3M Dynatel 965AMS User manual

February 2009
78-8140-2658-5-A
Future-Proof Testing Platform
3
Dynatel™Advanced Modular System 965AMS
30-Megahertz Spectrum Analyzer
DSL User’s Guide

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3M™Dynatel™Advanced Modular System 965AMS 30-MHz Spectrum Analyzer

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3M™Dynatel™Advanced Modular System 965AMS 30-MHz Spectrum Analyzer
Contents
DSL (Digital Subscriber Line) ..........................................................5
DSL Loss ..................................................................................................5
DSL Noise.................................................................................................9
DSL Spectrum Analyzer .........................................................................13
Resistance Balance..................................................................................17
DSL Impulse Noise.................................................................................19

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3M™Dynatel™Advanced Modular System 965AMS 30-MHz Spectrum Analyzer

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3M™Dynatel™Advanced Modular System 965AMS 30-MHz Spectrum Analyzer
DSL (Digital Subscriber Line)
The DSL functions include: DSL Loss, DSL Noise, DSL
Spectrum Analyzer, Resistive Balance, and DSL Impulse Noise.
DSL>DSL Loss
Use DSL Loss function to measure the amount of loss in a
circuit at a specific frequency. This is typically accomplished
by sending tone with another 965AMS, a 3M™Dynatel™Far
End Device (FED), or test equipment that is capable of sending
wideband tone from 20 kHz to 30 MHz.
DSL>DSL Loss>Hook-Up
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3M™Dynatel™Advanced Modular System 965AMS 30-MHz Spectrum Analyzer
DSL>DSL Loss>Operation
1. Press the blue DSL key
to enter the DSL function.
Use the up and down arrow
keys to select DSL Loss.
Use a tone source at the
far end that is capable of
sending a known output
level such as a 965AMS.
Use 0dBm as the output
level or follow your method
of test.
2. Press DSL Setup to select
the type of service.
3. Use the up and down
arrow keys to select the
type of service that you are
measuring.
4. Press OK when finished.

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3M™Dynatel™Advanced Modular System 965AMS 30-MHz Spectrum Analyzer
DSL>DSL Loss>Operation
5. Press OK to make the
measurement.
6. The results of the
measurement will be
displayed as a –dBm level
at a specific frequency.
DSL>DSL Loss>Application Notes
DSL Loss measures the signal lost from a tone transmitter
(965AMS, 3M™Dynatel™Far End Device (FED) or other
capable device) to the measuring 965AMS.
High loss is an indication of:
1. A loop that is too long for the potential service.
2. Bridge tap.
To get a complete picture of loss, it is recommended that you use
a FED that will generate a sweep of frequency for the service
type. The sweep will indicate either a good circuit, high loss or
dips in the reading can be an indication of bridge tap. The image

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3M™Dynatel™Advanced Modular System 965AMS 30-MHz Spectrum Analyzer
below is a sweep that was performed with a 965AMS, a 3M™
Dynatel™Far End Device FED II and the selected service was
ADSL2.
Look at the before and after for these two readings. When
the bridge tap is removed then the slope no longer displays
frequency dips.
With 500 feet of bridge tap With bridge tap removed

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3M™Dynatel™Advanced Modular System 965AMS 30-MHz Spectrum Analyzer
DSL>DSL Noise
Use DSL Noise function to measure the Longitudinal or
Metallic Noise on a DSL line.
DSL>DSL Noise>Hook-Up
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DSL>DSL Noise>Operation
1. Press the blue DSL key
to enter the DSL function.
Use the up and down arrow
keys to select DSL Noise.
2. Press DSL Setup to select
the type of service.

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3M™Dynatel™Advanced Modular System 965AMS 30-MHz Spectrum Analyzer
DSL>DSL Noise>Operation
3. Use the up and down
arrow keys to select the
type of service that you are
measuring.
4. Press OK when finished.
5. Press OK to start the
measurement for DSL
noise.
6. Press Select Longitudinal to
measure longitudinal noise.

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3M™Dynatel™Advanced Modular System 965AMS 30-MHz Spectrum Analyzer
DSL>DSL Noise>Operation
7. Press Select Metallic to
measure metallic noise.
DSL>DSL Noise>Application Notes
Noise can affect wideband services by taking up valuable
bandwidth and reducing speed. Symptoms of high noise can
be data errors and loss of connection. The 965AMS measures
longitudinal as well as metallic noise. Having high noise in
either of these tests will prompt you to look at the circuit with a
Spectrum Analyzer to identify the source.
Longitudinal Noise is a
measured between Tip [A] and
Ring [B] (shorted internally)
and the shield/ground.
Longitudinal Noise measures
influences from outside the
cable (power induction,
AM radio or other outside
frequencies).
RED
GRN
BLK
Ring 1Ring 1
Ground
Ground
Tip 1
Tip 1
Shorted InternallyShorted Internally

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3M™Dynatel™Advanced Modular System 965AMS 30-MHz Spectrum Analyzer
Metallic Noise is a measured
between Tip [A] and Ring [B].
Metallic Noise measures the
active noise on a pair.
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Both tests are performed through filters based on the service that
is selected in Setup.

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3M™Dynatel™Advanced Modular System 965AMS 30-MHz Spectrum Analyzer
DSL>DSL Spectrum Analyzer
Use DSL Spectrum Analyzer (SA) to display a graph of useful
signals and interference/noise at specific frequencies up to
30 MHz.
DSL>DSL Spectrum Analyzer>Hook-Up
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DSL>DSL Spectrum Analyzer>Operation
1. Press the blue DSL key
to enter the DSL function.
Use the up and down arrow
keys to select DSL Spec.
Analyzer.
2. Press OK .

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3M™Dynatel™Advanced Modular System 965AMS 30-MHz Spectrum Analyzer
DSL>DSL Spectrum Analyzer>Operation
3. Press Span to change the
frequency range.
4. Use the left and right arrow
keys to move the cursor.
The cursor position will
display the frequency and
the signal level.
5. Once you have selected a span of 1M or 2M you may add a
noise mask.
The mask is initially set to “none.” Pressing F2 or F3, the
screen will show the following masks:
ADSL Downstream

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3M™Dynatel™Advanced Modular System 965AMS 30-MHz Spectrum Analyzer
DSL>DSL Spectrum Analyzer>Operation
ADSL Upstream
T1
HDSL
ISDN

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3M™Dynatel™Advanced Modular System 965AMS 30-MHz Spectrum Analyzer
DSL>DSL Spectrum Analyzer>Application Notes
Spectrum analysis allows you to visually see a disturbing
signal’s shape by reading and displaying the level of noise in a
frequency range.
The shape can be caused by ADSL, ISDN, HDSL, T1 or VDSL.
This chart shows the ADSL2+ spectrum with common disturbers
and chart 2 shows the VDSL spectrum with potential disturbers.
Center Frequencies
28
kHz
20
kHz
ADSL
Upstream
ADSL
Downstream
ADSL
Downstream
138
kHz
Nyquist
Frequency
140
kHz
1100
kHz
2200
kHz
DDS ISDN HDSL
T1 AM Radio 680 kHz+
40
kHz
196
kHz
772
kHz
1.1
MHz
US 0 DS 1 US 1 DS 2 US 2 US 2
3.75
MHz
5.2
MHz
8.5
MHz
12
MHz
30
MHz
VDSL Spectrum

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3M™Dynatel™Advanced Modular System 965AMS 30-MHz Spectrum Analyzer
DSL>Resistance Balance
Use Resistance Balance to measure the:
Loop resistance between the Red and Green test leads.•
Resistance of each conductor connected to the Red and•
Green test leads.
Resistance difference between the two conductors.•
DSL>Resistance Balance>Hook-Up
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DSL>Resistance Balance>Operation
1. Press the blue DSL key
to enter the DSL function.
Use the up and down arrow
keys to select Resistance
Balance.
Press OK .
2. Connect the strap at a ‘far-
end’ access point. The strap
should be connected to all
three of the conductors at
the far end.

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3M™Dynatel™Advanced Modular System 965AMS 30-MHz Spectrum Analyzer
DSL>Resistance Balance>Operation
3. Press Test to start the
test.
DSL>Resistance Balance>Normal Values
Service % Ohms Difference
POTS 3%
Wideband 1%
DSL>Resistance Balance>Application Notes
The resistance balance test is used to identify a high resistance
open or a bad splice.
The test will also identify a loop that is resistively too long for
the selected autotest.

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3M™Dynatel™Advanced Modular System 965AMS 30-MHz Spectrum Analyzer
DSL>DSL Impulse Noise
Use Impulse Noise to measure short spikes of random amplitude
and random frequency. These short bursts can damage data
transmission if the amplitude and frequency are spiking into
used transmission paths. The 965AMS measures spikes eight
times per second.
DSL>DSL Impulse Noise>Hook-Up
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DSL>DSL Impulse Noise>Operation
1. Press the blue DSL key
to enter the DSL function.
Use the up and down arrow
keys to select Impulse
Noise.
2. Press DSL Setup to select
the type of service.

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3M™Dynatel™Advanced Modular System 965AMS 30-MHz Spectrum Analyzer
DSL>DSL Impulse Noise>Operation
3. Use the up and down
arrow keys to select the
type of service that you are
measuring.
4. Press OK when finished.
5. Press OK to start the
Impulse Noise test.
6. Press Setup to select:
Count Threshold
Time
Spread
Metallic or Longitudinal
7. Press OK when finished.