Multiband random channel address crystal-lock tuning system

Claim 2

A television tuning system comprising: tuning means for receiving radio frequency signals corresponding to any one of a plurality of television channels in at least first and second bands of frequencies and having tunable local osCillator means for producing a corresponding oscillator signal in at least fourth and fifth bands of frequencies; sweep generator means coupled to said oscillator means for varying the tuning thereof in a predetermined manner through at least said fourth and fifth bands of frequencies; signal generating means for producing reference signals at frequencies corresponding to television channel oscillator frequencies in said fourth and fifth bands; frequency discriminator means having first and second inputs coupled to said oscillator means and to said signal generating means, respectively, for producing an output signal representative of frequency differences between said oscillator signal and each of said reference signals as said tuning is varied; counting means coupled to said discriminator means for producing an output count representative of said oscillator signal passing through a predetermined frequency relationship with respect to each of said reference signals; channel selector means having an output terminal for producing at said output terminal a stored count representative of a selected television channel; comparator means coupled to said counting means and to said channel selector means for providing a hold signal to said sweep generator means in response to a match between said output count and said stored count; decoder means coupled to said counting means for identifying the presence of a particular output count; bandswitch means for producing a band selection signal to condition said tuning means for reception of said first band of radio frequencies when said output count is less than or equal to said particular count and to condition said tuning means for reception of said second band of radio frequencies when said output count is greater than said particular count; and means for resetting said sweep generator means, in response to a match between said output count and said particular count and the absence of said hold signal, to a condition suitable for initiating variation of the tuning of said oscillator means through said fifth band of frequencies.

Claim 3

The combination as in claim 1 wherein said reference signals are produced at frequencies which have said predetermined frequency relationship with corresponding oscillator signals in at least said fourth and fifth bands of frequencies.

Claim 4

The combination as in claim 2 wherein said signal generating means comprises a reference oscillator for producing a base reference frequency and each of said reference signals are at harmonics of said base reference frequency.

Claim 5

The combination as in claim 3 wherein said base reference frequency is equal to the frequency difference between adjacent ones of said channels.

Claim 6

The combination as in claim 4 wherein said base reference frequency is six megahertz.

Claim 7

The combination as in claim 2 wherein said predetermined frequency relationship is a positive difference in frequency between said reference frequency and said local oscillator frequency in said fourth band of frequencies and a positive difference in frequency between said local oscillator frequency and said reference frequency in said fifth band of frequencies.

Claim 8

The combination as in claim 6 wherein said tuning means is voltage tunable and said sweep generator means provides a voltage for varying the tuning of said oscillator.

Claim 9

The combination as in claim 7 wherein said voltage for varying the tuning changes substantially linearly when said sweep generator is varying the tuning of said oscillator means.

Claim 10

The combination as in claim 1 wherein said frequency discriminator means comprises: mixing means coupled to said first and second inputs for providing a frequency difference signal from said oscillator signal and said harmonically related signals; frequency sensitive means for producing said output signal of a first level when said frequency difference signals are greater than a predetermined frequency range and of a sEcond level when said frequency difference signals are less than said predetermined frequency range; and filter means for coupling a band of said frequency difference signals to said frequency sensitive means.

Claim 11

The combination as in claim 9 wherein said predetermined frequency range of said frequency sensitive means includes said predetermined frequency relationship.

Claim 12

The combination as in claim 10 wherein said predetermined frequency relationship is substantially one megahertz.

Claim 13

The combination as in claim 9 wherein said band of said frequency difference signals is between zero and less than half of the minimum frequency separation between said reference signals of said signal generating means.

Claim 14

The combination as in claim 12 wherein said band of said frequency difference signals is zero to less than three megahertz.

Claim 15

The combination as in claim 9 wherein said frequency discriminating means further comprises inverting means for producing said output signal of a first level when said frequency difference signal is less than said predetermined frequency range and of a second level when said frequency difference signals are greater than said predetermined frequency range.

Claim 16

The combination as in claim 14 wherein said inverting means produces said output signal of said frequency discriminator means in response to a match between said output count and said particular count and the absence of said hold signal.

Claim 17

The combination as in claim 1 wherein said counting means comprises means for resetting said output count to an initial output count in response to a change of said stored count.

Claim 18

The combination as in claim 16 wherein said initial output count is zero.

Claim 19

The combination as in claim 1 wherein said first band of frequencies comprises television low band very high frequencies and said second band of frequencies comprises television high band very high frequencies.

Claim 20

The combination as in claim 18 wherein said particular output count of said decoder is six.

Claim 21

The combination as in claim 1 wherein said first band of frequencies comprises television very high frequencies and said second band of frequencies comprises television ultra high frequencies.

Claim 22

The combination as in claim 20 wherein said particular output count of said decoder is thirteen.

Claim 23

A television tuning system comprising: tuning means for receiving radio frequency signals corresponding to any one of a plurality of television channels in at least first, second and third bands of frequencies and having tunable local oscillator means for producing a corresponding oscillator signal in at least fourth, fifth and sixth bands of frequencies; sweep generator means coupled to said oscillator means for varying the tuning thereof in a predetermined manner through at least said fourth, fifth and sixth bands of frequencies; signal generating means for producing reference signals at frequencies corresponding to television channel oscillator frequencies in at least said fourth, fifth and sixth bands, said reference signals being harmonically related; frequency discriminator means having first and second inputs coupled to said oscillator means and to said signal generating means, respectively, for producing an output signal representative of frequency differences between said oscillator signal and each of said reference signals as said tuning is varied; counting means coupled to said discriminator means for producing an output count representative of said oscillator signal passing through a predetermined frequency relationship with respect to each of said reference signals; channel selector means having an output terminal for producing at said output terminal a stored count representative of a selected television channel; comparator means coupled to said counting means and to said channel selector means for providing a hold signal to said sweep generator means in response to a match between said output Count and said stored count; decoder means coupled to said counting means for identifying the presence of a first and a second particular output count; bandswitch means for producing a first and a second hand selection signal to condition said tuning means for reception of said first band of radio frequencies when said output count is less than or equal to said first particular count and to condition said tuning means for reception of said second band of radio frequencies when said output count is greater than said first particular count, to condition said tuning means for reception of said fifth band of radio frequencies when said output count is greater than said second particular count; and means for resetting said sweep generator means, in response to a match between said output count and either said first or said second particular count and the absence of said hold signal, to a condition suitable for initiating variation of the tuning of said oscillator means through said fifth or said sixth band of frequencies, respectively.

Claim 24

A television tuning system comprising: tuning means for receiving radio frequency signals corresponding to any one of a plurality of television channels in at least first, second and third bands of frequencies and having tunable local oscillator means for producing a corresponding oscillator signal in at least fourth, fifth and sixth bands of frequencies; sweep generator means coupled to said oscillator means for varying the tuning thereof in a predetermined manner through at least said fourth, fifth and sixth bands of frequencies; signal generating means for producing reference signals at frequencies corresponding to television channel oscillator frequencies in at least said fourth, fifth and sixth bands, said reference signals being harmonically related; frequency discriminator means having first and second inputs coupled to said oscillator means and to said signal generating means, respectively, for producing an output signal representative of frequency differences between said oscillator signal and each of said reference signals as said tuning is varied; counting means coupled to said discriminator means for producing an output count representative of said oscillator signal passing through a predetermined frequency relationship with respect to each of said reference signals; channel selector means having an output terminal for producing at said output terminal a stored count representative of a selected television channel; comparator means coupled to said counting means and to said channel selector means for providing a hold signal to said sweep generator means in response to a match between said output Count and said stored count; decoder means coupled to said counting means for identifying the presence of a first and a second particular output count; bandswitch means for producing a first and a second hand selection signal to condition said tuning means for reception of said first band of radio frequencies when said output count is less than or equal to said first particular count and to condition said tuning means for reception of said second band of radio frequencies when said output count is greater than said first particular count, to condition said tuning means for reception of said fifth band of radio frequencies when said output count is greater than said second particular count; and means for resetting said sweep generator means, in response to a match between said output count and either said first or said second particular count and the absence of said hold signal, to a condition suitable for initiating variation of the tuning of said oscillator means through said fifth or said sixth band of frequencies, respectively.

Claim 25

The combination as in claim 22 wherein said reference signals are produced at frequencies which have said predetermined frequency relationship with said corresponding oscillator signals in at least said fourth, fifth and sixth bands of frequencies.

Claim 26

The combination as in claim 23 wherein said reference generating means comprises a reference oscillator for producing a base reference frequency and each of said reference signals are at harmonics of said base reference frequency.

Claim 27

The combination as in claim 24 wherein said base reference frequency is equal to a frequency difference between adjacent ones of said channels.

Claim 28

The combination as in claim 25 wherein said base reference frequency is six megahertz.

Claim 29

The combination as in claim 23 wherein said predetermined frequency relationship is a positive difference in frequency between said reference frequency and said oscillator frequency in said fourth and fifth bands of frequencies and a positive difference in frequency between said oscillator frequency and said reference frequency in said sixth band of frequencies.

Claim 30

The combination as in claim 27 wherein said tuning means is voltage tunable and said sweep generator means provides a voltage for varying the tuning of said oscillator.

Claim 31

The combination as in claim 28 wherein said voltage for varying the tuning changes substantially linearly when said sweep generator means is varying the tuning of said oscillator means.

Claim 32

The combination as in claim 22 wherein said frequency discriminator means comprises: mixing means coupled to said first and second inputs for providing a frequency difference signal from said oscillator signal and said harmonically related reference signals; frequency sensitive means for producing said output signal of a first level when said frequency difference signals are greater than a predetermined frequency range and of a second level when said frequency difference signals are less than said predetermined frequency range; and filter means for coupling a band of said frequency difference signals to said frequency sensitive means.

Claim 33

The combination as in claim 30 wherein said predetermined frequency range of said frequency sensitive means includes said predetermined frequency relationship.

Claim 34

The combination as in claim 31 wherein said predetermined frequency relationship is one megahertz.

Claim 35

The combination as in claim 30 wherein said band of said frequency difference signals is between zero and less than half of the minimum frequency separation between said reference signals of said signal generating means.

Claim 36

The combination as in claim 33 wherein said band of said frequency difference signals is zero to less than three megahertz.

Claim 37

The combination as in claim 30 wherein said frequency discriminating means further comprises inverting means for producing said output signal of a first level when said frequency difFerence signal is less than said predetermined frequency range and of a second level when said frequency difference signals are greater than said predetermined frequency range.

Claim 38

The combination as in claim 35 wherein said inverting means produces said output signal of said frequency discriminator means in response to a match between said output count and said second particular count and the absence of said hold signal.

Claim 39

The combination as in claim 22 wherein said counting means comprises means for resetting said output count to an initial output count in response to a change of said stored count.

Claim 40

The combination as in claim 37 wherein said initial output count is zero.

Claim 41

The combination as in claim 22 wherein said first band of frequencies comprises television low band very high frequencies, said second band of frequencies comprises television high band very high frequencies, and said third band of frequencies comprises ultra high frequencies.

Claim 42

The combination as in claim 39 wherein said first particular output count of said decoder is six and a second particular output count is thirteen.

Claim 43

The combination as in claim 22 wherein said frequency discriminator means is further coupled to said bandswitch means to provide for inversion of said output representative of frequency differences when said third band of radio frequencies is selected.

Claim 44

The combination as in claim 22 wherein said sweep generator means is further coupled to said frequency discriminator means to provide for varying the tuning of said oscillator means to maintain said predetermined frequency relationship between said oscillator signal and said harmonically related reference signal nearest said oscillator signal.

Claim 45

The combination as in claim 22 wherein said frequency discriminator means is further coupled to said tuning means to provide for changes in said predetermined frequency relationship in response to changes in said radio frequency signals.

Claim 46

The combination as in claim 22 wherein said sweep generator is further coupled to said frequency discriminator means to provide for disabling effect of changes of said radio frequency signal on said predetermined frequency relationship when said sweep generator is varying said oscillator signal.