WO1996005630A1 - Display for adjusting direction of satellite signal receiving antenna - Google Patents

Abstract

A direction adjusting display utilized when the direction of a satellite signal receiving antenna is adjusted. The direction of an antenna is determined watching the display on a display so that the antenna receives the strongest signals irrespective of the level of the satellite signal reaching the ground. At the same time the range of direction in which the antenna receives signals in a good condition is found on the basis of what is displayed on the display. The direction adjusting display generates a judgement reference level lower by a predetermined level than the peak level of the signal received by the antenna. The display judges the level of the received signal using the judgement reference level, and displays the result of judgement thereon.

Description

 Itoda Indicator for adjusting the direction of the satellite signal receiving antenna

 The present invention relates to an indicator for adjusting the direction of a satellite signal receiving antenna which is used when the antenna for receiving a satellite signal is turned toward a satellite. Background art

 As an indicator for adjusting the direction of this type of satellite signal receiving antenna, the level of a received signal output from an antenna that has received a microwave from a satellite is compared with a preset reference level, and the reference level is determined. In some cases, the indicator light is turned on when the level is exceeded, and turned off when the level is not exceeded (for example, see Japanese Utility Model Publication No. 2-244244). The indicator informs that the antenna is oriented in the good reception direction by turning on the indicator light. In such a configuration, if the above-mentioned reference level is set relatively high, the antenna signal in areas where the level of satellite signals (S-waves) falling onto the ground is relatively high, for example, the Nagoya area When used for direction adjustment, it has the following advantages. That is, the direction of the antenna is adjusted by sequentially changing its direction with the antenna facing the sky while watching the indicator light. In the process, when the antenna is oriented in a direction in which the radio wave from the satellite can be received by the perpell, that is, in a good reception direction, the indicator light is turned on. Otherwise, the indicator light is turned off. Therefore, by directing the antenna in the direction in which the indicator light turns on, the antenna can be directed in the good reception direction.

However, the direction adjustment indicator with the reference level set relatively high as described above is used when adjusting the direction of the antenna in an area where the level of the satellite signal falling onto the ground is relatively low, for example, in the offshore area. Has the following questions. That is, in the above area, the level of the signal received from the antenna is low regardless of the direction of the antenna. Therefore, when the level of the received signal reaches the reference level, the indicator remains off. As a result, there is a problem that a good reception direction to which the antenna is pointed is not known. Therefore, if the reference level is set low so that the indicator lights are turned on and off properly in the low repel area as described above, the direction of the antenna is changed as described above. Problem arises. In other words, in the high-level area, the indicator light stays on regardless of which direction the antenna is pointed. As a result, the correct direction to point the antenna is not known.

 The following are examples of the direction reversing display of the type that solves the above-mentioned questions. That is, the directional silk display device receives a reception signal that changes by changing the direction of the antenna from the satellite signal reception antenna, and captures a peak value of the reception signal; It comprises level discriminating means for discriminating the level of the received signal on the basis of the beak value, and an indicator light for performing a display corresponding to the discrimination result of the level discriminating means. No.)

 Such a thing works as follows. With the antenna facing the sky, change its orientation to one side. Then, the level of the received signal changes according to the change in the direction of the antenna. Therefore, the peak value of the repel of the received signal is obtained at any position in the path in which the direction of the antenna is changed. Next, the direction of the antenna is returned along the above route. In the process of returning, at first, the level of the received signal is lower than the peak value, and thus the indicator lamp is in a lighting state. Eventually, when the antenna is pointed again at the location where the above peak value is obtained, the indicator light goes out because the level of the received signal becomes equal to the above peak value. When the direction of the antenna is further changed, the level of the received signal becomes lower than the peak value during the passage, and the indicator light is turned on again. That is, the indicator notifies that the antenna is oriented in the good reception direction by turning off the indicator light. Therefore, by pointing the antenna where the indicator light is turned off, it is possible to point the antenna in the direction in which the best reception is possible.

 The above-described operation of the direction adjustment display S is the same in any region where the level of the satellite signal falling on the ground is entirely high and in the region where the level of the satellite signal falling on the ground is entirely low.

Therefore, according to the direction adjusting display having the above configuration, even if the received signal level is high or low in the whole area, it is not affected at all. The antenna can be directed in a direction that enables good reception.

 Further, the above configuration has the following advantages. That is, if the antenna is fixed in that position after the antenna is oriented in the direction in which the best reception is possible as described above, if the direction of the antenna is deviated, the level of the received signal decreases. Then, the indicator light is turned on and the operator can be notified that the direction of the antenna has been deteriorated. Therefore, it is possible to prevent the antenna from being fixed while being oriented in the wrong direction.

 Further, the above configuration has the following advantages. In other words, after the antenna is set to face the fastest receiving direction found as described above, if the antenna is pressed by strong wind and the direction becomes inappropriate, the level of the received signal of the antenna decreases. I do. Then, also in this case, the indicator lamp is turned on, and it is possible to clearly and promptly notify that the direction of the antenna has become bad, and to urge the user to take measures.

 However, the above configuration has the following problems. That is, if the deviation of the direction of the antenna in the above-mentioned fixing operation is small, the level of the received signal of the antenna is slightly reduced due to the deviation, and the reception characteristics are hardly deteriorated (for example, the received satellite). The picture quality of the TV picture obtained from the signal is hardly degraded). Even in such a case, the indicator light is turned on due to a decrease in the level of the received signal. As a result, there is a problem that the worker who adjusts the direction of the antenna relaxes the perception that the direction of the antenna is out of order and unnecessarily performs the direction adjustment again.

 In addition, the above configuration has the following problems. In other words, when the antenna is installed and used, a temporary cloud cover or a slight shift of the satellite Sf often occurs at a slight angle. Then, the level of the received signal of the antenna decreases. In this case, there is a problem that the indicator light is turned on, causing a misunderstanding that the direction of the antenna is wrong.

 An indicator for adjusting the direction of a satellite signal receiving antenna according to the present invention is provided to solve the above-mentioned problems of the prior art.

The first purpose is to adjust the orientation of the antenna when displaying the satellite signal on the ground, either in high or low areas. The aim is to be able to point the antenna in a direction that can receive satellite signals satisfactorily.

 The second object is to make it possible to know the range of directions in which satellite signals can be satisfactorily received based on the display on the display device in the above case.

 The third purpose is to determine the direction of the antenna near the center of the west, as a result of being able to know the above range, so that there is a slight deviation in the direction of the antenna when fixing the antenna. Even if it does, as long as the direction of the antenna is within the range of the direction in which satellite signals can be received well, it is possible to keep the display device in a good display state, and it is unnecessary to adjust the direction of the antenna. The goal is to avoid rework. The fourth purpose is to fix the antenna after setting the above direction, and if the direction of the antenna is increased to a direction where good reception is not possible, this should be done. The purpose of this is to make it possible for the operator to be informed by indicating the defect on the display device.

 The fifth purpose is to determine the direction of the antenna, fix it, and then use the antenna. Even if the level of the signal received from the TV decreases slightly, the display device should be kept in a good display condition as long as the level is within a range sufficient to maintain a proper image of the television receiver. Therefore, it is possible to prevent the misunderstanding from occurring.

 A sixth object is that when the antenna is used in the above-mentioned usage state, for example, when the direction of the antenna is largely changed due to a strong wind or the like, and the antenna becomes improper in the direction in which good reception is not possible, the fact is indicated by a display device. It is to be able to notify by the display of.

 Other objects and advantages will be more readily apparent from the drawings and the following description associated therewith. Disclosure of the invention

 The direction adjustment display of the satellite signal receiving antenna of the present invention,

Accepts the received signal from the satellite signal receiving antenna, and the level of the received signal A level reduction circuit for forming a level reduction signal in which the level of the received signal is reduced by a certain level, and a peak value of the level reduction signal that changes with a change in the level of the reception signal is detected and used as a reference value for determination. Low-decay beak value detection circuit

Level determining means for determining the level of the received signal based on the reference value for determination,

And a display device for performing display in accordance with the result of the determination by the level determining means.

 The present invention has the following effects.

 The indicator operates based on the peak level of the signal received from the antenna. Therefore, when adjusting the orientation of the satellite signal receiving antenna, the display device performs the same display operation in an area where the level of the satellite signal falling from the satellite is high or low. As a result, in any of the above regions, the antenna can be directed to a direction in which good reception is possible based on the display of the display.

 In the case of the above-described antenna direction adjustment, the display implements a good display in a range including, for example, a beak at the level of a signal received by the antenna and a right and left side of the beak. Therefore, the operator of the direction adjustment can know the range of the direction in which the satellite signal can be satisfactorily received based on the display on the display.

 Once such a range is known, the antenna can be oriented near the center of the range and fixed antenna cropping can be performed there. Then, even if there is a slight shift in the direction of the antenna when fixing the antenna, the display device will maintain a good display as long as the direction of the antenna is within the direction in which the satellite signal can be received well. You. As a result, it is possible to avoid unnecessary rework of antenna direction adjustment.

 When fixing the antenna above, if the direction of the antenna is misaligned by a large amount, the display will indicate a defect, so the operator can be prompted to correct the direction of the antenna.

 Further, the direction adjusting display of the satellite signal receiving antenna of the present invention,

The best way to receive the signal from the satellite signal receiving antenna and generate an output to indicate whether the level is good or bad according to whether or not the repell has reached the peak value. Direction determining means; A display device for performing a display corresponding to the determination result of the best direction determination means,

Minimum reference determination means for performing a repel determination on the level of the reception signal based on a minimum reference value corresponding to a minimum receivable level;

A display device for performing a display corresponding to the determination result of the minimum reference determination means.

 The present invention also has the following effects.

 In the state of use of the antenna after the direction of the antenna is determined and fixed as described above, the display device can receive the signal with the level of the signal received by the antenna that can maintain the delicate image of the television receiver. Maintain good indications as long as the minimum level is met. Therefore, the indicator remains in a good display state even if it is covered by thin clouds or a slight positional shift of the satellite position. As a result, it is possible to prevent the misunderstanding that the direction of the antenna is out of order as described above.

 In addition, in the use state, the display device displays a defect when the level of the reception signal cannot satisfy the minimum receivable level. Therefore, for example, when the direction of the antenna becomes inappropriate due to strong wind or the like so that good reception is not possible, this fact can be promptly notified by the display of the defect. BRIEF DESCRIPTION OF THE FIGURES

 Figure 1 is a perspective view of the installation state of the antenna for receiving satellite signals.

 Figure 2 is a block circuit diagram of a converter with a direction adjustment display.

 Fig. 3 is a diagram showing a path that changes the directional position of the antenna in the sky and the reception level on that path.

 Fig. 4A is a diagram showing the state of changes in the levels of various signals accompanying changes in the antenna pointing position fi in the case of antenna direction adjustment.

 FIG. 4B is a diagram showing a lighting state and an extinguishing state of the display device in the case of FIG. 4A.

 FIG. 5 is a block diagram of a comparator with a built-in direction adjustment display S of a different embodiment.

Fig. 6 shows the peak hold circuit, timed stop means and And circuit 囡 indicating a switch circuit.

 FIG. 7A is a diagram showing a path in which the directivity of the antenna is changed in the sky. FIG. 7B is a diagram showing a change in a received signal level and a display state of an indicator on the path of FIG. 7A.

 FIG. 8 is a block diagram showing another embodiment of a so-called direction indicator.

 FIG. 9 is a block diagram showing a different example of the reference value forming circuit for determination.

 FIG. 10 is a block diagram (partial view) showing still another different example of the direction adjusting display. Fig. 11 is a block diagram (partial view) showing still another different example of the direction adjusting display. FIG. 12 is a diagram showing the relationship between the direction of the antenna, the level of the received signal, and the range in which good display of the display is performed in the direction adjusting display of FIG. 11; BEST MODE FOR CARRYING OUT THE INVENTION

 Hereinafter, drawings showing an embodiment of the present application will be described. Figure 1 shows the installation state of an offset parabolic antenna 1 as an example of an antenna for receiving satellite signals, 2 is a reflection antenna, 3 is an arm, and 4 is a computer equipped with a primary radiator. . Numeral 5 is the power radiator of the primary radiator in the converter 4. As is well known, the antenna 1 is attached to a mast 6 using a support 7. The support member 7 can adjust the azimuth angle and the elevation angle of the antenna 1, and can fix the state in which each of them is inverted. Figure 8 shows the presence of geostationary satellites (broadcast satellites or communication satellites) transmitting satellite signals in the sky.

 Next, Fig. 2 shows a block diagram of the circuit of Comparator 4 above. In the circuit, reference numerals 11 to 16 indicate well-known components of this type of converter, and 11 is a primary radiator for receiving a satellite signal, a waveguide 12 for introducing a satellite signal and a satellite signal. And a probe 13 for taking out the target. Reference numeral 14 denotes a frequency conversion circuit for converting a received signal into an intermediate frequency signal, 15 denotes a heater filter 81, and 16 denotes an output terminal.

Next, reference numeral 17 denotes a direction adjusting display for adjusting the direction of the antenna 1, and shows an example in which the display is built in the computer 4. In the direction adjusting display 17, 17a is an input terminal for receiving a received signal from the antenna 1 for receiving a satellite signal, and is an example of a received signal. To receive the medium frequency signal. Reference numeral 17b denotes good direction discriminating means for discriminating whether or not the direction of the antenna 1 is within the range in which the signal from the satellite can be received satisfactorily based on the received signal. Reference numeral 23 denotes a display for displaying the determination result of the good direction determination means 17b.

 The direction adjustment display S 17 will be further described. Reference numeral 18 denotes a width S which is used for facilitating the handling of the received signal, and its input terminal is the input terminal 17a. A detection circuit 19 is used to convert the received signal into a form that can be easily handled by a circuit described later, and converts the intermediate frequency signal into a DC detection signal. Note that the detection signal is a signal having only one form and a one-to-one correspondence with the level of the reception signal entering the input terminal 17a. Therefore, in this specification, this detection signal is treated as a received signal in discussing the level in the direction adjustment display.

 Next, the good direction discriminating means 17b performs a discriminating reference value forming circuit 17c for forming a predetermined discriminating reference value, and performs level discrimination of the received signal based on the discriminating reference value. Level determination means 22 for determining The reference value for discrimination is set to a value lower by a certain level (for example, l dB) than the peak level of the received signal. The purpose of determining the reference value for discrimination to such a low value is to slightly widen the angle range in which the display device 23 can display good. If the angle range in which the good display is performed is so wide, it is easy to perform the operation of adjusting the antenna to the good reception direction by turning the antenna to the good reception direction while watching the good display by the display device 23. The reference value for determination may be set to a lower level. However, the level should be set higher than the minimum receivable level, that is, the minimum reception signal level that can guarantee the quality of the television image obtained from the signal received when the satellite signal is received. The receivable minimum level is, for example, the level of a received signal when a satellite signal having a CN ratio of 13 dB is received. The antenna 1 is intended for receiving ordinary satellite signals. Therefore, the peak value of the level of the received signal is usually sufficiently higher than the above-mentioned level corresponding to 13 dB, and thus the reference value for discrimination is set to a value higher than the minimum receivable level. Become.

The discrimination reference value forming circuit 17C is a base for forming the discrimination reference value as described above. The level reduction circuit 24 includes a level reduction circuit 24 for generating a level reduction signal serving as a foundation, and a reduction peak value detection circuit 21 for determining a reference value for S (i based on the level reduction signal. In order to form a reduced signal that accepts the detected signal and lowers its level by a certain level (see 5 in FIG. 4A, for example, a repell corresponding to 1 dB of the received signal). For example, a DC voltage signal of a Leppel obtained by multiplying the level of the detection signal by a decimal number is output as a low attenuation signal As the low attenuation circuit 24, for example, a resistance voltage dividing circuit is used. The reduced beak value detection circuit 21 detects a peak value of the level reduction signal, which changes with a change in the level of the reception signal, and uses the peak value as a reference value for determination. , One after another An example of a peak hold circuit that holds the maximum level (peak value) of the levels and constantly outputs a signal of the held peak value is used, for example, by charging a capacitor. Use a well-known configuration that holds the maximum value.

Next, a comparison circuit is exemplified as the level determining means 22. The comparison circuit 22 compares the level of a signal (for example, a received signal) input to one input terminal 22a with the level of a signal (for example, a reference value for discrimination) input to the other input terminal 22b. If the former is greater than the latter, and ② if the same, the L signal is output from the output terminal 22c as a good display output to cause the display to display good, and ③ the former is lower than the latter. Occasionally, an "H" signal is generated from the output terminal 22c as a defect display output for causing the display device to display a defect. The above ① may be included in the side of the defective display output instead of the side of the good display output. Also, the relationship between “ ^r L” and “H” may be opposite.

The display device 23 is a display corresponding to the determination result of the level determination means 22, that is, a display of good by the above-mentioned good display output and a display of failure by the bad display output, and is visually recognized from a distance fi. Light emitting diodes are used because of their good performance. The display device 23 performs a light-off display as an example of the good display and a light-on display as an example of the defective display. As shown in FIG. 1, the indicator 23 is provided on the outer surface of the housing 4 so as to be visible and protrude from the outside. Other indicators include a buzzer that stops the movement as a display of good quality as a display of a defect, or a needle that does not run out as a display of a poor run as a good display. Using a meter that displays Is also good.

 The operation of the converter 4 will be described. As is well known, a DC current for the operation of the comparator is supplied to the output terminal 16 from the outside through a transmission line connected to the output terminal 16. The DC current is output as indicated by an arrow 15a through a power supply separation filter S15, is supplied to a frequency conversion circuit 14 via a power supply circuit (not shown), and the circuit 14 enters an operation state. Current is also supplied from the * source supply circuit to each member of the display device, and they are in an operation state. The satellite signal coming from the satellite 8 is reflected by the reflector 2 and enters the waveguide 12 of the primary radiator 11. The signal is picked up by the probe 13, converted into an intermediate frequency signal by the frequency conversion circuit 14, and output from the output terminal 16 to the transmission line via the filter 15. The signal reaches the television receiver via the transmission line.

 On the other hand, the amplifier 18 receives the above-mentioned intermediate frequency signal as a reception signal and widens it.增 The width signal is detected by the detection circuit 19 and becomes a DC detection signal. The level reduction circuit 24 receives the detection signal at all times, and outputs a level reduction signal whose level is reduced by the predetermined level S. The reduced peak value detection circuit 21 receives the low attenuation signal and holds the beak value, that is, the highest value, of the low attenuation signals that have been input one after another up to the present time, and the signal of the held peak value (DC Signal) is always output as the reference value for determination. The level discriminating means 22 receives the detection signal and the discrimination reference value, performs the above-described operation, and turns on or off the display 23 according to the output.

 Next, the direction adjustment of the antenna 1 will be described. First, adjust the elevation angle of the antenna in advance. This is to ensure that the path of the directional position of the antenna passes through the position of the satellite 8 when the azimuth is adjusted later. Adjustment of the elevation angle is generally known in this type of antenna netting method for receiving a satellite signal.By adjusting the support 7, the elevation angle of the antenna 1 is set in the area B and the elevation angle is previously set to a known elevation angle. It is done by adjusting and fixing.

Next, in that state, the azimuth, which is the direction change of the antenna, is adjusted using the display 17. The process is described with reference to Figures 3, 4A and 4B and Table 1 below. In Fig. 3, 25 is the path through which the directional position of the antenna passes in the sky by adjusting the azimuth, and P3 is the path when antenna 1 is pointed at this point on path 25. The point is that the maximum reception level VH of the star signal (for example, 22 to 23 dB in the case of Meikon area) is obtained. The direction of this point P3 is the best receiving direction, and in this example, is the direction in which the star 8 is present. Reference numeral 28 denotes a range in which satellite signals can be received satisfactorily, that is, a range in a good reception direction.The reception level VM when the antenna is pointed in this range is smaller than the maximum reception level. This is the range where the decrease is within Δν. The diminished permissible level ΔV refers to a diminished level of the reception level that does not substantially deteriorate the reception characteristics as compared with the reception level in the best reception direction, and is, for example, about ldB. In this case, the range 28 in the good reception direction is about 1 degree around the best reception direction P3. The certain level in the level reduction circuit 24 is set to a voltage level difference corresponding to the above-mentioned permissible reduction level. In this example, the voltage level difference is set to, for example, 20%. The outgoing carpel is about 80% of the incoming carpels. The above range 28 is a range in which a reception level which is called an allowable limit in the industry can be obtained. 28 ', 28 "indicate the range in which the reception level VL when the antenna is pointed there is lower than the above-mentioned maximum reception level VΗ by more than the above-mentioned permissible reduction level Ρ. Shows the position fi at the boundary between the above range 28 and the ranges 28 ', 28 ". In FIG. 4A, Rfl indicates a reference value for determination, 19 s indicates a detection signal, and 24 s indicates a level reduction signal. Points A, B, and C in Table 1 show the states of the points denoted by the same reference numerals in FIG. 2, and the units of the numerical values of points A and B are milliports. In the state of the display device 23, the ginseng is turned off and the 〇 is lit.

table

 First, the azimuth of antenna 1 is sequentially changed in one direction. When the electrical pointing position of antenna 1 is sequentially changed from position P1 to positions P2 and P3 along path 25 described above, the level of the satellite signal received by antenna 1 sequentially increases, and The level of the signal and the level decrease signal rise as shown by the solid line and the broken line in FIG. 4A, respectively. The value held by the reduced peak value detection circuit 21 also rises sequentially with the same value as the level reduction signal (see Table 1). When the pointing position further moves to the position SP4 beyond the position SP3, the level of the satellite signal received by the antenna 1 sequentially decreases, and the detection signal and the level reduction signal gradually decrease. Therefore, in the process up to that point, the level of the level reduction signal becomes a beak at the position P3, and the beak value of the level reduction signal is stored in the reduction beak value detection circuit 21 and becomes the reference value for determination. . When the direction of the antenna 1 moves further and moves beyond the position P4 to the position S P5, the level of the received signal falls below the reference value for discrimination, so that the output of the level discriminating circuit 22 becomes “Η” and is displayed. Tool 23 lights to indicate that a peak has been found.

When the indicator 23 is turned on as described above, the direction in which the antenna 1 is moved is returned to the opposite direction along the path 25. In the returning process, as is clear from Table 1 and FIG. 4 4, the level of the detection signal becomes equal to the discrimination reference value at the first place SP4, so that the output of the level discrimination circuit 22 becomes “L j And the display 23 turns off. In the process of moving from the position P3 to the position P2 through the position P3, the level of the detection signal exceeds the reference value for discrimination, so that the indicator 23 remains off. Then, when the level reaches the level P2, the level of the detection signal becomes lower than the reference value for determination again, so that the display 23 lights up again.

 FIG. 4B shows the relationship between the operation of the antenna 1 and the state of the display 23 during the above process. The directional position of the antenna is changed in one direction as indicated by arrow 26. During this process, the indicator 23 is continuously turned off when the pointing position is from P1 to P4, and the indicator 23 is turned on at the position P4. When the indicator 23 is turned on, the direction in which the direction of the antenna 1 is changed at, for example, the position P5 is reversed, and the direction is changed to the arrow 27 direction. In the process of changing the directional direction of the antenna 1 as shown by the arrow 27, the indicator 23 is turned off at the position SP4, and the indicator 23 goes through the position P3 and immediately before reaching the position P2. The display 23 is kept off, and the display 23 is turned on when it reaches the position SP2. From the operation of the display device 23, the good reception direction range 28 is found.

 When the good reception direction range 28 is determined as described above, the direction of the antenna 1 is moved, for example, by eye measurement to the approximate center fi of the range 28 as indicated by an arrow 29. Then, antenna 1 is oriented toward the best receiving point. However, the difference in received signal level between the center and both ends of range 28 is at most 1 dB, and there is almost no difference in the reception characteristics. Good. However, when the direction of the antenna should be more severely adjusted, the indicator 23 is turned off only in the above range 28. Therefore, the direction of the antenna 1 is changed left and right several times and the range 28 is determined. The antenna may be directed to its central position if.

Next, when the orientation of the antenna 1 is adjusted as described above, the support 7 is clamped to fix the azimuth of the antenna 1. This completes the adjustment of the azimuth angle of antenna 1. In the case of this fixation, if the direction of the antenna 1 is shifted sideways due to the size of the support 7 or the like, the reception level of the satellite signal by the antenna decreases, and the level of the reception signal accepted by the input terminal 17a also decreases. However, when the deviation is slight as shown by arrow 30 in FIG. 4B (when the direction of antenna 1 is within the above range 28), the reception level is slightly reduced. There is almost no deterioration in image quality. In this case, since the level of the detection signal exceeds the discrimination reference value, the output of the level judgment circuit 22 maintaining the r _L j, the display device 2 3 keeps the display of good. On the other hand, when the azimuth angle of the antenna 1 is fixed, if the direction of the antenna deviates greatly from the good reception direction range 28, the level of the detection signal is determined as is clear from FIG. 4A. Therefore, the output of the repelling discrimination circuit 22 becomes ¹ "H j, and the indicator 23 lights to indicate a defect in the direction of the antenna 1. Accordingly, in this case, the azimuth angle as described above is used. Adjust the settings again.

 Next, a case in which the direction of the antenna 1 is adjusted using the direction adjusting display 17 in an area where the level of the satellite signal falling on the ground is low will be described. In this case, the level of the signal received from antenna 1 is lower than in the above case, and accordingly, the numerical values of the signals at points A and B are also generally lower than those in Table 1 above. However, since the reference value for determination is formed based on the level of the received signal as described above, the relative magnitude relationship between the received signal and the reference value for determination is the same. Therefore, the operation of the display device 23 is performed in exactly the same manner as in the above case. Therefore, based on the display of the display 23, the antenna 1 can be directed to the good reception direction in the same manner as in the above case.

 Next, the direction adjusting indicator 17 is housed in a separate case from the case of Comparator 4 and is an independent direction adjusting indicator. When adjusting the direction of the antenna, the direction adjusting indicator 17 is used. The input terminal 17a may be connected to the output terminal or monitor terminal of the converter in the antenna and used for adjusting the direction of the antenna.

 Next, FIGS. 5 to 7 showing different embodiments of the present application will be described. In this example, when the antenna orientation has been adjusted and the antenna has been fixed, the usage condition of the antenna may change, such as a change in the weather or a slight misalignment of the orientation of the antenna. If the level is low enough to maintain the proper image on the TV set, the display condition of the display will be maintained as good, and Shown below is an example of a direction adjustment indicator that indicates a defective display when the signal level of the received signal is significantly reduced so that the TV receiver cannot maintain an appropriate surface image. Things.

In FIG. 5, the direction adjusting display causes the display to indicate whether the level of the received signal received at the input terminal 17a has reached the peak value or not. The best direction discriminating means 17 d for generating an output for The direction adjustment display S indicates the level of the received signal as a minimum reference value corresponding to the minimum receivable level. It has a minimum reference discriminating means Π e for discriminating the repel based on. The best direction discriminating means 17d is used to direct the antenna to the best receiving direction for the antenna for adjusting the direction of the antenna. Further, the minimum reference determination means 17 e is used to know whether or not the antenna used for receiving the satellite signal is in a state where the direction adjustment is required. That is, it is determined whether or not the level of the received signal falls within the receivable repelling range, that is, the range between the peak value of the received signal and the minimum receivable level. The best direction discriminating means 17 d is exemplified by a circuit comprising a received signal beak value detecting circuit 21 A and a level discriminating means 22. The minimum reference determination unit 17 e is exemplified by a configuration including a minimum reference value forming circuit 75 for forming the minimum reference value and a level determination unit 22.

Next, the received signal beak value detection circuit 21A holds the peak value in the process of changing the level of the received signal, and constantly outputs the held beak value. However, when the control signal is received at the control terminal 21c, the beak value held until then is released, and the output of the peak value is stopped. Then, the hold of the new beak value is started by the disappearance of the control signal, and the held beak value is output. A well-known peak hold circuit can be used as the reception signal beak value detection circuit 21A. The minimum reference value forming circuit 75 is for forming a minimum reference value corresponding to the minimum receivable level. As the minimum reference value forming circuit 75, for example, a circuit for forming a DC brass pressure (for example, 10 mV) by a well-known resistance voltage dividing circuit can be used. The switching means for selectively providing one of the peak value held in the reception signal peak value detection circuit 21 A and the lowest reference value of the lowest reference value forming circuit 75 to the level determination means 22. Show. The switching means 76 may be a means for performing the above selection manually, but here, when the good display of the display device 23 is maintained for a predetermined time, a signal given to the level determination means 22 is changed from the peak value to the minimum value. The one that automatically switches to the reference value is used. For the above-mentioned predetermined time, in the case of the antenna orientation net preparation, turn the antenna to the good reception direction, then fix the antenna orientation and perform inspection work in that state, and then complete the direction adjustment work Is about 10 minutes, for example, 10 to 20 minutes plus an extra time, for example, about 10 minutes. Up The switching means 76 is, for example, configured by an hourly eye stop means 77 and a switch circuit 78. The time stop means 7 detects that the state of the good display of the indicator 23 has been maintained for a predetermined time, gives a control signal to the reception signal peak value detection circuit 21 A, and outputs the reception signal peak value detection circuit 21. Stop output of beak value from A. When the output of the peak value from the received signal peak value detection circuit 21A stops, the switch circuit 78 gives the minimum reference value from the minimum reference value forming circuit 75 to the level determination circuit 22 instead. However, even after the lapse of the predetermined time, the time stop means 77 immediately outputs the beak value to the received signal beak value detection circuit 21 A when the display 23 is in a state of performing a fault display. It is configured to return to the state. The time stop means 77 is exemplified by a timer circuit 79 and a stop circuit 80. The evening timer circuit 79 detects that a predetermined time has elapsed in the state of the above-mentioned good display, and generates a command for activating the stop circuit. The stop circuit 80 stops the output of the beak value from the received signal beak value detection circuit 21A when receiving a command from the timer circuit 79.

 The best direction discriminating means 17 d and the lowest reference discriminating means 17 e share the level discriminating means 22, but individual level discriminating means may be used for each. In this case, the display tools may be individually provided with display tools for performing display corresponding to the respective discrimination results of the individual level discriminating means. When the individual repell determination means is used, the switching means 76 is not used.

 Next, FIG. 6 showing an example of the above-described received signal peak value detection circuit 21A, time limit stop means 77, and switch circuit 78 will be described. First, the reception signal peak value detection circuit 21A has a well-known configuration using a capacitor for peak hold. 21a is an input terminal and 21b is an output terminal. 81, 82 are 增 -width circuits, for example, operational amplifiers are used.

83 is a capacitor for peak hold, and 84 is a diode for preventing discharge of the capacitor 83. Next, a well-known time constant circuit is exemplified as the timer circuit 79 in the time stop means 77. Reference numerals 86 and 87 denote time constant capacitors and resistors, respectively. Next, as the stop circuit 80, an example in which the peak value is released by discharging the beak hold capacitor 83 in the received signal peak value detection circuit 21A and the output thereof is stopped will be exemplified. Reference numeral 89 denotes a switch element for the above turtle, which is a semiconductor switch. An example is a switch (for example, a transistor). Reference numeral 90 denotes a switch element for rapidly discharging the capacitor 83 when the power of the display 17 is turned off. Yasuko 90a for controlling the switch is kneaded with the power circuit of the display 17. . Next, a switch circuit 78 exemplifies a circuit in which switch diodes 92 and 93 are connected as shown in the figure. The level of the output of the received signal peak value detection circuit 21A and the output of the lowest reference value formation circuit 75 is shown. The higher one is given to the level determination circuit 22. Therefore, even if the time stop means 77 does not stop the output of the reception peak value detection circuit 21 A, the output of the reception signal peak value detection circuit 21 A is higher than the output of the lowest reference value formation circuit 75. When the value is smaller, the switch circuit 78 supplies the output of the lowest reference value forming circuit 75 to the repell determination means 22.

The operation of the direction adjusting display having the above configuration is as follows. When a received signal is supplied to the input terminal 17a, the received signal peak value detection circuit 21A receives the detected signal from the detection circuit 19, and the peak value, that is, the highest value among the detection signals input one after another up to the present time. Hold the value and output the signal of the held peak value. The level discriminating circuit 22 receives the detection signal and the signal supplied through the switch circuit 78 and performs the above-described operation, and the display 23 turns on or off according to the output. Next, the direction adjustment of the antenna using the direction adjusting display will be described with reference to FIG. 7 and Table 2 below. In FIG. 7, reference numeral 95 denotes a path through which the directional position of the antenna passes in the sky by adjusting the azimuth, and P 14 denotes a best reception point on the path 95. A, B, and C in Table 2 indicate the states of the points denoted by the same reference numerals in Fig. 5, the units of the numerical values of points A and B are milliport, and the state of indicator 23 is off. , 〇 are lit.

Table 2

 First, the azimuth of antenna 1 is sequentially changed in one direction to find the peak value. As the antenna 1 is gradually changed from the position P 11 to the position ¾ P 12, P 13, and P 14 along the path 95 as indicated by the arrow 96, the antenna 1 The level of the satellite signal received at increases as shown by the line B1 in FIG. 7B. Therefore, the level of point A in the circuit rises as shown in Table 2. Further, as shown in Table 2, at the position P11 where the level of the detection signal is 0, the lowest reference value is given to the level discriminating circuit 22 so that the level of the point B is the lowest reference value level of 10 mV. is there. However, as the pointing position of the antenna 1 moves and the level of the detection signal increases, the output of the reception signal peak value detection circuit 21A increases, and when the pointing position exceeds P12, the reception signal beak value detection circuit The output of road 21 A exceeds the minimum reference value. Therefore, after the position P12, the level of the point A and the level of the point B are the same. In the above process, the output of the repelle discriminating circuit 22 becomes “H” at the position SP 11 and the display 23 lights up, but thereafter, the output of the level discriminating circuit 22 becomes “L j” and the display 23 becomes It is off.

Next, when the above-mentioned pointing position moves from position P14 to positions P15, P16, and P17 as shown by arrow 97, the level of the satellite signal received by antenna 1 decreases sequentially. However, the detection signal decreases sequentially. However, the received signal beak value detection circuit 21A outputs the peak value held at the position SP14 as shown in Table 2B. Therefore, in this process, the detection signal When the level falls below the peak value, the output of the level discriminating circuit 22 becomes “H” as is apparent from the assisting characteristic, and the display device 23 is turned on continuously. This continuous light indicates that the beak value of the received signal has been held.

 When the indicator 23 is turned on as described above, the direction for assisting the antenna 1 is returned in the opposite direction along the path 95 as shown by the arrow 98. In the return process, as is clear from Table 2 and FIG. 7B, the level of the detected signal is lower than the peak value in the first 1E P16 and P15. The display 23 remains lit. Then, when reaching the position P 14, the level of the detection signal becomes the same as the peak value, so that the output of the level discriminating circuit 22 becomes ΓL j and the display 23 turns off. As the detection signal level becomes lower than the peak value signal when the position goes further to position P13 or P12 beyond position P14, the output of the repel determination circuit 22 is displayed as `` H ''. The fixture 23 is turned on again.

 Therefore, if the worker adjusting the direction of the antenna turns the antenna 1 to the position P14 where the indicator 23 is turned off as described above in the course of returning the direction of the antenna 1, the antenna 1 is turned off. Orient correctly to the direction of the satellite 8 It will be in the optimal receiving direction. After that, since the display 23 goes out only when the directional position of the antenna 1 becomes P14, the change of the azimuth reciprocation as described above is repeated several times to determine the position SP14. You may then direct antenna 1 there. When the antenna 1 is oriented in the best receiving direction in this way, the support 7 is clamped there and the azimuth of the antenna 1 is fixed.

Next, the case where the direction of the antenna 1 is adjusted as described above in an area where the reception level of the satellite signal is low will be described. In this case, the level of the signal received from the antenna 1 is lower than the above case as shown by the line B2 in FIG. 7B, and accordingly, the numerical values of the signals at the points A and B are as shown in Table 2 above. More generally lower. However, the peak value is held in the process of changing the direction of the antenna toward one side, and it is determined that the detected signal becomes the same as the held peak value in the process of returning the antenna direction. The operation of the display device 23 is performed in exactly the same way as in the above case, since the assisting operation of the display device is not different from the above case. Therefore, based on the display of the display device 23, the antenna 1 is directed to the satellite 8 in the same manner as described above. You can turn to the direction.

 Next, the state after the antenna is oriented in the best receiving direction and fixed as described above will be described with reference to Table 3.

 Table 3

When the direction adjustment is completed as described above and the display of goodness of the display 23 is maintained for a predetermined time, the operation of the switching means 76 causes the display 23 to determine whether or not it is good or bad according to the determination result of the lowest reference determination means 17 e. Display is performed. That is, when the antenna 1 is oriented in the best receiving direction and the display 23 is turned off, the timer circuit 79 detects the light-off state based on the output of the level discriminating circuit 22 being r _L ". . If the timer circuit 79 determines that the light-off state has been maintained for a predetermined time, the timer circuit 79 sends a command to the stop circuit 80 to make the switch element 89 conductive. Then, the switch element 89 becomes conductive and discharges the capacitor 83 for peak hold. As a result, the peak value of the reception signal peak value detection circuit 21A is released, and the output of the peak value stops. When the output of the peak value is stopped, the lowest reference value of the lowest reference value forming circuit 75 is given to the level determination circuit 22 via the switch circuit 78 instead (see 10 mV of the B right in Table 3). In this state, even if the thin S151 in Fig. 1 passes between the satellite 8 and the antenna 1 and the reception level of the antenna 1 decreases slightly and the level of the detected signal decreases as shown in Table 3, the level remains at the minimum. Since the reference value has been exceeded, the output of the level discrimination circuit 22 remains ΓL ”and the indicator 23 is turned off. 2 Keep state. The same applies to the case where the position of the satellite 8 temporarily shifts slightly and the reception level by the antenna 1 decreases.

 Next, based on Table 4, the case where the antenna 1 is blown by a strong wind in the above state and the direction of the antenna 1 largely deviates in a direction in which a received signal of the lowest receivable level is not obtained will be described.

 Table 4

In this case, the reception level greatly decreases due to the deviation in the direction of the antenna. For example, the level of the detection signal greatly decreases to 5 mV as shown in Table 4. Then, since the level of the detection signal is lower than the lowest reference value, the output of the level determination circuit 22 becomes rHj, and the display 23 lights. In the above case, the television image due to the satellite signal received by the antenna becomes extremely poor. Then, the user of the antenna searches for an abnormal part, but by turning on the indicator 23, it is possible to quickly know that the direction of the antenna is abnormal. Therefore, it may be necessary to re-orient the antenna. In this case, the evening timer circuit 79 detects that the display is turned on because the output of the level determination circuit 22 has changed to "H", and stops the command to the stop circuit 80. As a result, the stop circuit 80 releases the output stop of the received signal peak value detection circuit 21A. Therefore, in the case of the operation of correcting the direction of the antenna, the antenna can be directed to the best receiving direction by operating the display 23 based on the judgment of the best direction judging means 17d again. 6 5 0

 2 2 Next, the case of temporary heavy rainfall in the above condition will be described based on Table 5.

 Table 5

 In this case, the indicator 23 is turned on in the state of heavy rain, as in the case where the direction of the antenna is shifted, and the television image is significantly deteriorated. However, as the weather recovers, the level of the received signal increases, the detection signal and the peak value also increase, the display 23 turns off, and a good television image is recovered.

 Note that, in the above embodiment, portions that are considered to be functionally the same as or equivalent to the previous embodiment and whose description is duplicated are given the same reference numerals as in the previous embodiment, and redundant description is omitted. (Also in the following embodiments, the same reference numerals are used for the same concept and the duplicate description will be omitted.)

Next, FIG. 8 shows still another embodiment of the direction adjusting display. In this direction conversion display, the display device performs the same display operation as in the embodiment of FIG. 2 in the process of adjusting the direction of the antenna and fixing the same, and in the state after fixing, the same as in the embodiment of FIG. The display operation of is performed. The direction adjusting display includes the good direction discriminating means 17b and the lowest reference discriminating means 17e. Also provided is a switching means 76 for switching from the means 17b to the means 17e. In the direction adjusting display having such a configuration, the direction of the antenna is first changed toward one side along the path 95 in FIG. 7A, and then the direction of the antenna is returned. The state of each point A, B, C in the circuit is as shown in Table 6 below.

 Table 6

 As is evident from Table 6 above, in the process of returning the antenna, the position SP 15 'slightly shifted from the position P 15 to the position P 14 and the position P 14 slightly shifted from the position P 13 Within the range of SP13 '(good reception direction range), the display is turned off, which is a good indication. Therefore, by pointing the antenna to a position substantially at the center of the range, the antenna is in the best receiving direction. When fixing the antenna at that position, if the direction of the antenna deviates greatly and is out of the range of the good reception direction from the position S P15 'to the position P 13', the display device is a defective display. Becomes However, if the deviation of the direction of the antenna is small and it is within the above range, the display device will maintain a good display.

 Next, the operation of the direction adjusting display after the antenna is oriented in the optimum receiving direction and fixed as described above is the same as that of FIG.

In the direction adjusting display having the configuration shown in FIG. 8, the level discriminating means 22 functions as the level discriminating means in the good direction discriminating means 17b in the process of adjusting the direction of the antenna. Also, after pointing the antenna to the optimal receiving direction and fixing it The level discriminating means 22 functions as the level discriminating means in the lowest reference discriminating means 17 e. That is, the good direction discriminating means 17b and the lowest reference discriminating means 17e share the level discriminating means 22. However, individual level discriminating means may be used for each of the discriminating means 17b and 17e. In this case, the display device may be individually provided with a display device that performs a display corresponding to each determination result of the individual repell determination means. When the individual level discriminating means is used, the switching means 76 is not used.

 Next, FIG. 9 shows a different example of the reference value forming circuit 17C for determination in FIG. The reference value forming circuit 17 c for discrimination in this example includes a reception signal peak value detection circuit 21 A that receives a reception signal and detects a peak value in the course of the change of the reception signal, and a beak value of the reception signal. And a level reduction circuit 24 A which lowers by a certain level and uses it as a reference value for determination. In this example, first, the detection signal is received by the reception signal peak value detection circuit 21A and the peak value is held. Next, the held peak value is received by the level reduction circuit 24A, and the level is reduced by a predetermined level to form the reference value for determination.

 Next, FIG. 10 shows still another embodiment of the direction adjusting display. In this example, when performing the work of adjusting the direction of the antenna, in order to be able to point the antenna in the best receiving direction, the display device should display good only at the position where the peak value is obtained. It is another object of the present invention to display a defect only when the direction of the antenna is out of the range of the good reception direction during the fixing work. The direction adjusting display includes a best direction discriminating means 17d and a good direction discriminating means 17b. FIG. 10 shows only the changed part of the circuit shown in the block circuit diagram of FIG. In this example, a reception signal peak value detection circuit 21A for holding the beak value of the reception signal is provided in addition to the determination reference value forming means 17c for forming the determination reference value. Then, one of the discrimination reference value formed by the discrimination reference value forming means 17c and the peak value held by the reception signal peak value detection circuit 21A is selected, and the level is discriminated. An externally manually operable switch means 33 for providing the means 22 is provided.

When the direction of the antenna is adjusted using the direction adjusting display having such a configuration, the switch means 33 is used to determine the level of the beak value from the received signal beak value detection circuit 21A. The state given to the means 22 is switched to adjust the direction of the antenna. In this case, the display device 23 displays a good indication only when the level of the received signal received at the input end of the direction adjustment display S reaches the peak value. Next, when fixing the direction of the antenna, the switch means 33 is switched so that the reference value for determination from the reference value forming means 17 c is supplied to the level determination means 22. In this state, as described in the embodiment of FIG. 2, the received signal received at the input terminal is compared with the reference value for determination lower than the peak value, and the above-described determination and the determination based on the determination are performed. An indication of the quality of the display is displayed.

 Next, FIG. 11 shows still another embodiment of the direction adjusting display. In this example, when performing the work of adjusting the direction of the antenna, fix the antenna so that the antenna is directed in a direction that is slightly narrower than the good reception direction range 28 in Figs. 3 and 4B. In some cases, when the direction of the antenna deviates from the good reception direction range 28, the purpose is to be notified by the display of the defect of the display device. FIG. 11 shows only the changed portions of the circuit shown in the block circuit diagram of FIG. In this example, a direction setting reference value forming means 34 for forming a direction setting reference value is provided in addition to the determination reference value forming means 17c for forming the determination reference value. Then, one of the discrimination reference value formed by the discrimination reference value forming means 17c and the direction setting reference value formed by the direction setting reference value forming means 34 is selected, and is selected. A switch means 37 that can be manually operated from the outside to provide the level determination means 22 is provided. The reference value for direction setting is a reference value used only when the operation of adjusting the direction of the antenna is performed, and is indicated by a symbol R f 2 in FIG. The direction setting reference value Rf 2 is set, for example, to an intermediate level between the peak value of the received signal level and the discrimination reference value (for example, a level lower by 0.5 dB than the peak value). The direction setting reference value forming means 34 is composed of a level decreasing circuit 35 and a decreasing peak value detecting circuit 36, for example, like the discriminating reference value forming means 17c.

When the direction of the antenna is adjusted using such a direction adjusting display, the switch means 37 is switched to a state in which the direction setting reference value is given to the level determining means 22, and the direction of the antenna is adjusted. In this case, when the level of the received signal received at the input terminal of the direction adjustment indicator becomes equal to or higher than the direction setting reference value, the indicator 23 becomes a good table. Perform the following. That is, as shown by reference numeral 38 in FIG. 12, good display is performed in a range narrower than the good reception direction range 28. When the range in which the display device 23 performs good display is determined as described above, the familiar operator adjusts the antenna direction to P21 near the center of the range 38. However, a worker who is unfamiliar with the antenna direction manipulation may, for example, adjust the position P22 at the corner of the above range 38. Even if the direction of the antenna is adjusted to such a place P22, it is possible to reduce the possibility that the display 23 displays a defect due to the displacement of the antenna during the fixing operation of the antenna. That is, when the direction of the antenna is fixed after the above-described direction adjustment, the switch means 37 is switched so that the reference value for determination is given to the level determination means 22. Then, the display device 23 performs a good display in the range 28 wider than the range 38 described above. Therefore, even when the direction of the antenna slightly shifts in the direction of arrow 39 when the antenna is fixed, there is a high probability that the direction of the antenna falls within the range 28 as indicated by reference numeral P23. As a result, it is unlikely that the display device 23 will display a defect.

Claims

The scope of the claims

1. A level reduction circuit for receiving a signal received from a satellite signal receiving antenna and forming a level reduction signal in which the level of the reception signal is reduced by a certain level. A low-decay peak value detection circuit that detects a beak value of the above-mentioned level-lowering signal that changes along with the peak value and uses it as a reference value for determination;

Level determining means for determining the level of the received signal based on the reference value for determination,

A display device for performing a display corresponding to a result of the determination by the level determining means, a direction adjusting indicator for a satellite signal receiving antenna.

2. A received signal peak value detection circuit that receives a received signal from an antenna for receiving a satellite signal and detects a peak value in a process of changing the received signal.

A level reduction circuit that reduces the peak value of the reception signal by a certain level and uses it as a reference value for determination;

Repel determining means for determining the level of the received signal based on the reference value for determination,

A display device for performing a display corresponding to a result of the determination by the level determining means, a direction adjusting indicator for a satellite signal receiving antenna.

3. A level reduction circuit for receiving a received signal from an antenna for receiving a satellite signal and forming a level-reduced signal in which the level of the received signal is reduced by a certain level;

A reduced peak value detection circuit that detects a peak value of the level reduction signal that changes with a change in the level of the reception signal and uses the peak value as a reference value for determination;

A reception signal peak value detection circuit that receives a reception signal from a satellite signal reception antenna and detects a peak value in the process of the change of the reception signal;

Switch for selecting one of the peak value of the received signal and the minimum reference value Means,

Level discriminating means for discriminating the level of the received signal based on a peak value or a reference value selected by the switch means,

A display device for performing a display corresponding to the result of the determination by the repelling determination means, a direction indicator for a satellite signal receiving antenna.

4. A level reduction circuit for receiving a signal from an antenna for receiving satellite signals and forming a level reduction signal in which the level of the received signal is reduced by a certain level;

A low-decay peak value detection circuit that detects a beak value of the level-decreasing signal that changes with a change in the level of the received signal and uses it as a reference value for determination;

Direction setting reference value forming means for forming a direction setting reference value at an intermediate level between the peak value of the received signal and the determination reference value,

Switch means for selecting one of the reference value for determination and the reference value for direction setting;

Level discriminating means for discriminating the level of the received signal based on the discriminating reference value or direction setting reference value selected by the switch means;

A display device for performing a display corresponding to a result of the determination by the level determining means, wherein the direction of the satellite signal receiving antenna is adjusted.

5. Receiving the received signal from the satellite signal receiving antenna, and generating the output for indicating on the display device whether it is good or bad according to whether the level has reached the peak value or not. Direction determining means;

A display device for performing a display corresponding to the determination result of the best direction determination means,

Minimum reference determining means for determining the level of the received signal based on a minimum reference value corresponding to a minimum receivable level;

A display device for performing a display corresponding to a result of the determination by the lowest reference determination means. A direction indicator for a satellite signal receiving antenna.

6. A received signal peak value detection circuit for receiving a received signal from an antenna for receiving a satellite signal and detecting a peak value in a process of changing the received signal;

A minimum reference value forming circuit for forming a minimum reference value corresponding to the lowest receivable level, switching means for selecting the detected beak value and the minimum reference value, and a switching of the level of the reception signal; Level discriminating means for discriminating levels based on the beak value or the lowest reference value selected by the means;

A display device for performing a display corresponding to a result of the determination by the level determining means, wherein the direction of the satellite signal receiving antenna is adjusted.

7. A level reduction circuit for receiving a received signal from an antenna for receiving a satellite signal and forming a level-reduced signal in which the level of the received signal is reduced by a certain level and a change in the level of the received signal. A low peak value detection circuit that detects a peak value of the level low signal that changes with the detection signal and uses the peak value as a reference value for determination;

Level discriminating means for discriminating the level of the received signal based on the discrimination reference value;

A display device for performing a display corresponding to the determination result of the repell determination unit,

Minimum reference determining means for determining the level of the received signal based on a minimum reference value corresponding to a minimum receivable level;

A display device for performing a display corresponding to a result of the determination by the lowest reference determination means. A direction indicator for a satellite signal receiving antenna.