VTN244 Equipment Manual

Versatile Telecommunications Node VTN244 Fiber Deep 2x2 Optical Node

Equipment Manual

365-095-22584-x.1

VTN244 Fiber Deep 2x2 Optical Node Equipment Manual

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©ARRIS Enterprises, Inc. 2013. All rights reserved. No part of this publication may be reproduced in any form or by any means or used to make any derivative work (such as translation, transformation, or adaptation) without written permission from ARRIS Enterprises, Inc. (“ARRIS”). ARRIS reserves the right to revise this publication and to make changes in content from time to time without obligation on the part of ARRIS to provide notification of such revision or change.

ARRIS and the ARRIS logo are all trademarks of ARRIS Enterprises, Inc. Other trademarks and trade names may be used in this document to refer to either the entities claiming the marks and the names of their products. ARRIS disclaims proprietary interest in the marks and names of others.

MOTOROLA and the Stylized M logo are trademarks or registered trademarks of Motorola Trademark Holdings, LLC and are used by ARRIS under license. All other product or service names are the property of their respective owners.

ARRIS provides this guide without warranty of any kind, implied or expressed, including, but not limited to, the implied warranties of merchantability and fitness for a particular purpose. ARRIS may make improvements or changes in the product(s) described in this manual at any time.


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Safety and Regulatory

Information

IMPORTANT SAFETY INSTRUCTIONS

WARNING: TO PREVENT FIRE OR SHOCK HAZARD, DO NOT EXPOSE THIS PRODUCT TO RAIN OR MOISTURE. THE UNIT MUST NOT BE EXPOSED TO DRIPPING OR SPLASHING.

CAUTION: DO NOT OPEN THE UNIT. DO NOT PERFORM ANY SERVICING OTHER THAN THAT CONTAINED IN THE INSTALLATION AND TROUBLESHOOTING INSTRUCTIONS. REFER ALL SERVICING TO QUALIFIED SERVICE PERSONNEL.

CAUTION: CHANGES AND MODIFICATIONS NOT EXPRESSLY APPROVED BY MOTOROLA MOBILITY FOR COMPLIANCE COULD VOID THE USER’S AUTHORITY TO OPERATE THE EQUIPMENT. SPECIAL SYMBOLS THAT MIGHT APPEAR ON THE EQUIPMENT

Special Symbols That Might Appear on the Equipment

INVISIBLE LASER RADIATION WHEN OPEN

PEAK POWER 10 mW

CLASS LASER PRODUCTI

CHAPTER 1 SUBCHAPTER JTHIS PRODUCT COMPLIES WITH 21CFR

DANGER

This is a class I product that contains a class IIIb laser and is intended for operation in a closed environment with fiber attached. Do not look into the optical connector of the transmitter with power applied. Laser output is invisible, and eye damage can result. Do not defeat safety features that prevent looking into the optical connector.

This product contains a class IIIb laser and is intended for operation in a closed environment with fiber attached. Do not look into the optical connector of the transmitter with power applied. Laser output is invisible, and eye damage can result. Do not defeat safety features that prevent looking into optical connector.

Dangerous voltage levels are present within the equipment. These voltages are not insulated and may be of sufficient strength to cause serious bodily injury when touched. (This symbol may also appear on schematics.) Refer to important installation, servicing, and operating instructions in the documentation accompanying the equipment.

The exclamation point, within an equilateral triangle, is intended to alert the user to the presence of important installation, servicing, and operating instructions in the documents accompanying the equipment.

For continued protection against fire, replace all fuses only with fuses having the same electrical ratings marked at the location of the fuse.

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SERVICE INSTRUCTIONS

CAUTION: These servicing instructions are for use by qualified personnel only. To reduce the risk of electrical shock, do not perform any servicing other than that contained in the installation and troubleshooting instructions unless you are qualified to do so. Refer all servicing to qualified service personnel.

FDA COMPLIANCE

This product meets the requirements of the Code of Federal Regulations, Title 21, Chapter I, Subchapter J, Sections 1010.2, 1010.3, 1040.10, and 1040.11.

CLASS 1 LASER PRODUCT

Declaration of Conformity

We Motorola, LLC. 101 Tournament Drive Horsham, PA 19044, U.S.A.

declare under our sole responsibility that the

Model VTN244 Node

to which this declaration relates is in conformity with one or more of the following standards:

EMC Standards

EN55022 EN50083-2 CISPR-22

Safety Standards

IEC 60950

following the provisions of the Directive(s) of the Council of the European Union:

EMC Directive 2004/108/EC Low Voltage Directive 2006/95/EC

WEEE Directive 2002/96/EC

RoHS Directive

2011/65/EC

EN55022/CISPR 22 Class A Statement

Warning

This is a Class A product. In a domestic environment this product may cause radio interference in which case the user may be required to take adequate measures.

For optical nodes with removable optical transmitter modules:

CAUTION: The module surfaces may be hot. Allow sufficient time for the module to cool before handling.

DANGER: To avoid possible injury or damage to the equipment, remove 60/90 volt AC power from the system before you install the module.


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Caring for the Environment by Recycling

When you see this symbol on a Motorola Mobility product, do not dispose of the product with residential or commercial waste.

Recycling your Motorola Equipment

Please do not dispose of this product with your residential or commercial waste. Some countries or regions, such as the European Union, have set up systems to collect and recycle electrical and electronic waste items. Contact your local authorities for information about practices established for your region. If collection systems are not available, call Motorola Mobility Customer Service for assistance.

Please visit http://www.motorola.com/recycle for instructions on recycling.

http://www.motorola.com/recycle


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Contents

Introduction ........................................................................................................................................... 1 VTN244 Overview ............................................................................................................................................................................ 1

About This Manual ................................................................................................................................................................. 1 Getting Help ...................................................................................................................................................................................... 3

Returning for Repair .............................................................................................................................................................. 3 Overview ................................................................................................................................................ 5 Description ......................................................................................................................................................................................... 6

VTN244 Node Features ......................................................................................................................................................... 6 Ordering Information ............................................................................................................................................................ 8

Illustrations ...................................................................................................................................................................................... 10 VTN244 Node Test Points ................................................................................................................................................. 10 VTN244 Node Accessories ................................................................................................................................................ 12 Router ....................................................................................................................................................................................... 13 ICS .............................................................................................................................................................................................. 16 Fiber Tray ................................................................................................................................................................................ 16 Block Diagrams ..................................................................................................................................................................... 17

Installation and Configuration ........................................................................................................... 18 Before You Begin .......................................................................................................................................................................... 18

Required Tools ...................................................................................................................................................................... 18 Torque Specifications ......................................................................................................................................................... 19 Housing Dimensions .......................................................................................................................................................... 20

Opening the VTN244 Node Housing .................................................................................................................................... 21 Attaching the Coaxial Connectors ................................................................................................................................ 22 Installing the Housing on a Strand ............................................................................................................................... 24 Installing the Housing on a Pedestal ............................................................................................................................ 25 Connecting Earth Ground ................................................................................................................................................ 26 Removing the RF E-Pack Module from the Housing .............................................................................................. 27 Installing the Accessories ................................................................................................................................................. 28 Installing the RF Module ................................................................................................................................................... 31 System Power ........................................................................................................................................................................ 33

Removing and Reinstalling Optical Module Components ........................................................................................... 38 Forward Receiver Module ................................................................................................................................................ 39 Return Transmitter Module ............................................................................................................................................. 40 Transponder Module .......................................................................................................................................................... 41 Connecting the Fiber Optical Service Cable ............................................................................................................. 42

Closing the VTN244 Node Housing ....................................................................................................................................... 44 Balancing and Setup ............................................................................................................................ 45 Overview .......................................................................................................................................................................................... 45


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Before You Begin ................................................................................................................................................................. 45 Balancing the Forward Path ..................................................................................................................................................... 46

Introduction ........................................................................................................................................................................... 46 Verifying the Forward Input Optical Power ............................................................................................................... 46 Setting Up the Forward Output Level ......................................................................................................................... 48 Determining the Output Slope ...................................................................................................................................... 51 Changing the Output Slope ............................................................................................................................................ 52

Balancing the Reverse Path ...................................................................................................................................................... 53 Setting Up the Reverse Input Levels ............................................................................................................................ 53 Setting Up the Equalizer Value for Reverse Path ..................................................................................................... 54 Setting Up the Return Transmitter Input Level ........................................................................................................ 55

Troubleshooting .................................................................................................................................. 56 Overview .......................................................................................................................................................................................... 56

Required Equipment .......................................................................................................................................................... 56 Low RF Output ...................................................................................................................................................................... 56 No Forward RF Signal ......................................................................................................................................................... 57 Low or Degraded Forward RF Signal ........................................................................................................................... 58 No Reverse RF Signal .......................................................................................................................................................... 58 Low or Degraded Reverse RF Signal ............................................................................................................................. 59 Troubleshooting Carrier-to-Noise Problems ............................................................................................................. 60 Miscellaneous Conditions ................................................................................................................................................ 61 No Power Supply ................................................................................................................................................................. 61

Cleaning Optical Connectors ................................................................................................................................................... 62 Connectors and Bulkheads .............................................................................................................................................. 63 To Clean Fiber-Optic Connectors .................................................................................................................................. 63 To Clean Bulkheads ............................................................................................................................................................. 64 To Verify Equipment Operation ..................................................................................................................................... 64

Appendix A – Accessories List ............................................................................................................. 65 Appendix B – Specifications ................................................................................................................ 67

Tables

Table 2-1: Ordering Information ................................................................................................................................................ 8 Table 3-1: Torque specifications ............................................................................................................................................. 19 Table 3-2: VTN244 Power/Current draw .............................................................................................................................. 34 Table 3-3: Fuse specifications .................................................................................................................................................. 35 Table 3-4: Typical AC system installation specifications ............................................................................................... 37 Table 4-1: Items needed for balancing ................................................................................................................................. 45 Table 4-2: VTN Receiver Typical Parameters ...................................................................................................................... 47 Table 5-1: Low RF Output Troubleshooting ....................................................................................................................... 56


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Table 5-2: No Forward RF Signal Troubleshooting .......................................................................................................... 57 Table 5-3: Low or Degraded Forward RF Signal Troubleshooting ............................................................................ 58 Table 5-4: No Reverse RF Signal Troubleshooting ........................................................................................................... 58 Table 5-5: Low or Degraded RF Signal Troubleshooting .............................................................................................. 59 Table 5-6: Carrier-to-Noise Problems Troubleshooting ................................................................................................. 60 Table 5-7: Miscellaneous Problems Troubleshooting .................................................................................................... 61 Table 5-8: No Power Supply Troubleshooting .................................................................................................................. 61 Table A-9: Accessories list .......................................................................................................................................................... 65 Table B-1: Optical Receiver Characteristics ......................................................................................................................... 67 Table B-2: Station RF Characteristics ..................................................................................................................................... 67 Table B-3: VTN244 General Characteristics ......................................................................................................................... 68 Table B-4: VTN244 Performance, 77 Channels .................................................................................................................. 68 Table B-5: VTN-DFBT RF specifications ................................................................................................................................. 68 Table B-6: VTN-DFBT/3 RF specifications ............................................................................................................................. 69

Figures

Figure 2-1 — VTN244 Node ......................................................................................................................................................... 5 Figure 2-2 — VTN244 Node RF test points ......................................................................................................................... 10 Figure 2-3 — VTN244 Node housing lid test points ....................................................................................................... 11 Figure 2-4 — VTN244 Node accessory locations ............................................................................................................. 12 Figure 2-5 — Forward/Return Router locations ............................................................................................................... 13 Figure 2-6 — Forward Router .................................................................................................................................................. 14 Figure 2-7 — Return Router ..................................................................................................................................................... 15 Figure 2-8 — Ingress Control Switch .................................................................................................................................... 16 Figure 2-9 — Fiber Tray accessories location .................................................................................................................... 16 Figure 2-10 — VTN244 Block Diagram ................................................................................................................................. 17 Figure 3-1 — VTN244 Node housing front view .............................................................................................................. 20 Figure 3-2 — VTN244 Node housing top view ................................................................................................................. 20 Figure 3-3 — Opening the VTN244 Node Housing ......................................................................................................... 21 Figure 3-4 — VTN244 RF connector seizure screws ........................................................................................................ 22 Figure 3-5 — VTN244 RF pin-type connectors.................................................................................................................. 23 Figure 3-6 — View of RF seizure screw mechanisms ...................................................................................................... 23 Figure 3-7 — Installing the housing on a strand .............................................................................................................. 24 Figure 3-8 — Installing the housing on a pedestal ......................................................................................................... 25 Figure 3-9 — Connecting Earth Ground ............................................................................................................................. 26 Figure 3-10 — Removing the RF Module ............................................................................................................................ 27 Figure 3-11 — E-Pack Attenuator Pad locations .............................................................................................................. 28 Figure 3-12 — Housing Lid pads ............................................................................................................................................ 29 Figure 3-13 — Equalizer locations ......................................................................................................................................... 30


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Figure 3-14 — Retainer screw locations .............................................................................................................................. 31 Figure 3-15 — Attaching the cable harness....................................................................................................................... 32 Figure 3-16 — RF/Power Ports ................................................................................................................................................ 33 Figure 3-17 — Power Supply ................................................................................................................................................... 34 Figure 3-18 — Fuse locations .................................................................................................................................................. 35 Figure 3-19 — Power schematic ............................................................................................................................................. 36 Figure 3-20 — VTN244 90 to 260 VAC .................................................................................................................................. 37 Figure 3-21 — Optical components ...................................................................................................................................... 38 Figure 3-22 — Forward Receiver Module ........................................................................................................................... 39 Figure 3-23 — Return Transmitter Module ........................................................................................................................ 40 Figure 3-24 — Transponder Module .................................................................................................................................... 41 Figure 3-25 — Fiber Connectors and Fiber Optical Service Cable ............................................................................ 42 Figure 3-26 — Attaching the Fiber Connectors ............................................................................................................... 43 Figure 3-27 — Housing closure bolts torquing sequence ........................................................................................... 44

VTN244 Fiber Deep 2x2 Optical Node Equipment Manual Introduction

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Introduction

VTN244 Overview

The VTN244 (Versatile Telecommunications Node) platform is designed to address the needs of today's evolving broadband networks. The VTN244 provides performance and reliability in a compact, user-friendly design, and offers the following differentiating features:

• Supports forward segmentation, return segmentation, and redundant network power supplies

• Optional Euro-DOCSIS and DOCSIS transponders provide operators the ability to remotely proactively monitor node performance

• Optional Local Channel Injection ports enable operators to combine a locally generated signal into the channel lineup

About This Manual

This manual provides instructions for installing, configuring, setting up, and troubleshooting the VTN244 Node.

Scope

This manual covers the following topics:

• Description of the VTN244 Node

• Installation and Configuration of the VTN244 Node

• Balancing and Setup of Node Forward and Reverse Paths

• Troubleshooting the VTN244 Node

• Description of Configuration Options and Accessories

Who Should Use This Document

This document is intended for authorized service personnel who have prior experience working with similar equipment.

Service personnel should have appropriate background and knowledge to complete the procedures described in this document.

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Qualified Personnel

CAUTION: Allow only qualified and skilled personnel to install, operate, maintain, and service this product. Otherwise, personal injury or equipment damage may occur.

Only appropriately qualified and skilled personnel should attempt to install, operate, maintain, and service this product.

Document Version

This is the first release of this guide (Rev 1.0).

Document Conventions Before you begin using the VTN244 Node, familiarize yourself with the stylistic conventions used in this manual:

Style Description

SMALL CAPS Denotes silk screening on the equipment, typically representing front and rear panel controls, input/output (I/O) connections, and LEDs.

*(asterisk) Indicates that several versions of the same model number exist and the information applies to all models; when the information applies to a specific model, the complete model number is given.

Italic type Denotes a displayed variable, a variable that you must type, or is used for emphasis.

Note: Information that is useful to the process:

Note: You may record the time…

CAUTION Information that is essential to the process:

CAUTION: Do not reboot …

WARNING!

Information that is required to the process where certain steps may lead to physical danger to personnel and/or equipment:

WARNING: Allow only qualified and skilled personnel to operate this equipment…


365-095-22584-x.1 3

Getting Help

Help with your Motorola product is available online and by phone:

• Find technical documentation in the CustomerCare 360 Documentation Center (motorola.com/doccenter).

• Call the Technical Assistance Center (TAC) at 888-944-HELP (888-944-4357) or 847-725-4011 24 hours a day, 7 days a week.

• Get release updates and download software on DigitalCM (digitalcm.motorola.com).

Returning for Repair

Contact the Motorola Mobility Technical Assistance Center (TAC) at 888-944-4357 (direct dial 847-725-4011) for assistance in verifying that repair is necessary. The Technical Assistance Center (TAC) will create an RSA for repair or an RA for replacement (if the equipment qualifies).

CAUTION The RSA number must be prominently displayed on all equipment cartons.

Shipping Instructions

When shipping equipment for repair, follow these steps:

1. Pack the unit securely.

2. Complete and enclose the checklist provided with the unit.

3. Enclose a copy of the invoice that verifies the warranty status.

4. Ship the unit PREPAID to the address supplied by the Tech Support representative during your call.

http://motorola.com/doccenter

http://digitalcm.motorola.com/


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List of Countries and Phone Numbers

Country Toll-Free Number

BELGIUM 0-800-72-163

DENMARK 80-88-6748

FINLAND 0-800-114-263

FRANCE 0-800-90-7038

GERMANY 0-800-18-73019

HUNGARY 06-800-18164

IRELAND 1-800-55-9871

Golden Lines 1-809-25-2071

ISRAEL Bezeq 1-809-42-9181

Barak 1-809-31-5435

ITALY 800-788-304

NETHERLANDS-HOLLAND 0-800-022-0176

NORWAY 800-15-670

POLAND 00-800-111-3671

PORTUGAL 800-81-3461

SPAIN 900-99-1771

SWEDEN 020-79-0241

SWITZERLAND 0-800-561-872

UNITED KINGDOM 0-800-404-8439

ALL OTHER COUNTRIES +1-847-725-4011

Note: If you find any toll-free number listed that is not in service, please dial +1-847-725-4011.

VTN244 Fiber Deep 2x2 Optical Node Equipment Manual Overview

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Overview

This chapter introduces you to the VTN244 Node and describes its main components, configuration options, and accessories:

Figure 2-1 — VTN244 Node

For more information regarding this product, consult the Motorola product catalog or contact your sales representative.

2


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Description

The VTN244 node is designed for evolving fiber-deeper HFC networks. It features four independent high level Gallium Arsenide (GaAs) RF outputs. Each port has individual attenuation and equalization facilities that use standard plug-in JXP pads and unique EQs.

The VTN244 node housing is composed of base and lid assemblies that are connected by RF and powering cables:

The lid contains the power supply(s), forward receiver module(s), reverse transmitter module(s), and the status monitor transponder.

The base contains the removable RF Electronics Package.

The following chapters provide a detailed description of the VTN244 node components and the RF E-Pack module.

VTN244 Node Features

The VTN244 Node has the following characteristics:

• 1006 MHz RF passband

• Modular design for ease of service and maintenance

• Four high-level outputs

• AGC optical input range of –7 to 0 dBm

• Standard plug-in attenuators to adjust gain

• Surge-resistant circuitry ensures resistance to high voltage transients (6kV)

• On-board thermal circuit for gain movement over temperature compensation

• 15A power current passing capability

• Optical power TP and LEDs

• SC/APC optical connectors

Fiber Entry Ports

The VTN244 housing lid has one fiber entry port on each side that can accept fiber service cables.


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Configuration

VTN244 Nodes are pre-configured with the following items:

• Forward Attenuator

• Reverse Attenuator

• Forward Equalizer

• Reverse Equalizer

Test Points Multiple -20 dB RF test points enable the technician to easily set up the node:

• FRX1 TP– Forward Receiver 1 Test Point

• FRX2 TP- Forward Receiver 2 Test Point

• Common Ports 1 and 3 Test Point

• Common Ports 2 and 4 Test Point

• Output Test Point, Ports 1, 2, 3 and 4

• Return Input Test Points Ports 1, 2, 3, and 4

• TX1 TP – Return Transmitter 1 Test Point

• TX2 TP – Return Transmitter 2 Test Point

Fuses The VTN-244 Node has six fuses located near the ports of the VTN244 Node. These fuses are used to direct AC current to and from the VTN244 output ports.

See the Fuse Management section of this guide for additional information.

CAUTION When replacing a fuse, be sure to use only a fuse of the same ampere rating (32V/25A).


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Ordering Information

Table 2-1: Ordering Information

Character # 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19

Model # VTN - 4 - 3 N 2 0 2 0 2 2 S A 2 1 1

FIELD

1 Product family

VTN Versatile Telecommunications Node

2 Number of RF output ports

4 4 output ports

3 Node configuration

1 Segmented w/o local channel injection function

2 Segmented w/ local channel injection function

2 Redundant w/o local channel injection function

4 Redundant w/ local channel injection function

4 Bandwidth split

K 42/54 split

A 65/85 split

N 85/104 split

5 Optical receiver configuration

1 1 FRX with -7 to 0 dBm optical input power

2 2 FRX with -7 to 0 dBm optical input power

6/7 Optical transmitter configuration

00 No transmitter

02 DFB 1310 nm w/isolator 0dBm

03 DFB 1550 nm w/isolator 0 dBm

C1 CWDM DFB 1270 nm w/isolator +3dBm








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FIELD (Continued)

6/7 CA CWDM DFB 1450 nm w/isolator +3dBm

CB CWDM DFB 1470 nm w/isolator +3dBm

CC CWDM DFB 1490 nm w/isolator +3dBm

CD CWDM DFB 1510 nm w/isolator +3dBm

CE CWDM DFB 1530 nm w/isolator +3dBm

CF CWDM DFB 1550 nm w/isolator +3dBm

CG CWDM DFB 1570 nm w/isolator +3dBm

CH CWDM DFB 1590 nm w/isolator +3dBm

CI CWDM DFB 1610 nm w/isolator +3dBm

8 Transponder

0 No transponder

1 US DOCSIS transponder

2 Euro DOCSIS transponder

9 Optical connector

SA SC/APC

SU SC/UPC

FA FC/APC

FU FC/UPC

10 Number of Power Supply units

1 Single

2 Dual

11 Power Supply

1 Cable power 27 ~ 90V

2 Mains power 90 ~ 260V

12 Housing

1 Strand mount


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Illustrations

The following pages provide detailed images of VTN244 component and configuration applications and testing.

VTN244 Node Test Points

The following diagram shows the VTN244 Node RF module test points (all test points are -20 dB):

Figure 2-2 — VTN244 Node RF test points

The following diagram shows the VTN244 Node housing lid test points (all test points are -20 dB):


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Figure 2-3 — VTN244 Node housing lid test points


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VTN244 Node Accessories

The following diagram identifies accessory locations for the VTN244 Node:

Figure 2-4 — VTN244 Node accessory locations


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Router

The forward and return routers are installed in the Housing Lid, and feature a switch to control its output:

• R: Redundant

• S: Segmented

Figure 2-5 — Forward/Return Router locations


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Forward Router

The forward router configuration plug-in directs downstream signal flow from the primary and secondary receivers to the main Electronics Package. A user-accessible switch determines redundant or segmented operation.

Figure 2-6 — Forward Router

• When a single receiver is installed in lid slot FRX1, the switch on the forward router module should be in the right (R) position. This directs the signal flow from the single receiver to each of the router outputs (RX1 and RX2). RF cables carry the signals from RX1 and RX2 to the main E-Pack where each pair is split to the four outputs. RX1 delivers signals to RF Ports 2 and 4, while RX2 delivers signals to RF Ports 1 and 3.

• When two receivers are installed in lid slot FRX1 and FRX2, and redundant operation is desired, the switch on the forward router module remains in the right (R) position. This directs the signal flow from the primary receiver FRX1 to each of the router outputs (RX1 and RX2). When the input level of the primary receiver drops below -7 dBm, the router switches to the secondary receiver FRX2.

• When two receivers are installed in lid slot FRX1 and FRX2, and segmented operation is desired, the switch on the forward router module is set to the left (S) position. This directs the signal flow from the receiver in slot FRX1 to router output RX1 and E-Pack outputs Ports 2 and 4. Signals from the receiver in slot FRX2 are directed to router output RX2 and E-Pack outputs Ports 1 and 3.

CAUTION To maintain optimum performance in redundant and segmented mode, the optical input levels into to each receiver should be as close as possible.


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Return Router

The return router configuration plug-in directs upstream signal flow from the main Electronics Package to the primary and secondary transmitters. A user accessible switch determines redundant or segmented operation.

Figure 2-7 — Return Router

• When a single transmitter is installed in lid slot RTX1, the switch on the return router module should be in the right (R) position. This combines the signal flow from the router inputs TX1 and TX2 to the transmitter. RF cables carry two pairs of upstream signals from the main E-Pack, Ports 2 and 4 are combined on the RF cable connected to TX1, while Ports 1 and 3 are combined on the RF cable connected to TX2. All four RF returns are present on the RTX1 in this configuration.

• When two transmitters are installed in lid slot RTX1 and RTX2, and redundant operation is desired, the switch on the return router module remains in the right (R) position. This splits the combined return and two identical signals are present on RTX1 and RTX2.

• When two transmitters are installed in lid slot RTX1 and RTX2, and segmented operation is desired, the switch on the return router module is set to the left (S) position. This directs the signal flow from the return router input TX1 (RF Ports 2 and 4) to the transmitter in slot RTX1. The signals from the return router input TX2 (Ports 1 and 3) are directed to the return transmitter in slot RTX2.


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ICS

The ICS (Ingress Control Switches) offers three attenuated switches which are transponder-controlled; they are 0, -6, <-30 respectively.

Figure 2-8 — Ingress Control Switch

Note: If ICS is not installed in the VTN244, then jumpers are present.

Fiber Tray

The fiber tray secures any excess fiber, providing a location for storing SC fiber optical connector pairs. The fiber management tray provides superior protection for fiber cables and splices, and is conveniently located in the lid. This tray pivots out of the way to allow quick access to the optical modules. Additional pads, equalizers and fuses are provided in the storage clips of the fiber tray to allow technicians easy access when adjustments are required.

The following diagram shows the location of the accessories in the fiber tray:

Figure 2-9 — Fiber Tray accessories location

VTN244 Fiber Deep 2x2 Optical Node Equipment Manual Installation and Configuration

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Block Diagrams

VTN244 Electronics PackageP 3

P 1

FUS

E

RFAC

AC

C

hoke

FUS

E

RFAC

AC

C

hoke

P

P

EQ P

L

H EQ P

EQ

P

ICS

P 2P 4

FUS

E

RFAC

AC

C

hokeFU

SE

RFAC

AC

C

hoke

L

H

P

P

EQP

LHEQP

EQ

P

FUS

E FUS

E

T.P.

T.P.

T.P.

T.P.

T.P.

T.P.

T.P.

T.P.

T.P.

ICS

T.P.

AC+DCSMLH

LDR

etur

n TX

1

LDR

etur

n TX

2

POWER SUPPLY POWER SUPPLY

Tran

spon

der

PD

Forw

ard

RX

2PD

Forw

ard

RX

1

ACCSDC ACCS DCGND GND

SW

1

SW

2 SW

1

SW

2

Fiber

Local + Main Power

Fiber

PPMCU

Red./Seg.

SWFWD

SWREV

Red./Seg.

T.P.

T.P.

T.P. T.P.

Figure 2-10 — VTN244 Block Diagram


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Installation and Configuration

Before You Begin

The procedures in this chapter assume that you have completed the following tasks:

• Prepared the installation site

• Located the coaxial cable, with or without pin-type coaxial connectors mounted on the cable

Required Tools

Before you start, make certain that you have the following tools:

• Torque wrench with a 1/2-inch socket

• Flat-blade screwdrivers

ο 3/16” (4.8 mm) for optics modules

ο ¼” ( 6.4 mm) for E-Pack module

• Phillips #1 screwdriver

• Heavy-duty wire cutters or snips

• Torque wrench set

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Torque Specifications

The following table details the torque specifications for the VTN244 Node.

Table 3-1: Torque specifications

Fastener Torque Specification Illustration

Housing retainer screws 1.5 Nm to 1.8 Nm

(1.106 to 1.327 Ft-lb)

Housing closure bolts 6.8 Nm to 9.0 Nm

(5.015 to 6.638 Ft-lb)

Housing grounding screw 0.9 Nm to 1.0 Nm

(0.663 to 0.737 Ft-lb)

Housing plugs test point port plugs

6.8 Nm to 9.0 Nm

(5.015 to 6.638 Ft-lb)

RF F-Cable connector

Follow manufacturer instructions

Hard Line cable connector

Follow manufacturer instructions


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Housing Dimensions

The following diagram shows the dimensions (in inches and millimeters) of the VTN244 Node housing. Use these measurements to calculate clearance requirements for your installation.

Figure 3-1 — VTN244 Node housing front view

Figure 3-2 — VTN244 Node housing top view

CAUTION! Before unscrewing the housing bolts, make sure the removable hinge locking pin is in place. The locking pin prevents the separation of the lid from the base.


365-095-22584-x.1 21

Opening the VTN244 Node Housing

To open the VTN244 Node housing:

1. Loosen the six ½-inch housing closure bolts on the housing lid:

Figure 3-3 — Opening the VTN244 Node Housing

2. Open the housing, allowing the lid to swing away from the base.

Note: The closure bolts should remain attached to the housing.


365-095-22584-x.1 22

Attaching the Coaxial Connectors

To prepare the VTN244 node for installation, complete the following steps:

1. Loosen the four RF seizure screws with a Phillips #1 screwdriver.

The following figure identifies the four screw locations:

Figure 3-4 — VTN244 RF connector seizure screws


365-095-22584-x.1 23

2. Place the connector next to the trim gauge on the side of the housing to determine proper length and cut as required:

Figure 3-5 — VTN244 RF pin-type connectors

Note: The VTN244 Node requires pin-type connectors for all RF connections. The 5/8’’ RF connector will be needed for pins extending from 35.0 mm to 38.0 mm.

3. Screw the RF cable connector adapter onto the housing.

4. Tighten the connector adapter nut according to manufacturer specifications.

5. Tighten the RF seizure screw from 0.9 Nm to 1.0 Nm.

6. Repeat steps 3 through 5 for each RF port used.

7. Depending on your particular type of installation, proceed to the Installing the Housing on a Strand or Installing the Housing on a Pedestal sections of this manual.

Figure 3-6 — View of RF seizure screw mechanisms


365-095-22584-x.1 24

Installing the Housing on a Strand

To install the housing on a strand (aerial), complete the following steps. The housing does not need to be opened for strand installation.

WARNING: Be aware of the size and weight of the housing while strand mounting. Ensure that the strand can safely support the weight of the housing.

1. Loosen the ½” strand clamp bolts.

2. Lift the housing into its proper position on the strand.

IMPORTANT: The minimum strand diameter should be 5/16 inch.

3. Slip the strand clamps over the strand and finger-tighten the clamp bolts. This allows additional movement of the housing as needed.

4. Move the housing as needed to install the coaxial cable and connectors.

The following diagram illustrates this procedure:

Figure 3-7 — Installing the housing on a strand

5. Using a ½-inch torque wrench, tighten the strand clamp bolts from 6.8 Nm to 9.0 Nm (5.015 to 6.638 Ft-lb). Make certain that there is good mechanical contact between the strand and the housing.

6. Connect the coaxial cable to the pin connector according to the section Attaching the Coaxial Connectors.

7. Proceed to the Installing the Accessories section of this manual.


365-095-22584-x.1 25

Installing the Housing on a Pedestal

To install the housing on a pedestal, complete the following steps:

1. Drill two 5/8” holes in the mounting plate or mounting bracket with 190.5 mm (7.5”) distance.

Note: The thickness of the metal plate is 10 to 15 mm (0.39” to 0.59”).

2. Lift the housing to its proper position on the wall or cabinet.

3. Align the pedestal mounting holes on the bottom of the housing with the two holes drilled in the metal plate and insert the bolts through the mounting plate into the two threaded mounting holes, as shown below:

Figure 3-8 — Installing the housing on a pedestal

4. Using a ½-inch torque wrench, tighten the pedestal clamp bolts from 6.8 Nm to 9.0 Nm (5.015 to 6.638 Ft-lb).

5. Connect the coaxial cable to the pin connector according to the section Attaching the Coaxial Connectors.

6. Proceed to the Installing the Accessories section of this manual.


365-095-22584-x.1 26

Connecting Earth Ground

For aerial or pedestal installations, the VTN244 housing requires a good earth ground to function properly. You can bond the node housing to a good earth ground by attaching a wire from earth ground to the housing base grounding screw in the figure below.

Figure 3-9 — Connecting Earth Ground

1. Torque the housing ground screw to 0.9 Nm to 1.0 Nm (0.663 to 0.737 Ft-lb).


365-095-22584-x.1 27

Removing the RF E-Pack Module from the Housing

Complete the following steps when it becomes necessary to remove the RF Module.

1. Open the housing. See Opening the VTN244 Node Housing for additional information.

2. If you are working with a node station in which AC is present, remove the fuses from the node before removing the RF Module from the housing.

3. Unplug the 8-pin power connector, connectors of forward RF input cables, connectors of reverse RF output cables, and status monitor interface connector from the RF module.

WARNING: RF connectors and housing seizure assemblies can be damaged if fuses are not removed from the RF Module before installing or removing the RF Module from the housing.

Figure 3-10 — Removing the RF Module

4. Remove the power cable harness from the white plastic retainer clips.

5. Unsnap the cable guide from the holes in the RF module cover.

Note: The cables can remain plugged into the housing lid.

6. Using a flat-blade screwdriver, loosen the five module retainer screws.

7. Remove the RF module from its housing and place it on a secure surface.


365-095-22584-x.1 28

Installing the Accessories

The VTN244 node comes pre-configured for station output slope. The following pages contain information on installing various accessory components, such as attenuator pads and equalizers to adjust the node to specific design criteria.

Note: For best results, follow all accessory installation procedures.

Accessories — Attenuator Pads

To install the attenuator pads in the VTN244 Node, complete the following steps:

1. Begin this procedure with the housing open. For additional information, reference Opening the VTN244 Node Housing.

Note: These accessories can be installed without removing the E-Pack chassis cover.

2. Install the pad(s) specified by the design print in the appropriate pad slot(s).

CAUTION Make certain that all the pins on the attenuator pad bottom align with the pin holes in the attenuator pad slot, allowing the attenuator pad to install flat against the VTN244 Node.

The following diagram shows the VTN244 Node E-Pack Pad Locations:

Figure 3-11 — E-Pack Attenuator Pad locations


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Accessories — Housing Lid Pads

The following diagram shows the VTN244 Node Housing Lid pads:

Figure 3-12 — Housing Lid pads

3. Install other options or accessories as desired.


365-095-22584-x.1 30

Accessories — Equalizers

Complete the following steps to install the equalizers in the VTN244 Node:

1. Begin this procedure with the housing open. For more information, see Opening the VTN244 Node Housing.

Note: These accessories can be installed without removing the VTN244 E-Pack chassis cover.

Figure 3-13 — Equalizer locations

2. Install other options or accessories as desired.


365-095-22584-x.1 31

Installing the RF Module

The RF Electronics Package (E-Pack) module plugs into the housing base and engages via RF connectors on the bottom side of the E-Pack module.

WARNING: RF connectors and housing seizure assemblies can be damaged if fuses are not removed from the RF Module before installing or removing the RF Module from the housing.

To install the RF Module, complete the following steps if you are working with a node station where AC is present:

1. Remove the appropriate fuses from the module ports where AC power is present.

2. Push the RF module into the housing.

3. Secure the RF module to the housing by tightening the five system RF module retainer screws. Tighten the module retainer screws from 1.5 Nm to 1.8 Nm (13.27 to 15.93 in-lb).

4. Install the fuse in the node after you install the RF module in the housing.

The following illustration shows the location of the retainer screws:

Figure 3-14 — Retainer screw locations

5. Snap the power cable harness into place.

6. Attach the 8-pin keyed power connector, connectors of forward RF input cables, connectors of reverse RF output cables, and status monitor interface connector to the RF module.


365-095-22584-x.1 32

CAUTION The connectors are keyed in order to ensure proper orientation. Make certain that each connector is securely attached to the RF E-Pack module.

7. Route the excess cable between the end of the molded power harness and the 8-pin connector and RF cable into the white plastic retainer clips on the module cover.

Note: Ensure that the power harness locking tabs are fully seated under the Node cover.

Figure 3-15 — Attaching the cable harness

8. Continue to the following section, System Power.


365-095-22584-x.1 33

System Power

The VTN244 Node draws AC power from the coaxial cable external AC power supply source.

The following pages cover the topics of AC power and fusing.

Network Power (27V~90VAC)

Voltage sources can be connected from either of the output ports, and fuses are present to either pass or block AC RF continuity. To set the power direction, install a fuse for the ports through which you wish to pass AC. For additional details, see Fuses.

Before powering the VTN244 Node, make sure all accessories are installed and properly seated.

Figure 3-16 — RF/Power Ports

IMPORTANT: The four ports represent all RF/Power Ports in the equipment.


365-095-22584-x.1 34

Network Power Supply

The VTN244 features modular network power supplies. A single power supply supports a fully configured station. A second supply can be added for redundancy. The recommended input power voltages for the VTN244 node are 27 VAC to 90 VAC or 90 VAC to 260 VAC.

An optional mains powered supply is available that accepts 90 VAC to 260 VAC input power.

Figure 3-17 — Power Supply

Table 3-2: VTN244 Power/Current draw

AC Current(A) Power(W) AC Current(A) Power(W) AC Current(A) Power(W)90VAC 0.836 51.2 0.932 55.6 1.023 60.175VAC 0.953 51.3 1.051 55.8 1.121 60.360VAC 1.116 51.5 1.216 56.2 1.282 60.453VAC 1.254 51.9 1.347 56.3 1.454 61.152VAC 1.268 51.8 1.364 56.4 1.463 6145VAC 1.456 52.4 1.553 57.1 1.693 6244VAC 1.468 52.3 1.597 57.4 1.707 6238VAC 1.71 53.4 1.852 58.5 1.998 64.1

2x2 (Transponder and Dual P/S)2x2 (Dual P/S)1x1 (Dual P/S)Input AC Voltage


365-095-22584-x.1 35

Fuse Management

Check the system maps to determine which fuse should be inserted.

1. Open the housing. See Opening the VTN244 Node Housing for more information.

2. Plug the appropriate VTN244 fuse into the fuse locations.

Note: Spare fuses can be stored in the fiber tray.

3. Close the housing. See Closing the VTN244 Node Housing for more information.

CAUTION In order for Fuses 1 and 3 to function, Fuse 5 must be installed. For Fuses 2 and 4 to function, Fuse 6 must be installed.

Figure 3-18 — Fuse locations

Table 3-3: Fuse specifications

Fuse Identification Purpose Rating

Fuse 1 Passes ac to/from port 1 32V/25A




Fuse 5 Must be in place for normal operation of Fuse 1 and 3 32V/25A

Fuse 6 Must be in place for normal operation of Fuse 2 and 4 32V/25A


365-095-22584-x.1 36

Figure 3-19 — Power schematic


365-095-22584-x.1 37

Mains Power (90 to 260 VAC)

The VTN244 Node can draw AC power from the local mains power. The following information is applicable to the optical nodes powered by 90 to 260 VAC.

CAUTION Before powering the VTN244 Node, make certain that all accessories are installed and properly seated.

Figure 3-20 — VTN244 90 to 260 VAC

The following information is applicable to VTN-244 nodes powered by 90 to 260 VAC. The mains power supply is located in the housing lid next to the return transmitter modules. The AC power cord is not terminated and left intentionally with bare leads and enters the housing lid through a strain relief.

Use the following color scheme when connecting AC to the VTN with MAINs powered power supplies:

Table 3-4: Typical AC system installation specifications

VTN MAINs Power Cord AC Power

Blue Neutral

Brown Phase/Line

Green with yellow stripe Chassis Ground

CAUTION Before powering the VTN-244 node, make certain that all accessories are installed and properly seated.


365-095-22584-x.1 38

Removing and Reinstalling Optical Module Components

The following optical components can be removed and reinstalled from the VTN244 Node optical section:

• Main Forward Receiver Module (FRX1)

• Aux Forward Receiver Module (FRX2)

• Main Return Transmitter Module (RTX1)

• Aux Return Transmitter Module (RTX2)

Figure 3-21 — Optical components


365-095-22584-x.1 39

Forward Receiver Module

Complete the following steps to remove or reinstall an optical receiver:

1. Open the housing.

See Opening the VTN244 Node Housing for additional information.

2. Rotate the fiber tray to enable access to the optics modules.

3. Remove the fuse or pull out the power plug (mains power).

See System Power for additional information.

4. Disconnect the fiber connector from the forward receiver module.

5. Using a flat-blade screwdriver, loosen the mounting screw and pull up on the module to remove.

Figure 3-22 — Forward Receiver Module

6. Reconnect the fiber connector to the Forward Receiver Module.

7. Insert the fuse.


8. Close the housing.

See Closing the VTN244 Node Housing for additional information.


365-095-22584-x.1 40

Return Transmitter Module

Complete the following steps to remove or reinstall the optical transmitter from the optical section:

1. Open the housing.

See Opening the VTN244 Node Housing for additional information.


3. Remove the fuse or pull out the power plug (mains power).


4. Disconnect the fiber connector from the return transmitter module.

5. Using a flat-blade screwdriver, loosen the mounting screw and pull up on the module to remove.

Figure 3-23 — Return Transmitter Module

When installing the return transmitter module:

6. Insert the return transmitter module in the housing lid, aligning the guide slots on the bottom of the module with the guide pins on the housing lid. Ensure that the module 14-pin connector seats properly.

7. Use a flat-blade screwdriver to tighten the mounting screw.

8. Reconnect the fiber connector to the Return Transmitter Module.

9. Insert the fuse.





365-095-22584-x.1 41

Transponder Module

Complete the following steps to remove or reinstall a transponder from the optical section:

1. Open the housing. See Opening the VTN244 Node Housing for additional information.


3. Remove the fuse or pull out the power plug (mains power). See System Power.

4. Using a flat-blade screwdriver, loosen the mounting screws to remove the transponder module.

Figure 3-24 — Transponder Module

When installing the transponder module:

5. Insert the transponder module in the housing lid, aligning the guide slots on the bottom of the module with the guide pins on the housing lid. Ensure that the module 20-pin connector seats properly.

6. Use a flat-blade screwdriver to tighten the two mounting screws.

7. Insert the fuse.





365-095-22584-x.1 42

Connecting the Fiber Optical Service Cable

The following illustration shows the fiber connectors available with the VTN244 Node when using fiber optic service cables:

Figure 3-25 — Fiber Connectors and Fiber Optical Service Cable


365-095-22584-x.1 43

Attaching the Fiber Connectors

Complete the following steps to attach the fiber connectors:

1. With the fiber tray in the closed position, carefully insert the fiber pigtail breakouts through the appropriate fiber entry port depending on the installation.

2. Tighten and torque the main nut to 6.8 Nm to 9.0 Nm, and then tighten and torque the secondary nut to 9.0 Nm to 12.0 Nm.

3. Carefully route the pigtails through the fiber retainer clips one at a time.

• Route the fiber pigtails clockwise within the tray to take up the excess

• Be careful not to use a tight fiber radius (the radius should be at least 30 mm)

4. Clean the tips of the fiber connectors.

5. Attach the fiber connectors as shown in the figure below. The suggested fiber of connecting the Forward Receiver Module length is 54.5 cm (21.45”) and connecting the Return Transmitter Module length is 116.5 cm (45.86”).

6. Insert the forward input optical connector into Forward Receiver Module.

7. Ensure the fiber tray can rotate between the open and close position without placing stress on the fibers.

Figure 3-26 — Attaching the Fiber Connectors


365-095-22584-x.1 44

Closing the VTN244 Node Housing

Complete the following steps to close the VTN244 Node housing.

CAUTION Avoid moisture damage and RF leakage! Follow the procedure exactly as shown below to ensure a proper seal. Ensure that all the cables are out of the way when closing the housing.

1. Make sure that the housing gaskets are clean and in the correct position. Wipe off any excess dirt and debris.

2. Ensure all fiber and cables will stow properly and not be pinched by the housing when closed.


4. Lightly secure the six ½-inch closure bolts with a hex driver.

5. Using a torque wrench, tighten the six closure bolts to 2.8 Nm (24.78 in-lb).

IMPORTANT: Tighten the closure bolts in the correct sequence as specified in Torquing Sequence (see Figure 3-26 below).

6. Using the same pattern, tighten the housing closure bolts from 6.8 Nm to 9.0 Nm (5.01ft-lb to 6.63 ft-lb).

Torquing Sequence

The following diagram shows the proper torquing sequence for the housing closure bolts:

Figure 3-27 — Housing closure bolts torquing sequence

VTN244 Fiber Deep 2x2 Optical Node Equipment Manual Balancing and Setup

365-095-22584-x.1 45

Balancing and Setup

Overview

This chapter provides instructions for selecting and implementing the correct balancing methods for the VTN244 Node in your cable system. Balancing sets the operating levels of the station to ensure proper performance.

IMPORTANT: Use the information in this chapter to identify the equipment needed for balancing and to determine the correct forward path balancing method for your system installation.

Before You Begin

Before you begin balancing, it is important to review and understand the following information. This information will show you which balancing process is appropriate for your VTN244 Node.

Before balancing, make sure you have configured the node module according to the specifications in your design print; additionally, confirm that the Node has warmed up for approximately one hour.

The following table shows the items required for balancing.

Table 4-1: Items needed for balancing

You need a ... To ...

Copy of the design print Determine expected input and output signal levels

Torque wrench with 1/2-inch socket Open and close the system Node housing

Spectrum analyzer or signal analysis meter capable of working with frequencies up to the highest design frequency

Determine absolute and relative signal levels

Test point probe Access the test points

Length of 75 Ohm coaxial cable with F-connectors on each end

Connect the test point probe to the test equipment

4


365-095-22584-x.1 46

Balancing the Forward Path

The following pages provide information on selecting and implementing the proper balancing methods. For optimal results, follow all instructions exactly.

Introduction

Be sure to use the correct procedure for forward path balancing. See Verifying the Forward Input Optical Power for help in identifying the procedure that best fits your system installation and node type. Before you begin, also make sure that the RF module is configured according to the specifications in the design print, and that the node has warmed up for approximately one hour.

The forward section of the VTN244 Node performs conversion, amplification, equalization and test point functions for the forward path signal.

Verifying the Forward Input Optical Power

Follow these steps to set the AGC ON/OFF and test input optical power:

1. Clean the input fiber interface.

2. Use an optical power meter to determine the optical power level present.

3. Connect the input fiber connector to see the Optical LED in the Forward Receiver Module.

4. Measure the DC test point of the Forward receiver. The recommended range is -7 dBm to 0 dBm. The test point is scaled 1V/ mW.

The following table lists the expected receiver parameters with AGC OFF:


365-095-22584-x.1 47

Table 4-2: VTN Receiver Typical Parameters

Optical Input Level

dBm/mW

TP Voltage 1 V = 1 mW

FRX TP Output (dBmV) @

547.25 MHz

Actual RX dBmV Optical LED Status

1.0/1.26 1.26 18.5 38.5 High level alarm

0.5/1.1 1.10 17.5 37.5 Normal

0.0/1.00 1.00 16.5 36.5 Optimum

–0.5/0.9 0.90 15.5 35.5 Normal

–1.0/0.8 0.80 14.5 34.5 Normal

–1.5/0.71 0.71 13.5 33.5 Normal

–2.0/0.6 0.60 12.5 32.5 Normal

–2.5/0.56 0.56 11.5 31.5 Normal

–3.0/0.5 0.50 10.5 30.5 Normal

–3.5/0.44 0.44 9.5 29.5 Normal

–4.0/0.4 0.40 8.5 28.5 Normal

–5.0/0.3 0.30 6.5 26.5 Normal

-6.0/0.25 0.22 4.5 24.5 Normal

-7/0.20 0.20 2.5 22.5 Low Level Alarm

Table notes:

a. VTN-RX typical Output Levels (Test Points Are –20 dB)

b. Optical modulation index (OMI) for 77 channels (per channel): 0.0403

c. For 1550 nm operation, the RF levels out of the transmitter will be 0.42 dB higher at any given optical input d. OMI for 110 channels (per channel): 0.0337

e. Optical transmitter wavelength is 1310 nm

5. Compare the measured levels to the design levels

6. Connect the test point probe and measure the RF at the FRX TP location to ensure expected levels are present.

Note: When you turn the AGC Switch ON, the Forward Receiver Module attempts to maintain a constant RF output regardless of optical input levels. When you turn the AGC Switch OFF, the Forward Receiver Module behaves in manual mode, where changes in optical input levels result in changes in RF output levels.


365-095-22584-x.1 48

Setting Up the Forward Output Level

After ensuring the receiver has the proper input and output levels, complete the following steps to select the proper pad values for the node. The output level of the node can be adjusted by varying attenuator pad values.

1. Connect the test probe to the forward output test point(s).

The test points are -20 dB.

2. Measure the output level at the high test design frequency, and compare this level with the design level (on the design print).

a. If the output level is within ±0.5 dB of the design output level, no changes are necessary.

b. If the output level is more than the design output level, replace the forward pad with a higher value pad.

c. If the output level is less than the design level, replace the forward pad with a lower value pad.

3. Repeat steps 1 through 3 until each output level is correct. Proceed to Setting Up the Reverse Input Level.

AGC ON Mode Chart

The following table illustrates the typical padding required for optimum performance with an analog 79-channel load.

• Digital levels are 6 dB below analog.

• Output level is analog carrier at 547.25 MHz.

• Recommended operation is in AGC ON Mode.

Output Level

Forward Pad 40 41 42 43 44 45 46 47

Input JXP 8 7 6 5 4 3 2 1

Output JXPs 0 0 0 0 0 0 0 0

CAUTION If the receiver AGC is switched off, additional padding must be added to ensure proper performance.


365-095-22584-x.1 49

AGC OFF (Manual) Mode Chart

The following table illustrates the typical padding required for optimum performance with an analog 79-channel load.

• Digital levels are 6 dB below analog.

• Output level is analog carrier at 547.25 MHz.

Input Output Level

dBm/mW Forward Pad 40 41 42 43 44 45 46 47

0.0/1.0 Input JXP Output JXPs

11 9

11 8

11 7

11 6

11 5

11 4

11 3

11 2

–0.5/0.9 Input JXP Output JXPs

11 8

11 7

11 6

11 5

11 4

11 3

11 2

11 1


11 7

11 6

11 5

11 4

11 3

11 2

11 1

11 0


11 6

11 5

11 4

11 3

11 2

11 1

11 0

10 0


11 5

11 4

11 3

11 2

11 1

11 0

10 0

9 0


11 4

11 3

11 2

11 1

11 0

10 0

9 0

8 0


11 3

11 2

11 1

11 0

10 0

9 0

8 0

7 0


11 2

11 1

11 0

10 0

9 0

8 0

7 0

6 0


11 1

11 0

10 0

9 0

8 0

7 0

6 0

5 0


11 0

10 0

9 0

8 0

7 0

6 0

5 0

4 0


10 0

9 0

8 0

7 0

6 0

5 0

4 0

3 0


9 0

8 0

7 0

6 0

5 0

4 0

3 0

2 0


8 0

7 0

6 0

5 0

4 0

3 0

2 0

1 0


7 0

6 0

5 0

4 0

3 0

2 0

1 0

0 0


6 0

5 0

4 0

3 0

2 0

1 0

0 0

0 0


365-095-22584-x.1 50

CAUTION For optimum performance, the output level in each port should not exceed 55dBmV at 1 GHz. Otherwise, output module damage may occur, which can result in amplifier distortion.


365-095-22584-x.1 51

Determining the Output Slope

Complete the following steps to determine the output slope of the node.

1. Connect the test point probe to the forward output test points.

2. Consult the design print to find the proper output tilt.

3. To determine the actual output tilt, calculate the difference (in dB) between the levels of the lowest and highest specified frequencies.

4. Proceed to the Changing the Output Slope section of this guide.


365-095-22584-x.1 52

Changing the Output Slope

The forward output slope of each port can be adjusted using the Forward Linear Equalizer (FLEQ). The FLEQ are available in a range of values from 0 to 15 dB.

• Increasing the equalizer value reduces the level at lower frequencies, relative to the level at 1 GHz.

• Decreasing the equalizer value increases the level at lower frequencies, relative to the level at 1 GHz.

Note: The node features internal circuitry that develops a portion of the overall station slope in conjunction with the value of the Equalizer.

The following table shows the expected FLEQ value used to achieve the overall Output Slope:

FLEQ VALUE

OUTPUT SLOPE

54-1006 MHz

12 1811 1710 169 158 147 136 125 10


365-095-22584-x.1 53

Balancing the Reverse Path

This section assumes that the reverse RF amplifier cascade has been properly balanced. Balancing refers to the process of individually aligning reverse amplifier station gain and tilt characteristics to achieve optimum, repeatable transmission characteristics (Unity Gain).

There are a variety of test equipment combinations that enable proper balancing of the reverse path. Regardless of the type of equipment used, the balancing process is fundamentally the same.

Setting Up the Reverse Input Levels

Complete the following steps to ensure proper RF levels in the return:

1. To determine return signals present at each of the RF input ports, use the four reverse input test points:

Note: The recommended total input power is 20 dBmV.

2. Legs with excessive levels can be attenuated at each of the reverse input pad locations.


365-095-22584-x.1 54

Setting Up the Equalizer Value for Reverse Path

In some instances it may be necessary to compensate each pair of returns for tilt in the return path. The reverse output tilt can be adjusted using the Reverse Linear Equalizer (RLEQ). Each RLEQ has a range of values from 0 to 10 dB.

• Ports 1 and 3 are adjusted by RLEQ 1

• Ports 2 and 4 are adjusted by RLEQ 2

1. Connect the test point probe to the reverse input test point.

2. Compare the calculated tilt with the design tilt (on the design print).

3. Measure the reverse output tilt If the output tilt is within ±0.5 dB of the design tilt, proceed to the next step.

a. If the output tilt is more than the design tilt, replace the reverse EQ with a lower value.

b. If the output tilt is less than the design tilt, replace the reverse EQ with a higher value.

4. Measure the reverse output tilt again, and then remove the test probe from the test point.

Note: The reverse equalizer is installed at the factory with 0 dB pad.


365-095-22584-x.1 55

Setting Up the Return Transmitter Input Level

After making certain that the proper input power and return tilt is present from the E-Pack, complete the following steps to select the proper pad values for the return transmitter.

Note: There is approximately 9 dB insertion loss between the Node output ports and the input to the TX (regardless of router switch position).

IMPORTANT: On optical nodes that have not yet been placed into service, a single CW tone can be injected into the forward test point at a level of 40 dBmV for alignment purposes.

Connect the test equipment to the RTX input test point shown in the following figure:

Note: The recommended input range that should be measured at the RTX TP is – 9 dBmV total power.

5. Measure the input level, and compare this with the design level. The test point attenuates input signals by 20dB.

6. Select the proper JXP pad value to achieve desired level. Repeat for the other transmitter if required.

7. Remove the test probe from the RTX input test point.

Start Stop Ret BW

Node Input

Total RF Power

Forward RF TP Inject Total

Power

Transmitter Input Total

Power

Factory Transmitter JXP Pad

Transmitter TP Total Power

3.2 MHz DOCSIS Channel

6.4 MHz DOCSIS Channel

6 MHz DOCSIS Channel

[MHz] [MHz] [MHz] [dBmV] [dBmV] [dBmV] [dB] [dBmV] [dBmV] [dBmV] [dBmV]5 42 37 20 40 11 0 -9 -19.6 -16.6 -16.95 65 60 20 40 11 0 -9 -21.7 -18.7 -19.05 85 80 20 40 11 0 -9 -23.0 -20.0 -20.2

VTN244 Fiber Deep 2x2 Optical Node Equipment Manual Troubleshooting

365-095-22584-x.1 56

Troubleshooting

Overview

This chapter describes the steps you may take to troubleshoot the VTN244 Node.

Required Equipment

The following equipment may be necessary to perform some troubleshooting procedures:

• Compressed air

• Lint-free wipes moistened with optical-grade (99%) isopropyl alcohol

• Optical connect scope

• Optical power meter to measure light levels

• Proper fiber connector for optical power meter to make optical connections

• Spectrum analyzer or a field strength meter to measure RF levels

Low RF Output

Use the steps listed in the following table to troubleshoot low RF output of the VTN244 Node:

Table 5-1: Low RF Output Troubleshooting

Possible Cause Solution

Low RF input at the transmitter. Verify correct RF input to the transmitter.

Check the amplifiers preceding the transmitter for proper inputs and outputs.

Defective or improperly spliced optical coupler (between headend transmitter and Node).

Replace or re-splice the coupler.

Make sure all unused fiber pigtails are terminated.

Unterminated leg of the optical coupler. Make sure all unused fiber pigtails are terminated.

Low optical input to the Node. The optical input level should be typically -7 to 0 dBm. Refer to the system design print for the proper level.

• If connectors are dirty, clean them. See Cleaning Optical Connectors for more information.

• Inspect fiber routing that might be wrapped too tightly.

• Check for proper optical output from transmitter. • Check the link loss. • Replace any scratched connectors.

5


365-095-22584-x.1 57


Failure in the optical receiver. Replace the optical receiver. Use the FRX output test point of the optical receiver to verify output levels.

No Forward RF Signal

The forward RF signal can be measured at the –20 dB RF test point on the RF module.

Note: Before you begin troubleshooting for No Forward RF signal, verify that the VTN244 Node is receiving the proper optical input signal from the forward transmitter.

Table 5-2: No Forward RF Signal Troubleshooting


No forward RF signal at the forward input test point.

• Verify that the RF module is receiving the proper forward RF input signal from the optical interface board.

• Verify that the Node is receiving the proper forward RF input signal from the Local injection port.

Important: You cannot balance the node without the proper forward RF input signal.

There is a proper forward RF signal at the forward input test point, but a low or degraded signal at one or all of the forward output test points.

• Verify that all the proper accessories, pads, EQs and ICS are firmly installed in the correct locations.

• Verify that the factory installed accessories are firmly installed in the correct locations.

• Replace the RF module.


365-095-22584-x.1 58

Low or Degraded Forward RF Signal

The forward RF signal can be measured at the –20 dB RF test point on the RF module.

Before you begin troubleshooting for Low or Degraded Forward RF signal, verify that the VTN244 Node is receiving the proper forward optical input signal from the forward transmitter.

IMPORTANT: You cannot balance the Node without the proper forward RF input signal.

Make certain that you have configured the RF module according to the specifications in the design print and that the Node has warmed up for approximately one hour.

Table 5-3: Low or Degraded Forward RF Signal Troubleshooting


There is a proper forward RF signal at the forward output test point, but a low or degraded signal at one or all of the forward output test points.

• Verify that all the proper accessories, pads, EQs, and ICS are firmly installed in the correct locations.



No Reverse RF Signal

The reverse RF signal can be measured at the RF module reverse input test points and FTX input test point.

Before you begin troubleshooting for No Reverse RF signal, verify that the Node is receiving the proper reverse RF input signals from the downstream amplifiers at the Node reverse input ports.

IMPORTANT: You cannot balance the Node without the proper reverse RF input signals.

Table 5-4: No Reverse RF Signal Troubleshooting


No reverse RF signal at the reverse input test point(s).

• Verify the connection of the RF Cable Connector. • Verify that the Node is receiving the proper reverse RF

input signals. Important: You cannot balance the Node without the proper reverse RF input signals.

There are proper reverse RF signals at the reverse input test points, but no signal at the RTX input test point.

• Verify that the RF module is receiving the proper forward RF signal. See No Forward RF Signal.





365-095-22584-x.1 59

Low or Degraded Reverse RF Signal

The reverse RF signal can be measured at the RF module reverse input test points and FTX input test point.

Before you begin troubleshooting for Low or Degraded Reverse RF signal, verify that the Node is receiving the proper reverse RF input signals from the downstream amplifiers at the Node reverse input ports.

IMPORTANT: You cannot balance the Node without the proper reverse RF input signals.

Make sure you have configured the RF module according to the specifications in the design print and that the Node has warmed up for approximately one hour.

Make sure you are using the proper total tilt reference when setting reverse level.

Table 5-5: Low or Degraded RF Signal Troubleshooting


Low or degraded reverse RF signal at the reverse input test point.

Verify that the Node is receiving the proper reverse RF input signals.

Important: You cannot balance the Node without the proper reverse RF input signals.

There are proper reverse RF signals at the reverse input test points, but a low or degraded signal at the RTX input test point.

• Measure the reverse input test point. Subtract the reverse amplifier gain and add the pad values and EQ insertion loss to verify proper reverse amplifier gain.



• Verify that any unused RF ports are properly terminated.

Reverse RF signal still low or degraded. If degradation is generated by the downstream amplifier reverse RF signal, troubleshoot the RF module feeding this station.


365-095-22584-x.1 60

Troubleshooting Carrier-to-Noise Problems

Complete the steps listed on the following table to troubleshoot carrier-to-noise problems:

Table 5-6: Carrier-to-Noise Problems Troubleshooting


Low optical input to the Node. The standard optical input level should be typically -3 to +2 dBm and The high gain receiver optical input level should be typically -7 to 0 dBm. Refer to the system design print for the proper level.

• If connectors are dirty, clean them. See Cleaning Optical Connectors for more information.

• Inspect fiber routing that might be wrapped too tightly. • Check for proper optical output from transmitter. • Check the link loss. • Replace any scratched connectors.

Low RF input at transmitter. • Verify RF input to the transmitter. • Check all amplifiers preceding the transmitter for proper

inputs and outputs.

Failure in optical receiver. Replace the forward receiver.

Defective or improperly spliced optical coupler between headend transmitter and Node.

• Replace or re-splice the coupler. • Make sure all unused fiber pigtails are terminated.

Unterminated leg of optical coupler. Make sure all unused fiber pigtails are terminated.


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Miscellaneous Conditions

Complete the following steps to troubleshoot miscellaneous problems.

Table 5-7: Miscellaneous Problems Troubleshooting


No RF signal present in network. • Check network power supply. • Verify that power is present at the Node power supply. • Check that the optical signal is present on fiber. • Check that voltage level on the optical receiver is the

same as it was when commissioned. • Check that output RF is present at forward output test

point.

Poor pictures on network. • Check RF input level at transmitter. • Check optical output of transmitter. • Check optical levels at forward optical receiver. • Check and clean fiber connectors. See Cleaning Optical

Connectors for more information. • Check RF levels at VTN244 Node outputs.

No RF output from headend or hub reverse optical receiver.

• Check fiber connector in headend or hub. • Check fiber for optical input level. • Check fiber connections. • Check reverse transmitter module in Node. • Check RF input level to transmitter in Node. • Ensure that cable is connected and not crushed. • Check for RF at amplifier reverse input test point.

Excessive noise in return. • Check fiber connections and clean if necessary. • Check noise level at transmitter test point.

No Power Supply

Before you begin troubleshooting for the power supply, verify that the power supply is receiving power.

IMPORTANT: You cannot balance the Node without the proper power supply.

Table 5-8: No Power Supply Troubleshooting


No power supply • Verify that the power supply is receiving power. • Replace the Power Supply.


365-095-22584-x.1 62

Cleaning Optical Connectors

Cleaning fiber-optic connectors can help prevent interconnect problems and aid system performance. When optical connectors are disconnected or reconnected, the fiber surface can become dirty or scratched. If not quickly addressed, dirt or damage may lead to interconnect problems and reduced system performance. Fiber-optic connectors should be inspected prior to mating and cleaned as needed to remove all dust and contaminants without leaving any residue. Connectors should be visually inspected after cleaning to confirm that they are clean and undamaged.

Note: The proper procedure for cleaning optical connectors depends on the connector type. The following describes general instructions for cleaning optical connectors. Many companies have established procedures for cleaning conductors which should be followed. If your company has established procedures, the following instructions should be considered along with your procedures.

• Connect or disconnect fiber only when equipment is OFF or in Service mode.

• Do not apply power to this equipment if the fiber is unmated or un-terminated.

• Do not look into an unmated fiber or at any mirror-like surface that could reflect light that is emitted from an un-terminated fiber.

• Do not view an activated fiber with optical instruments such as eye loupes, magnifiers, or microscopes.

• Use safety-approved optical fiber cable to maintain compliance with applicable laser safety requirements.

Recommended Equipment

The following equipment is recommended to clean the ends of fiber-optic connectors:

• CLETOP ® or OPTIPOP® ferrule cleaner

• Compressed air (also called “canned air”)

• Lint-free wipes moistened with optical-grade (99%) isopropyl alcohol

• Optical connector scope

Tips for Optimal Fiber-Optic Connector Performance

Follow these guidelines to ensure optimal connector performance:

• Do not connect or disconnect optical connectors while optical power is present.

• Always use compressed air before cleaning the fiber-optic connectors.

• Always use end caps on connectors when they are not in use.

• Always use compressed air to clean the end caps.

• If you have any degraded signal problems, clean the fiber-optic connector.

• Advance a clean portion of the ferrule cleaner reel for each cleaning.

• Turn off optical power before making or breaking optical connections in order to avoid microscopic damage to fiber mating surfaces.


365-095-22584-x.1 63

Connectors and Bulkheads

Most fiber-optic connectors are of the physical contact (PC) type. PC type connectors are designed to touch their mating connectors, thereby preventing air gaps which cause reflections. For optimum performance, all dirt must be removed.

Bulkheads can also become dirty enough to affect performance, either from airborne dust or from contamination introduced by connectors.

IMPORTANT: Read all warnings before performing cleaning procedures.

To Clean Fiber-Optic Connectors

Connector cleanliness is crucially important for optimum results in fiber-optic communications links. Even the smallest amount of foreign material can make it impossible to obtain the expected insertion and return losses. This can reduce the range of the equipment, shorten its expected service life, and possibly prevent the link from initializing at all.

New equipment is supplied with clean optical connectors and bulkheads. All optical connectors (bulkheads and jumpers) should be inspected using an appropriate optical scope prior to connector mating. If endface contamination is observed, the connector should be cleaned and then re-inspected to verify cleaning.

Important:

• All external jumper connectors must be cleaned before inserting them into the optical module.

• Before you begin, remove optical power from the module or ensure that optical power has been removed.

Complete the following steps to clean fiber-optic connectors that will be connected to the optical module:

1. Inspect the connector through an optical connector scope. If the connector is damaged, for example, scratched, burned, and so forth, replace the jumper.

2. If the connector is dirty but otherwise undamaged, clean the connector as follows:

a. Make several swipes across the face of the connector with the appropriate ferrule cleaner. This will remove dust and some films.

b. Listen for a slight "squeak" typically generated during this process, indicating a clean connector.

c. Inspect the connector again through the scope to confirm that it is clean.

3. If a second inspection indicates that further cleaning is needed:

a. Use 99% isopropyl alcohol and a lint-free wipe to clean the connector.

b. Use the appropriate ferrule cleaner again to remove any film left over from the alcohol.

c. Inspect the connector again through the scope and confirm that it is clean.

4. If necessary, repeat steps 3a-3c until the connector is clean.


365-095-22584-x.1 64

To Clean Bulkheads

IMPORTANT:

• Do not detach the bulkhead from the module front panel for cleaning under any circumstances. There is little or no slack in the fiber attached to the bulkhead, and any attempt to remove the bulkhead will risk damage to the fiber.

• It is generally more difficult to clean bulkhead connectors and verify their condition due to the inaccessibility of the fiber end face. For this reason, you should only attempt to clean a bulkhead connector when a dirty connector is indicated.

Complete the following steps to clean the bulkhead.

1. Insert a dry bulkhead swab into the bulkhead and rotate the swab several times.

2. Remove the swab and discard.

CAUTION Swabs may be used only once.

3. Check the bulkhead optical surface with a fiber connector scope to confirm that it is clean. If further cleaning is needed:

a. Moisten a new bulkhead swab using a lint-free wipe moistened with optical grade (99%) isopropyl alcohol.

b. With the connector removed, fully insert the bulkhead swab into the bulkhead and rotate the swab several times.

c. Remove the swab and discard. Swabs may be used only once.

d. Repeat steps 1 and 2 with a new dry bulkhead swab to remove any excess alcohol or residue.

e. Check with a fiber connector scope again to confirm that there is no dirt or alcohol residue on the optical surface.

f. If any alcohol residue remains, repeat steps 3d-3f.

4. Mate all connectors to bulkheads and proceed to Verifying Equipment Operation.

5. It is also recommended that all connectors be visually inspected after cleaning to verify the connector is clean and undamaged.

To Verify Equipment Operation

Perform circuit turn-up. If the equipment does not come up, that is fails verification or indicates a reflection problem, clean the connectors and bulkheads again.

VTN244 Fiber Deep 2x2 Optical Node Equipment Manual Appendix A – Accessories List

365-095-22584-x.1 65

Appendix A – Accessories List

Table A-9: Accessories list

Motorola Part Number Motorola Model Description

589941-001-00 VTN-RX-SC VTN-RX-SC, RCVR, VTN, -7 TO 0 DBM, OAGC

589935-003-00 VTN-DFBT-1550-SC VTN-200-DFB RTX,VTN-200 1550NM DISTRIBUTED FEEDBACK ISOL, 0 DBM, RETURN TX

589935-004-00 VTN-DFBT-SC VTN-DFBT-SC, RTX, VTN, 1310 NM, ISOL DISTRIBUTED FEEDBACK, 0 DBM

589937-001-00 VTN-DFBT3-1270-CWDM-SC VTN-DFBT3-1270-CWDM-SC, RTX, VTN, ISOL DFBT, CWDM, 3 DBM













A

VTN244 Fiber Deep 2x2 Optical Node Equipment Manual Appendix A – Accessories List

365-095-22584-x.1 66




589918-001-00 VTN-EURO-DOCSIS VTN-EURO-DOCSIS, VTN, TRANSPONDER, EURO-DOCSIS, FREQUENCY AGILE

589918-002-00 VTN-DOCSIS VTN-DOCSIS, VTN, TRANSPONDER, DOCSIS, FREQUENCY AGILE

589944-001-00 VTN-PS VTN-PS, VTN, POWER SUPPLY, NETWORK

VTN244 Fiber Deep 2x2 Optical Node Equipment Manual Appendix B – Specifications

365-095-22584-x.1 67

Appendix B – Specifications

Specifications for the VTN244 are valid over the given bandpass and operating temperature range listed in this section. The current catalog may contain additional information not provided below.

Table B-1: Optical Receiver Characteristics

Parameter Specification

Optical wavelength 1290 nm through 1610 nm

Received optical power

Range

Maximum

–7 dBm to 0 dBm (continuous)

+1 dBm

Optical input return loss 45 dB minimum

Equivalent input noise current 7 pa/Hz1/2

Receiver minimum output level with –3 dBm input level, 79-channel load

10 dBmV at 547.25 MHz

Table B-2: Station RF Characteristics


Forward passband frequency 52 MHz through 1003 MHz (dependent upon split)

Return passband, each port 5 MHz through 85 MHz (dependent upon split)

Splits

K

A

N

5-42/54-1003 MHz

5-65/85-1003 MHz

5-85/104-1003 MHz

Return loss 16 dB

Flatness over passband ±1.75 dB

Operational slope (linear)

Standard

1006 MHz

14.5 dB ±1.0 dB

B


365-095-22584-x.1 68

Table B-3: VTN244 General Characteristics

Parameter Specifications

AC input voltage 27 VAC to 90 VAC quasi-squarewave

AC bypass current 15 A

Hum modulation –60 dBc at 15 A bypass current (5 to 1003 MHz)

Operating temperature range –40 °C to +60 °C (–40 °F to +140 °F)

Housing dimensions 38.0 cm(L) × 23.3 cm(W) × 16.5 cm(D)

Weight 10.5 kg (23.1 lbs)

Table B-4: VTN244 Performance, 77 Channels


Carrier-to-Composite Noise (CCN) 50dB Minimum

Composite Triple Beat (CTB) -63 dBc Maximum

Composite Second Order (CSO) -59 dBc Maximum

Notes:

a. Link: VTN-RX w/GX2-LM1000*, 77 ch, 2 0km b. Loss budget 9.0 dB c. 14 dB tilt 1003 MHz virtual level of 54 dBmV d. 450 MHz of compressed data 6 dB below analog channel level e. Output level (1003, 550, 55 MHz), 54/48/40 dBmV

Table B-5: VTN-DFBT RF specifications


Nominal RF input impedance 75 Ohms

RF passband 5 MHz through 85 MHz

Flatness (peak to valley) 1.00 dB maximum

Recommended total input power -9 dBmV at Transmitter Test Point

Optical output power 1 mW (0 dBm), nominal

Noise power ratio over dB input dynamic range typical 40 dB NPR over 11 dB dynamic range


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Table B-6: VTN-DFBT/3 RF specifications


Nominal RF input impedance 75 Ohms

RF passband 5 MHz through 85 MHz

Flatness (peak to valley) 1.00 dB maximum

Recommended total input power -9 dBmV at Transmitter Test Point

Optical output power 2 mW (3 dBm), nominal

Noise power ratio over dB input dynamic range typical 40 dB NPR over 13 dB dynamic range

Corporate Headquarters ARRIS * Suwanee * Georgia * 30024 * USA T: 1-678-473-2000 F: 1-678-473-8470 http://www.arrisi.com

365-095-22584-x.1

http://www.arrisi.com/

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