CATV Linx 2809 Guide

825 Park Street Christiansburg, VA 24073 • TEL [phone] • FAX [phone] • USA [phone] • [e-mail] • www.forceinc.com
Model 2809
LDS CATV Receiver
IOM2809
Revision 2.0, March 2004
Instructions for Installation and Use
Read this manual before installing or using this product.
Observe all safety warnings and cautions.
Copyright © 2004 by Force, Incorporated. All rights reserved. Force, Incorporated reserves the right to make changes
to the product described in this document in the interest of document improvement.

Model 2809 CATVLinx® LDS CATV Receiver
Revision 2.0 ii
About this Manual
This manual explains how to configure and install the Model 2809 LDS CATV
receiver. It is intended for engineers and technicians who will install the 2809R
receivers with companion transmitter, Model 2806 (see IOM2806). While this
guide provides basic information on how to configure and install the units, it
assumes that you as the user are familiar with:
• the installation and manipulation of electronic and fiber optic equipment
• the installation and manipulation of CATV video/audio equipment
This manual is divided into the following sections:
•Section 1, page 1: Describes the LDS CATV receiver, lists technical specifica-
tions, performance graphs, system applications, and ordering information.
•Section 2, page 7: Describes the installation of the LDS CATV receiver, connec-
tions, and safety precautions.
•Section 3, page 11: Describes the operation of the LDS CATV link, trouble-
shooting, and user maintenance.
A quick-reference index completes the user manual.
Related Documentation
• IOM2806: User Manual for Model 2806 LDS Transmitter
• AN123: North American Television Frequencies
• AN128: Care and Feeding of Analog CATV Fiber Optic Links
• AN141: System Solutions for CATV HFC Networks
•Fiber Optic Reference Guide, 3rd Edition. by David R. Goff (Focal Press 2002):
General theory and operation of fiber optic units.
• Web Site: Our web site, http://www.forceinc.com may be used to download
the latest versions of this manual.
Preface

Model 2809 CATVLinx® LDS CATV Receiver Preface
Revision 2.0 iii
Technical Support
If you encounter any kind of problem after reading this manual, contact your local
distributor or a Force, Inc. Applications Engineer. To reach technical support:
Warranty
Force, Incorporated standard products are warranted to be free from defects in
materials and workmanship, meeting or exceeding factory specified performance
standards for a period of three (3) years from date of purchase.
Force Obligations
Force will, at its discretion and expense, repair any defect in materials or work-
manship or replace the product with a new product. Force will, upon receipt of
the return, evaluate the product and communicate to the customer the nature of
the problem, and determine if the claim falls under warranty coverage.
If during the warranty period, Force is unable to repair the product to the original
warranted state within a reasonable time, or if subcomponents of the unit have
been obsoleted or discontinued, then Force has the option to provide an equiva-
lent unit.
Exclusions
This warranty does not extend to any product that has been damaged due to acts
of God, accident, misuse, abuse, neglect, improper system design or application,
improper installation, improper operation or maintenance, or connection to an
improper voltage supply.
The Force warranty does not cover fuses, batteries, and lamps. Modifications or
alterations of Force products (including but not limited to installation of non-Force
equipment or computer programs), except as authorized by Force, will void this
warranty. Removal or breaking of the seals on the product will also void the war-
ranty. In addition, cost of repair by unauthorized persons within the warranty
period of the product will not be covered by Force, Incorporated. Such repairs
will void the warranty.
On the Web: http://www.forceinc.com
By Phone (Monday through Friday 8:00 am
to 5:00 pm EST):
USA [phone]
TEL [phone]
By Fax: [phone]
By Email: [email protected]

Preface Model 2809 CATVLinx® LDS CATV Receiver
iv Revision 2.0
Force, Incorporated makes no other representation or warranty of any other kind,
express or implied, with respect to the goods, whether as to merchantability, fit-
ness for a particular purpose, or any other matter. Force, Incorporated’s liability
shall not include liability for any special, indirect or consequential damages, or for
any damages arising from or attributable to loss of use, loss of data, loss of good-
will, or loss of anticipated or actual revenue or profit, or failure to realize expected
savings, even if Force, Incorporated has been advised of the possibility of such
damages. This warranty constitutes Force, Incorporated’s entire liability and the
customer’s sole remedy for defects in material and workmanship.

Model 2809 CATVLinx® LDS CATV Receiver
Revision 2.0 v
Preface................................................................................................................. ii
Section 1 Product Technical Bulletin..................................................................... 1
1.1 Product Overview................................................................................................. 1
1.2 FCC Notice ........................................................................................................... 1
1.3 Optical, Video, Electrical Characteristics ................................................................ 1
1.4 Environmental and Physical Characteristics ........................................................... 2
1.5 Specification Notes ............................................................................................... 2
Figure 1.1 In-Band Frequency Response .......................................................... 2
Figure 1.2 Expanded Frequency Response ....................................................... 3
Figure 1.3 CNR vs. Receiver Optical Input at 77 Channels .............................. 3
Figure 1.4 RF Output Level Behavior of 2809R................................................4
1.6 Applications.......................................................................................................... 5
Figure 1.5 Private Network Configuration ....................................................... 5
1.7 Ordering Information............................................................................................ 5
Section 2 Installation Instructions ................................................................ 7
2.1 General Installation Requirements......................................................................... 7
2.2 Items Provided...................................................................................................... 7
2.3 Items Required ..................................................................................................... 7
2.4 Inspection............................................................................................................. 8
2.5 Module Placement................................................................................................8
2.6 Unit Outline Drawing ........................................................................................... 8
Figure 2.1 Model 2809 CATVLinx®LDS CATV Receiver..................................... 8
2.7 Connections ......................................................................................................... 9
2.8 Safety Precautions ................................................................................................ 9
2.8.1 Laser Safety Procedures ....................................................................... 9
2.9 Shipping and Handling Precautions..................................................................... 10
2.10 Storing the Unit ................................................................................................ 10
Contents

Contents Model 2809 CATVLinx® LDS CATV Receiver
vi Revision 2.0
Section 3 Operating Instructions ........................................................................ 11
3.1 Theory of Operation ...........................................................................................11
Figure 3.1 Model 2809 Block Diagram ..........................................................11
3.2 Power-up and Operation ....................................................................................11
3.3 Measuring RF Input Levels at the Transmitter .....................................................12
3.4 Performance Verification..................................................................................... 12
3.5 Cleaning ............................................................................................................. 13
3.5.1 Connector Cleaning...........................................................................13
3.5.2 Connector Handling...........................................................................14
3.6 Troubleshooting..................................................................................................14
3.7 Repair Service .....................................................................................................14
Index ................................................................................................................. 15

Model 2809 CATVLinx® LDS CATV Receiver
Revision 2.0 1
1.1 Product Overview
The Force, Incorporated CATVLinx®Model 2809 Limited Distance Solution
(LDS) CATV Receiver, working with the Model 2806 LDS transmitter, provides
a low-cost system for transporting 77 channels of VSB/AM modulated signals over
a single-mode optical fiber. The LDS link provides excellent performance up to 10
km with full channel loading, high sensitivity, and 40-550 MHz of usable band-
width. With a wide optical input range of -8.0 dBm to +4.5 dBm and an RF output
of +18 dBmV at 0 dBm optical input, the Model 2809 allows high quality signal
transport for intra-facility limited distance applications, such as corporate CATV
delivery and FTTC where cost, small size, and performance are major consider-
ations. This low-cost system allows CATV providers with the ability to provide a
reliable limited distance fiber optic video distribution system.
1.2 FCC Notice
The Model 2809 has been tested and found to comply with the limits for a Class A
digital device, pursuant to Part 15 of the FCC Rules. These limits are designed to
provide reasonable protection against harmful interference when the equipment
is operated in a commercial environment. This equipment generates, uses, and
can radiate radio frequency energy and, if not installed and used in accordance
with the instructions in this manual, may cause harmful interference, in which
case the user must correct the interference at the user’s own expense. Compliance
with applicable regulations depends on the use of shielded I/O cables. The user is
responsible for procuring the appropriate cables.
1.3 Optical, Video, Electrical Characteristics: @ 25 °C, SM Fiber (Note 9)
Min. Typ. Max. Units Notes
See Section 1.5
Operating Wavelength 1290 1310 1330 nm
Operating Wavelength 1490 1550 1610 nm
Optical Input Power -8.0 +4.5 dBm
Channel Loading 77 Channels
Bandwidth 40 550 MHz
Required Fiber Bandwidth 2,000 MHz
Output Impedance 75 Ohms
RF Output Level +18 dBmV 1, 2
Section 1 Product
Technical Bulletin

Product Technical Bulletin Model 2809 CATVLinx® LDS CATV Receiver
2Revision 2.0
1.4 Environmental and Physical Characteristics
1.5 Specification Notes
1) The 2809 receiver does not include an adjustable RF output level. The unit is
designed to give approximately an RF output of +18 dBmV per channel at an
optical input of 0 dBm. The RF level will change by 2 dB for every 1 dB
change in optical input. At an optical input of -8.0 dBm, the RF level will be
about +2 dBmV per channel. At an optical input of +4.5 dBm, the RF level
will be approximately +27 dBmV per channel.
2) Figure 1.1 shows the typical frequency response of a 2806T/2809R link over
the specified frequency range. The gain flatness is ±1.5 dB over this range.
The flatness is typically less than ±0.1 dB over a standard 6 MHz channel
bandwidth. See Application Note AN123 for additional information on North
American Television Frequencies.
Figure 1.1 In-Band Frequency Response
Output Return Loss 16 dB
Composite Second Order (CSO) -63 dBc
Composite Triple Beat (CTB) -66 dBc
Carrier-to-Noise Ratio (CNR) See Figure 1.3, page 3. 3
Backreflection Tolerance -50 dB 5
Power Supply Voltage +8 +10 VDC 6
Power Dissipation 2 Watts
Min. Typ. Max. Units Notes
See Section 1.5.
Operating Temperature Range 0 +50 °C 7
Storage Temperature Range -20 +70 °C
Humidity 5 95 % 8
Weight 6.6 oz.
187 g
Physical Dimensions 3.75 x 2.95 x 1.12 in.
95 x 75 x 29 mm
Min. Typ. Max. Units Notes
See Section 1.5
0 100 200 300 400 500 600 700 800 900 1000
-30
-25
-20
-15
-10
-5
0
5
Frequency (MHz)
Response (dB)

Model 2809 CATVLinx® LDS CATV Receiver Product Technical Bulletin
Revision 2.0 3
Figure 1.2 shows an expanded view of the frequency response of a typical
2806T/2809R link.
Figure 1.2 Expanded Frequency Response
3) Figure 1.3 show the CNR versus received optical input power and number of
channels. The horizontal axis is the amount of optical light that reaches the
receiver. (It is not the loss between the transmitter and receiver.) The vertical
axis shows the CNR.
Figure 1.3 CNR vs. Receiver Optical Input at 77 Channels (2806T with 2809R)
The link CNR is usually specified for a received optical power of -3 dBm or
more. Thus, a 2806T-SCSP optical transmitter, with an optical output of +4.5
dBm, will provide optimal performance with up to 7.5 dB of optical loss at full
channel loading. If lower channel loading is used, then the link can operate at
higher optical losses and still provide exceptional CNR.
Typical transmitter output is +4.5 dBm, so a received optical power of -3.5
dBm corresponds to an optical loss of 8 dB. Five curves are plotted; the top
curve is the typical result when only 5 channels are transmitted through the
link. It can be seen that very high CNR results and in fact the output is quite
usable with receiver optical inputs as low as -12 dBm, corresponding to 16 dB
of optical loss! As the channel loading gets higher, the maximum achievable
CNR drops.
50 100 150 200 250 300 350 400 450 500 550
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
Receiver Optical Input (dBm)
Carrier-to-Noise Ratio (dB)
5 Ch.
10 Ch.
24 Ch.
40 Ch.
77 Ch.
36
38
40
42
44
46
48
50
52
54
56
58
60
62
64
-12 -11 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1 01234

Product Technical Bulletin Model 2809 CATVLinx® LDS CATV Receiver
4Revision 2.0
4) Figure 1.4 shows the RF output behavior of the 2809 receiver. The blue line
shows the nominal Rf output level versus optical input. Over the optical input
range from -8 dBm to +4.5 dBm, the RF output level varies by 2 dB for every
1 dB drop in optical input power. Operating below -8 dBm optical input will
cause the CNR to degrade rapidly for channel loads of 77 or more.
Figure 1.4 RF Output Level Behavior of 2809R
In Figure 1.4 the central green area is the region that should be used for new
designs. So while the receiver is rated to optical input powers as low as -8
dBm, it is recommended that -6 dBm be the minimum for a newly installed
system. That leaves 2 dB of margin for the optical power to drop and still pro-
vide good operation. The yellow region is the safety band. The unit is rated to
operate in this region; however, the margin will probably be inadequate for a
newly installed design. The red regions are outside the recommended operat-
ing parameters of the 2809R and must be avoided to ensure reliable opera-
tion.
5) This product must be used only with APC type optical connectors or
fusion spliced connections. There is some folklore which suggests that the
only critical backreflection is the one closest to the transmitter. Our experience
does not support that view. We find that all backreflections matter, regardless
of their distance from the transmitter.
6) Force, Inc. recommends using the Model PS095 wall-mount power supply
(see TB043) with the Model 2809 receiver.
7) Most parameters are relatively unaffected by varying temperature. A moving
air environment is recommended at ambient temperatures above +35°C.
8) Humidity is RH non-condensing.
9) The CATVLinx®LDS CATV receiver is optimized for single-mode operation only.
Use on multimode fiber is not recommended, even for short distances,
because of the large amount of modal noise that could result.
-10
-2
0
2
4
6
8
10
RF Output Level (dBmV/Channel)
12
14
16
18
20
22
24
26
28
30
-8
Optical Input (dBm)
-6 -4 -2 0246

Model 2809 CATVLinx® LDS CATV Receiver Product Technical Bulletin
Revision 2.0 5
1.6 Applications
Figure 1.5 illustrates a small private CATV network, such as one might find in an
educational or business campus, where local cable feeds can be routed through-
out the campus to multiple receiver sites.
Figure 1.5 Private Network Configuration
1.7 Ordering Information
Part Number Description
2809R-SFSP LDS CATV VSB/AM Rx, SM, 1310/1550 nm, SC/APC Connector
2809R-SFAP* LDS CATV VSB/AM Rx, SM, 1310/1550 nm, FC/APC Connector
*Note: The FC/APC interface uses the “wide-key” standard. This means that the units are
optimized for use with FC/APC connectors that have a 2.14 mm wide alignment key. “Nar-
row-key” FC/APC connectors (2.02 mm) may be used but will produce inferior results. Stan-
dard FC/PC connectors have a 2.36 mm wide key and cannot be plugged into either unit.

Product Technical Bulletin Model 2809 CATVLinx® LDS CATV Receiver
6Revision 2.0
Notes:

Model 2809 CATVLinx® LDS CATV Receiver
Revision 2.0 7
2.1 General Installation Requirements
The installation of these units is very simple. There are no special unpacking
instructions, except that care should be taken to handle units gently. Fiber optic
links are sensitive electronics devices that should be handled with care. Like most
electronics, they are susceptible to ESD. Proper ESD techniques, such as wearing
a wrist grounding strap, should be observed at all times when handling a unit. The
units should not be dropped. No assembly is required.
Do not install the equipment near sources of excessive heat, such as furnace out-
lets or above heat producing units, such as large power supplies and tube-type
equipment. Observe temperature and relative humidity requirements specified in
Section 1.3, page 2.
2.2 Items Provided
The following is a list of items provided with each Model 2809 LDS CATV
Receiver:
2.3 Items Required
Qty. Mfr. P/N Description
AR Force, Inc. 2809R-SFXX
CATVLinx®LDS CATV Rx, SM, 1310/1550 nm,
SC/APC Connector Standard, FC/APC
Optional
1 per
connector Any Any Active Device Receptacle Caps for RF and Optical Connectors
Qty. Mfr. P/N Description
AR Force, Inc. 2806T-SCXX
CATVLinx®77 Ch. LDS CATV Tx, SM, 1310 nm,
SC/APC Connector Standard, FC/APC
Optional
1 per Rx Force, Inc. PS095-1 Power Supply for Receiver, +9 Volts DC, 500
mA, 2-Pin Power Connector
4 per unit Any Any 6-32 Panhead Mounting Screws with Lock
Washers and Nuts
AR Any Any Straight Screwdriver
AR Any Any 9/125 µm Single-mode Fiber
Section 2 Installation
Instructions

Installation Instructions Model 2809 CATVLinx® LDS CATV Receiver
8Revision 2.0
2.4 Inspection
Remove the unit from its shipping container. Any in-shipment damage that may
have occurred should be visually apparent. Look for bent or damaged connectors
or mounting brackets. Claims for damage incurred in shipment should be made
directly to the transportation company in accordance with their instructions. Save
the shipping cartons until installation and performance verification are completed.
2.5 Module Placement
Units may be mounted in any orientation on most flat, dry surfaces. Secure pan-
head screws through mounting holes provided at the base of the module. If the
unit is placed in a location where temperatures may exceed 38°C (100°F), a good
heat sink should be secured. The use of silicone thermal pads is recommended
between the module and the plate to maximize heat transfer.
2.6 Unit Outline Drawing
Figure 2.1 Model 2809 CATVLinx®LDS CATV Receiver
(Dimensions in parentheses are in millimeters.)
A
2.95"
(75)
BCD
1.12
"
(29)
2.50"
(64)
.16" DIA. MOUNTING
HOLES (4 PLACES)
3.75"
(95)
3.375"
(86)
Pin 1
A. Optical Level LED (Tri-colored LED): Indicates
that the unit is receiving sufficient optical pow-
er. If the optical input is too low, the LED will be
yellow. If the optical input is too high, the LED
will be red.
B. RF Out (F Connector): RF output from the re-
ceiver.
C. Power (2-Pin Weidmuller Connector): Inter-
face connector for the Model PS095-1 wall-
mount power supply, which provides +8 to
+10 Volts DC power to the receiver. See Sec-
tion 2.7, page 9 for pin connections.
D. Optical In (SC/APC Standard, FC/APC Option-
al): Optical input to the receiver.
WARNING
Invisible laser radiation emitted from the fiber
that attaches to this connector. Avoid direct
eye contact with the beam.

Model 2809 CATVLinx® LDS CATV Receiver Installation Instructions
Revision 2.0 9
2.7 Connections
2.8 Safety Precautions
The optical emission from the transmitters used with this product are laser-based
Class IIIb, as are the emission from the optical connector that connects to the
receiver optical port. Class IIIb laser emissions may present eye hazards if improp-
erly used. NEVER USE ANY KIND OF OPTICAL INSTRUMENT TO VIEW
THE OPTICAL OUTPUT OF THE UNIT. As always, be careful when working
with optical fibers. Fibers can cause painful injury if they penetrate the skin.
2.8.1 Laser Safety Procedures
1) ALWAYS read the product data sheet and the laser safety label before power-
ing the product. Note the operating wavelength, optical output power, and
safety classification.
2) If safety goggles or other eye protection are used, be certain that the protec-
tion is effective at the wavelength(s) emitted by the device under test
BEFORE applying power.
3) ALWAYS connect a fiber to the output of the device BEFORE power is
applied. Power should never be applied without an attached fiber output. If
the device has a connector output, a connector should be attached that is
connected to a fiber. This ensures that all light is confined within the fiber
waveguide, virtually eliminating all potential hazard.
4) NEVER look in the end of a fiber to see if light is coming out. NEVER! Most
fiber optic laser wavelengths (1310 nm and 1550 nm) are totally invisible to
the unaided eye and will cause permanent damage. Shorter wavelength
lasers (e.g. 780 nm) are visible and are very damaging. Always use instru-
ments, such as an optical power meter, to verify light output.
5) NEVER NEVER NEVER look into the end of a fiber on a powered device
with ANY sort of magnifying device. This includes microscopes, eye loupes,
and magnifying glasses. This WILL cause a permanent, irreversible burn on
your retina. Always double check that power is disconnected before using
such devices. If possible, completely disconnect the unit from any power
source.
6) If you have questions about laser safety procedures, please call Force, Incor-
porated for assistance before powering your product. A Sales Engineer or
Applications Engineer may be reached at [phone].
Connector Name Connector Type Connector Function
Optical In
SC/APC or FC/APC* Optical Input
It is imperative that backreflections be controlled to very low levels.
This product must be used only with angle physical contact (APC)
connectors.
RF Out F Connector RF Output
Power
+9 VDC
2-Pin Weidmuller Con-
nector
Pin Function
1+8 to +10 Volts DC
(+9 Volts DC Typ.)
2Ground
*Note: The FC/APC interface uses the “wide-key” standard. This means that the units are
optimized for use with FC/APC connectors that have a 2.14 mm wide alignment key. “Nar-
row-key” FC/APC connectors (2.02 mm) may be used but will produce inferior results.
Standard FC/PC connectors have a 2.36 mm wide key and cannot be plugged into either
unit.

Installation Instructions Model 2809 CATVLinx® LDS CATV Receiver
10 Revision 2.0
7) Laser safety classes for the Model 2805 are as follows:
2.9 Shipping and Handling Precautions
The units are, in general, very rugged and can withstand the stresses of most ship-
ping and handling circumstances. However, the following precautions should be
taken:
1) When the units are shipped they should be wrapped in a protective material,
such as bubble wrap, to protect against excessive jarring and to prevent dam-
age to the external finish of the units. Always use packing material to separate
multiple units that are packaged together.
2) Care should be taken not to drop or strike the units in any way, especially
around the optical connectors.
3) The units should never be submersed in any liquid. SEVERE SHOCK HAZ-
ARD!
2.10 Storing the Unit
If a unit is to be out of use for an extended period of time, the following steps
should be taken to ensure the preservation of the unit:
1) The storage temperature range is -20°C to +70°C.
2) A low humidity environment is preferable for long term storage.
3) All connectors should be covered with active device receptacle caps.
Class Wavelength Range Optical Power Accession Limits
IIIb 180 nm to 400 nm Varies with λand exposure time.
400 nm to 106nm 0.5 Watt

Model 2809 CATVLinx® LDS CATV Receiver
Revision 1.0 11
3.1 Theory of Operation
The 2809 is a sophisticated, state-of-the-art CATV receiver. It provides an impres-
sive set of capabilities in an extremely small package. Key features include:
• Low power operation
• Very cost effective
• Very wide optical input range
• Exceptional CNR performance over the full optical input range
• High output RF level
Figure 3.1 shows a block diagram of the 2809R.
Figure 3.1 Model 2809 Block Diagram
3.2 Power-up and Operation
1) Install the links as described in Section 2, page 7.
2) Measure the RF level BEFORE making any connections to the transmitter. This
measurement is described in Section 3.3, page 12.
3) Clean the optical connectors. See Section 3.5, page 13 for cleaning instruc-
tions. Be sure all optical connectors are APC type.
4) Connect the optical fiber to the transmitter and the receiver. Be sure that the
fiber has continuity and less than the maximum allowable optical loss. Also be
Preamplifier
Photodiode
A1 A2
Power Amplifier
RF Output
Status & Alarm
Circuitry Status LEDs
Section 3 Operating
Instructions

Operating Instructions Model 2809 CATVLinx® LDS CATV Receiver
12 Revision 1.0
certain that the fiber is the proper size. This product can only be used with sin-
gle-mode fiber. The input power to the Rx must be less than +4.5 dBm. The
units will work back-to-back with the Model 2806 transmitter.
5) Connect the RF source (VCR, camcorder, cable television, etc.) to the RF
input on the transmitter.
6) Connect the RF output on the receiver to the monitor input. The monitor
input should present a 75 Ohm impedance.
7) Connect the AC power cord to the transmitter and the PS095 wall-mount
power supply to the receiver.
8) The unit is now fully operational. Verify the proper operation of the link by fol-
lowing the steps in Section 3.4, page 12. No user adjustment or attention is
required. See Section 3.5, page 13 for instructions on maintaining and clean-
ing the link. See Section 3.6, page 14 for information on troubleshooting.
3.3 Measuring RF Input Levels at the Transmitter
Excessive RF input to a fiber optic CATV transmitter WILL destroy the laser even if
the unit is not powered. Lasers can be destroyed by being overdriven for as little
as one nanosecond (10-9 seconds). Because they can be destroyed so quickly, it is
essentially impossible to design a circuit or “fuse” that will blow before the laser is
destroyed. Therefore it is imperative that the RF level be within acceptable limits
BEFORE the cable is attached to the transmitter.
1) Using a spectrum analyzer, determine that the RF level input to the transmitter
is within safety bounds.
2) The “RF In” LED on the unit gives a positive indication of the RF level. If the
LED is yellow, the RF level is too low. Increase in 2 dB steps until the LED turns
green. If the LED is red, the RF input level is too high. Disconnect the RF input
immediately. Decrease RF levels by 6 dB and reconnect the RF input until the
LED turns yellow or green. If it turns yellow, increase RF levels by 2 dB steps
until the LED turns green.
Ideally, the RF level should be checked with an instrument such as a spectrum
analyzer to verify that the levels are appropriate. If instrumentation is not
available to actually measure the RF levels, Force recommends adding 40 dB
of attenuation at the transmitter input; 40 dB of attenuation will adequately
protect the unit from the highest RF levels that might be seen in a typical
CATV installation. Do not attach the RF cable at this time, just verify the RF
levels and/or add the appropriate attenuators at the transmitter input.
3.4 Performance Verification
No user maintenance is required. The Model 2809 CATVLinx®LDS CATV Receiver
contains no user-serviceable parts and requires no routine service. Contact the
factory if the unit requires warranty repair work. Once the units have been
installed, verify that the picture quality is good. If the picture quality is not good,
there are several likely causes:
1) The optical fiber may have large backreflections. Use an OTDR to examine the
fiber run.
2) There may be non-APC optical connectors somewhere in the system. These
cause unacceptable levels of backreflection.
WARNING
OPTICAL LASER RADIATION IS PRESENT AT THE TRANSMITTER OPTICAL CONNEC-
TOR AND THE FIBER THAT ATTACHES TO THE RECEIVER OPTICAL CONNECTOR
WHEN THE UNIT IS ACTIVATED. AVOID DIRECT EYE EXPOSURE TO THE BEAM.

Model 2809 CATVLinx® LDS CATV Receiver Operating Instructions
Revision 1.0 13
3) The RF input spectrum may not be flat. It is possible to have a green RF Level
LED even if the input spectrum has a large amount of tilt. All Force CATV
products are designed to operate with a flat input spectrum.
4) There may extraneous (i.e., non-video) signals in the input RF. Be sure to filter
out all non-desirable signals.
5) The optical input power at the receiver may be too low. Assuming that the
receiver shows a yellow light, the optical input level may be too low. See Fig-
ure 1.4 for the expected CNR versus the channel loading and received optical
power.
3.5 Cleaning
If the units need to be cleaned, avoid the use of all solvents and use low-pressure
clean air to remove loose dirt. Use low-pressure clean air to clear the connectors
of any debris. Dirty or scratched connector end faces will greatly reduce the unit’s
performance. Foam-tipped swabs such as the 2.5mm Mini Foam Swab offered by
Fiber Instrument Sales (P/N F1-0005) may be saturated with denatured alcohol*
and inserted into the optical port for cleaning. DO NOT INSERT A DRY SWAB
INTO THE OPTICAL PORT AS THIS MAY DAMAGE THE FIBER END FACE. Many
fiber optic installations experience degraded performance due to dirty optical con-
nector end faces. The following procedure should be used to properly clean the
optical connector end faces.
3.5.1 Connector Cleaning
Required Cleaning Equipment:
•Kimwipes
®or any lens-grade, lint-free tissue. The type sold for eyeglasses work
quite well.
• Denatured Alcohol.
• 30X Microscope.
• Canned Dry Air.
Directions for Cleaning:
1) Fold the tissue twice so it is four layers thick.
2) Saturate the tissue with alcohol.
3) First clean the sides of the connector ferrule. Place the connector ferrule in
the tissue, and apply pressure to the sides of the ferrule. Rotate the ferrule sev-
eral times to remove all contamination from the ferrule sides.
4) Now move to a clean part of the tissue. Be sure it is still saturated with alcohol,
and it is still four layers thick. Put the tissue against the end of the connector
ferrule. Put your fingernail against the tissue so that it is directly over the fer-
rule. Now scrape the end of the connector until it squeaks. It will sound like a
crystal glass that has been rubbed when it is wet.
5) Use the microscope to verify the quality of the cleaning. If it isn’t completely
clean repeat the steps with a clean tissue.
6) Mate the connector immediately! Don’t let the connector lie around and col-
lect dust before mating.
7) Air can be used to remove lint or loose dust from the port of a transmitter or
receiver to be mated with the connector. Never insert any liquid into the
ports.
NOTE
Use only industrial grade 99% pure isopropyl alcohol. Commercially available isopropyl
alcohol is for medicinal use and is diluted with water and a light mineral oil. Industrial
grade isopropyl alcohol should be used exclusively.

Operating Instructions Model 2809 CATVLinx® LDS CATV Receiver
14 Revision 1.0
3.5.2 Connector Handling
1) NEVER TOUCH THE FIBER END FACE OF THE CONNECTOR.
2) Connectors not in use should be covered over the ferrule by a plastic dust
cap. It is important to note that inside of the ferrule dust caps contains a sticky
gelatinous residue that is the by-product of the making of the dust cap. This
residue will remain on the ferrule end after the cap is removed. Therefore it is
critical that the ferrule end be cleaned thoroughly BEFORE it is mated to the
intended unit.
3.6 Troubleshooting
Common problems include lack of continuity in the optical fiber, lack of power (or
reversed power), or improper input levels. The units are designed to work with a
75 Ohm system. Consult IOM2806 for additional troubleshooting of the transmit-
ter. If problems persist, contact the factory.
3.7 Repair Service
For equipment repair or technical assistance, contact Customer Service (800) 732-
5252 (USA) or [phone]. A Returned Material Authorization (RMA) number
must be issued by Customer Service before the return of a failed unit. Units should
be returned in their original shipping carton, if available. Always include a com-
plete description of the failure or observed anomalies. All units are marked with
model number and serial number. This identification sticker is placed on the rear
panel (transmitter) or on the product label (receiver). The serial number is a date
code used as a reference for warranty service.
Problem Check Comments
No optical power out of Tx. Check Tx AC power connec-
tion.
If AC power is connected,
check the primary AC power
source to verify it is working.
Contact Force, Inc. if no
cause for this problem can be
found.
No optical power at the 2809
Rx.
Check optical power output at
the Tx.
If there is optical power at the
Tx output, verify proper fiber
is connected to the Rx. If the
proper fiber is connected,
ensure the integrity of the
fiber.
Signal out of 2809 Rx is noisy. Check optical power at the
Rx.
See IOM2806 for the correct
transmitter input levels
required for proper opera-
tion. Be sure to ground the
case of the Tx and Rx. Also,
verify that all optical connec-
tors are APC type.
No signal out of Rx. Verify the input signal at the
Tx.
See IOM2806 for the correct
transmitter input levels
required for proper opera-
tion.
Signal out of Rx is distorted.
Verify input signal at Tx.
The Tx input must be within
the specs given in IOM2806.
A larger signal will cause dis-
tortion.
Verify fiber size. Single-mode fiber must be
used with this product.