JPH0998070A - High frequency channel selection circuit for radio receiver and production of tuning circuit constructing the channel selection circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the degree of designing freedom of a radio receiver by making each tuning circuit constructing a high frequency channel selection circuit into a single block. SOLUTION: The variable capacitance diodes are sorted for every necessary rank and the fixed capacitors are sorted for every necessary capacitance value respectively. Then the fixed capacitors corresponding to the ranks of variable capacitance diodes are selected for every tuning circuit. The variable capacitance diodes, the fixed capacitors selected according to the ranks of variable capacitance and the coils are connected together. Thus a block of a tuning circuit is formed. As a result, the capacitance variable ratio that is set by every tuning circuit is secured in a common tuning voltage range. Then the inductance of every tuning circuit is controlled at a common tuning voltage level, so that no tracking error is caused. Therefore, the tuning voltage range can cover the range of the receiving bands.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio frequency tuning circuit of a radio receiver which does not require inductance adjustment for tracking adjustment on a circuit board, and a method of manufacturing a tuning circuit constituting the tuning circuit.

[0002]

2. Description of the Related Art In an electronic tuning type radio receiver, an antenna tuning circuit, a high frequency tuning circuit and a local oscillation tuning circuit which form a high frequency tuning circuit are formed by using a coil, a variable capacitance diode and a capacitor, respectively. When such a tuning circuit is formed by using individual circuit elements on the circuit board of the radio receiver, the inductance of the coil forming each tuning circuit is adjusted in advance so that it is in the center of its variable range. , Tracking adjustment is performed again after mounting on the circuit board. This tracking adjustment adjusts the inductance of the oscillation coil so that the lower limit of the tuning voltage of the varactor diode can obtain the lower limit oscillation frequency of the local oscillation tuning circuit, and is then called the tracking point on the low frequency side of the reception frequency. The inductance of the coil of the antenna tuning circuit and high frequency tuning circuit is adjusted so that the audio output is maximized at a certain frequency.

Further, trimmer capacitors of the antenna tuning circuit and the high frequency tuning circuit may be used so that the audio output becomes maximum at the tracking point on the high frequency side. When the tuning circuit is formed on the circuit board by using the individual circuit elements as described above, it is necessary to adjust the coil three times in addition to the adjustment of the coil before the mounting, and the adjustment is performed at different frequencies. Be seen. When the trimmer capacitor is added, it is necessary to perform the adjustment at the tracking point on the low frequency side and the adjustment of the trimmer capacitor on the high frequency side while reciprocating, and it is necessary to adjust the coil 7 to 9 times on the circuit board. become.

In order to reduce the number of adjustments on such a circuit board, the antenna tuning circuit, the high frequency tuning circuit, and the local oscillation tuning circuit are grouped into a block, and tracking adjustment is performed under the same conditions as on the circuit board of the radio receiver. By doing so, it is also possible to aim for no adjustment on the circuit board. However, if the entire tuning circuit is made into blocks, the number of parts is increased, so that a circuit board is mounted and a board for connecting the circuit elements in the block is required, which is expensive. Further, since the antenna tuning circuit, the high frequency tuning circuit, and the local oscillation tuning circuit are close to each other, the effect of radiation of the local oscillation tuning circuit becomes remarkable when the frequency becomes high, as in the FM radio, and the circuits in the block are connected to each other. It is necessary to design the layout of circuit elements and the layout of wiring patterns for preventing interference in consideration of various restrictions.

[0005]

SUMMARY OF THE INVENTION The present invention eliminates the need to adjust the inductance of the coil for tracking adjustment on the circuit board of the radio receiver, and reduces the interference between circuits and the placement of circuit elements at high frequencies. It is to provide a method of manufacturing a tuning circuit and a tuning circuit that constitutes the tuning circuit. Another object of the present invention is to provide a high frequency tuning circuit that can reduce a tracking error even if there is a variation in the characteristics of the variable capacitance diode and can easily perform tracking adjustment.

[0006]

SUMMARY OF THE INVENTION The present invention is a high frequency tuning circuit of a radio receiver having an antenna tuning circuit, a high frequency tuning circuit, and a local oscillation tuning circuit, each tuning circuit being a coil, a variable capacitance diode, and a fixed capacitor. And are mounted on the same circuit board as a block for each tuning circuit, and each tuning circuit has a coil inductance to eliminate tracking error when at least one common tuning voltage is applied to the varactor diode. Is adjusted, and the capacitance value of the fixed capacitor in the block of the same tuning circuit is made different according to the rank of the capacitance value of the variable capacitance diode so that the capacitance variable ratio set in the block can be obtained. The blocks of each tuning circuit are characterized in that they are controlled by a common tuning voltage in the reception band. Further, in the manufacturing method of the antenna tuning circuit, the high frequency tuning circuit, and the local oscillation tuning circuit which constitute the high frequency tuning circuit of the radio receiver of the present invention, each tuning circuit is formed by using a coil, a variable capacitance diode, and a fixed capacitor. When tuning each tuning circuit into blocks, the process of obtaining the capacitance variable ratio set for each tuning circuit by selecting the fixed capacitor according to the rank of the capacitance value of the variable capacitance diode, tracking with one common tuning voltage It is characterized by including the step of adjusting the inductance of the coil of each tuning circuit so as to eliminate the error.

[0007]

[Function] The tuning circuit is divided into an antenna tuning circuit, a high frequency tuning circuit, and a local oscillation tuning circuit, and the distance between the circuits can be set freely so that no interference occurs between the circuits and the circuit elements are arranged. Since it is not necessary to consider the constraint of, the degree of freedom in designing the radio receiver is improved. Further, by selecting a fixed capacitor according to the rank of the variable capacitance diode, the set capacitance variable ratio can be obtained in each tuning circuit. Then, the tracking adjustment by the coil is performed with one common tuning voltage before mounting on the receiver circuit board, and it is necessary to perform the adjustment on the tuning circuit formed by mounting each tuning circuit on the circuit board. Therefore, the number of adjustments of the coil inductance can be extremely reduced.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a high frequency tuning circuit of a radio receiver according to the present invention will be described below with reference to FIGS. 1 to 3 are circuit diagrams, and FIG. 4 is a sectional view showing the configuration of a channel selection circuit. FIG. 1 shows an antenna tuning circuit which constitutes a high frequency tuning circuit. Variable capacitance diodes D1 and D2 connected in series and a fixed capacitor C1 are connected in parallel between both ends of an antenna coil L1. The cathodes of the variable capacitance diodes D1 and D2 are connected, and a tuning voltage is applied to the connection point from the terminal 1 via the resistor R1. Coil L
The antenna input from the terminal 2 is applied to the tap of 1. Further, one end of the coil L1 is connected to the high frequency amplifier circuit 3 via the coupling capacitor C2, and the other end is grounded. Then, the portion surrounded by the dotted line is integrally formed as a block.

FIG. 2 shows a high frequency tuning circuit. One end of the primary side coil L2 of the tuning transformer is connected to the high frequency amplifying circuit 3, the other end is grounded via the capacitor C3 and the bias voltage is applied from the terminal 4 via the resistor R2. Can be added. Variable capacitance diodes D3 and D4 connected in series and a fixed capacitor C4 are connected in parallel between both ends of the secondary coil L3. The cathodes of the variable capacitance diodes D3 and D4 are connected, and a tuning voltage is applied to the connection point from the terminal 5 via the resistor R3. Both ends of the coil L3 are coupling capacitors C
5 and C6 to connect to the mixing circuit 6. Then, the portion surrounded by the dotted line is integrally formed as a block.

FIG. 3 shows a local oscillation tuning circuit, which is a variable capacitance diode D connected in series between both ends of an oscillation coil L4.
5, D6 and the fixed capacitor C7 are connected. The cathodes of the variable capacitance diodes D5 and D6 are connected, and a tuning voltage is applied to the connection point from the terminal 7 via the resistor R4.
One end of the coil L4 is connected to the local oscillation circuit 8 via the coupling capacitor C8. Then, the portion surrounded by the dotted line is integrally formed as a block. As described above, in the present invention, the three tuning circuits forming the tuning circuit are divided into blocks for each circuit. Further, each tuning circuit selects the capacitance value of the fixed capacitor according to the rank of the variable capacitance diode so that the variable range of the capacitance value set for each circuit, that is, the capacitance variable ratio can be obtained. Then, the three tuning circuits are mounted on the same circuit board. The resistance connected to each tuning circuit has little relation to the tracking adjustment, but it may be housed in a block to improve the degree of integration.

FIG. 4 is a cross-sectional view showing the physical constitution of each tuning circuit which is made into blocks, and three circuits can be constructed in the same manner. In FIG. 4, 10 is a case of synthetic resin, 11 is a coil, 12 is a variable capacitance diode, and 13 is a fixed capacitor. Reference numeral 14 is a partition wall in which the coil 11 and the variable capacitance diode are separately housed in the case 10. Reference numeral 15 is a terminal of the coil 11, and 16 is a terminal of the variable capacitance diode. The coil 11 is a synthetic resin base 17
The wire rod 19 is formed by winding the wire rod 19 around the upper bobbin 18, and the wire rod 19 is connected to the terminal 15 planted on the lower side of the base 17. The fixed capacitor 13 is housed in the base 17, and the lead 21 is connected to the terminal 15. The storage technology of such a fixed capacitor 13 is well known. 20
Is a screw core screwed to the bobbin 18, and the screw 20
The inductance can be adjusted by rotating the.

The circuit elements in the block are connected to each other by using the wiring pattern on the board by mounting the block on the adjustment board or the circuit board, except for the coil 11 and the capacitor 13 which are easily connected. Is formed. Since the circuit element is simply inserted into the case 10 and fixed inside, the substrate is not used unlike the circuit that is blocked by using the conventional substrate. Although FIG. 4 shows an example of a block structure, a variable capacitance diode may be fixed to the side surface of the case that covers only the coil. The case 10 may be made of metal and may also serve as a shield case. Further, the coil covered with a metal case may be housed in a synthetic resin case together with the variable capacitance diode to form a block. When this block is an antenna tuning circuit, it is clear that the coil 11 corresponds to the antenna coil L1, the variable capacitance diode 12 corresponds to the variable capacitance diodes D1 and D2, and the fixed capacitor 13 corresponds to the fixed capacitor C1.

Each tuning circuit which constitutes such a high frequency tuning circuit is manufactured by carrying out tracking adjustment as follows. A laboratory manufacturing method will be described first to facilitate understanding. First, the blocked antenna tuning circuit, high frequency tuning circuit, and local oscillation tuning circuit are mounted on the adjustment board for performing tracking adjustment, and the circuit elements in each circuit block are connected via the wiring pattern of the adjustment board. Connection is made. Then, the tuning voltage is fixed to one point within the voltage range that covers the reception frequency, and this common tuning voltage is applied to the antenna tuning circuit, the high frequency tuning circuit, and the local oscillation tuning circuit. Here, the antenna tuning circuit and the high frequency tuning circuit are arranged so that the coil L1,
The inductance of the coil L3 is adjusted. Moreover, the local oscillation tuning circuit is (reception frequency-
The inductance of the oscillation coil L4 is adjusted so as to tune at the intermediate frequency). In this way, the adjustment is performed so that the tracking error does not occur with this one common tuning voltage.

The reception frequency tuned by a common tuning voltage is
Below the center of the reception band is desirable. For example, if the tuning voltage of 1.2 to 7 V covers the FM broadcast reception band of 76 to 90 MHz in Japan, then 78 V at 1.5 V.
If the receiver is designed to receive, the antenna tuning circuit and the high frequency tuning circuit are tuned to 78 MHz, and the oscillation tuning circuit is tuned to 67.3 MHz (78-10.7). When tuning each tuning circuit with this one tuning voltage, if there is a fixed capacitor or stray capacitance that affects the tuning frequency on the receiver circuit board, the adjustment board also has a correction capacitor. The same state as the circuit board appears on the adjustment board by connecting, for example.

In any case, by performing tracking adjustment of each tuning circuit with one common tuning voltage, matching between the circuits at that tuning voltage is guaranteed. This is assured even among a large number of tuning circuits that have been subjected to tracking adjustment at this tuning voltage. That is, if tracking adjustment is performed between the first, second, and third antenna tuning circuits, the high-frequency tuning circuit, and the local oscillation tuning circuit, the first, second, and third sets are distinguished. Even if the antenna tuning circuit, the high frequency tuning circuit, and the oscillation tuning circuit are combined with each other on the circuit board to form a high frequency tuning circuit, matching is guaranteed. Therefore, it is not necessary to adjust the coil even if the tuning circuit on which the tracking adjustment is performed on the adjustment board is mounted on the circuit board of the receiver and combined. In addition, it is not necessary to adjust each tuning circuit in combination,
The tuning voltage may be adjusted independently for each tuning circuit with one common tuning voltage.

This is a common tuning voltage, eg
This is because no tracking error occurs at 1.5 V.
However, a voltage other than the common tuning voltage may cause a large tracking error. This is often due to variations in the characteristics of the variable capacitance diode. In order to make the characteristics uniform, the variable capacitance diodes are generally classified by rank and sold with similar capacitance values. This rank classification classifies the range of capacitance values when a specific tuning voltage is applied into 4 to 5 types. For example, a variable capacitance diode called "KV1410" manufactured and sold by the applicant is as follows. Are classified into four types. This variable capacitance diode is used in the tuning voltage range of 2 to 8V. The range of the rank 1 capacitance value when the tuning voltage is 2V is
41.33 to 42.59PF, Rank 2 is 42.49 to 42.49PF, Rank 3 is 43.69 to 45.02PF, Rank 4 is 44.92 to 46.29PF
It is. The capacitance value is a value when two variable capacitance diodes are connected in series as in the embodiment. Even if the tuning voltage is 4V, 6V, and 8V, they are similarly classified into four types.

Therefore, as an example, the variable capacitance diode of rank 1 at 2V may be classified into rank 3 at 4V, rank 2 at 6V, and rank 2 at 8V. In that case, the variable-capacitance diode is sold with a rank-coded reference such as rank "1-3-2-2". The variable-capacitance diodes of the same rank thus classified are housed in the same package and supplied to the customer as having uniform characteristics in the range from the lower limit to the upper limit of the tuning voltage. On the other hand, in each tuning circuit of the tuning circuit, the required capacity variable ratio, that is, the ratio of the maximum capacity and the minimum capacity is set, the antenna tuning circuit and the high frequency tuning circuit are almost equal, and the oscillation tuning circuit is the same in the upper heterodyne method. It is smaller than that of the above circuit, and is larger in the case of the lower heterodyne system.

Therefore, irrespective of the rank of the capacitance value of the variable capacitance diode, if the capacitance variable ratio of each tuning circuit is always the set variable ratio, the tracking adjustment is performed at a certain frequency and the tracking error is caused at other frequencies. Can occur in a state in which the By the way, the maximum frequency f _max , the minimum frequency f _min , the maximum capacitance C _{max of} the tuning circuit,
The relationship of formula (1) is established between the minimum capacities C _min . However, the inductance of the coil of the circuit is constant regardless of the frequency. f _max / f _min = (C _max / C _min ) ^1/2 (1) Since the maximum capacitance C _max and the maximum capacitance C _max are the combined capacitances of the variable capacitance diode and the fixed capacitor, the formula (2) is established. C _max / C _min = (C _Vmax + C _S ) / (C _Vmin + C _S ) (2) where C _Vmax and C _Vmin are the maximum and minimum capacitances of the variable capacitance diode, and C _S is the capacitance value of the fixed capacitor. .

If it is an antenna tuning circuit, C _Vmax , C
_Vmin is the maximum capacity and the minimum capacity obtained by the variable capacitance diodes D1, D2 which are connected in series, C _S corresponds to the capacity of the fixed capacitor C1, f _max, f _min is the maximum frequency 90MHz and minimum frequency 76MHz receiving frequency Equivalent to. Therefore, according to the formula (2), the maximum capacitance C _Vmax and the minimum capacitance C are different depending on the rank of the variable capacitance diode.
_{Even if Vmin} changes, if the capacitance value C _S of the fixed capacitor is made different for each rank, the capacitance variable ratio of the tuning circuit, that is, C
It is clear that _max / _Cmin can be kept constant. The maximum capacitance C _Vmax of the variable capacitance diode is obtained when the tuning voltage used is minimum, and the minimum capacitance C _Vmin is obtained when the tuning voltage used is maximum.

Therefore, the maximum capacity C in the equation (2) is
_Vmax and the minimum capacitance C _Vmin may be obtained by substituting the capacitance values of the variable capacitance diode when the tuning voltage is minimum and maximum, respectively. Since the variable capacitance diodes are classified into ranks, it is advisable to substitute the median value of the range of capacitance values in that rank.
For example, the variable capacitance diode of "KV1410" described above has a maximum capacitance C _Vmax at a tuning voltage of 2 _V , but when the rank is 1, substituting 41.96PF, which is the median value of the rank 1 capacitance values, Good. The same idea can be applied to the maximum capacity C _Vmax . In each tuning circuit of the antenna tuning circuit, the high frequency tuning circuit, and the local oscillation tuning circuit, the capacity variable ratio necessary to eliminate the tracking error is set, but the capacity variable ratio set for each tuning circuit is always As can be obtained, the capacitance value C _S of the fixed capacitor may be changed according to the rank of the variable capacitance diode.
If there is a capacitor that affects the tuning frequency on the circuit board, in addition to the capacitor that is integrally formed as a block, make sure that the variable capacitance ratio is constant, including the capacitance value. The capacitance value may be different.

The method of manufacturing each tuning circuit constituting the high frequency tuning circuit of the present invention is such that the occurrence of tracking error is eliminated by one common tuning voltage, and each tuning is performed according to the rank of the variable capacitance diode. The main requirement is to connect to each tuning circuit a fixed capacitor having a capacitance value such that the variable capacitance ratio set by the circuit can be obtained. Actually, the capacitance value of the fixed capacitor for obtaining the capacitance variable ratio set in each tuning circuit can be determined in advance at the experimental stage or the design stage according to the rank of the variable capacitance diode. Therefore, the actual manufacturing becomes efficient by performing the manufacturing process along the process chart as shown in FIG. First, the variable-capacitance diodes are classified according to required ranks, and the fixed capacitors are classified according to required capacitance values. Since fixed capacitors have a capacitance classification according to the E24 series, which is a general international standard, and variable capacitance diodes have a normal rank classification according to the capacitance value, such classification can be easily performed at the time of purchase. (Step 1)

Next, a fixed capacitor corresponding to the rank of the variable capacitance diode is selected for each tuning circuit. (Step 2) Then, a variable capacitance diode, a fixed capacitor selected according to the rank of the variable capacitance diode, and a coil are connected to form a block of a tuning circuit. As a result, the capacitance variable ratio set by each tuning circuit can be obtained within a common tuning voltage range. (Step 3) Next, the inductance of each tuning circuit is adjusted at one common tuning voltage so that tracking error does not occur. (Step 4) With this, the range of the tuning voltage is set to a range that covers the reception band. The adjustment of the inductance may be performed by mounting the antenna tuning circuit, the high frequency tuning circuit, and the local oscillation tuning circuit on the adjustment substrate at the same time, or separately. The process 2 and the process 3 can be regarded as one process. In this way, the tuning circuit, which is a combination of the antenna tuning circuit, high frequency tuning circuit, and local oscillation tuning circuit mounted on the circuit board of the receiver, does not require adjustment of the coil inductance to reduce the reception band. Tracking error can be reduced in all bands.

The tuning circuit of the present invention assembled on the circuit board can make the tracking error extremely small even if it is controlled by a common tuning voltage as shown in the connection diagram briefly shown in FIG. However, like the connection diagram shown in FIG.
In addition to the tuning voltage applied to the local oscillation tuning circuit 33 controlled by the PLL circuit, the tuning voltage passed through the correction circuit 30 can be applied to the antenna tuning circuit 31 and the high frequency tuning circuit 32. By finely adjusting and changing the tuning voltage for each tuning circuit, the tracking error can be almost eliminated. This correction circuit 30 is usually controlled by a microcomputer, but it can be used particularly effectively in the high frequency tuning circuit of the present invention which does not require inductance adjustment after it is mounted on a circuit board.

It should be noted that an antenna tuning circuit, a high frequency tuning circuit, and
Finely adjusting the tuning voltage applied to the local oscillation tuning circuit is known, for example, from JP-A-3-145339.
The effect is still unsatisfactory. This is due to the lack of the ability of such a computer-controlled correction circuit that the voltage can be controlled finely, but it is difficult to control a wide range of voltage, so it is already possible to make the tracking error extremely small with the common tuning voltage. The effect can be fully exhibited only by using the tuning circuit of the present invention. Reference numeral 34 is a circuit board, 35 is a terminal to which a tuning voltage is applied, and 36 is a wiring pattern. The same portions in FIGS. 6 and 7 are designated by the same reference numerals. Although the circuit board 34 is also mounted with other circuit elements constituting the receiver, only the portion where the tuning circuit is mounted is shown. In the embodiment, the number of fixed capacitors integrally formed as a block is one, but there may be a plurality of capacitors that affect tracking depending on the circuit configuration.
In that case, one capacitor having the greatest influence may be integrated or a block structure including a plurality of capacitors may be formed.

[0025]

As described above, the radio frequency tuning circuit of the radio receiver of the present invention is integrally formed into blocks for each of the tuning circuits constituting the radio frequency tuning circuit. Further, the connection between the circuit elements in the block is made by the wiring pattern of the adjustment substrate or the circuit substrate. Since each tuning circuit is divided into blocks, interference between the individual circuits of the tuning circuit, that is, the antenna tuning circuit, high-frequency tuning circuit, and local oscillation tuning circuit is less likely to occur, and there is no restriction on the arrangement of circuit elements. The degree of freedom in design is improved. This is a particularly important effect in a high frequency FM receiver. Further, according to the method of manufacturing the tuning circuit that constitutes the tuning circuit of the present invention, the capacitance value of the fixed capacitor is selected so that the capacitance variable ratio set in each tuning circuit can be obtained according to the rank of the capacitance value of the variable capacitance diode. And eliminating the occurrence of tracking errors with one common tuning voltage. As a result, even if the capacitance value of the variable capacitance diode varies due to the difference in rank, the high frequency tuning circuit assembled by mounting each tuning circuit on the circuit board does not require adjustment of the coil inductance. Therefore, it is possible to obtain a very important effect that the complicated adjustment of the inductance on the circuit board, which has been conventionally performed, is all gone, and the tracking adjustment becomes easy. Further, since it is not necessary to limit the ranks of the varactor diodes, there is an economical effect that all ranks can be used without waste. Further, recently, as shown in FIG. 7, there has been an attempt to perform tracking adjustment by using a computer-controlled voltage correction circuit for each tuning circuit, and an IC for that purpose has been developed. Even in this case, since the tracking error can be made extremely small by using the block of the tuning circuit of the present invention, more accurate tracking adjustment can be performed by using the voltage correction circuit.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an embodiment of an antenna tuning circuit of a radio frequency tuning circuit of a radio receiver of the present invention.

FIG. 2 is a circuit diagram showing an embodiment of a high frequency tuning circuit of the same.

FIG. 3 is a circuit diagram showing an embodiment of a local oscillation tuning circuit of the same.

FIG. 4 is a cross-sectional view showing a physical configuration example of each tuning circuit that constitutes the channel selection circuit of the radio receiver of the present invention.

FIG. 5 is a process drawing showing a manufacturing method of a tuning circuit which constitutes a high frequency tuning circuit of the radio receiver of the present invention.

FIG. 6 is a connection diagram of the high frequency channel selection circuit of the present invention.

FIG. 7 is another connection diagram of the high frequency tuning circuit of the present invention.

[Explanation of symbols]

 L1 Antenna coil D1, D2 Variable capacitance diode

Claims (5)

[Claims] 1. In a high frequency tuning circuit having an antenna tuning circuit, a high frequency tuning circuit and a local oscillation tuning circuit, each tuning circuit is composed of a coil, a variable capacitance diode and a fixed capacitor and is divided into blocks for each tuning circuit. They are mounted on the same circuit board, and each tuning circuit has its coil inductance adjusted to eliminate tracking errors when at least one common tuning voltage is applied to the varactor diode. The capacitance value of the fixed capacitor is different according to the rank of the capacitance value of the variable capacitance diode so that the capacitance variable ratio set in the block can be obtained. . 2. In a high frequency tuning circuit having an antenna tuning circuit, a high frequency tuning circuit and a local oscillation tuning circuit, each tuning circuit is formed of a coil, a variable capacitance diode and a fixed capacitor, and each tuning circuit is divided into blocks. They are mounted on the same circuit board, and each tuning circuit has its coil inductance adjusted to eliminate tracking errors when at least one common tuning voltage is applied to the varactor diode. The fixed capacitor's capacitance value is made different according to the rank of the capacitance value of the variable capacitance diode so that the capacitance variable ratio set in the block can be obtained, and each tuning circuit block has a common tuning in the reception band. High frequency tuning circuit of radio receiver characterized by being controlled by voltage. 3. In a high frequency tuning circuit having an antenna tuning circuit, a high frequency tuning circuit and a local oscillation tuning circuit, each tuning circuit is composed of a coil, a variable capacitance diode and a fixed capacitor and is divided into blocks for each tuning circuit. They are mounted on the same circuit board, and each tuning circuit has its coil inductance adjusted to eliminate tracking errors when at least one common tuning voltage is applied to the varactor diode. The capacitance value of the fixed capacitor is different according to the rank of the capacitance value of the variable capacitance diode so that the capacitance variable ratio set in the block can be obtained.The tuning voltage of the block of the antenna tuning circuit and the high frequency tuning circuit is Is the tuning voltage through the computer controlled compensation circuit in the reception band, A high frequency tuning circuit for a radio receiver, which is controlled by a tuning voltage different from the tuning voltage of the local oscillation tuning circuit. 4. A method of manufacturing an antenna tuning circuit, a high frequency tuning circuit, and a local oscillation tuning circuit constituting a high frequency tuning circuit, wherein each tuning circuit is formed by using a coil, a variable capacitance diode, and a fixed capacitor. The process of obtaining the capacitance variable ratio set in each tuning circuit by selecting the fixed capacitor according to the rank of the capacitance value of the variable capacitance diode when dividing into blocks, eliminating the tracking error with one common tuning voltage A method of manufacturing a tuning circuit for a radio frequency tuning circuit of a radio receiver, comprising the step of adjusting the inductance of the coils of each tuning circuit. 5. A method of manufacturing an antenna tuning circuit, a high frequency tuning circuit, and a local oscillation tuning circuit constituting a high frequency tuning circuit, wherein each tuning circuit is formed by using a coil, a variable capacitance diode and a fixed capacitor. Tracking error with one common tuning voltage after obtaining the capacitance variable ratio set for each tuning circuit by selecting a fixed capacitor according to the rank of the capacitance value of the variable capacitance diode when blocking each A method of manufacturing a tuning circuit for a radio frequency tuning circuit of a radio receiver, characterized in that the inductance of the coil of each tuning circuit is adjusted so as to eliminate the above.