Frequency generator with decadic adjustment for use in frequency characteristics tests

Claim 2

A frequency generator comprising: a plurality of decadic counters each having 10 cyclically triggerable stages; a like plurality of decadic networks each assigned to a respective counter, each of said networks including 10 normally blocked gates and 10 sources of fixed equispaced frequencies respectively connected to said gates; stepping means for cyclically triggering the stages of said counters at decadically related rates to register a progressively changing multidigit numerical value on said counters, the stages of each counter being connected to respective gates of the associated network for unblocking same upon triggering by said control means to pass the corresponding fixed frequency; a frequency synthesizer including circuitry for weighting the frequencies passed by said gates and for combining the frequencies so weighted into a composite output frequency proportional to said numerical value; monitoring means connected to the stages of each counter for registering the state of actuation of said stages as a measure of said output frequency, said monitoring means comprising a coincidence gate with a number of inputs corresponding to the number of said counters; adjustable presetting means for selectively connecting each of said inputs to any one stage of a respective counter; and control means connected to an output of said coincidence gate for modifying the operation of said stepping means upon said composite output frequency attaining a value selected by said presetting means.

Claim 3

A frequency generator as defined in claim 1 wherein said stepping means includes an emitter of stepping pulses connected in parallel to the stages of one of said counters for periodically enabling same.

Claim 4

A frequency generator as defined in claim 2 wherein said control means includes switch means connected to said emitter for discontinuing said stepping pulses upon attainment of the selected value.

Claim 5

A frequency generator as defined in claim 1, further comprising switchover means for selectively applying the pulses from said emitter to the stages of any counter in the least significant decades.

Claim 6

A frequency generator as defined in claim 4, further comprising oscillator means for generatiNg a standard frequency, said emitter being connected to be driven by said oscillator means, and a harmonic frequency changer in the connection between said oscillator means and said emitter for selectively varying the cadence of said stepping pulses.

Claim 7

A frequency generator as defined in claim 5 wherein said frequency changer and said switchover means are provided with a common actuator.

Claim 8

A frequency generator as defined in claim 1 wherein said counters are provided with visual indicators respectively connected to the stages thereof for displaying the state of actuation of said stages.

Claim 9

A frequency generator comprising: a plurality of denominational counters each having a multiplicity of cyclically triggerable stages; a like plurality of denominational networks each assigned to a respective counter, each of said networks including a like multiplicity of normally blocked gates and as many sources of fixed frequencies of progressively different magnitudes respectively connected to said gates; stepping means for cyclically triggering the stages of said counters at denominationally related rates to register a progressively changing multidigit numerical value on said counters the stages of each counter being connected to respective gates of the associated network for unblocking same upon triggering by said control means to pass the corresponding fixed frequency; a frequency synthesizer including circuitry for weighting the frequencies passed by said gates and for combing the frequencies so weighted into a composite output frequency proportional to said numerical value; monitoring means connected to the stages of each counter for registering the state of actuation of said stages as a measure of said output frequency, said monitoring means comprising a coincidence gate with a number of inputs corresponding to the number of said counters; adjustable presetting means for selectively connecting each of said inputs to any one stage of a respective counter; and control means connected to an output of said coincidence gate for modifying the operation of said stepping means upon said composite output frequency attaining a value selected by said presetting means.

Claim 10

A frequency generator comprising: a plurality of denominational counters each having a multiplicity of cyclically triggerable stages; a like plurality of denominational networks each assigned to a respective counter, each of said networks including a like multiplicity of normally blocked gates and as many sources of fixed frequencies of progressively different magnitudes respectively connected to said gates; stepping means for cyclically triggering the stages of said counters at denominationally related rates to register a progressively changing multidigit numerical value on said counters the stages of each counter being connected to respective gates of the associated network for unblocking same upon triggering by said control means to pass the corresponding fixed frequency; a frequency synthesizer including circuitry for weighting the frequencies passed by said gates and for combing the frequencies so weighted into a composite output frequency proportional to said numerical value; monitoring means connected to the stages of each counter for registering the state of actuation of said stages as a measure of said output frequency, said monitoring means comprising a coincidence gate with a number of inputs corresponding to the number of said counters; adjustable presetting means for selectively connecting each of said inputs to any one stage of a respective counter; and control means connected to an output of said coincidence gate for modifying the operation of said stepping means upon said composite output frequency attaining a value selected by said presetting means.

Claim 11

A frequency generator as defined in claim 8 wherein said control means includes switch means for arresting said stepping means upon attainment of the selected value.

Claim 12

A frequency generator as defined in claim 8 wherein said control means further includes an enabling circuit for sequentially making the stages of each counter responsive to said stepping means, and switch means for connecting the output of said coincidence gate to said enabling circuit to vary the sequence of actuation of said stages.

Claim 13

A frequency generator as defined in claim 10 wherein said enabling circuit has a first branch for actuating said stages in a forward-counting sequence and a second branch for actuating said stages in a backward-counting sequence, said switch means being effective in an energized condition of one of said branches to deenergize same and energize the other of said branches, thereby reversing the sense of counting in response to an output signal from said coincidence gate.

Claim 14

A frequency generator as defined in claim 10, further comprising receiving means operable by said switch means to trigger a preselected stage of each counter in response to an output signal from said coincidence gate.

Claim 15

A system for determining the transmission characteristics of a transmitting station and a receiving station, at least one of said stations including a frequency generator as defined in claim 8, modulating means at said transmission station for combining a progressively varying output frequency from said frequency synthesizer with a fixed intermediate frequency and applying the modulation products to a test object demodulating means at said receiving station for reconstituting said intermediate frequency from a range of frequencies sequentially recovered from said test oBject, and measuring means connected to receive the reconstituted intermediate frequency from said demodulating means.

Claim 16

A system as defined in claim 13 wherein said stations are provided with substantially identical frequency generators, said demodulating means being connected to receive the output frequency of the frequency generator of said receiving station.

Claim 17

A system as defined in claim 14, further comprising a synchronizing connection between the stepping means of said frequency generators.

Claim 18

A system as defined in claim 14 wherein said stations are interconnected only by a transmission link including said test object, the stepping means at said receiving station having a slightly higher operating cadence than the stepping means at said transmitting station and being provided with switch means responsive to an output signal from the coincidence gate of the associated monitoring means for halting the count upon the output frequency of the associated frequency synthesizer reaching a predetermined level, further comprising signal-generator means at the transmitting station responsive to attainment of a corresponding level by the output frequency of the frequency synthesizer thereof to transmit a synchronizing signal to the control means of the frequency generator at said receiving station for restarting the stepping means thereof.

Claim 19

A system as defined in claim 13 wherein said measuring means comprises an oscilloscope, said monitoring means including a digital-analog converter for generating an electric variable proportional to said numerical value, said oscilloscope having a sweep circuit connected to the output of said converter.