JPH0486084A - Bidirectional catv repeater - Google Patents
Bidirectional catv repeaterInfo
- Publication number
- JPH0486084A JPH0486084A JP2200475A JP20047590A JPH0486084A JP H0486084 A JPH0486084 A JP H0486084A JP 2200475 A JP2200475 A JP 2200475A JP 20047590 A JP20047590 A JP 20047590A JP H0486084 A JPH0486084 A JP H0486084A
- Authority
- JP
- Japan
- Prior art keywords
- intermodulation distortion
- distortion
- switch
- repeater
- switch circuit
- 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.)
- Granted
Links
- 230000002457 bidirectional effect Effects 0.000 title claims description 10
- 238000011144 upstream manufacturing Methods 0.000 claims description 15
- 238000001514 detection method Methods 0.000 claims description 14
- 239000002184 metal Substances 0.000 abstract description 8
- 229910052751 metal Inorganic materials 0.000 abstract description 8
- 230000005540 biological transmission Effects 0.000 abstract description 7
- 238000012544 monitoring process Methods 0.000 description 9
- 150000002739 metals Chemical class 0.000 description 6
- 238000010586 diagram Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 230000008878 coupling Effects 0.000 description 2
- 238000010168 coupling process Methods 0.000 description 2
- 238000005859 coupling reaction Methods 0.000 description 2
- 239000000284 extract Substances 0.000 description 2
- GGKNTGJPGZQNID-UHFFFAOYSA-N (1-$l^{1}-oxidanyl-2,2,6,6-tetramethylpiperidin-4-yl)-trimethylazanium Chemical compound CC1(C)CC([N+](C)(C)C)CC(C)(C)N1[O] GGKNTGJPGZQNID-UHFFFAOYSA-N 0.000 description 1
- 101710194905 ARF GTPase-activating protein GIT1 Proteins 0.000 description 1
- 102100029217 High affinity cationic amino acid transporter 1 Human genes 0.000 description 1
- 101710081758 High affinity cationic amino acid transporter 1 Proteins 0.000 description 1
- 230000003321 amplification Effects 0.000 description 1
- 238000003199 nucleic acid amplification method Methods 0.000 description 1
Landscapes
- Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は、ＣＡＴＶシステムに使用される双方向中継器
に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a bidirectional repeater used in a CATV system.
［従来の技術］
双方向ＣＡＴＶ中継器には、信号を伝送する幹線から、
上り、下り方向信号を分岐するものがある−このような
双方向ＣＡＴＶ中継器の一例を第２図に示す。この従来
の双方向ＣＡＴＶ中継器は、第２図に示すように、セン
ターから各端末への下り方向信号（７０ＭＨｚ〜４５０
ＭＨｚ帯域）および各端末装置などからの上り方向信号
（１０ＭＨｚ〜５０ＭＨｚ帯域）を増幅する増幅部２３
．２５と、幹線より各上り、下り信号を分岐するための
方向性ろ波器２日とを有する。さらに、この双方向ＣＡ
ＴＶ中継器は、入力端子２１と、出力端子３１と、方向
性ろ波器２２．３２と、中継器監視制御部２４と、スイ
ッチ回路部２６と、分配端子２９を備える４分配器２７
と、下り方向信号増幅器３０とを有している。[Prior Art] A two-way CATV repeater has a main line that transmits signals,
There is one that branches up and down signals; an example of such a bidirectional CATV repeater is shown in FIG. As shown in Figure 2, this conventional two-way CATV repeater transmits downstream signals (70 MHz to 450 MHz) from the center to each terminal.
MHz band) and an amplification unit 23 that amplifies uplink signals (10MHz to 50MHz band) from each terminal device, etc.
．． 25, and two directional filters for branching each upstream and downstream signal from the main line. Furthermore, this bidirectional CA
The TV repeater includes an input terminal 21, an output terminal 31, a directional filter 22, 32, a repeater monitoring control section 24, a switch circuit section 26, and a 4-way divider 27 including a distribution terminal 29.
and a downstream signal amplifier 30.
このような双方向ＣＡＴＶ中継器では、４分配器２７の
使用していない分配端子には通常、終端を施す、例えば
７５Ωの終端を施すことになる。In such a bidirectional CATV repeater, the unused distribution terminals of the 4-way divider 27 are normally terminated, for example, with a 75Ω termination.
このとき、使用していない分配端子に施された終端器に
よる金属間の接触状態の不完全により、一定間隔である
周波数の相互変調歪が発生する。At this time, intermodulation distortion occurs at frequencies at regular intervals due to incomplete contact between metals due to the terminator provided at the unused distribution terminal.
そして、この相互変調歪が双方向ＣＡＴＶシステムの上
り方向信号雑音として障害を与えた場合、センターより
中継器監視制御部２４へ制御信号を伝送し、スイッチ制
御によりスイッチ回路２６を開閉することにより、双方
向ＣＡＴＶシステムへの上り方向信号雑音からの影響を
阻止している。If this intermodulation distortion causes a disturbance as upstream signal noise in the two-way CATV system, a control signal is transmitted from the center to the repeater monitoring control unit 24, and the switch circuit 26 is opened and closed by switch control. This prevents the influence of upstream signal noise on the two-way CATV system.
上述した従来の双方向ＣＡＴＶ中継器では、使用しない
分配端子に使用した終端器による金属間の接触状態の不
完全から生ずる戻信号の相互変調歪が発生し、双方向Ｃ
ＡＴＶシステムの上り方向信号雑音として障害を与えた
場合、センターより手動で上り方向信号を幹線から切り
離すためのスイッチ回路の開閉を行う。このため、相互
変調歪の発生源を特定するに要する時間が必要となり、
特定するまで上り方向信号雑音の影響を、双方向ＣＡＴ
Ｖシステムが受ける欠点がある。In the conventional two-way CATV repeater described above, intermodulation distortion of the return signal occurs due to incomplete contact between metals due to the terminator used for the unused distribution terminal, and the two-way CATV repeater
If a disturbance occurs due to upstream signal noise in the ATV system, the center manually opens and closes a switch circuit to disconnect the upstream signal from the main line. Therefore, it takes time to identify the source of intermodulation distortion.
The effect of uplink signal noise is evaluated by bidirectional CAT until it is identified.
There are drawbacks to which the V system suffers.
本発明の目的は、このような欠点を除去し、上り方向信
号雑音の影響を減少できる双方向ＣＡＴ■中継器を提供
することにある。SUMMARY OF THE INVENTION An object of the present invention is to provide a bidirectional CAT-1 repeater that can eliminate such drawbacks and reduce the influence of uplink signal noise.
本発明は、上りの幹線系と方向性ろ波器との間を結ぶ分
配系に設けられたスイッチ部と、センターの指示により
このスイッチ部の開閉を制御する制御部とを備える双方
向ＣＡＴＶ中継器において、方向性ろ波器から分配系に
送出される相互変調歪を検出すると、スイッチ部の開閉
を制御して幹線系を分配系から切り分ける検知手段とを
有し、スイッチ部の開閉の情報を、制御部を経由してセ
ンターへ送ることを特徴としている。The present invention provides a two-way CATV relay that includes a switch section provided in a distribution system connecting an uplink trunk system and a directional filter, and a control section that controls opening and closing of this switch section according to instructions from the center. When the intermodulation distortion sent from the directional filter to the distribution system is detected, the detector controls the opening/closing of the switch section to separate the trunk system from the distribution system. is characterized in that it is sent to the center via the control unit.
前述した本発明において、検知手段は、方向性ろ波器か
ら分配系に送出される相互変調歪を検出する歪検知部と
、
この歪検知部が相互変調歪を検出すると、スイッチ部の
開閉を制御するスイッチ制御部とを有するのが好適であ
る。In the present invention described above, the detection means includes a distortion detection section that detects the intermodulation distortion sent from the directional filter to the distribution system, and when the distortion detection section detects the intermodulation distortion, opens and closes the switch section. It is preferable to have a switch control section for controlling.
次に、本発明の実施例について図面を参照して説明する
。Next, embodiments of the present invention will be described with reference to the drawings.
第１図は、本発明の一実施例を示すプロ・ンク図である
。第１図に示す双方向ＣＡＴＶ中継器は、方向性ろ波器
２，４．８と、増幅器３． ６．１０と、中継器監視制
御部５と、４分配器９と、歪周波数検知部１２と、スイ
ッチ回路制御部１３と、スイ・ンチ回路７とを備えてい
る。FIG. 1 is a diagram showing one embodiment of the present invention. The bidirectional CATV repeater shown in FIG. 1 includes directional filters 2, 4.8, amplifiers 3. 6.10, a repeater monitoring control section 5, a four-way divider 9, a distortion frequency detection section 12, a switch circuit control section 13, and a switch circuit 7.
このような双方向ＣＡＴＶ中継器の方向性ろ波器２は入
力端子工を備えており、方向性ろ波器４は出力端子１４
を備えている。また、方向性ろ波器８は、４つの分配端
子１１を具備する４分配器９に接続されている。The directional filter 2 of such a two-way CATV repeater is equipped with an input terminal, and the directional filter 4 is equipped with an output terminal 14.
It is equipped with Further, the directional filter 8 is connected to a four-way divider 9 having four distribution terminals 11.
増幅器３は、方向性ろ波器２と４の間を結ぶ下り幹線に
設けられており、下り方向信号を増幅する下り方向信号
増幅器である。増幅器６は、方向性ろ波器２と４の間を
結ぶ上り幹線に設けられており、上り方向信号を増幅す
る上り方向信号増幅器である。また、増幅器１０は、下
り方向信号増幅器３からの出力をさらに増幅して方向性
ろ波器８に送る下り方向信号増幅器である。The amplifier 3 is provided on the downlink main line connecting the directional filters 2 and 4, and is a downlink signal amplifier that amplifies the downlink signal. The amplifier 6 is provided on the upstream main line connecting the directional filters 2 and 4, and is an upstream signal amplifier that amplifies the upstream signal. Further, the amplifier 10 is a downstream signal amplifier that further amplifies the output from the downstream signal amplifier 3 and sends it to the directional filter 8.
中継器監視制御部５は、下り方向信号増幅器３への入力
側と上り方向信号増幅器６の出力側との間に設けられて
いる。そして、センターの指示により、スイッチ回路７
を開閉する。The repeater monitoring control unit 5 is provided between the input side to the downstream signal amplifier 3 and the output side of the upstream signal amplifier 6. Then, according to instructions from the center, switch circuit 7
Open and close.
スイッチ回路７は、上り方向信号増幅器７の入力側と方
向性ろ波器８との間に設けられている。The switch circuit 7 is provided between the input side of the upstream signal amplifier 7 and the directional filter 8.
そして、中継器監視制御部５の制御およびスイッチ回路
部１３の制御により開閉を行う。Then, opening and closing are performed under the control of the repeater monitoring control section 5 and the switch circuit section 13.
歪周波数検知部１２は、方向制御ろ波器８からの相互変
調歪を検知する。このような歪周波数検知部１２は、例
えば、上り方向伝送の分岐結合部に一定間隔に発生する
規則的な周波数成分を抽出するフィルタと、この抽出し
た周波数成分を増幅する増幅回路と、この出力を整流回
路に入力し、この整流回路により出力された直流電圧値
と特定した基準電圧値とを比較するコンパレータとによ
り構成される。The distortion frequency detection section 12 detects intermodulation distortion from the direction control filter 8. Such a distortion frequency detection section 12 includes, for example, a filter that extracts regular frequency components that occur at regular intervals in the branching and coupling section of uplink transmission, an amplifier circuit that amplifies the extracted frequency components, and an output input into a rectifier circuit, and a comparator that compares the DC voltage value output by the rectifier circuit with a specified reference voltage value.
スイッチ回路制御部１３は、歪周波数検知部１２が相互
変調歪を検出した場合、スイッチ回路７を制御して、上
り方向信号増幅器６と方向性ろ波器８との間の分配系と
、幹線系とを切り分ける。When the distortion frequency detection section 12 detects intermodulation distortion, the switch circuit control section 13 controls the switch circuit 7 to connect the distribution system between the upstream signal amplifier 6 and the directional filter 8 and the main line. Separate the system.
次に、本実施例の動作について説明する。Next, the operation of this embodiment will be explained.
この双方向ＣＡＴＶ中継器において、増幅器３６がセン
ターから各端末への下り方向信号（７０Ｍｔｌｚ〜４５
０ＭＩＩｚ帯域）および各端末装置などからの上り方向
信号（１０ＭＨｚ〜５０ＭＨｚ帯域）を増幅する。また
、方向性ろ波器８が幹線より各上り、下り信号を分岐す
る。一方、４分配器９の、使用されない分配端子には、
通常、終端を施す（−船釣に７５Ω）。In this bidirectional CATV repeater, an amplifier 36 transmits downlink signals (70 Mtlz to 45 Mtlz) from the center to each terminal.
0 MIIz band) and uplink signals (10 MHz to 50 MHz band) from each terminal device, etc. are amplified. Further, a directional filter 8 branches each upstream and downstream signal from the main line. On the other hand, the unused distribution terminals of the 4-way divider 9 have
Usually terminated (-75Ω for boat fishing).
ところで、このように終端された分配端子において、分
配端子１１で使用しない分配端子に終端を施すことによ
り金属間の接触状態の不完全が生じ伝送信号による相互
変調歪が発生するときがある。By the way, in the distribution terminals terminated in this manner, if the distribution terminals which are not used in the distribution terminal 11 are terminated, the contact state between the metals may be incomplete, and intermodulation distortion due to the transmission signal may occur.
このようなとき、この一定周波数間隔で発生する歪（例
えば、６ ＭＨｚ間隔）を検知する歪周波数検知部１２
において検知する。そして、検知した場合、スイッチ回
路制御部１３は、分配系と幹線系とを切り分けるため、
スイッチ回路７を制御し開閉する。In such a case, the distortion frequency detection unit 12 detects the distortion that occurs at a constant frequency interval (for example, at a 6 MHz interval).
Detected at When detected, the switch circuit control unit 13 performs the following steps to separate the distribution system and the trunk system.
Controls the switch circuit 7 to open and close it.
また、そのスイッチ回路７の開閉の情報は、データとし
て中継器監視制御部５へ伝達され、さらに、中継器監視
制御部５より、幹線伝送路を介してセンターへデータと
して送出される。そして、センターより上述したスイッ
チ回路に対し開閉の制御信号を送出することによって、
中継器監視制御部５を介し強制的にスイッチ回路７を開
閉する。Further, information on the opening and closing of the switch circuit 7 is transmitted as data to the repeater monitoring control unit 5, and further sent as data from the repeater monitoring control unit 5 to the center via the main transmission line. Then, by sending an opening/closing control signal from the center to the above-mentioned switch circuit,
The switch circuit 7 is forcibly opened and closed via the repeater monitoring control section 5.
このように、本実施例である双方向ＣＡＴＶ中継器は、
上り方向伝送の分岐結合部に、ある一定間隔に発生する
規則的な周波数成分を抽出するフィルタと、この抽出し
た周波数成分を増幅する増幅回路と、この出力を整流回
路に入力し、この整流回路により出力された直流電圧値
と特定した基準電圧値とを比較するコンパレータよりな
る検知部を具備し、この検知部とスイ・ソチ制御回路を
接続し、双方向増幅器の上り分岐結合部に前述したフィ
ルタで抽出する周波が入力した場合、上り伝送の分岐入
力回路を備えたスインチを制御する手段とを備えている
。In this way, the two-way CATV repeater of this embodiment is
In the branching and coupling section of upstream transmission, there is a filter that extracts regular frequency components that occur at certain intervals, an amplifier circuit that amplifies the extracted frequency components, and the output of this is input to a rectifier circuit. It is equipped with a detection section consisting of a comparator that compares the DC voltage value outputted by When a frequency to be extracted by the filter is input, the transmitter is provided with means for controlling a switch equipped with a branch input circuit for upstream transmission.
これにより、本実施例は、使用しない分配端子に終端器
（−船釣に７５Ω）を接続した時、金属間の接続状態の
不完全から生じる伝送信号による一定周波数間隔で発生
する相互変調歪（例えば６ Ｍ）Ｉｚ間隔）を検知し、
幹線系と分配系を切り分けるだめのスイッチ回路を制御
する回路部を構成することにより、必要としない分配端
子に接続された終端器による金属間の接続状態の不完全
から生じる一定周波数間隔の相互変調歪が発生した場合
、即座にスイッチ回路を制御し、幹線系を分配系から切
りわけることが可能となる。As a result, in this embodiment, when a terminator (-75Ω for boat fishing) is connected to an unused distribution terminal, intermodulation distortion (intermodulation distortion) that occurs at constant frequency intervals due to the transmission signal caused by incomplete connection between metals. For example, detecting 6 M)Iz interval),
By configuring a circuit that controls a switch circuit that separates the trunk system from the distribution system, intermodulation at constant frequency intervals caused by incomplete connections between metals due to terminations connected to unnecessary distribution terminals can be avoided. When distortion occurs, it is possible to immediately control the switch circuit and separate the trunk system from the distribution system.
また、スイッチ回路の開閉情報はデータ信号としてセン
ターへ送出されるので、センターにおいてその金属間の
接続状態の不完全から生じる相互変調歪の発生源を特定
することが容易となる。さらに、そのスイッチ回路の開
閉制御は、センターにおいても可能である。Further, since the switching circuit open/close information is sent to the center as a data signal, it becomes easy to identify the source of intermodulation distortion caused by imperfect connections between metals at the center. Furthermore, the opening/closing control of the switch circuit can also be performed at the center.
以上説明したように本発明によれば、相互変調歪による
幹線への上り信号雑音の影響を最小限とすることができ
る。また、スイッチ部の開閉の情報を、データ信号とし
てセンターへ送出するので、センターにおいて相互変調
歪の発生源を特定することが容易となる効果を有する。As described above, according to the present invention, it is possible to minimize the influence of uplink signal noise on the main line due to intermodulation distortion. Furthermore, since the information on the opening and closing of the switch section is sent to the center as a data signal, it has the effect of making it easier to identify the source of intermodulation distortion at the center.
第１図は、本発明の一実施例を示すブロック図、第２図
は、従来の双方向ＣＡＴＶ中継器の一例・を示すブロッ
ク図である。
１・・・・・入力端子
２４．８・・・方向性ろ波器
３１０・・・下り方向信号増幅器
５・・・・・中継器監視制御部
６・・・・・上り方向信号増幅器
７・・・・・スイッチ回路部
９・・・・・４分配器
１１・・・・・分配端子
１２・・・・・歪周波数検知部
１３・・・・・スイッチ回路制御部
１４・・・・・出力端子FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a block diagram showing an example of a conventional two-way CATV repeater. 1... Input terminal 24.8... Directional filter 310... Downlink signal amplifier 5... Repeater monitoring control section 6... Uplink signal amplifier 7. ... Switch circuit section 9 ... Four-way distributor 11 ... Distribution terminal 12 ... Distortion frequency detection section 13 ... Switch circuit control section 14 ... Output terminal
Claims (2)
に設けられたスイッチ部と、センターの指示によりこの
スイッチ部の開閉を制御する制御部とを備える双方向Ｃ
ＡＴＶ中継器において、方向性ろ波器から分配系に送出
される相互変調歪を検出すると、スイッチ部の開閉を制
御して幹線系を分配系から切り分ける検知手段とを有し
、スイッチ部の開閉の情報を、制御部を経由してセンタ
ーへ送ることを特徴とする双方向ＣＡＴＶ中継器。(1) A bidirectional C that includes a switch section provided in the distribution system that connects the upstream trunk system and the directional filter, and a control section that controls the opening and closing of this switch section according to instructions from the center.
In the ATV repeater, when intermodulation distortion sent from the directional filter to the distribution system is detected, the detection means controls the opening/closing of the switch section to separate the trunk system from the distribution system. A two-way CATV repeater characterized in that the information is sent to a center via a control unit.
する歪検知部と、 この歪検知部が相互変調歪を検出すると、スイッチ部の
開閉を制御するスイッチ制御部とを有する請求項１記載
の双方向ＣＡＴＶ中継器。(2) The detection means includes a distortion detection unit that detects intermodulation distortion sent from the directional filter to the distribution system, and a switch that controls opening and closing of the switch unit when the distortion detection unit detects intermodulation distortion. The two-way CATV repeater according to claim 1, further comprising a control section.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2200475A JP2891754B2 (en) | 1990-07-27 | 1990-07-27 | Bidirectional CATV repeater |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2200475A JP2891754B2 (en) | 1990-07-27 | 1990-07-27 | Bidirectional CATV repeater |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0486084A true JPH0486084A (en) | 1992-03-18 |
| JP2891754B2 JP2891754B2 (en) | 1999-05-17 |
Family
ID=16424937
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2200475A Expired - Lifetime JP2891754B2 (en) | 1990-07-27 | 1990-07-27 | Bidirectional CATV repeater |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2891754B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0716473U (en) * | 1993-08-25 | 1995-03-17 | 兼藤産業株式会社 | Terminal device of amplifier in CATV system |
| US6990682B1 (en) | 1999-06-29 | 2006-01-24 | Fujitsu Limited | Two-way CATV system |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63159980U (en) * | 1987-04-08 | 1988-10-19 | ||
| JPS6464483A (en) * | 1987-09-03 | 1989-03-10 | Nec Corp | Catv line monitoring control system |
-
1990
- 1990-07-27 JP JP2200475A patent/JP2891754B2/en not_active Expired - Lifetime
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63159980U (en) * | 1987-04-08 | 1988-10-19 | ||
| JPS6464483A (en) * | 1987-09-03 | 1989-03-10 | Nec Corp | Catv line monitoring control system |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0716473U (en) * | 1993-08-25 | 1995-03-17 | 兼藤産業株式会社 | Terminal device of amplifier in CATV system |
| US6990682B1 (en) | 1999-06-29 | 2006-01-24 | Fujitsu Limited | Two-way CATV system |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2891754B2 (en) | 1999-05-17 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| USH1858H (en) | Radio frequency sensed, switched reverse path tap | |
| US4075440A (en) | Automatic communication system reconfiguration apparatus | |
| JPH0486084A (en) | Bidirectional catv repeater | |
| US6637033B1 (en) | Signal splitter and gain adjustment system for a cable data system | |
| JP3335920B2 (en) | Relay amplifier for bidirectional CATV | |
| JP2616389B2 (en) | Bidirectional CATV system and bidirectional CATV repeater / amplifier used therefor | |
| JP2000244882A (en) | Indoor booster for bidirectional catv system | |
| JP3698962B2 (en) | Repeater | |
| JP2917692B2 (en) | CATV transmission line switch monitoring system | |
| JPH0686286A (en) | Incoming confluence noise preventing system | |
| JPH10178628A (en) | Noise mixed point detector of catv system | |
| JPH05304672A (en) | Inflow noise preventing circuit | |
| JP2866849B2 (en) | CATV system | |
| JP2001145069A (en) | Catv repeater | |
| JPH04296186A (en) | Two-way catv system | |
| JP2830140B2 (en) | Transmission output amplifier circuit | |
| JPS63262982A (en) | Bidirectional catv system | |
| JP3591794B2 (en) | Station device connection interface device | |
| JP2944383B2 (en) | CATV transmission equipment | |
| JPS63119330A (en) | Level adjusting device | |
| JPH02107012A (en) | Automatic gain controller | |
| JP2000324357A (en) | Two-way community reception facility | |
| JPH04240942A (en) | Tap-off | |
| JPH0722873A (en) | Repeating amplifier for communication system | |
| JPH05219507A (en) | Backup method for amplifier in two-way catv system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| S111 | Request for change of ownership or part of ownership |
Free format text: JAPANESE INTERMEDIATE CODE: R313115 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20080226 Year of fee payment: 9 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20090226 Year of fee payment: 10 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20100226 Year of fee payment: 11 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20100226 Year of fee payment: 11 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110226 Year of fee payment: 12 |
|
| EXPY | Cancellation because of completion of term | ||
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110226 Year of fee payment: 12 |