JPS626746Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an antenna terminal, and more particularly to a terminal having a set of terminals, one end of which is connected to an antenna and the other end serving as a power receiving end of a feeder.

In the conventional antenna terminal of this type, a terminal A is installed at the tip of a feeder 2 which is divided into two systems from an antenna 1 as shown in FIG.
If a radio or television 22 is connected to only one of the terminals, the impedance of the receiving end of the feeder 2 connected to the unused terminal A becomes infinite. The incident wave from antenna 1 to terminal A is reflected at the receiving end, and the reflected wave propagates through feeder 2 to the other terminal A in use. The waves and the above-mentioned reflected waves that were slightly delayed propagated, causing problems such as ghost images appearing on the radio and television 22 connected to terminal A, and audio becoming muddy.

The present invention has been devised in view of the above-mentioned problems, and its purpose is to prevent ghost images and muddy audio due to reflected waves from unused terminals.

Embodiments of the present invention will be described below with reference to the accompanying drawings. The antenna terminal according to the present invention is a terminal A having a pair of terminals 3, 3 connected to the other end serving as a power receiving end of a feeder 2 connected to an antenna 1 at one end, and having a characteristic impedance of the feeder 2. One end of a dummy load 4 having a size equal to that is pivotally connected to one terminal 3, and the other end is attached so that it can be freely opened and closed with the other terminal 3. In this embodiment, it is used as the feeder 2. An example is shown where it is connected to a coaxial cable. As shown in FIG. 2, in the terminal A, a terminal bolt 6 that penetrates the terminal block 5 made of an insulator such as synthetic resin is inserted from the back side, and a nut 7 with a knob is attached to the leg of the terminal bolt 6. It is formed by screwing together.
There are three terminal bolts 6, and on the back side of the terminal block 5, a metal presser foot 8 is attached between two of them to clamp the outer conductor of the coaxial cable 2 between the terminal block 5 and the other one. The main terminal bolt 6 is located on the perpendicular bisector of the straight line connecting the previous two bolts, and a receiver 9 is installed between the terminal block 5 and the bolt head, and the inner conductor of the coaxial cable 2 is attached here. Connected. Terminal block 5
On the front side as well as the back side, a presser foot 8 is attached to the leg of the terminal bolt 6 that is connected to the outer conductor of the coaxial cable 2 on the back side to clamp the outer conductor of the coaxial cable 2 between it and the terminal block 5. The inner conductor of the coaxial cable 2 is also connected to the leg of the terminal bolt 6 which is connected to the inner conductor of the coaxial cable 2 on the surface thereof. Then, on the surface of the terminal block 5, the dummy load 4 is attached so as to be openable and closable between the terminal bolt 6 connected to the inner conductor and the terminal bolt 6 connected to the outer conductor. The dummy load 4 is formed as shown in FIGS. 3 to 5. That is, the central part becomes a support part 10 formed of an insulator, terminal parts 11 protrude from both ends of the support part 10, and a resistor 1 having a size equal to the characteristic impedance of the coaxial cable 2 is installed between the terminal parts 11.
2 is installed. The support part 10 has a resistor 1
A support hole 14 into which the main body 13 of No. 2 is mounted and a groove 16 into which the lead wire 15 of the resistor 12 is mounted are formed. A hole 17 through which the terminal bolt 6 is inserted is formed in one terminal portion 11, and a notch 18 into which the terminal bolt 6 is hooked is formed in the other terminal portion 11. Further, a protrusion 20 having a receiving hole 19 for fixing both ends of the lead wire 15 of the resistor 12 is formed on both terminal portions 11, 11, respectively, and the lead wire 15 is inserted into the receiving hole 19 and fixed by caulking or soldering. That's what I do. As shown in FIG. 6, the dummy load 4 has terminal parts 11 at both ends of an insulator support part 10, and conductive paint is applied so that the resistance value between both terminal parts 11 is equal to the characteristic impedance of the coaxial cable 2. The resistance portion 21 may be formed by doing so. The dummy load 4 thus formed is inserted between the terminal block 5 and the nut 7 by having one terminal bolt 6 inserted through the hole 17 provided in one terminal portion 11 .
The dummy load 4 pivotally attached to the terminal bolt 6 in this manner is attached between the terminals 3 and 3 when the terminal A is not in use and the coaxial cable 2 is not connected, as shown in FIG. 7a. When coaxial cable 2 is connected to terminal A,
It is sufficient to tighten the nut 7 of one terminal 3 in the state shown in FIG.

As described above, in the present invention, one end of the dummy load having a size equal to the characteristic impedance of the feeder is pivotally connected to one terminal, and the other end is attached so that it can be freely opened and closed with the other terminal. Even if there are terminals that are not used among the terminals that are branched and connected to multiple systems from one antenna, reflections from the unused terminals can be prevented by simply installing a dummy load between the terminals.
This prevents ghost images on television and muddy audio on radio.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing the usage state of the present invention;
Figures 2a, b, and c are respectively a top view, a plan view, and a rear view of the same, Figure 3 is an exploded perspective view of the dummy load used in the same, and Figure 4 is a plan view of the dummy load used in the same. Fig. 5 is an enlarged perspective view of Fig. 4, Fig. 6 is a plan view showing another embodiment of the dummy load used in the above, and Fig. 7 a and b are front views showing the same in use. , 1 is an antenna, 2 is a feeder, 3 is a terminal, 4 is a dummy load, and A is a terminal.

Claims (1)

[Scope of utility model registration request] A terminal having a pair of terminals, one end of which is connected to the receiving end of a feeder connected to an antenna, and the other end of which is connected to the feeder, and one end of a dummy load having a magnitude equal to the characteristic impedance of the feeder is connected to one terminal. An antenna terminal that is attached so that the other end can be opened and closed with the other terminal.