C-COR NA15T Series Reference guide

1550 Transmitter - NA15T Series
and 1550 EDFA - NA25E Series
Procedures Manual
1550 Transmitter
1550 EDFA
1550 EDFA
1550 Transmitter
1550Cover.fm Page 1 Tuesday, October 5, 1999 3:02 PM

C-COR
1550 Transmitter - NA15T Series
and 1550 EDFA - NA25E Series
MX0860.fm Page 1 Wednesday, August 25, 1999 1:34 PM

1550 Transmitter - NA15T Series and 1550 EDFA - NA25E Series:
Copyright © 1999 C-COR.net Corp. All rights reserved.
C-COR Document Number: MX0860 Revision B
C-COR®, C-COR.net, and FlexNet®are registered trademarks of C-COR.net Corp.
Navicor™ and CNM™ are trademarks of C-COR.net Corp.
All other brand and product names are trademarks or registered trademarks of their respective companies.
Contents and specifications within this manual are subject to change without notice.
For additional information:
Call C-COR’s Technical Customer Service (TCS) Department Monday through Friday during
business hours
(8 AM to 5 PM ET [+5GMT]):
State College Office: [phone]
Toll Free (US and Canada only): 800-233-2267
Hotline (Emergencies Only): [phone]
Write to us at:
C-COR.net Corp.
Attn: TCS Department
60 Decibel Road
State College, PA 16801
USA
Visit us on the World Wide Web at:
http://www.c-cor.com
To give us feedback on this document:
Send an e-mail to [e-mail] mentioning the document number and page number(s) to
which the feedback applies.
MX0860.fm Page 2 Wednesday, August 25, 1999 1:34 PM

MX0860 Revision B Introduction 3
1.0 Introduction
This document details the installation and operation of the Navicor 1550 Externally Modulated 1RU
Transmitter (C-COR NA15T Series) and the Navicor 1550 Erbium Doped Fiber Amplifier or EDFA (C-COR
NA25E Series). The transmitter converts RF signals to optical signals on optical fiber. The EDFA amplifies
an input from several optical fibers and outputs it to one optical fiber. For specifications other than those
shown here, consult the specification sheets for the individual model and consult C-COR as necessary to
define link performance.
Table 1. Transmitter (NA15T series) Input/Output Specifications
Wavelength 1550-1560 nm
1552±3nm
1555±3 nm
NA15T-x-xA0xxx
NA15T-x-xB1xxx
NA15T-x-xB2xxx
Frequency Range 40-862 MHz
79 NTSC Channel
RF Input 24±3 dBmV
42 Channel Cenelec
RF Input 26±3 dBmV
Transportation Distribution Extended Range High Output
Distribution
(NA15T-S) (NA15T-T) (NA15T-D) (NA15T-E) (NA15T-H)
Output Power
(dBm)
(Output 1/Output 2)
7.0/6.0 7.0 8.5/8.5 7.0
Second output is 6.0 but
does not give similar CSO
performance
10.5/10.5
Range at specified
performance
(Output 1/Output 2)
assuming 0 dBm
arriving at Receiver
(2 dBm for
NA15ST-x-xBxxxx)
65 km
(40.6 mi)
with an
immediately
following
EDFA
65 km
(40.6 mi)
with an
immediately
following
EDFA
35 km
(21.9 mi)
at both outputs
65-100 km
(40 - 62 mi)
when used in conjunction
with an immediately
following EDFA, and an
EDFA at 45 km (27.9 mi).
Longer distancesare possible
with reduced performance.
45 km
(27.9 mi)
at both outputs
SBS Suppression
Limit (defines the
maximum dBm of
input by any EDFA
within the link)
16 16 EDFAs can be
used if launch
power into fiber
is >12dBm.
Output of EDFA
must be split.
13 12
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4 Introduction MX0860 Revision B
Table 2. EDFA (NA25E series) Basic Input/Output Specifications
Input Power 0 to 12 dBm
Wavelength 1555±5 nm
Model Number NA25E-
13S 16S 19D 19L 22D 22L 24D 24L
Output
(dBm Typical)
with Š3dBm Input 13.3 16.3 16.0 19.0
±0.25 15.5 22.0
±0.25 15.25 24.0
Output
(dBm min)
with ≥3dBm Input 13.0 16.0
15.5 at
eachof
2
outputs
18.5
15.3 at
eachof
the 4
outputs
21.5
14.75
at each
of 6
outputs
23.5
Table 3. Environmental / Powering (for Transmitter and EDFA)
Dimensions Width: 48.3 cm (19.0 in)
Height: 4.4 cm (1.75 in)
Depth: 35.6 cm (18.6 in)
Weight 9.1 kg (20 lbs) maximum
Optical Connector Types FC/APC, SC/APC
E2000/APC
Storage Temperature -25° C to 70° C
Operating Temperature 0° C to 50° C
Operating Humidity 20% to 85% non-condensing
AC Powering 90 to 260VAC, 50/60 Hz
DC Powering (-48VDC)-36 to -60VDC
MX0860.fm Page 4 Wednesday, August 25, 1999 1:34 PM

MX0860 Revision B Introduction 5
1.1 Statement of Warranty
C-COR shall, at its expense, correct any defect in material and workmanship in products manufactured by
C-COR which may appear within the warranty period, as set forth herein. C-COR MAKES NO OTHER
REPRESENTATION OR WARRANTY OF ANY OTHER KIND, EXPRESS OR IMPLIED, WITH
RESPECT TO THEGOODS, WHETHER AS TOMERCHANTABILITY, FITNESS FOR A PARTICULAR
PURPOSE OR ANY OTHER MATTER.
The “warranty period” is as follows:
1. Distribution electronics, such as amplifiers, main line passives, and power supplies: five (5) years
from date of shipment.
2. AM fiber optic products: three (3) years from date of shipment.
3. Cable Network Manager (CNM™) network management software and associated equipment:
fifteen (15) months from date of shipment. Network Management Transponders (NMT): warranted
as unit in which they are installed for a maximum of three (3) years. When installed in unit already
in the field, NMT will have remaining warranty of that unit, up to three (3) years and no less than
one (1) year.
4. Terminal, modem, and translator products: one (1) year from date of shipment.
5. Specialty goods manufactured in C-COR’s Equipment Service Center: CATV products: three (3)
years from date of shipment; DATA products: one (1) year from date of shipment.
6. All other goods: ninety (90) days from date of shipment.
C-COR’s warranty shall not cover fuses, batteries, and lamps. It does cover transistors and integrated circuits
to the extent that C-COR is warranted by the original manufacturer. Modifications or alterations of C-COR
products (including but not limited to installation of non-C-COR equipment or computer programs) except
as performed by C-COR or its authorized representative, will void this limited warranty.
1.2 Conventions
The following symbols are used throughout this document:
Note: Read for added information and reminders. A note can tell you when a service
interruption could occur.
Caution: Equipment damage may result if instructions are not followed.
Warning: Personal injury could result if instructions are not followed.
Laser Warning for Service Group SG3b: Disconnected optical connectors may emit
invisible optical radiation.Avoid direct eye exposure to the beam. Laser light, visible or
invisible, can seriously injure eyes or even cause blindness.
!
Caution
Warning
DANGER
laser light
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6 Introduction MX0860 Revision B
1.3 Network Management
1550 EDFA and Transmitters will be compatible with C-COR’s Cable Network Management (CNM™)
system (to be added by C-COR). Call C-COR for more information.
1.4 Statements of Compliance
FCC Compliance:
This device complies with Part 15 of the FCC Rules. Operation is subject to the following two conditions:
(1) This device may not cause harmful interference, and (2) this device must accept any interference received,
including interference that may cause undesired operation.
FDA Compliance:
This device complies with 21 CFR 1040. Use of controls or adjustments or performance of procedures other
than those specified herein may result in hazardous radiation exposure.
OSHA/ANSI Compliance:
This device complies with ANSI Z136.2.
CE Compliance:
This device conforms to the protection requirements of Council directive 89/336/EEC on the approximation
of the laws of the Member States relating to electromagnetic compatibility.
MX0860.fm Page 6 Wednesday, August 25, 1999 1:34 PM

MX0860 Revision B Introduction 7
1.5 Tools and Materials
Table 4 describes the tools, equipment, and materials that may be required to maintain the 1550 EDFA and
transmitter. Anyone performing the procedures in this manual is expected to be familiar with the appropriate,
safe use of these tools. Tools or equipment with superior specifications may be substituted for those listed.
Table 4. Tools and Materials
Tools/Equipment Required Characteristics Uses
Torque wrench/driver Up to 66 in-lbs (4.0 to 7.5 N·m), with
interchangeable 7/16 inch or 11 mm
hex socket, Phillips, flat blade, and
TORX®or TORX PLUS®bits
Strand mounting, housing closing,
tightening various fasteners; C-
COR recommends torquing all bolts
and screws to the appropriate values
whenever specified
Nutdriver*
*An 11 mm nutdriver or wrench can normally be used in place of a 7/16 inch tool if the bolt and nutdriver are manufactured
to nominal “across the flat” tolerances. A non-fit will occur if the nutdriver is manufactured to minimum dimensions and the
bolt head to maximum dimensions.
7/16 inch (11 mm) Housing opening and closing
Phillips screwdriver†
†Small, hold-down screws may be Phillips head screws or TORX PLUS head screws. Use the appropriate driver.
#2 Centerseizure screws, module cover
screws, power supply and
transponder hold-down screws
TORX®or TORX PLUS®
driver†T15 (TORX®) or 15 I.P. (TORX PLUS®)may be required for small fasteners
Flat blade screwdrivers 1/4 inch, 5/16 inch may be required for small fasteners
Fuse puller Non-conductive (C-COR Part
Number FP-1) Fuse removal and installation
Compressed air non-residue, inert gas, ultra-filtered
to <0.2 microns; recommended for
optical systems
Fiber cleaning
Lint-free cloth and 99%
isopropyl alcohol — Fiber cleaning
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8 Introduction MX0860 Revision B
1.6 FDA/ANSI Classifications
The wavelengths of light typically transmitted through the optical fibers used in hybrid fiber/coaxial cable
(HFC) architecture fall in the infrared band of the light spectrum and are not visible to the human eye. Lasers
that generate beams of very intense light are classified according to their optical power. Optical receivers and
transmitters are, thus,classified according to thelaser radiation associated with the respectiveoptical module.
Refer to Section 1.2 for laser warnings.
Laser Class Power Comments
1
(Exempt) —Considered to be incapable of producing damaging radiation levels
during operation or maintenance.
2
(Low) < 1mW Emits in the visible portion of the spectrum (400 to 700nm). Normal
blink reflex (aversion response to bright light) provides adequate eye
protection.
Divided into subclasses 2 and 2a:
■Subclass 2 lasers are not capable of emitting accessible radiation
greater than the Class 1 Accessible emission Limit (AEL) when
0.25 seconds is used as the exposure duration.
■Subclass 2a lasers do not emit radiation that exceeds the Class 1
AEL for an exposure duration of ≤1000 seconds.
3
(Medium) 1mW–
500mW Hazardous under direct and specular reflection viewing conditions. Diffused reflection usually not a hazard. Not a fire hazard.
Divided into subgroups 3a and 3b:
■Subclass 3a lasers are potentially hazardous only if the output is
collected and focused into the eye or onto the skin.
■Subclass 3b lasers produce acute eye hazards even at the shortest
exposure duration.
4
(High) > 500mW Poses hazards to the eye and skin not only from direct beam but also
from diffused reflection. Can be a fire hazard.
Optical modules Optical Power/Wavelength ANSI/FDA
Laser Class ANSI Service Group
Transmitters
NA15T series between 6 and 8.5mW of
1550±10nm radiation Class 3b SG3b
EDFAs
NA25E series between 13 and 22mW of
1550±10nm radiation Class 3b SG3b
MX0860.fm Page 8 Wednesday, August 25, 1999 1:34 PM

MX0860 Revision B Fiber Care and Cleaning 9
2.0 Fiber Care and Cleaning
The fiber optic medium does not suffer from problems associated with copper-based coaxial cables, such as
electromagnetic interference and increasing loss of signal power at higher frequencies and cable lengths.
However, the ability of the optical fiber, a thin, flexible strand of silica glass, to enable light to travel through
it with as little impedance as possible depends on the purity of the glass, the manner of its construction, and
its care during handling, splicing, and installation. The information in the following sections should be
considered before installation. Consult Recommended Practices for Optical Fiber Construction and Testing
published by the Society of Cable Telecommunications Engineers (SCTE) for further information.
2.1 Fiber Handling
Often fiber optic cable must be unreeled before installation. SCTE recommends the figure-eight method to
avoidtwistingor bending.Forshorterlengthsof fiber cable(~2000 feet or600meters),removethefibercable
from the reel, and coil it on the ground into a figure-eight about 15 feet (4.5 meters) in length, with coils
5 feet (1.5 meters) in diameter. For longer lengths of fiber cable, coil the fiber cable into a figure-eight about
30 feet (9 meters) in length, with coils 10 feet (3 meters) in diameter. Use cardboard shims between sections
of fiber cable at the crossover locations of the figure-eight to relieve excess pressure.
Singlemode fiber, typically used in HFC architecture, is composed of an 8µm glass core, surrounded by
100-200µm of cladding, which protects the core and serves to bendthe optical energy back into the core. The
cladding is protected by a 1mm plastic buffer coating. To ensure that the integrity of the cladding and glass
core are maintained, proper handling of the fiber cable is required.
When installing fiber optic cables in ducts, on above-ground strands, or underground:
■do not exceed the fiber cable manufacturer’s maximum pulling tension
■do not exceed the fiber cable manufacturer’s minimum bending radius
■do not subject the fiber cable to crushing forces.
If cable specification documents are not availablefrom the system manager, pulling tension should not exceed
600 pounds (~273 kg) during installation of non-connectorized fiber optic cable. The general minimum
bending radius for a fiber cable under tension is 20 times the diameter of the fiber cable. The general
minimum bending radius for a fiber cable not under tension—and in fiber management within a fiber optic
node—is 10 times the diameter of the fiber cable. When securing connectorized fiber leads within node
housings with cable ties, use caution to avoid crushing the plastic buffer or cladding.
Bare fibers are extremely sharp and can easily break. SCTE recommends wearing both
gloves and safety glasses while preparing fiber optic cable and also properly disposing
of broken optical fibers to avoid injury to the skin or eyes.
Use cautionwhen handling fiber (for example, feedingfiber connectors through housing
ports and managing fiber within housings), to avoid a bend radius of less than 2 inches
(50 mm) in the fiber leads.
Caution
MX0860.fm Page 9 Wednesday, August 25, 1999 1:34 PM

10 Fiber Care and Cleaning MX0860 Revision B
2.2 Fiber Cleaning
The quality of interconnections in fiber optic systems must be comparable to that of the optical fiber itself to
minimize attenuationand, thus,maximize the performance of the link. Connector loss, typically measured for
a mated pair of connectors, is caused by several conditions, such as lateral offset, end separation, angular
misalignment, and core diameter mismatch. Ensuring a clean optical fiber connection is critical.
The presence of dirt or lint at the interface between two fibers degrades performance significantly. Keep the
ends of fibers covered with dust caps when not in use to protect the fiber endfaces from dirt or damage.
Always follow standard laser safety procedures when handling or cleaning fiber and fiber cable connectors.
2.2.1 Cleaning Fiber Cable Connectors
1. Wipe the fiber tip with a lint-free cloth (such as Kimwipes®) moistened with 99% isopropyl alcohol.
2. Wipe the fiber tip with a new dry lint-free cloth or the dry side of the same lint-free cloth.
3. Hold the can of compressed air specified above in an upright position, at an angle to the fiber tip,
and about 6 inches away from the connector.
4. After spraying a few short bursts at the fiber tip, the connector is clean and ready for connection.
2.2.2 Cleaning Bulkhead Connectors
1. Remove the bulkhead connector’s dust cover if necessary.
2. Hold the can of compressed air with the specifications above about 6 inches away from the bulkhead
connector.
3. After spraying a few short bursts directly into the connector, the connector is clean and ready to
accept a fiber connector.
Using compressed air improperlyon fiber cable connectors or bulkhead connectors can
scratch the fiber endface or leave a residue and thereby degrade signal performance.
Dust caps do not keep connectors completely free of dust or contaminants. Perform the
procedures below each time fiber is handled and connections are made.
Use compressed air with at least the following specifications:
■Non-residue, inert gas for precision dust removal
■Ultra-filtered to <0.2 microns
■Recommended for optical systems.
Follow the manufacturer’s directions and cautions when using compressed air to clean
fiber connectors.
Do not tilt, invert, or shake the can of compressed air during use.
Caution
Caution
MX0860.fm Page 10 Wednesday, August 25, 1999 1:34 PM

MX0860 Revision B Fiber Care and Cleaning 11
2.3 Fiber Connectors
Optical bulkhead connectors are extremely fragile. After cleaning, use caution when joining fiber cable
connectors to bulkhead connectors. (Refer to Figure 1 for types of fiber cable connectors.)
In particular, FC/UPC and FC/APC fiber connectors have special requirements. FC connectors must be
installed into or removed from the bulkhead connector by unscrewing the retainer and inserting/withdrawing
the fiber tip straight into or out of the bulkhead connector (see Figure 2). The fiber tip must not be inserted or
withdrawn at an angle. Inserting or withdrawing the fiber tip at an angle may damage the ceramic sleeve
inside the bulkhead connector. A damaged ceramic sleeve may completely inhibit laser signal transmission.
All ceramic sleeves in FC/UPC and FC/APC connectors have a uniform slot running the length of the sleeve.
Do not mistake this manufactured slot for a crack, which will have uneven edges. An example of an unbroken
ceramic sleeve and examples of damaged ceramic sleeves are shown in Figure 2.
Figure 1. Connector Types
Before connecting fiber cable connectors to bulkhead connectors, use an optical power
meter to ensure that the received optical power is within the specified range.
Received optical power greater than the specified maximum level can damage forward
optical receivers.
FC connectors must have a keyway no wider than mm.
When feeding fiber connectors through housing ports, do not pull the assembly by the
connectors. Instead, gently push the connectors through the entry ports.
Do not overtighten fiber stub cable connector bodies. Do not use wrenches. Use hand
pressure only.
Caution
2.03 0.05
0.00
–
+
FC/APC
(angled tip) E2000
SC/APC
(angled tip)
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12 Fiber Care and Cleaning MX0860 Revision B
Figure 2. Bulkhead Connector Installation and Damage Examples
Installing/removing fiber connector
(ensure that fiber tip enters parallel to
ceramic sleeve in bulkhead connector)
Unbroken ceramic sleeve
(with slot visible)
Section of ceramic
sleeve broken out within the connector
Ceramic sleeve cracked and completely
collapsed along the connector
Fiber Tip
MX0860.fm Page 12 Wednesday, August 25, 1999 1:34 PM

MX0860 Revision B Unpacking 13
3.0 Unpacking
All units are inspected before shipment and found to be free of mechanical and electrical defects.
1. Unpack all units.
2. Keep all packing materials until your inspection is complete. When possible, save the shipping
container for future reshipment and/or storage.
3. Examine all units for any damage due to transit.
If damage is discovered, file a claim with the carrier immediately. Notify your C-COR representative as soon
as possible. Product deemed defective by the original purchaser must be returned to C-COR prepaid in the
original packing material (or equivalent) with a Return Material Authorization (RMA) from the C-COR
Equipment Service Center ([phone]).
MX0860.fm Page 13 Wednesday, August 25, 1999 1:34 PM

14 Unpacking MX0860 Revision B
MX0860.fm Page 14 Wednesday, August 25, 1999 1:34 PM

MX0860 Revision B Mounting the Units in a Rack 15
4.0 Mounting the Units in a Rack
The following steps are designed to be performed in sequence. Refer to Figure 3 as necessary.
Figure 3. Mounting Units in a Rack
1. Place the module into the rack following these guidelines:
■Maintain 1.75 inches (1 rack unit) of vertical space between a transmitter module and other
units within a rack
■EDFA units do not require space in between for mounting
■Do not block the front or back panel of any module
■Maintain sufficient space in front of and behind the rack for air circulation.
2. Align the mounting holes on the front flange of the module with the corresponding holes in the rack.
3. Install and tighten screws securely.
Standard
EIA 19 inch
rack
MX0860.fm Page 15 Wednesday, August 25, 1999 1:34 PM

16 Transmitter Controls and Indicators MX0860 Revision B
5.0 Transmitter Controls and Indicators
Figure 4. Navicor 1550 Transmitter
Rear View (AC Model)
21
15
13
12
11
10
914
876
5
4
3
Front View (AC and -48V Models)
16
Rear View (-48V Model)
15
13
12
11
10
914 17 18
19 20
MX0860.fm Page 16 Wednesday, August 25, 1999 1:34 PM

MX0860 Revision B Transmitter Controls and Indicators 17
Table 5. Transmitter Controls and Indicators
Item Label Function
1STATUS LED LED lights green to indicate that RF is present and that the transmitter is
functioning normally with laser active.
LED lights yellow (Minor Alarm) to indicate a parameter that will not cause
damage or affect operation of the transmitter, but may be near an operational
limit.
LED lights red (Major Alarm) to indicate a parameter that could affect the
operation of the transmitter.
Alarms are generated for Laser Temperature, Laser Bias Current, Laser Cooler
(TEC) Current, Manual Shutdown State, Keyswitch state. The transmitter will
shut down under certain conditions. After shutdown, the transmitter may
power up again if the monitored values return to normal.
2LASER keyswitch ON position—Laser is enabled when the key is turned to this position. The
STATUS LED will flash yellow for a few seconds when keyswitch is turned,
indicating the laser is not in a steady state.
OFF position—Laser is off—Yellow STATUS LED should not be lit.
3MOD ADJUST Allows adjustment of the RF signal level of carriers before they are modulated
onto the optical fiber(s) when the unit is in MANUAL mode. Pressing the
recessed ▲and ▼buttons, raises or lowers the RF signal level by ~0.25 dB
for each press of a button. The recessed RESET button resets the modulation
index back to the default, factory-preset level.
The LED panel at the left shows the amount of change in LED segments that
each indicate ~0.5 dB of signal change. Illuminated segments above the center
markings indicate a setting above the preset level. Illuminated segments below
indicate a setting below the preset level. Refer to Section 10.2 for information
on distortion effects when adjusting RF Modulation.
4MANUAL LED LED lights when in Manual mode. Manual mode provides a constant gain. In
Manual mode, the modulation index can be adjusted with the MOD ADJUST
controls.
5CW LED lights when in Continuous Wave (CW) mode. CW mode sets up an
appropriate RF level for the number of carriers specified on the specification
sheet. When different channel loads are applied to the unit, the Automatic
Gain Control (AGC) maintains constant total band power (meaning fewer
carriers will cause the AGC to increase the carrier amplitude of the remaining
channels to maintain the same total amount of power). This mode is normally
used for certain FCC tests and to manually verify that performance is within
specified limits.
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18 Transmitter Controls and Indicators MX0860 Revision B
6VIDEO LED LED lights when in Video mode. In Video mode, the AGC accounts for power
and carrier peak level changes associated with carrier modulated envelopes
and maintains proper RF gain through the path to provide correct operation
with actual carriers.
7(none) Pushing this recessed button changes the AGC mode to the next mode in the
sequence VIDEO, CW, or MANUAL as shown by the adjacent LEDs.
8RF TEST POINT Outputs -20±0.5dB from the input RF level.
9OPTICAL (1and 2) Connection location for output fiber with the proper type of optical connector
(FC/APC, SC/APC, or E2000/APC) for the purchased model.
10 RS - 232 Reserved for future use.
11 RF INPUT F-connector for accepting a maximum of 60dBmV composite RF input to the
unit.
12 MONITOR RS-485 connection. Reserved for future use.
13,14 MANUAL
SHUTDOWN/
ACTIVE HIGH
If a jumper does not connect the screws at 13 and 14, the unit will not start up.
15 I/0 On/Off switch. Allows full shut off of the unit (i.e., no electrical power entry).
16 INPUT POWER IEC AC standard three-pronged, UL approved plug for power input to unit.
17 -48V Provides input connection from -48V power source.
18 -48VRTN Provides return connection to -48V power source.
19 FUSE 2A Provides overcurrent protection.
20 GROUND Common ground.
Table 5. Transmitter Controls and Indicators (continued)
Item Label Function
MX0860.fm Page 18 Wednesday, August 25, 1999 1:34 PM

MX0860 Revision B Setting Up a Transmitter 19
6.0 Setting Up a Transmitter
1. Turn the LASER keyswitch to the OFF position.
2. Verify that the RF input levels to all transmitters are correct using a signal level meter. Refer to
Figure 5. See the appropriate specification sheet for recommended RF input levels.
Laser Warning For Sevice Group SG3b: Disconnected optical connectors may emit
invisible optical radiation.Avoid direct eye exposure to the beam. Laser light,visible or
invisible, can seriously injure eyes or even cause blindness.
Never turn on a laser transmitter if all optical connectors are not covered.
RF signal input levels in excess of +60 dBmV @ 1 NTSC channel loading can damage
transmitter components. Ensure that RF Input is less than 60 dBmV @ 1 NTSC channel
loading. Derate the maximum RF input levels according to channel loading.
You can find the maximum RF level per channel for a given NTSC/PAL channel loading
by using the following equation where n equals number of channels:
(PAL will be within 0.15 dBmV of the correct value using this equation.)
This calculation is used only to determine the input level where transmitter damage may
occur. Operation outside of the RF input level shown in the specification sheet may
degrade transmitter performance. Refer to Figure 5.
Using mismatched connectors will damage the connectors and degrade system
performance. Transmitters are available with FC/APC, SC/APC, or E2000/APC
bulkheadconnectors.Ensure that each fiberhasamatchingconnector.RefertoFigure 1
for a picture of the various optical connectors.
The following describes normal operation conditions:
When the transmitter is in the Video or CW mode, there is an RF automatic gain control
(AGC) that maintains a constant total RF power to the laser. For example, with a
recommended RF level of 24 dBmV for 79 channels, if the number of channels are
reduced by half to 40 channels, the AGC will automatically compensate by raising the
internal gain by 3 dB.
If it is desired to maintain a constant RF level, as the number of channels changes, it is
recommended that the transmitter be operated in the manual mode—this maintains a
constant RF gain in the transmitter.
DANGER
laser light
Warning
Caution
Analog Input Level (dBmv) 10 1
n
---

 60 dBmv+log=
!
MX0860.fm Page 19 Wednesday, August 25, 1999 1:34 PM