JPH029491B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a level measuring device, and an object thereof is to provide a level measuring device that allows easy level reading.

Embodiments of the present application will be described below with reference to the drawings.

Figure 1 is a perspective view showing how the level measuring device is used, and shows how the antenna is adjusted while measuring the output level of a BS converter for satellite broadcast reception. Reference numeral 1 indicates a level measuring device, which is used to measure the output level of a BS converter for receiving satellite broadcasting. 2
Turns level measuring device 1 on and off using the power switch.
It is for the purpose of 3 is an input terminal, and an F-type connector or the like is used. Next, 11 indicates the broadcasting satellite, channel BS-11, channel BS-15
satellite broadcasts are being sent. 12 is an antenna reflector, and an offset antenna is used.
Reference numeral 13 indicates a primary radiator provided at the focal point of the reflecting mirror 12, and reference numeral 14 indicates a BS converter. 1
Reference numeral 5 indicates an output terminal of the BS converter 14, from which the above-mentioned satellite broadcast signal converted to an intermediate frequency is output. 16 indicates a support arm. 17 is a support that is installed on top of the roots of the house or on the ground. 18 is an adjustment mechanism that adjusts the azimuth and angle to maximize the reception sensitivity of broadcast radio waves.
This is for adjusting the elevation angle using the antenna reflector 12, and also has a function that allows the antenna to be fixed at the best azimuth and elevation angle after adjustment. 19 is BS converter 1
A coaxial cable connecting 4 and level measuring device 1 is shown. 20 indicates a coordinator.

Next, FIG. 2 shows a front view of the level measuring device. Components that are the same as those in the previous figure are given the same reference numerals, and redundant explanations will be omitted. A channel selection knob 4 is used to select the channel of the level-measured signal. For example, channel BS-11 or channel BS-15 converted to the center frequency is selected. 5 is a meter, and various types of meters such as a moving coil type, a moving iron piece type, and a rectifying type are used. 5a is a level scale, and logarithmic intervals are provided on the surface of the scale plate 5b. 6 is the minimum value display part of the scale 5a, 7 is the scale 5a
8 indicates the intermediate value display section of the scale 5a, and indicates 0 dBμ, 10 dBμ, and 5 dBμ, respectively. The scale 5a becomes 1 as it approaches the minimum value display section 6.
The scale interval per unit (1 dB in this example) is narrow, and the closer you get to the maximum value display section 7, the wider the scale interval per unit. 5c indicates a guideline. 9 is an attenuator, and 9a is a switching knob which can be rotated to switch the amount of attenuation. 9b shows an attenuation scale, and the amount of attenuation is added. The attenuator 9 is
The attenuation amount is switched in steps of half the difference between the level displayed on the maximum value display section 7 and the level displayed on the minimum value display section 6 on the scale 5a, that is, in this example, in steps of 5 dB. Naturally, the scale 9b is also displayed in the above-mentioned steps, that is, in steps of 5 dB. Note that 9c indicates an index provided on the knob. Reference numeral 10 indicates a front panel on which each of the above-mentioned parts is attached.

Next, a method of using the level measuring device 1 when adjusting the azimuth angle and elevation angle of the antenna will be explained using FIGS. 1 and 2. The antenna reflector 12 is adjusted so that the level of the output signal of the BS converter 14 is maximized.
If you adjust the direction of the antenna, that direction is the optimal antenna direction. First, install each device as shown in Figure 1, and set the selected channel to, for example, BS.
-11, set the attenuator 9 to the maximum attenuation amount, and connect the BS converter 14 and the level measuring device 1 with the coaxial cable 19. Next, align the horizontal direction of the antenna with the approximate direction of the satellite.
The amount of attenuation of the attenuator 9 is reduced until the pointer 5c starts to swing out. In this state, the reflector 12 is slightly moved horizontally to the left and right, the direction in which the pointer 5c of the instrument 5 swings to the maximum is confirmed, and the azimuth is fixed. When fine-tuning the azimuth angle, even if the pointer 5c happens to indicate a part with narrow scale intervals as shown by dotted line A in Fig. 2,
When the knob 9a of the attenuator 9 is moved to reduce the attenuation amount by one step (so that the index 9c moves from the position A' to the position B'), the position of the pointer 5c will be at the center position as shown by the solid line B. This makes the indicator scale easier to read. Next, move the antenna reflector 12 vertically up and down to confirm the direction in which the pointer 5c of the meter 5 can swing further to the maximum, and fix the elevation angle. Even during this fine adjustment, if the pointer 5c points near the minimum value display section 6 of the scale, the attenuation amount of the attenuator 9 is reduced by one step, and the pointer 5c points near the middle value display section 8 of the scale. It is designed to give instructions and is easy to read.

After aligning the antenna reflector 12 as described above, the level of the output signal of the BS converter 14 can be measured. When the pointer 5c of level measuring device 1 is at position B and the index 9c is at position B', the input level of level measuring device 1 is the sum of 6 dB indicated by needle 5c and 50 dB indicated by index 9c. This means that it is 56dBμ. The output level of the BS converter 14 is the sum of this 56 dBμ and the loss of the measurement cable 19.

Although the deflection of the pointer 5c changes greatly during rough adjustment, as in the adjustment work of the antenna direction described above, on the other hand, in the case of work involving fine adjustment in which the deflection of the pointer 5c changes finely, the level of this embodiment is Measuring instruments are particularly useful.

Although the above description has been about level measurement when installing an antenna, it goes without saying that the level measuring device 1 is also useful for level measurement during periodic inspections of installed equipment.

Next, FIG. 3 is a front view showing a different example of the level measuring device 1. Those having the same or equivalent functions as those in the previous figure are given the same reference numerals and an alphanumeric letter "e", and redundant explanation will be omitted. In the following, different examples will be shown based on the same idea, with f added to the end of the reference numerals. The meter 5e has a scale 5ae in which the minimum value display section 6e, the maximum value display section 7e, and the intermediate value display section 8e have different display values. Correspondingly, the attenuator 9e also has different display values on the attenuation amount scale 9be.

FIG. 4 is a front view showing a still different example of the level measuring device 1, in which the meter 5f is an indicator composed of a row of light emitting diodes, and when the light emitting diode corresponding to the position of the measured level value lights up, This allows you to read the level. 21 indicates a lit light emitting diode.

Although the level measuring device has been described above, it goes without saying that the present invention can also be applied to electric field strength measuring devices. Also, the selected channel is TV VHF
and UHF channels.

As described above, the present invention provides a level measuring device that calculates a measured level by adding together the indicated values of the level scale of the meter and the attenuation scale of the attenuator, in which the steps of the attenuation scale of the attenuator are It is characterized by a value step that is half the difference between the maximum value and minimum value that can be displayed on the level scale, and has the following effects. That is, since the step of the attenuation scale 9b of the attenuator 9 is set to half the difference between the maximum and minimum values that can be displayed on the meter 5, the level is displayed near the intermediate value of the level scale 5a of the meter 5. This has the effect of making it easier for the level measurer to read the indicated value.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is a perspective view showing how the level measuring device is used, FIG. 2 is a front view of the level measuring device, and FIG. 3 is a front view of a different level measuring device. FIG. 4 is a front view of a still different level measuring device. 1...Level measuring device, 5...Meter, 6...Minimum value display section, 7...Maximum value display section, 8...Intermediate value display section, 9...Attenuator.

Claims (1)

[Claims] 1. In a level measuring device that calculates the measured level by adding together the indicated values of the level scale of the meter and the attenuation scale of the attenuator, the step of the attenuation scale of the attenuator shall be the maximum displayable value on the level scale of the meter. A level measuring device characterized in that the step is half the difference between a value and a minimum value.