JPH0836008A - Radio wave leakage detecting device for catv line - Google Patents

Radio wave leakage detecting device for catv line

Info

Publication number
JPH0836008A
JPH0836008A JP6189033A JP18903394A JPH0836008A JP H0836008 A JPH0836008 A JP H0836008A JP 6189033 A JP6189033 A JP 6189033A JP 18903394 A JP18903394 A JP 18903394A JP H0836008 A JPH0836008 A JP H0836008A
Authority
JP
Japan
Prior art keywords
radio wave
antenna
wave leakage
loop antenna
wave
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP6189033A
Other languages
Japanese (ja)
Inventor
Hideki Nagaoka
秀樹 長岡
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hitachi Cable Ltd
Original Assignee
Hitachi Cable Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hitachi Cable Ltd filed Critical Hitachi Cable Ltd
Priority to JP6189033A priority Critical patent/JPH0836008A/en
Publication of JPH0836008A publication Critical patent/JPH0836008A/en
Pending legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/08—Locating faults in cables, transmission lines, or networks
    • G01R31/081—Locating faults in cables, transmission lines, or networks according to type of conductors
    • G01R31/083—Locating faults in cables, transmission lines, or networks according to type of conductors in cables, e.g. underground

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Testing Of Short-Circuits, Discontinuities, Leakage, Or Incorrect Line Connections (AREA)

Abstract

PURPOSE:To locally detect a wave leakage part so as to improve the detection accuracy by providing a compact loop antenna having a half-wave length by- pass line function as an antenna for receiving the leaked radio wave, and providing an electric field intensity measuring unit. CONSTITUTION:A loop antenna 4b is substituted for a dipole antenna, and a lead wire 6 is connected to an electric field intensity measuring unit 5, and level of the current leakage from a cable 1 or an amplifier 2 is detected. A wave leakage detecting device is downsized so as to facilitate the work by using the compact loop antenna 4b. This antenna 4b is provided with a half- wave length (lambda/2) alternative line 4:1 balun function. Furthermore, since this device is a converting device having the impedance matching function for matching impedance of balance (antenna) and unbalance (lead wire), the leaked radio wave can be accurately detected.

Description

【発明の詳細な説明】Detailed Description of the Invention

【０００１】[0001]

【産業上の利用分野】この発明は、ＣＡＴＶ線路の電波
漏洩検知装置に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio wave leakage detecting device for a CATV line.

【０００２】[0002]

【従来の技術】ＣＡＴＶ線路は自動車の振動などにさら
される状態にあり、そのため同軸ケーブルの外部導体に
亀裂が発生したり、増幅器またはタップオフとケーブル
の接続部が不完全な状態となることがあり、電波漏洩が
散発している。これらの電波漏洩を測定するのに、従来
は図３に示すように測定を行っていた。例えば、電柱３
上に張り渡された同軸ケーブル１または増幅器２との接
続部からの漏洩電波を、ダイポールアンテナ４ａで受信
し、リード線６を介して電界強度測定器５を接続して漏
洩電波のレベルを測定するものである。2. Description of the Related Art CATV lines are exposed to vibrations of automobiles, which may cause cracks in the outer conductor of the coaxial cable or incomplete connection between the amplifier or tap-off and the cable. , Radio waves are scattered. In order to measure these radio wave leaks, conventionally, the measurement was performed as shown in FIG. For example, telephone pole 3
The dipole antenna 4a receives the leaked radio wave from the connection portion with the coaxial cable 1 or the amplifier 2 stretched over and measures the level of the leaked radio wave by connecting the electric field strength measuring device 5 via the lead wire 6. To do.

【０００３】[0003]

【発明が解決しようとする課題】ところで、上述した従
来の測定法は、ダイポールアンテナ４ａが大型であるた
め、高所などでの検出作業が困難である。また、ダイポ
ールアンテナ４ａを使用しているため、電波漏洩個所を
局部的に特定することが不可能である。さらに、電波漏
洩個所が特定できないため、補修の時間（電波の停波時
間）が長くかかり、視聴者に大きな迷惑を与えているな
どの問題点があった。By the way, in the above-mentioned conventional measuring method, since the dipole antenna 4a is large in size, it is difficult to perform the detecting work in a high place. Further, since the dipole antenna 4a is used, it is impossible to locally specify the radio wave leakage point. Further, since the location of radio wave leakage cannot be specified, repair time (radio wave stoppage time) is long, which causes a great deal of trouble to viewers.

【０００４】この発明はこのような点に鑑みてなされた
もので、電波漏洩検知装置のアンテナを小型にして作
業をし易くする。電波漏洩個所を局部的に検知可能に
する。検知精度を向上させることにより補修時間を短
時間にできるようにし、停波による視聴者への影響を最
小限にする、ＣＡＴＶ線路の電波漏洩検知装置を提供す
ることを目的とする。The present invention has been made in view of the above circumstances, and makes the antenna of the radio wave leakage detection device small to facilitate the work. Enables local detection of radio wave leakage points. An object of the present invention is to provide a radio wave leakage detection device for a CATV line, which can shorten the repair time by improving the detection accuracy and minimize the influence of a wave stop on the viewer.

【０００５】[0005]

【課題を解決するための手段】この発明は、ＣＡＴＶ線
路の電波漏洩検知において、漏洩電波を受信するアンテ
ナとして半波長（λ／２）迂回ライン４：１バラン機能
を有する小型ループアンテナと電界強度測定器から構成
するＣＡＴＶ線路の電波漏洩検知装置である。The present invention provides a small loop antenna having a half-wavelength (λ / 2) detour line 4: 1 balun function and an electric field strength as an antenna for receiving a leaked radio wave when detecting a radio wave leak in a CATV line. It is a CATV line radio wave leakage detection device configured from a measuring instrument.

【０００６】[0006]

【作用】電波漏洩の受信アンテナを従来の大型のダイポ
ールアンテナから小型ループアンテナとし、電波漏洩検
知装置を小型化して作業を容易にした。このループアン
テナは半波長（λ／２）迂回ライン４：１バラン機能を
備えているので、平衡（アンテナ）と不平衡（リード
線）とのインピーダンスマッチング機能を持たせた変換
装置であるので、漏洩電波を精度よく検出することが可
能である。The radio wave leakage receiving antenna is changed from the conventional large dipole antenna to a small loop antenna, and the radio wave leakage detection device is downsized to facilitate the work. Since this loop antenna has a half-wavelength (λ / 2) detour line 4: 1 balun function, it is a converter having an impedance matching function between balanced (antenna) and unbalanced (lead wire). It is possible to accurately detect leaked radio waves.

【０００７】[0007]

【実施例】以下、図面に基づいてこの発明のＣＡＴＶ線
路の電波漏洩検知装置の実施例を説明する。図２は実施
例の電波漏洩検知装置のループアンテナの構成を示し、
インピーダンスＺ0 （Ω）を有するリード線６と、これ
と平行に設けたＵ字状の半波長（λ／２）の短縮率を有
するλ／２迂回ライン７を配置し、これらを上部におい
てシールド線同士を接続するとともに、ループ線８を４
Ｚ0 （Ω）に構成し、この両端をリード線６およびλ／
２迂回ライン７を介してリード線６に接続したものであ
る。従って、４：１のバラン機能を有している。受信周
波数は通常使用されている３００〜４５０ＭＨｚを受信
可能なものとする。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of a radio wave leakage detecting device for a CATV line according to the present invention will be described below with reference to the drawings. FIG. 2 shows the configuration of the loop antenna of the radio wave leakage detection device of the embodiment,
A lead wire 6 having an impedance Z 0 (Ω) and a λ / 2 detour line 7 having a U-shaped half-wavelength (λ / 2) shortening ratio provided in parallel with the lead wire 6 are arranged, and these are shielded at the upper part. Connect the wires together and connect the loop wire 8 to 4
Z 0 (Ω), and both ends of the lead wire 6 and λ /
It is connected to the lead wire 6 via the 2 bypass line 7. Therefore, it has a 4: 1 balun function. The reception frequency is assumed to be 300-450 MHz which is normally used.

【０００８】ちなみに、波長λは、３００ＭＨｚのと
き、〔３００×１０6 （ｍ／ｓ）〕／〔３００×１０6
（Ｈｚ）〕となり１ｍである。また、上記バランとは、
平衡（アンテナ）と不平衡（リード線）のインピーダン
スマッチング機能を持たせた変換装置を意味する。Incidentally, when the wavelength λ is 300 MHz, [300 × 10 6 (m / s)] / [300 × 10 6
(Hz)] and is 1 m. Also, with the above balun,
It means a converter that has the impedance matching function of balanced (antenna) and unbalanced (lead wire).

【０００９】図１は上記ループアンテナを使用して漏洩
電波検出装置で検出している状態を示す。即ち、従来技
術で説明したダイポールアンテナ４ａの代わりにループ
アンテナ４ｂを使用し、リード線６を電界強度測定器５
に接続し、ケーブル１または増幅器２の接続部からの電
波漏洩のレベルを検知する。FIG. 1 shows a state in which the leaked radio wave detection device uses the loop antenna for detection. That is, the loop antenna 4b is used in place of the dipole antenna 4a described in the related art, and the lead wire 6 is connected to the electric field intensity measuring device 5
To detect the level of radio wave leakage from the connection part of the cable 1 or the amplifier 2.

【００１０】[0010]

【発明の効果】以上説明したとおり、この発明のＣＡＴ
Ｖ線路の電波漏洩検知装置によれば、アンテナが小型で
あり、測定作業が高所でも容易に行うことができる。ま
た、小型ループアンテナを使用するため、電波漏洩個所
を局部的に検知することが可能である。さらに、検知精
度を向上させたため、補修時間を非常に短時間に行うこ
とができるので、視聴者への影響を最小限に抑えること
ができる。As described above, the CAT of the present invention
According to the V-line radio wave leakage detection device, the antenna is small, and the measurement work can be easily performed even in a high place. Moreover, since a small loop antenna is used, it is possible to locally detect the location of radio wave leakage. Further, since the detection accuracy is improved, the repair time can be shortened to an extremely short time, so that the influence on the viewer can be minimized.

【図面の簡単な説明】[Brief description of drawings]

【図１】実施例のＣＡＴＶ線路の電波漏洩検知装置で漏
洩電波を検出している状態の説明図、FIG. 1 is an explanatory diagram of a state in which a leaked radio wave is detected by a radio wave leakage detection device for a CATV line according to an embodiment,

【図２】図１のループアンテナの構成を示す側面図、FIG. 2 is a side view showing the configuration of the loop antenna of FIG.

【図３】従来のＣＡＴＶ線路の電波漏洩検知装置で漏洩
電波を検出している状態の説明図である。FIG. 3 is an explanatory diagram of a state in which a leaked radio wave is detected by a conventional radio wave leakage detection device for a CATV line.

【符号の説明】[Explanation of symbols]

１ 同軸ケーブル ２ 増幅器 ３ 電柱 ４ａ ダイポールアンテナ ４ｂ 小型ループアンテナ ５ 電界強度測定器 ６ リード線 ７ λ／２迂回ライン ８ ループ線 1 coaxial cable 2 amplifier 3 utility pole 4a dipole antenna 4b small loop antenna 5 electric field strength measuring device 6 lead wire 7 λ / 2 detour line 8 loop wire

Claims (2)

【特許請求の範囲】[Claims] 【請求項１】 ＣＡＴＶ線路の電波漏洩検知において、
漏洩電波を受信するアンテナとして半波長（λ／２）迂
回ライン４：１バラン機能を有する小型ループアンテナ
と電界強度測定器から構成することを特徴とするＣＡＴ
Ｖ線路の電波漏洩検知装置。1. A method for detecting electric wave leakage on a CATV line,
A CAT characterized by comprising a small loop antenna having a half-wavelength (λ / 2) detour line 4: 1 balun function and an electric field strength measuring device as an antenna for receiving leaked radio waves.
V line radio wave leakage detection device. 【請求項２】 上記小型ループアンテナは、３００〜４
５０ＭＨｚを受信可能なものであることを特徴とする請
求項１記載のＣＡＴＶ線路の電波漏洩検知装置。2. The small loop antenna comprises 300 to 4
The radio wave leakage detection device for a CATV line according to claim 1, which is capable of receiving 50 MHz.
JP6189033A 1994-07-20 1994-07-20 Radio wave leakage detecting device for catv line Pending JPH0836008A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP6189033A JPH0836008A (en) 1994-07-20 1994-07-20 Radio wave leakage detecting device for catv line

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP6189033A JPH0836008A (en) 1994-07-20 1994-07-20 Radio wave leakage detecting device for catv line

Publications (1)

Publication Number Publication Date
JPH0836008A true JPH0836008A (en) 1996-02-06

Family

ID=16234178

Family Applications (1)

Application Number Title Priority Date Filing Date
JP6189033A Pending JPH0836008A (en) 1994-07-20 1994-07-20 Radio wave leakage detecting device for catv line

Country Status (1)

Country Link
JP (1) JPH0836008A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0487437A (en) * 1990-07-31 1992-03-19 Fujitsu Ltd Circuit branching system
JP2018128418A (en) * 2017-02-10 2018-08-16 Ｄｘアンテナ株式会社 Electromagnetic wave measuring instrument and facility diagnosis system using the same

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0487437A (en) * 1990-07-31 1992-03-19 Fujitsu Ltd Circuit branching system
JP2018128418A (en) * 2017-02-10 2018-08-16 Ｄｘアンテナ株式会社 Electromagnetic wave measuring instrument and facility diagnosis system using the same

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