and second output terminals for deriving a variable DC control potential; reference means connected to the bridge circuit for providing different DC reference voltages therefrom; first connecting means for connecting different ones of the different DC reference voltages to each of said resonant circuits; and second connecting means for connecting the variable DC control potential to the voltage variable capacitance devices in each of the resonant circuits to effect tuning simultaneously of each of said resonant circuits, the resonant circuits being simultaneously tuned to different frequencies as established by the different reference voltages connected thereto.

Claim 10

A continuous wave signal translation device including at least an RF tuned circuit and a variable frequency oscillator, the RF tuned circuit and said oscillator each including a tunable resonant circuit having a voltage responsive variable capacitance device therein for selecting the frequency of said tuned circuits to accomplish tuning of said wave signal translation device, said device including in combination: a source of direct current potential; a bridge circuit having first and second input terminals and first and second output terminals, with said first and second input terminals connected between said source of direct current potential and a point of reference potential; control means connected across said first and second output terminals for deriving a variable DC control potential; reference means connected to the bridge circuit for providing different DC reference voltages therefrom; first connecting means for connecting different ones of the different DC reference voltages to each of said resonant circuits; and second connecting means for connecting the variable DC control potential to the voltage variable capacitance devices in each of the resonant circuits to effect tuning simultaneously of each of said resonant circuits, the resonant circuits being simultaneously tuned to different frequencies as established by the different reference voltages connected thereto.

Claim 11

The combination according to claim 8 wherein the bridge circuit is a four-arm bridge circuit, three of the arms of which constitute resistor means and the fourth arm of which includes a Zener diode.

Claim 12

The combination according to claim 9 wherein the control means connected across said first and second output terminals of the bridge includes a potentiometer, the tap of which provides the variable DC control potential, and wherein one of the different reference voltages obtained from the bridge is obtained from one of said first or second output terminals and wherein a second of the reference voltages obtained from the bridge is obtained from said point of reference potential.

Claim 13

The combination according to claim 10 wherein each of the resonant circuits is a parallel tuned circuit including a voltage variable capacitor and a blocking capacitor connected in parallel with an inductance and further wherein the reference voltage and the variable voltage are connected across the voltage variable capacitor in each of said tuned circuits.

Claim 14

The combination according to claim 10 wherein the arm of the bridge including the Zener diode further includes temperature-compensating means connected in series with the diode.

Claim 15

The combination according to claim 12 wherein the temperature-compensating means includes a silicon diode connected in series with the Zener diode.