Acterna CLI-1450 Installation and operation manual

Section 1: Introduction to Leakage
Quick Reference – Measure a Leak . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-1
Leakage: The Beast and This Book . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-4
Why Monitor & Measure Cable Leakage? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-6
Control of Cable Leakage in 2000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-6
Government Regulation of System Leakage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-6
Implementing An Effective CLI Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-7
Section 2: Practical Information about Leakage
What is Leakage? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-1
How Leakage Egresses Into the Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-1
Common Leakage Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-2
Underground Leakage Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-5
Damaged Cable Sheathing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-7
Other Hardware Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-8
Troubleshooting The Cable System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-8
Section 3: Leakage Detection Equipment
Introduction to Leakage Test Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-1
What Equipment is Needed For Leakage Detection? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-2
Leakage Detection Meters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-2
Features of the CLI 1450 and CLI-1750 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-2
Unique Features of the CLI-1750 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-3
Review of Leakage Meter Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-4
Secondary Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-5
Important Leakage Meter Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-6
Screen Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-6
Leakage Screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-6
Measurement Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-6
Find and Fix Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-7
Antenna Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-8
Alarm (Volume Control and Mute) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-8
Set Leakage Configuration Screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-8
Alarm Condition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-9
Alarm Threshold . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-9
Alarm Mute Time-Out . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-10
Leakage Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-10
Measurement Frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-10
Measurement Carrier Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-11
Tag Modulation Frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-11
Reference Distance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-11
Peak-hold Reset Period (Peak-the-Leak) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-13
Edit Antenna Factor (Antenna Factor) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-13
Antennas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-15
How Antennas Work . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-15
The Monopole Antenna . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-17
The Dipole Antenna . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-17
Features of the HD-1 Dipole Antenna . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-18
Docking Station, DS-1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-19
Tagger, LT1000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-20
Signal Transmitter, LST-1700 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-21
Table of Contents
continued on next page

Section 4: Leakage Detection Guide
Set-Up Your Leakage Meter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-1
Test Your Equipment –Calibrated Leak for Drive-Outs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-2
Patrol/Drive-Outs for Leakage Sources in the Field . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-5
Measure a Specific Leakage Source (Walk-About) in the Field . . . . . . . . . . . . . . . . . . . . . . . . .4-8
Triangulation Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-9
Measure Leakage Source for FCC Compliance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-10
Ingress Measurement –Why and When . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-12
Guide for Leakage Detection in the Home . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-14
Section 5: APPENDIX A
The FCC and the Cable Industry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-1
Testing Beyond Regulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-1
General FCC Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-2
Regular Leakage Monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-2
Annual Leakage Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-2
Ground Based Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-2
System Fly-over Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-2
Cumulative Leakage Index (CLI) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-3
Computer Software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-3
Section 6: Appendix B
European CENLEC –EN 50083-3 Regulations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-1
Section 7: Appendix C
Length of Antenna Elements for the HD-1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-1
Section 8: Appendix D
Most Frequently Asked Questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8-1
Table of Contents

~ Quick Reference
Measure a Leak
1. Choose Your Weapon: Acterna offers
two leakage detection meters, the CLI-
1450 and the CLI-1750. Both meters
are fully equipped to measure egress
and ingress leakage sources and have
similar features and functions. The
CLI-1750 includes additional options
that can be used for home-wire-testing.
2. Know Your Meter: Turn your meter
“ON”. Press the “SHIFT icon”key and
the Leakage key to access the leakage
screen. Check your meter to see if
you are in the “Measurement”mode.
Check the screen for the vehicle
mount antenna option.
3. Check Your Meter Settings: While in the
leakage screen, press the “SHIFT icon”
key and the Configuration key, check the
default settings for each of the func-
tions. Check the following: alarm condi-
tion, alarm threshold, measurement fre-
quency, and reference distance. Adjust
the defaults on the meter functions that
are not correct for your situation.
(for more detailed information about setting the con-
figuration, see chapter 3 page 8.)
1-1
Introduction to Leakage 1
Vehicle Mounted
Antenna Icon
Leakage settings
Use the up and
down arrow keys
to scroll through
leakage settings.
Press the search
softkey to
toggle between
“Measurement”
and “Find & Fix”
modes
Press the antenna type softkey until the vehicle
mount antenna icon appears on the top of the
screen.

4. Patrol for Leakage: Connect the meter
to the vehicle’s antenna through your
vehicle’s docking station. Turn your
meter “ON”, set-up your leakage
screen, check for the “Measurement
Mode”, and vehicle antenna icon.
Adjust your alarm signal and start to
patrol.
5. During Patrol: Look for leakage
sources by listening for rapid alarm
signals when driving. Observe the
field strength in the leakage screen
and the peak level while the alarm
detects leakage sources in the area.
Identify a leak source with a leakage
potential of 20 µV/m or more. After a
general leak site is identified, stop the
vehicle and locate the specific leakage
source. Note: Always check with poli-
cies set by your cable system regard-
ing minimum leakage levels required.
6. Locate Specific Leakage Source:
Disconnect your meter from the dock-
ing station and connect your meter to
an HD-1 hand-held dipole antenna.
7. Set Your Meter: Turn “ON”your leak-
age screen, select the dipole antenna
from the leakage screen, clear the old
peak reading, and select the “Find &
Fix”Mode.
1-2
Peak hold high-
est level reading.
Current leakage
level.

8. Scan For Leakage Source: Hold the HD-
1 antenna in the air and rotate anten-
na slowly until the meter alarm indi-
cates a strong signal and a new peak
reading is reported. If the leakage level
identified is greater than or equal to
the minimum leakage level specified
by your cable system, repair the leak-
age source or report it for repair.
9. Follow-up Check: After the identified
egress leakage source is repaired,
check for additional egress leakage in
the area. If no other leaks are found
in the area, check for ingress, and
then return to your patrol vehicle and
search for other leakage sources.
10. Why Check for Ingress: Most leakage
sources are located at drop areas, there-
fore most ingress checks are completed
at residential sites. You should always
check and repair all sources of egress
during home installation before check-
ing for ingress. If your egress sources
are eliminated, you will also eliminate
most of your sources for ingress.
11. Check for Ingress: Locate the resi-
dential ground block and connect
your meter and RF Input Line. Turn
your meter “ON”and use the
Navigator button to select the Ingress
option. View the Ingress display
screen. If your screen indicates “Pass”
at the top of your screen, your ingress
levels are in the acceptable range. If
your screen indicates “Fail”, you need
to locate the ingress source.
Reconnect all service cable connec-
tions when your job is completed.
1-3
Ingress screen

12. Acterna Home-Wiring Test Kit
(HWTK): Extensive testing shows that
one of the main challenges of the suc-
cessful offering of new services is the
current home wiring. The model CLI-
1750, used in conjunction with the
Model LST-1700 Signal Transmitter
helps to identify and locate potential
problems with home wiring prior to
activating these new services.
13. Contact Acterna Customer Support:
1-800-662-5515 for the latest in mul-
timedia and classroom training.
We’re here to help.
~ Leakage: The Beast and
This Book
Successful detection and measure-
ment of signal leakage requires a
combination of science and art. The
science of how leakage exists and the
art of leakage detection are not easily
explained. Signal leaks can be
deceptive and very unpredictable. For
example, weather and temperature
can affect leakage; one day a leak may
appear and the next day it may be
gone. Radio waves can bounce off
buildings; large leaks can mask small-
er ones; standing waves can go unde-
tected; and the field technician’s lack
of field experience can all contribute
to inaccurate leakage detection.
For the field technician, accurate
detection of leakage can only result
from training, ongoing field experi-
ence, repetition, the use of quality
equipment, and learning the tricks of
the trade. Therefore, this manual was
developed to assist you with:
•Understanding the importance of
RF signal leak detection.
1-4
Good news!
I know why
we’ve spent
the last 6
hours look-
ing for the
leak. Bad
news... it’s
you!

•Evaluating, selecting and using
RF signal leak detection equip-
ment.
•Developing skills needed to
detect and record signal leakage
accurately.
•The importance of using a cali-
brated leak for drive-out equip-
ment verification.
•The use of tagging especially in
overbuild situations.
•Using the hand-held dipole
antenna for “Walk-About’and “In-
Home”leakage detection.
•The “Find-and-Fix”measurement
mode allows user to find leaks
quickly.
•Tips for ingress checking.
•Diagrams, tips and tricks
designed to help train and teach
your technical staff.
Always Remember: The science of find-
ing signal leakage cannot be com-
pletely taught nor documented. A
combination of field experience, on-
going discussion with cable industry
peers, and the usual blood, sweat,
and tears are the only effective train-
ing tools recognized by the most suc-
cessful field technicians.
Our Advice: You can best deal with “the
beast”through on-going training and
by using a good set of standard
processes and procedures. If your
cable system has a CLI Measurement
Practice Program, we suggest that you
follow it closely. The implementation
of a good CLI program will not only
improve your measurement tech-
niques, but will provide a consistent
set of policies and procedures for
everyone to follow. A cable system
committed to the goal of “Taming the
Beast”will prosper as a result of
improving the quality of customer
service and holding the bottom line.
1-5

~ Why Monitor & Measure
Cable Leakage?
Control of Cable Leakage in 2000
The Federal Communications
Commission (FCC) in the United
States and the CENELEC in Europe
are two government agencies respon-
sible for regulating the cable industry
and enforcing technical standards
regarding cable system leakage in
their respective countries. Each regu-
latory body closely monitors the cable
industry in order to protect the public
from radio frequency (RF) signal leak-
age escaping out of cable systems.
For example, unmanaged signal leak-
age can have a dramatic effect on
external radio signals critical for air
traffic control. In order to insure
public safety, the FCC and CENELEC
require that cable systems maintain
their signal leakage levels within
acceptable limits or face the conse-
quences of extensive fines and/or loss
of the use of certain channels. For
more information regarding govern-
ment regulations, please refer to
Appendix A and B.
There are two types of leakage, egress
and ingress. Egress is RF signals that
escape out of the cable system into
the environment. Ingress is RF sig-
nals, noise or interference that get
into the cable system causing prob-
lems related to customer service.
Controlling signal leakage out of the
system has a beneficial two-fold
effect. As we discussed, control of
leakage out of the system will reduce
potential hazards to public safety.
Consequently, a second benefit
results, when signal leakage out of the
cable system is controlled, the poten-
tial for signal leakage into the cable
system is also reduced. By prevent-
ing leakage into the cable system, we
are preventing signal interference,
which can disrupt service to cus-
tomers using advanced cable modem,
digital TV set-tops, and telephony-on-
cable. Cable operators agree that
future labor costs spent on finding
leakage and internal interference
sources can be reduced by as much as
20%-30% if signal leakage could be
detected and repaired more efficient-
ly. To assist field technicians combat
service interrupted by ingress, ACTER-
NA provides leakage meters equipped
with ingress measurement functions.
Government Regulation of System
Leakage
In order to enforce government cable
leakage regulations, the FCC conducts
random bi-annual fly-overs using a
sensitive airborne measurement sys-
tem designed to map the overall leak-
age of the cable system in a designat-
ed area. Results of these inspections
are taken very seriously by the cable
industry. Recent research shows that
preventing ingress improves the over-
all quality of cable service. All cable
plant services, including analog TV,
improve. Cable systems should con-
sider the benefits of implementing an
1-6

extensive Cumulative Leakage Index
(CLI) program to systematically moni-
tor the overall cable system for egress
and ingress and to prevent non-com-
pliance with government regulations.
What becomes increasingly clear, is
that the leakage limits (20 µV/m) pro-
vided are not strong enough to allow
the new interactive services (e.g. cable
modems) to work properly.
~ Implementing an Effective
CLI Program
At no other time in our history have
the airwaves been used more exten-
sively than in the past decade.
Through the use of technology, the
average person can communicate,
conduct business and use household
conveniences in ways unimagined 25
years ago. Though the future of tech-
nology looks bright, the opportunity
that technology provides can be
equally matched with challenges. As
professionals in the cable system
industry, we must ask ourselves; How
can we continue to provide customers
with quality service which can also co-
exist safely in a rapidly changing high
technology environment?
One of the most effective ways to
improve the efficiency and productivi-
ty of every person involved in the
cable industry involves a commitment
1-7
Big Leak
Medium Leak
Small Leak
the flight path
Headend
450 m

to continuous improvement. Through
the development and adoption of an
effective Cumulative Leak Index (CLI)
Program, field technicians can contin-
ually improve the skills needed to
effectively identify and repair sources
of cable system leakage. As a result of
commitment to improvement, field
technicians will be able to perform
leakage repairs more accurately and
efficiently, customers will receive a
higher quality product and the cable
industry will prosper as a safe and
multifaceted service to its clients.
With that it mind, what are the com-
ponents of an effective CLI program?
•All cable industry personnel must
have a basic understanding of the
problems associated with signal
leakage and its impact on the
world around it.
•All cable industry personnel must
have a good understanding of the
FCC or CENELEC government reg-
ulations regarding detecting and
repairing signal leakage sources.
•Field technicians must be provid-
ed quality leakage detection
equipment.
•Field technicians must be provid-
ed the proper training to use
equipment to its fullest potential.
•Field technicians must be provid-
ed training to properly calibrate
and maintain equipment before
and after use.
•Inexperienced and experienced
field technicians should be pro-
vided the opportunity to learn
and share experiences related to
detecting leakage in a variety of
real field situations.
•Field technicians must be provid-
ed the proper training to detect,
repair and report leakage sources.
•Whenever possible, the field tech-
nician should always check for
and repair ingress problems while
testing for egress. Prevention of
ingress problems can save time
and costs involved with later
“truck roll”.
Developing and implementing an
effective CLI program is the responsi-
bility of everyone in the cable indus-
try. Doing your part, in a continuous
improvement process, is required for
any program to be successful. The list
of CLI program components listed
above are all-important to the success
of your program. It is our hope, that
the contents of this manual can pro-
vide a ground floor for an effective
training and CLI program for your
cable system.
1-8

~ What Is Leakage?
Leakage can be defined as “the
amount of radio frequency (RF) signal
that escapes or infects the cable sys-
tem as a result of one or a combina-
tion of the following factors: improper
cable installation, component corro-
sion, poor product design, vandalism,
cable breaks, poor connections, etc.”
There are two types of leakage, egress
and ingress. Egress is RF signal leak-
age out of the cable system. (See
Figure 1). Egress occurs when cables
are damaged or improperly installed.
Ingress refers to the RF noise or inter-
ference that leaks into the cable sys-
tem (See Figure 2). Ingress occurs
when RF signals emitted from the sur-
rounding environment (e.g. hair dry-
ers, microwaves, radios, welders, etc.)
have the opportunity to enter the
cable system through a break or exter-
nal leak in the cable system. RF or
noise ingress can also feed back into
the coax drop and into the system
from bad TV sets, center conductors
that are too long, customer amplifiers,
VCRs, jumpers, etc.
2-1
Practical Information about Leakage 2
~ How Leakage Egresses into
the Environment
The nature of RF leakage allows a sig-
nal, radiating from a cable system, to
follow any path that provides the least
resistance. Leakage signals may fol-
low paths that include free space,
strand, power, and telephone lines.
Understanding how RF frequency radi-
ate outside of its intended source
helps us to understand why interfer-
ence between frequency signals can
lead to problems.
The illustration provided below indi-
cates how RF frequency signals radiate
out of their source. A typical wavelength
signal is generally 6-9 feet (1-3 meters).
The path that leakage chooses to take
will vary from situation to situation.
FIGURE 1: Egress FIGURE 2: Ingress at point of Egress

When a signal radiates from a fault in
the cable, it propagates in a pattern of
waves. As the signal’s strength
increases and decreases along the
wave, the level of the wave will rise
and fall. The field technician should
remember that wave fluctuations do
not indicate the existence of multiple
leakage points in the cable.
The ability to accurately detect leak-
age levels can only be achieved
through knowledge of RF signals and
through field experience. The field
technician should have a general
understanding of how RF frequency
reacts in the environment when
released from a cable source. The list
provided below give examples of how
leakage detection can be deceptive to
the experienced and inexperienced
technician.
•A large leak can mask a smaller
one (troubleshoot one leak at a
time).
•Leaks may radiate from the true
source down the cable, strand
and down guys.
•Radio signals may bounce off
buildings and other surfaces cre-
ating false readings.
•A leak may be active one day and
seem to disappear the next day.
•Very strong leaks may overload a
detection meter (use scan or
spectrum mode)
•Metal objects can distort radia-
tion patterns received by your
antenna.
•Sometimes a slight change in posi-
tion of a damaged cable or connec-
tor will cause leaks to subside.
Consequently, the leak source
must still be found and fixed
because it will undoubtedly return.
2-2
~ Common Leakage Sources
Your first step toward locating a
potential leakage site is to combine
common sense with knowing where to
look. Leakage can occur at any point
in a cable system, but the experienced
technician is able to pinpoint a general
location by following the cable or visu-
ally recognizing typical cable egress
indicators. Once the general area of a
leak is identified, the field technician

can eliminate potential leak sources
using a process of elimination.
Cable leakage is more common in the
following areas of the cable system.
2-3
Potential
Leak Site Definition What to look for?
Headend The control center of a cable televi-
sion system, where incoming signals
are amplified, converted, processed
and combined into a common cable
along with any origination cable-cast-
ing for transmission to subscribers.
The system usually includes antennas,
pre-amplifiers, frequency converters,
demodulators, modulators, proces-
sors, and other equipment.
Check for bad cable
connections, malfunc-
tioning equipment,
and worn or
damaged cable.
Trunk The main distribution lines leading
from the headend of the cable tele-
vision system to the various areas
where feeder lines are attached to
distribute signals to subscribers.
Check for bad connectors
or terminators. Look for
worn or damaged cable.
Also check for poor
craftsmanship which
involves using poor quali-
ty materials and poor
quality installation.
Drop or
Subscriber’s
Terminal
The line from the feeder cable to the
subscriber’s television or converter.
Check for improper
installation and malfunc-
tioning equipment. The
drop is the most common
cable leakage source.
Bridger, Bridging
Amplifier, or
Distribution
Amplifier
An amplifier connected directly into
the main trunk of the CATV system.
It serves as a sophisticated tap, pro-
viding isolation from the main trunk,
and has multiple high level outputs
that provide signal to the feeder por-
tion of the distribution network.
Check for bad connec-
tors or terminators.
Look for worn or dam-
aged cable. Check to
see if housing is not
closed. Check for poor
quality materials and
poor installation.
continued on next page

The term “drop”refers to the connec-
tion of the main cable system from the
tap to 5-10 homes or to one or several
Multiple Dwelling Units (MDUs).
Experience has shown that the most
common sources of leaks are drop
related. Although drop related leaks
are the most abundant, leaks from the
trunk and distribution equipment may
be more serious. For example, a leak
emanating from trunk or bridger out-
put is likely to radiate greater RF ener-
2-4
Potential
Leak Site Definition What to look for?
Splices and Fittings A mechanical/electrical connection to
join two wires or cables together.
Water and weather can
result in pulled-out,
sucked-out, loose or
corroded fittings.
Splices at Taps,
Line-Extenders,
Splitters,
Amplifiers, and
Ground Blocks
Refer to the Glossary of Terms found
in Appendix E for the following defi-
nitions: Tap, Line-Extenders, Splitters,
Amplifiers, and Ground Blocks.
Check for bad connec-
tions, connectors and/or
terminators. Look for
worn or damaged
cable. Also check for
poor craftsmanship
which resulted from
using poor quality
materials and poor
quality installation.
Cable, Distribution
Equipment
One or more electrical or optical con-
ductors found within a protective
sheathing. When multiple conductors
exist, they are isolated from each other.
Check for cable cuts,
breaks and exposure.
Illegal Hook-ups Cable hook-ups completed by unau-
thorized cable system personnel.
Check for twin leads
inferior passive devices,
poor or no connectors,
and improperly termi-
nated splitters. Also
check for jumpers from
drops to taps and/or
ground blocks. Center
conductors stuck into tak
spigots. Drops should
have no splices in them.
(note that weather boots or heat
shrinks should be used when replac-
ing jumpers on splices)

gy than a drop source and could pro-
duce a much greater effect on the sys-
tem’s total leakage into the airwaves.
Other less common leakage sources
include:
•Malfunctioning television sets
and VCRs
•Bad converters
•FM splitters
•Inferior quality coaxial cable
•Two piece fittings
•Splitters used outside without
weather bonding
•F-fittings with pinched jackets
as a result of poorly adjusted
hex crimper
2-5
~ Underground Leakage
Sources
The potential for damage to under-
ground cable is more common near
driveways, roads and sidewalks.
Cables that are buried near high traf-
fic areas will naturally attract greater
opportunities for accidental cable
damage. Similarly, it is not uncom-
mon to check near fence-lines or mail-
box posts when checking for leaks.
Buried cables can be cut or gashed
any time digging occurs in the vicinity.
Buried cables in streets without con-
duit (direct buried) will crack and
eventually break.
Common underground drop related
leaks are often found at the pedestal
taps which are caused by broken or
unterminated tap ports; malfunction-
ing terminators; loose F-connectors at
the tap; and cracked feeder cable. The
table on the next page (2-6), identifies
common potential leak sites when
checking for underground leakage.

Underground leakage sources are most
common at the following locations:
2-6
Potential
Leak Site Definition What to look for?
Bore
(Trench)
Cable system term used to describe
the trench or hole dug prior to bury-
ing the cable underground.
Knowing the path of
where the cable is
buried will assist you in
locating broken or dam-
aged cable sources.
Pedestal Housing-
Taps
Pedestal Housing is an environmental
protection device used to house sub-
scriber isolation units and passive dis-
tribution amplifiers in underground
CATV systems. Synonymous with
Underground Housing.
Broken or unterminated
tap ports, corroded and
water damaged taps.
Loose or damaged tap
plates, connectors, fit-
tings, or cracked cable
feeder. Water, ingress,
corroded center conduc-
tor and braid.
Malfunctioning
Terminators
A resistive load for an open coaxial
line used to eliminate reflections and
to terminate a line in its characteris-
tic impedance.
Check for wear, loose fit-
tings and corrosion.
Check quality of a termi-
nator.
Loose F-
Connectors
The F-connector is the male end con-
necting device that allows a cable
drop to be attached to a cable inlet
source (female end) tap.,spygot, etc.
Check for wear,
stripped threads, loose
fittings and corrosion.
Check quality of the
F-connector.
Loose-Fittings Result when clamps, wire covers, etc.,
are not installed properly, have become
loose because of age, or are broken.
Cable connections that
appear loose, worn or
broken.
Poor Quality
Material
Manufacturer’s material that were
defective before they were installed.
The original plant was
installed using scraped
and perforated cable
sheaths, poorly spliced
lines, and crimped cable
with small bending
radii. Check for poor
quality materials.

A most difficult and costly problem
exists if the underground leak, located
in a feeder or trunk line, is caused by
extremely poor workmanship or inferi-
or materials. In the past, some con-
tractors were known to have construct-
ed cable systems poorly by using
below grade supplies which can handle
analog CATV, but are incapable of han-
dling advanced services. The best
solution to this problem, and also the
most costly, is to have the entire cable
system in that area replaced.
2-7
~ Damaged Cable Sheathing
Another form of damage occurs when
cracks, slices or holes form in the
cable sheath. Water enters the cable
through these holes, causing corro-
sion inside the cable. Even a tiny
hole in the sheath can suck water into
the cable. Water damage in foam
cable is less of a problem because
there are fewer tendencies for water
migration to occur with the solid foam
dielectric. However, in fused disk
cable, the water collects inside the
cable, where it corrodes the center
conductor and sheath. Water and fur-
ther corrosion can migrate (flow) up
or down the cable. The water
migrates and will find eventually the
connectors and center conductors.
Then it will also migrate along the
center conductors. Also when the
sheath is corroded enough you begin
to lose ground impedance
When checking for damage to the
coaxial cable, evaluate the following
chronic trouble spots:
•Always check for holes and possi-
ble water migration at or near
suspension clamps, bonding
clamps, span clamps, guy lines,
trees, and expansion loops.
•Pole hardware rub-through is a
major cause of cable damage.
Provide insulation to cable at rub
points by using straps and spac-
ers to prevent damage. Use tree
guard.
•Be extra careful with span clamps,
both at the pole and at mid-span.
Span clamps can cause problems
when carelessly installed.
•Down guys and overhead pole-to-
pole guys can come into contact
with the cable and eventually
wear through the cable sheath.
•Use tree guards to protect the
cable. Tree limbs and branches
can be a problem if trees are not
properly trimmed and the cable is
not properly insulated.
•Cable may be damaged by animal
chews (particularly squirrels).
•As with everything, a good cable
will degrade with age even though
it may show no visible damage.

~ Other Hardware Problems
Expansion and drop loops are common
problems in older cable systems, espe-
cially with a 0.412 (inches) cable.
Repeated seasonal expansion and con-
traction eventually causes the cable to
crack at the flex points. If a crack is
found in the cable, splice out the dam-
aged section of cable and check to see
if the problem is corrected. If the prob-
lem persists, it may be necessary to
replace the entire span; otherwise the
existing cable span will cause on-going
problems and cable system costs.
Water damage to equipment occurs
when a poor seal is made between the
housing and its cover or lid. Water
will travel via the center conductor
into cable. Over a period of time,
water can collect inside the housing,
eventually causing corrosion and
component failure Poor seals of lids
also cause some egress. This is why
good lid seals have both rubber and
braided bonds to prevent leakage.
2-8
~ Troubleshooting the Cable
System
A leak source that exceeds the legal
limit of 20 µV/m should be recorded
and reported as soon as it is discov-
ered. Cable leakage that exceeds this
legal limit must be repaired as soon
as possible. If a leakage is discovered
at 50 µV/m or higher, it should be
reported; repaired as soon as possi-
ble; and must be officially logged for
FCC compliance. Note: Always check
and follow the specific policies
required by your cable system.
When evaluating a cable leak source,
moving or shaking the leak source can
change the leakage level and may
even eliminate it temporarily. This is
a very good method to find out if this
is a leak or very near the source of the
leakage. Many intermittent leaks may
be found when the wind is strong
enough to move the cable.
For most leaks at fittings, repair gen-
erally involves finding the defective
component and then tightening it or
replacing it with a new fitting that is
well prepared and sound. After a leak
source is repaired, be sure to do a fol-
low-up check of your work. Use a
meter to confirm that the leak you
repaired is no longer a problem and
that the leak repaired was the actual
leakage source. If the leakage signal
persists, as a result of your follow-up
check, there may be additional leak-
age sources in the area or there is
another leak at the same source that
was masked by the fixed leak.

~ Introduction to Leakage Test
Equipment
As technology advances, the need for
sophisticated, easy to use, equipment
will be required by all field techni-
cians in the cable industry. ACTERNA
has developed a full line of equip-
ment specifically designed with the
field technician in mind.
ACTERNA’s Leakage Test Equipment
is:
•Priced Economically –minimal
amount of equipment needed for
reliable leakage detection.
•Designed with Multiple Features
—- faster; more accurate; leakage
level sensitive; high resolution
screen; international icons; detects
ingress and egress; and designed
to be time and labor efficient.
•Ease of Handling –portable &
convenient —the field technician
can monitor leaks between serv-
ice calls and installations.
•FCC and CENELEC Compliant —
measure leaks according to gov-
ernment standards —ideal for
collecting data
•Technologically Sophisticated and
Uniquely Comprehensive —
designed to quickly uncover both
common and problematic cable
leakage.
Combo Leakage / Signal Level Meter
Models CLI-1450 and CLI-1750
SLM Features of the CLI-1450/1750
meter include:
An installation check mode.
A comprehensive channel level
measurement screen.
Full channel scan with online
limit check.
Automated testing and logging.
Ability to store and scan tilt
screens.
Multiple channel plans /
Analog and Digital Limits.
Reports are printed directly
to a printer or uploaded to
StealthWare (data software).
Ability to scan and locate
ingress problems —forward
and reverse.
The user interface can be fully
converted to the international
language requested: German,
French, Spanish, Portuguese, Dutch
and Italian.
3-1
Leakage Detection Equipment 3

~ What Equipment Is Needed
For Leakage Detection?
Two of the most important require-
ments, for a successful CLI program, are
having the right equipment and know-
ing how to use the equipment correctly.
Throughout this section, we will discuss
the features and functions of each piece
of equipment and briefly discuss the
most important operating procedures
needed for leakage detection.
The primary equipment needed for
successful leakage detection includes
the following:
•Leakage Detection Meters (CLI-
1450 and CLI-1750)
•Vehicle-Mount-Antenna –
Monopole VMA-3
•Dipole Antenna –HD-1
•Adjustable 10-foot Pole –PL-1
(optional for calibrated leaks and
government leakage tests)
•Tagger —LT1000 (optional for
signal detection sensitivity and
overbuild situations)
•Signal Transmitter LST-1700
(optional for home-wire-testing,
used with CLI-1750 only)
•Docking Station –DS-1 (optional
for patrol vehicles)
3-2
~ Leakage Detection Meters
(CLI-1450 and CLI-1750)
There are two types of leakage detec-
tion meters available through ACTER-
NA; these models include the CLI-1450
and CLI-1750. Both leakage detection
meters have many features in com-
mon. The primary difference between
both models, for leakage detection, is
the CLI-1750 can be used as part of the
Home-Wiring-Test-Kit (HWTK).
In the text below, a combined model
number (e.g. CLI-1450/CLI-1750) will
represent similarities between mod-
els. For the purpose of this section,
we will only discuss meter functions
that are needed to measure leakage.
Please refer to the operation manual
for each model regarding specific
information or instrument capabilities
not discussed in this guide.
Features of the CLI-1450/CLI-1750
Include:
•Each meter can be hand-held for
convenience.
•Measurement Mode assists the
technician with locating leakage
sources up to 40-60 feet away.