Ameritec AM-48E, AM-48 User Manual

Models AM-48 and AM-48E

Personal Transmission

Test Set

INSTRUCTION MANUAL

Models AM-48 and AM-48E

Personal Transmission

Test Set

Instruction Manual

February 4, 2000

Technical Data Subject to

Change without Notice

760 Arrow Grand Circle

Covina, CA 91722 USA

TEL [phone]
FAX [phone]

www.ameritec.com

For extra copies of
this manual, order
Part No. 18-0015 © 2000 Ameritec Corporation

Record of Revisions

A September 1992 Initial Release.
B January 28, 1998 Minor Update Changes.
C October 2, 1998 Changed Generator

Accuracy Specs.

C1 October 9, 1999 Changed Distortion

specification on 1-6.

D February 4, 2000 Reformatted Manual to

provide new soft copy.
E January 19, 2004 Made a Better PDF
F April 19, 2004 Option

0015-TPG

ii

AM-48 Test Set (18-0015) Table of Contents

Table of Contents

1. INTRODUCTION ......................................................................................1-1

1.1 Manual Overview............................................................................... 1-1

1.2 General Description........................................................................... 1-2

1.3 AM-48 Technical Specifications........................................................1-4

1.4 AM-48E Technical Specifications....................................................1-11

2. RECEIVING AND UNPACKING.............................................................. 2-1

2.1 Introduction ........................................................................................2-1

2.2 Inspection when Received ................................................................2-1

2.3 Verification of Contents ..................................................................... 2-1

3. PHYSICAL & FUNCTIONAL DESCRIPTION......................................... 3-1

3.1 Introduction ........................................................................................3-1

3.2 General ..............................................................................................3-1

3.3 Component Location..........................................................................3-2

3.4 Connectors and Cables..................................................................... 3-3

3.5 Switches............................................................................................. 3-5

3.6 Keyboard.......................................................................................... 3-14

3.7 Display .............................................................................................3-17

3.8 Microphone/Speaker........................................................................3-19

3.9 Hand-Held Printer............................................................................ 3-20

3.10 Impedance Adapter .......................................................................3-24

4. POWER CONSIDERATIONS..................................................................4-1

4.1 General ..............................................................................................4-1

4.2 Battery Compartment ........................................................................4-1

4.3 Battery-Selector Switch.....................................................................4-1

4.4 Battery Installation.............................................................................4-3

4.5 Battery Information ............................................................................ 4-3

4.6 AC Power........................................................................................... 4-4

4.7 Power On/Off Switch .........................................................................4-4

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Table of Contents (18-0015) AM-48 Test Set

5. SELF-TEST INSTRUCTIONS.................................................................. 5-1

5.1 General ..............................................................................................5-1

5.2 Self-Test Setup..................................................................................5-1

5.3 Quiet Send Mode............................................................................... 5-4

5.4 Send 1004 Hz....................................................................................5-5

5.5 Send PAR (Peak-to-Average Ratio)..................................................5-7

5.6 Dialing ................................................................................................5-8

5.7 Parameter Values for Send Sweep.................................................5-10

6. CONNECTION AND CONFIGURATION.................................................6-1

6.1 Introduction ........................................................................................6-1

6.2 General ..............................................................................................6-1

6.3 Connectors and Cables..................................................................... 6-2

6.4 600Ω/900Ω Line Termination Impedances......................................6-7

6.5 Impedance Adapter ...........................................................................6-9

6.6 Configurations.................................................................................. 6-10

7. OPERATING INSTRUCTIONS................................................................ 7-1

7.1 Introduction ........................................................................................7-1

7.2 General Instructions and Notes.........................................................7-3

7.3 General Operating Notes...................................................................7-3

7.4 Figure Format .................................................................................... 7-4

7.5 General Switch Setup........................................................................ 7-6

7.6 Multiple Use of Keys.......................................................................... 7-8

7.7 Memory..............................................................................................7-9

7.8 General Procedure to Set New Parameter Values.........................7-12

7.9 Send (Generator) Modes and Parameter Settings......................... 7-13

7.10 Types of Send Signals...................................................................7-13

7.11 Send Quiet.................................................................................... 7-14

7.12 Set Parameters from Quiet Display .............................................7-15

7.13 Send Momentary Variable Tones.................................................7-17

7.14 Send 1004 Hz...............................................................................7-18

7.15 Send Continuous Variable Tone..................................................7-19

iv

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AM-48 Test Set (18-0015) Table of Contents

7.16 Send Set of Slope Tones .............................................................7-19

7.17 Send Variable Sweep................................................................... 7-20

7.18 Send PAR Waveform ................................................................... 7-22

7.19 Send Momentary 2713 Hz Tone..................................................7-22

7.20 General Instructions and Notes for MEASURE Modes............... 7-22

7.21 Accuracy of Measurements.......................................................... 7-22

7.22 Absolute and Relative Measurements.........................................7-23

7.23 Special Measurement Requirements........................................... 7-24

7.24 Timed Tests..................................................................................7-26

7.25 MEASURE Modes........................................................................7-27

7.26 Measure Level and Frequency.....................................................7-27

7.27 Measure Noise..............................................................................7-28

7.28 Measure PAR................................................................................7-29

7.29 Measure Impulse Noise................................................................7-29

7.30 Measure Notched Noise............................................................... 7-32

7.31 Measure S/N Ratio .......................................................................7-34

7.32 Measure Phase Jitter....................................................................7-34

7.33 Measure Amplitude Jitter..............................................................7-35

7.34 Measure Transients...................................................................... 7-36

7.35 Miscellaneous Operations............................................................ 7-40

7.36 Store and Recall...........................................................................7-40

7.37 Dialing...........................................................................................7-43

7.38 Talking...........................................................................................7-45

7.39 Printing.......................................................................................... 7-45

7.40 Auto Study Result Save................................................................7-56

7.41 Impedance Adapter Measurement Corrections........................... 7-56

7.42 Auto Calibrate...............................................................................7-59

8. EXPLANATION AND APPLICATION OF MEASUREMENTS...............8-1

8.1 Introduction ........................................................................................8-1

8.2 Units of Measurement .......................................................................8-1

8.3 Level (Loss or Gain) and Frequency.................................................8-4

8.4 Idle Channel Noise ............................................................................ 8-4

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Table of Contents (18-0015) AM-48 Test Set

8.5 Notched Noise (Noise with Tone) ..................................................... 8-4

8.6 Signal-to-Noise (S/N) Ratio...............................................................8-5

8.7 P/AR Measurements..........................................................................8-6

8.8 Gain Slope .........................................................................................8-8

8.9 Idle Channel Impulse Noise ..............................................................8-9

8.10 Phase Jitter.................................................................................... 8-11

8.11 Amplitude Jitter..............................................................................8-11

8.12 Notched Impulse Noise .................................................................8-12

8.13 Phase Hits......................................................................................8-12

8.14 Gain Hits ........................................................................................8-12

8.15 Dropouts.........................................................................................8-12

9. CIRCUIT DIAGRAMS...............................................................................9-1

9.1 Introduction ........................................................................................9-1

9.2 AM-48 Simplified Block Diagram.......................................................9-1

9.3 Impedance Adapter Schematic.........................................................9-3

10. WARRANTY, SERVICE, AND CALIBRATION ..................................10-1

10.1 Warranty.........................................................................................10-1

10.2 Service Policy ................................................................................10-1

10.3 Calibration Policy........................................................................... 10-1

10.4 Return of Unit.................................................................................10-2

11. GLOSSARY........................................................................................... 11-1

vi

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AM-48 Test Set (18-0015) Table of Contents

List of Figures

Figure 3-1. AM-48 Location of Components................................................ 3-3

Figure 3-2. AM-48 Connectors.....................................................................3-4

Figure 3-3. Standard AM-48 Cables ............................................................3-4

Figure 3-4. Optional AM-48 Cables..............................................................3-5

Figure 3-5. AM-48 Switch Identification Numbers .......................................3-6

Figure 3-6. AM-48 Keyboard Identification Numbers ................................ 3-15

Figure 3-7. AM-48 Liquid Crystal Display ..................................................3-18

Figure 3-8. Hand-Held Printer, External View............................................3-22

Figure 3-9. Hand-Held Printer, Internal View............................................. 3-23

Figure 3-10. Impedance Adapter................................................................3-24

Figure 4-1. Battery Installation and Selector Switch.................................... 4-2

Figure 5-1. AM-48 Setup for Self-Test (Looped Back)................................5-2

Figure 5-2. General Switch Setup for Self Test...........................................5-3

Figure 5-3. Quiet Send Mode Self Test........................................................5-4

Figure 5-4. Send 1004 Hz Self Test, Switch Settings..................................5-6

Figure 5-5. Send 1004 Hz Self Test, Displays............................................. 5-7

Figure 5-6. Send PAR (Peak-to-Average Ratio).......................................... 5-8

Figure 5-7. Dialing.......................................................................................5-10

Figure 5-8. Default Parameter Settings for SWEEP Send Mode.............. 5-14

Figure 6-1. 2-Wire AM-48 Line Connections................................................6-3

Figure 6-2. 4-Wire AM-48 Line Connections................................................6-4

Figure 6-3. AM-47 Hand-Held Printer Connection with AC Power..............6-5

Figure 6-4. 4-Wire End-to-End Testing......................................................6-11

Figure 6-5. 4-Wire Testing with Responder...............................................6-13

Figure 6-6. 2-Wire Network Testing with Responders............................... 6-14

Figure 7-1. Parameter Settings from QUIET SEND

Figure 7-2. Parameter Settings from 1004 Hz and VAR Tone Displays ...7-18

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vii

Display.....................7-15

Table of Contents (18-0015) AM-48 Test Set

Figure 7-3. Parameter Settings from 3-TONE Slope and

PAR SEND Displays......................................................... 7-20

Figure 7-4. Parameter Settings from SWEEP SEND Display...................7-21

Figure 7-5. L/F, NOISE, and PAR MEASURE Displays............................ 7-28

Figure 7-6. IMPLS MEASURE Displays.....................................................7-32

Figure 7-7. Notched NOISE and S/N Ratio MEASURE Displays .............7-33

Figure 7-8. Phase JTR and Amplitude JTR MEASURE Displays............. 7-35

Figure 7-9. TRANS MEASURE Displays..........................................7-39, 7-40

Figure 7-10. Recall and Store Operations .................................................7-42

Figure 7-11. SEND Printouts...................................................................... 7-52

Figure 7-12. MEASURE Printouts, Absolute Measure Mode.................... 7-54

Figure 7-13. MEASURE Printouts, Relative Measure Mode..................... 7-55

Figure 7-14. Impedance Adapter Correction Value Memory Aid............... 7-58

Figure 7-15. AM-48 Auto Calibrate Prompts..............................................7-60

Figure 8-1. Level and Noise Units of Measurement....................................8-2

Figure 8-2. Impulse Noise Thresholds and Blanking Intervals.................. 8-10

Figure 9-1. Simplified Block Diagram of the AM-48.....................................9-2

Figure 9-2. Schematic Diagram of the Impedance Adapter........................9-4

viii

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AM-48 Test Set (18-0015) Table of Contents

List of Tables

Table 1-1. AM-48 General Technical Specifications ...................................1-5

Table 1-2. AM-48 Generator (Send) Technical Specifications.................... 1-6

Table 1-3. AM-48 Receiver (Measure) Technical Specifications................1-8

Table 1-4. AM-48 Power/Physical Technical Specifications .....................1-11

Table 2-1. AM-48 Standard Equipment .......................................................2-2

Table 2-2. AM-48 Optional Equipment ........................................................2-2

Table 3-1. Front Panel/Switches Color Coding............................................3-2

Table 3-2. AM-48 SEND, MEASURE, and FILTER Menus.......................3-19

Table 3-3. AM-47 Hand-Held Printer Technical Specifications................. 3-21

Table 7-1. Setup Requirements for Different Keyboard Applications .........7-8

Table 7-2. Steps for Up and Down Arrow Keys........................................... 7-9

Table 7-3. User-Programmable Parameter Values Stored in Memory.....7-11

Table 7-4. Acceptable Holding Tone Ranges............................................7-25

Table 7-5. Special Measurement Requirements........................................ 7-26

Table 7-6. Setup Requirements for Dialing................................................ 7-44

Table 7-7. MF and DTMF Tone Pairs.........................................................7-44

Table 7-8. Impedance Adapter Correction Values.....................................7-57

Table 8-1. P/AR Requirements of Telephone Lines.................................... 8-6

0015-TOC

ix

AM-48 Test Set (18-0015) Introduction

1. INTRODUCTION

1.1 Manual Overview

This instruction manual describes Ameritec Corporation’s AM-48

and AM-48E Personal Transmission Test Sets.

Note: Throughout this manual, all references to the "AM-48" also

apply to the "AM-48E", unless otherwise noted. See ¶1.4

for a summary of the differences between the AM-48 and

the AM-48E.

The other paragraphs in this Introduction section are:

1.2 General Description

1.3 AM-48 Technical Specifications

1.4 AM-48E Technical Specifications

The balance of the manual is divided into the following sections:

2. Receiving and Unpacking

3. Physical and Functional Description

4. Power Considerations

5. Self-Test Instructions

6. Connection and Configuration

7. Operating Instructions

8. Explanation and Application of Measurements

9. Circuit Diagrams

10. Warranty, Service, and Calibration

11. Glossary

Index

0015-S01

1-1

Introduction (18-0015) AM-48 Test Set

Note: It is suggested that the foldout at the back of the manual be

extended when using this manual. The FOLDOUT, a front view
of the AM-48, defines the numbers of the switches which are
used to identify the switches throughout this manual.

Glossary . Refer to the Glossary to become familiar with the

terminology used in this manual.

Power . Be sure to read Section 4 and observe the WARNING in ¶4.3

before powering up the AM-48.

Self Test . Perform the Self Test in Section 5 to:

1. confirm that all AM-48 circuits and basic functions are

working properly, and

2. obtain "hands-on" experience with the AM-48 to learn how

the controls operate.

Transmission Measurements . Note that Section 7, Operating

Instructions, gives procedures to

explanation and application of the measurements, see Section 8.

For

perform transmission measurements.

1.2 General Description

Definition and Purpose . In one (1) hand-held unit, the AM-48

provides the field engineer with two (2) instruments:

1. a transmission test set, and

2. a telephone "butt-set".

transmission test set tests the integrity and quality of 2-wire or

The

4-wire voice and data transmission lines by sending selected analog

signals and measuring standard parameters of the received signals.

0015-S011-2

AM-48 Test Set (18-0015) Introduction

3

The telephone "butt set" enables the field engineer to dial up and

speak back-and-forth with a field engineer at the far end of the

system. The compact and light-weight AM-48 eliminates the need to

carry multiple, bulky test sets.

Functional Overview

AM-48 can send:

• any frequency from 200 Hz to 20 kHz @ -50 to +10 dBm

• continuous 3-tone slope (404, 1004, 2804 Hz)

• continuous, user-defined, sweep tones

• fixed 1004 Hz

• P/AR waveform

• momentary 2713 Hz for WECO 829 loopback

AM-48 can measure:

• level, -65 to +10.9 dBm (absolute or relative)

• frequency, 0 to 19,999 Hz

• idle channel noise

• noise with tone

• three-level impulse noise

• phase jitter

• gain jitter

• transients (dropouts, phase and gain hits, impulse noise)

• signal-to-noise (S/N) ratio

• peak-to-average ratio (P/AR)

Noise filters provided (each with optional 1010 Hz notch)::

• C-Message (Psophometric for AM-48E)

• 3 kHz

• 15 kHz

• Program (Sound-weighted for AM-48E)

0015-S01

1-

Introduction (18-0015) AM-48 Test Set

Other features:

• High impedance bridge, 600 or 900 Ohm termination

• Display prompts help in set-up and testing sequences

• On-board memory can store & recall up to 10 user-defined

test set-ups

• Dials: pulse, DTMF, and MF

• Talk/Listen capability

• Printer interface for hard copy of set-up and test results

• Battery life: Alkaline, 6 to 7 hours; NiCad, 3 to 4 hours

• NiCad batteries can be recharged without removing them

from the unit

Testing Configurations: (For details, see ¶6.6)

There are three (3) basic AM-48 configurations used to test

2-wire/4-wire telephone/data communication lines:

1. End-to-end -- requiring two (2) AM-48 units

2. Loopback

3. Testing with responders

1.3 AM-48 Technical Specifications

AM-48 technical specifications are presented in four (4) parts:

1. General (Table 1-1)

2. Generator (Send) (Table 1-2)

3. Receiver (Measure) (Table 1-3)

4. Power/Physical (Table 1-4)

0015-S011-4

AM-48 Test Set (18-0015) Introduction

5

Table 1-1. AM-48 General Technical Specifications

Characteristic Specification

Measurements

Level -65 to +10.9 dBm

Frequency 0 to 19,999 Hz

Noise 10 to 99 dBrn

Notched Noise 10 to 99 dBrn

Signal to Noise 0 to 60 dB

P/AR 0 to 120

Amplitude Jitter 0.0 to 25.0%

Phase Jitter 0.0 to 25.0 degrees

3-Level Impulse Noise Counts from 0 to 9999

Transient Measurements

Dropouts 0 to 9999

Gain Hits 0 to 9999

Phase Hits 0 to 9999

3-Level Impulse Noise Counts from 0 to 9999

Dial Built-in 16 button keypad for dial pulse, DTMF (Touch

Talk Built-in microphone and speaker with push-to-talk

Holding A single line holding circuit is provided for 2-wire

Impedances 600 and 900 ohm.

Tone), or MF dialing.

operation on both 2-wire and 4-wire lines. Earphone
jack for optional earphone.

operation, or the send pair of 4-wire circuits. It
electronically simulates a holding coil with a DC
resistance of approximately 200 ohms. The AC
impedance is high enough to give no more than 0.2 dB
loss at 600 ohm impedance.

Balance > 60 dB below 4 kHz, decreasing 6 dB.octave
above 5 kHz.

Return loss > 30 dB 200-5000 Hz, > 15 dB 5-20 kHz.

DC blocking - 150 Volts.

Bridging impedance > 25 kohms.

0015-S01

1-

Introduction (18-0015) AM-48 Test Set

Characteristic Specification

Printer Current loop interface to optional printer for hard copy

of unit setup and measurement results

Store/Recall 10 complete unit setups may be stored by user in

internal nonvolatile memory, and recalled for ease of
repeating frequently-used tests. In addition, the results
of the last impulse or transient study (along with the
associated setups) are stored to nonvolatile memory at
the completion of the study. They are recalled
automatically whenever the unit is turned on.

Also stored in nonvolatile memory are four (4) user-set
parameters (each set from the QUIET mode):

1. Touch Tone/MF Dial Level

2. Power Down Time with momentary power switch

3. Blanking interval for impulse and transient tests

4. 10 user-programmable momentary frequencies

Table 1-2. AM-48 Generator (Send) Technical Specifications

Characteristic Specification

Variable Frequency: 200 Hz to 19,999 Hz in 1 Hz steps.

Frequency may be entered directly via the keypad or
stepped up or down in 10 Hz steps with auto-repeat
steps of 100 Hz (4 steps/second) for fast frequency
slewing. Frequencies are crystal-controlled and
accurate to ±.72 Hz ±.01%.

Level: -50.0 dBm to +10.0 dBm in .1 dB steps. Level
may be entered directly via the keypad or stepped up

or down in .1 dB steps with auto-repeat steps of 1.0 dB
(4 steps/second) for fast level slewing. Level accuracy
is as follows:

+10 dBm

-40 dBm

-50 dBm

200 Hz

±0.2 ±0.5

±0.5 ±1.0

15 kHz 20 kHz

1004 Hz A fixed 1004 Hz holding tone is provided. The

frequency is accurate to ±.025%. Level is the same as
variable.

0015-S011-6

AM-48 Test Set (18-0015) Introduction

Characteristic Specification

3-Tone A three-tone slope frequency mode is provided, which

cycles continuously between 404 Hz, 1004 Hz, and
2804 Hz, giving 5 seconds of each tone. Frequency
accuracy is the same as variable. Level is the same
as variable.

Sweep A programmable frequency sweep generator is

provided. It generates tones continuously from a user­specified START frequency (200 Hz to 19,999 Hz) to a
user-specified STOP frequency (200 Hz to 19,999 Hz),
at a user-specified frequency STEP interval (1 Hz to
19,999 Hz), and at a user-specified step RATE (0.1
second to 19,999 seconds/frequency). Frequency
accuracy is the same as variable. Level is the same
as variable.

PAR A PAR waveform generator is provided, which

generates the 16 simultaneous frequency PAR
waveform per Bell 41009 specifications. The level
may be set from -40.0 dBm to 0.0 dBm, with 0.1 dBm
resolution. Level accuracy is ±0.5 dBm.

Quiet In quiet mode, the line is terminated with a passive

resistance equal to the line impedance. Also, when in
Quiet, one of 10 user-programmable tones may be
momentarily applied to the line by depressing the (0)
thru (9) keys.

Programmable from this mode are (1) Touch Tone dial
level (-50.0 to 7 dBm), (2) Power down Time Off (1 to
255 minutes), (3) Impulse and Transient test Blanking
Interval (1 to 255 ms), and (4) 10 user-programmable
tones for later instant recall.

Aux Tone A momentary pushbutton is provided for the

generation of an auxiliary tone (2713 Hz), used to
activate remote 829-type loopback devices.

SF Skip A Signaling Frequency (SF) Skip mode prevents the

generation of tones between 2450 Hz and 2750 Hz in
variable or sweep modes.

Distortion Total distortion is < -50 dB @ 1004 fixed tone and

< -40 dB @ any other frequency.

0015-S01

1-7

Introduction (18-0015) AM-48 Test Set

Table 1-3. AM-48 Receiver (Measure) Technical Specifications

Characteristic Specification

Level/Freq Level is measured with an average responding detector.

Range is -65.0 to +10.9 dBm with 0.1 dBm resolution.
Accuracy is as follows:

+10 dBm

-40 dBm

-65 dBm

Note: Accuracy is ±0.1 dBm at 1004 Hz from -20

dBm to 0.0 dBm.

Frequency is measured from 200 Hz to 19,999 Hz with an
accuracy of ±.01% ±1 Hz, and a resolution of 1 Hz. Input

level -40 to +10 dBm.

PAR Peak-to-Average Ratio (PAR) is measured from 0 to 120

PAR units to a resolution of 1 PAR unit. Accuracy is ±2
from 30 to 110, ±4 from 0 to 120 over a signal range of -40
to 0 dBm.

PAR signal level is measured from -40 to 0 dBm, with a
resolution of 1 dBm, using an RMS detector.

Noise Noise is measured with an RMS responding detector from

10 to 99 dBrn to 1 dBrn resolution. Accuracy is ±1 dBrn
from 20 to 99 dBrn, and ±2 dBrn from 10 to 20 dBrn.

Weighting Filters are 3 kHz flat, 15 kHz flat, CMSG, and
Program filter.

Notched Noise Notched Noise is the same as noise with the addition of a

1010 Hz notch filter, minimum 50 dB deep from 995 to 1025
Hz.

S/N ratio Signal-to-Noise (S/N) ratio display the ratio of signal

(holding tone) to notched noise. The signal must be -40 to
+10 dBm. The notched noise may be 10 to 70 dBrn. The
S/N ratio may be from 10 to 50 dB. Resolution is 1 dB.
Accuracy is ±1 dB for notched noise 20 to 70 dBrn, and ±2
dB for notched noise from 10 to 20 dBrn.

200 Hz

±0.2 ±0.5

±0.4 ±0.8

15 kHz 20 kHz

0015-S011-8

AM-48 Test Set (18-0015) Introduction

9

Characteristic Specification

Amplitude Jitter Displays the incidental amplitude modulation of a holding

Phase Jitter Displays the incidental phase modulation of a holding tone.

Impulse Noise Three (3) noise thresholds are established: Low, Middle,

Transients Counts dropouts, gain hits, phase hits, and 3-level impulse

tone. The holding tone must be -40 to +10 dBm, 990 to
1030 Hz. Amplitude jitter is displayed from 0.0 to 25.0%
with a resolution of .1% and an accuracy of ±.2%, ±5% of
reading.

Weighting filter selection: 20-300 Hz or 4-300 Hz.

The holding tone must be -40 to +10 dBm, 990 to 1030 Hz.
Phase jitter is displayed in degrees from 0.0 to 25.0
degrees with a resolution of .1 degree and an accuracy of
±.2 degree, ±5% of reading.

Weighting filter selection: 20-300 Hz or 4-300 Hz.

and High levels, with an equal interval between them called
the Delta. The maximum High threshold is 105 dBrn for
600 ohm impedance (or 104 dBrn for 900 ohm). The

minimum Low threshold is 30 dBrn. Delta can be 2, 3, 4, or
6 dB. Threshold accuracy: ±1 dB. A user-selected
blanking interval of 1 to 255 ms for each threshold, blocks
further counting of impulses at that threshold.

The study duration timer may be set from .1 minute to

1999.9 minutes in .1 minute steps, or continuous. Each
threshold has a count capacity of 0-9999. Weighting filters
same as noise.

noise with tone. Holding tone must be -40 to +10 dBm, 995
to 1025 Hz

Dropout threshold is -12 dB from the initial level of the
holding tone. A dropout will be counted if the holding tone

drops below the threshold for at least 4 ms ±.5 ms.
Counting of dropouts, gain hits, phase hits, and impulses is
inhibited for a blanking interval which lasts until 1 second
after the holding tone is restored to a level above the
dropout threshold.

0015-S01

1-

Introduction (18-0015) AM-48 Test Set

Characteristic Specification

Transients
(cont.)

Gain hit threshold can be 2, 3, 4, or 6 dB. A gain hit will be
counted if the level of the holding tone changes up or down

by more than the threshold for at least 4 ms ±.5 ms. A
blanking interval, that is user-set from 1 to 255 ms, blocks
further counting of gain hits.

Phase hit threshold can be 5 to 45 degrees in 1 degree
steps, with an accuracy of ±.5 degrees ±10% of the setting.

A phase hit will be counted if the phase of the holding tone
changes by more than the threshold fro at least 4 ms ±.5
ms. A blanking interval, that is user-set from 1 to 255 ms,
blocks further counting of phase hits.

The three-level impulse noise low threshold can be set from
30 to 110 dBrn with threshold differences of 2, 3, 4, or 6 dB.

Threshold accuracy: ±1 dB. An independent blanking
interval for each threshold, user-set from 1 to 255 ms,
blocks further counting of impulses at that threshold.

The study duration timer may be set from .1 minute to

1999.9 minutes in .1 minute steps, or set to 0 for a
continuous study.

Each transient has a count capacity of 0-9999.

Filters same as noise.

Damping A damp mode reduces the display update rate from

approximately 4 times/second to approximately 2
times/second for reading widely fluctuating measurements.

The same switch, when in <DAMP> position, also changes
the monitoring point of the receive (RCV) monitor speaker
to the output of the auto-range amplifier (significantly
increasing the speaker level).

Term/Bridge When in terminate, the receiver terminates the line in the

selected impedance. When in bridge, the line is bridged by
a high impedance, causing no more than .2 dB loss on a
600 ohm line.

0015-S011-10

AM-48 Test Set (18-0015) Introduction

Table 1-4. AM-48 Power/Physical Technical Specifications

Characteristic Specification

Power Four 1.5 VDC "AA" alkaline batteries provide about six

Physical Size: 4.2" (106mm)W x 7.6" (193mm)H x 1.7" (43mm) D.

hours operation. NiCad batteries provide about half the life
of alkaline.

External AC adapter powers unit from 120 VAC and
charges optional NiCad batteries in the unit.

Auto shutoff after last switch actuation is user­programmable for 0 (no shutoff), or from 1 to 255 minutes.

May be overridden by placing power switch in the <ON>
position. Does not turn itself off while timed study is in
progress.

Weight: 23 oz. with alkaline batteries (slightly less with
NiCad).

Connections to phone line via dual bantam jacks and
RJ11C modular jack.

1.4 AM-48E Technical Specifications

AM-48E is an international version transmission test set which meets

CCITT standards. All specifications for the AM-48 in Tables 1-1

thru 1-4 are identical for the AM-48E, except as described below:

1. Instead of the C-Message

AM-48E has the

Psophometric (PSHO) noise-weighting filter .

See Figures 3-6 and 3-7.

2. Instead of the Program

AM-48E has the

Sound-weighted (SWTD) filter . See Figures

3-6 and 3-7.

3. Instead of the

3TONE slope frequency send mode of 404 Hz,

1004 Hz, and 2804 Hz @ 5 seconds, the AM-48E has a 4-tone

SLOPE frequency send mode of 404 Hz , 1004 Hz , 2004 Hz , and

3004 Hz @ 5 seconds. See Figures 3-6 and 3-7.

(CMSG) noise-weighting filter, the

(PROG) noise-weighting filter, the

0015-S01

1-11

Introduction (18-0015) AM-48 Test Set

4. Instead of Signal Frequency (SF) Skip 2450 Hz to 2750 Hz, the

AM-48E has

SF SKIP from 2130 Hz to 2430 Hz .

5. On all noise displays, instead of units of dBrn , the AM-48E

displays the noise in units of

dBm . See ¶8.2 and Figure 8-1 for

definitions and corresponding values of dBrn and dBm units.

0015-S011-12

AM-48 Test Set (18-0015) Receiving and Unpacking

2. RECEIVING AND UNPACKING

2.1 Introduction

This section covers procedures to follow when the AM-48 is first

received in its shipping container:

2.2 Inspection when Received

2.3 Verification of Contents

2.2 Inspection when Received

The AM-48 was thoroughly tested and carefully packed before

shipment, and was in good condition when turned over to the carrier

for transport.

The name of the carrier will be noted on the packing slip which

accompanied the shipment.

Upon receipt, thoroughly inspect the outside of the shipping container

for damage. If the container is damaged, and the AM-48 is found to

be damaged or non-operational, immediately contact the carrier and

submit a claim for damages.

Note: To test if the unit is operational, see Section 4 for Power

Considerations and Section 5 for Self-Test Instructions.

2.3 Verification of Contents

After opening and unpacking, use the following equipment lists to

verify that all ordered items have been received. Note that some

items are standard and always included; other items are optional, and

only shipped when specially ordered.

0015-S02

2-1

Receiving and Unpacking (18-0015) AM-48 Test Set

Table 2-1. AM-48 Standard Equipment

Amount Part Number Description

1

4

1

1

1

1

1

AM-48 unit

24-0006 AA-size 1.5 VDC alkaline batteries

48-0049 Modular input cord with minigator clips

82-0005 Earphone

70-0029 AC Adapter

18-0015 AM-48/AM-48E Instruction Manual

87-0009 AC Adapter

Table 2-2. AM-48 Optional Equipment

Amount Part Number Description

1

4

4

1

1

1

1

1

1

1

1

1

1

24-0005 Impedance Adapter (1200, 150, 135, 75 ohms)

24-0006 AA-size alkaline batteries (replacement set)

24-0007 AA-size NiCad (rechargeable) batteries

AM-47 Hand-held printer - includes roll of paper, ribbon

cartridge, and 48-0079 Printer Cable.

26-0014 roll of paper for Hand-held printer

26-0015 ribbon cartridge for Hand-held printer

48-0047 Bantam (M) to Bantam (M) Cable (6') (two

required for 4-wire operation)

48-0048 Bantam (M) to 310 (M) Cable (6') (two required for

4-wire operation)

48-0049 Modular to Minigator Cable (7')

48-0062 Bantam (M) to Minigator Cable (6') (two required

for 4-wire operation)

48-0078 Printer Cable for use with an EIA printer

48-0079 Printer Cable for use with Ameritec Hand-held

printer.

87-0016 AM4 Soft Carrying Case

See Figure 3-3 for illustrations of the cables listed in Tables 2-1 and
2-2.

0015-S02

2-2

AM-48 Test Set (18-0015) Unit Description

3

3. PHYSICAL & FUNCTIONAL DESCRIPTION

3.1 Introduction

This section illustrates and explains the components of the AM-48.

Also described are the Hand-held Printer and the Impedance Adapter.

This section is divided into the following paragraphs:

3.2 General

3.3 Component Location

3.4 Connectors and Cables

3.5 Switches

3.6 Keyboard

3.7 Display

3.8 Microphone/Speaker

3.9 Hand-held Printer

3.10 Impedance Adapater

See ¶4.2 for the description of the battery compartment.

3.2 General

The AM-48 weighs 23 ounces (with batteries) and measures 4.2" x

7.6" x 1.7" (106mm x 193mm x 43mm).

All electronic components are mounted on three (3) interlocking

printed circuit boards, housed in a high-impact injection-molded ABS

plastic case. The case is factory-sealed, since there are no user-

serviceable parts inside.

To stand or hang the AM-48, use the hinged wire bail at the top of the

case. Lift the bail until it snaps into the detent of the desired position.

The front panel and switches are color-coded to tie together

associated functions.

0015-S03

-1

Unit Description (18-0015) AM-48 Test Set

Table 3-1. Front Panel/Switches Color Coding

Color Description

Black & Blue Line controls. Associated with configuring the AM-48 for the

Yellow Send controls. Associated with selecting the desired signal

Red/Pink Measure controls. Associated with selecting the desired

Orange On menus: all noise-weighting filters and the measurements

type of line to be measured.

generator (send) function and controlling the signal generator.

measurement function and measurement characteristics.

that require a noise-weighting filter.

3.3 Component Location

Figure 3-1 shows the location of components on the front panel and

sides.

Front Panel . Liquid crystal display and keyboard.

Sides . There are two (2) slide switches on the left side and a total of

12 color-coded rocker switches along the left and right sides. The

rocker switches are protected from abuse by integral "ribs" molded

into the case. A thumb wheel speaker volume control and slots for

the microphone are also located on the left side.

Top and Bottom . The slots at the top are for the speaker.

Connectors for the transmission line, AC adapter, earphone, and

printer are located along the bottom, as illustrated in Figure 3-2.

Rear Panel . You may access the battery compartment through a slide

door in the rear panel. See ¶4.2 and 4.3 for details.

0015-S033-2

AM-48 Test Set (18-0015) Unit Description

3-3

Ameritec

SPEAKER

ON

∇

•

∇

ON/
OFF

MF

LIQUID
CRYSTAL
DISPLAY

∇

•

∇

∇

∇

∇

∇

∇

∇

∇

∇

∇

•

∇

∇

•

∇

∇

∇

ROCKER
SWITCHES

KEYBOARD

THUMB
WHEEL

SLIDE
SWITCHES

MICROPHONE

PERSONAL TRANSMISSION TEST SET

MODEL AM-48

QUIET 1004 VAR

VOL

∇

MON RCV
MON SND

•

∇

TALK

∇

TERM

∇

BRDG

∇

TONE
PULSE

•

∇

ON HK

∇

900Ω
600Ω

∇

∇

2W
4W

•

4W REV

∇

MIC

PRT EARDC9V

PAR

SEND MEASURE FILTER

*

∇

HOLD

L/F

NOISE NOISE S/N

TONE

PAR3 TONE SWEEP

∆

IMPLS ØJTR JTR TRANS

∇

21 A3

54 B6

87 C9

0

STOPSTART

∇

4W/2W

SND4WRCV

ETR/NEXT

ETR/PREV

CANCEL

D#

+/-

3K C-MSG

15K PROG

RCL/STO

ABS

REL

SEND

DAMP

OFF

DTMF
SHIFT

SF SKP

NOR

X TONE

PRINT

SEL

SEL

SEL

CONNECTORS (On Unit End) (Shown in Figure 3-2)

Figure 3-1. AM-48 Location of Components

3.4 Connectors and Cables

AM-48 connectors are shown in Figure 3-2. Figures 3-3 and 3-4

illustrate the standard and optional cables available for use with the

AM-48. See ¶6.3 for cable connection instructions.

0015-S03

Unit Description (18-0015) AM-48 Test Set

Note: The AM-47 Hand-held Printer includes its own cable, P/N

48-0079. The Printer Cable P/N 48-0078 is for connection

to the RS-232 port (25-pin female) of most other serial EIA

printers..

PRINTER JACK

<PRT>

AC ADAPTER

PLUG <DC 9V>

4-WIRE RECEIVE

BANTAM JACK

RJ-11

2.5 mm JACK

EARPHONE JACK

<EAR>

4-WIRE SEND,

2-WIRE

BANTAM JACK

Figure 3-2. AM-48 Connectors

CABLE 48-0049, 7 Ft

AC ADAPTER 70-0029, 6 Ft

EARPHONE 82-0005, 3 Ft

Figure 3-3. Standard AM-48 Cables

RJ11 MODULAR

JACK

YELLOW

GREEN

RED

BLACK

0015-S033-4

AM-48 Test Set (18-0015) Unit Description

3-5

GREEN

BANTAM PLUG

CABLE 48-0062, 6 Ft

RED

BLACK

R

T

S

BANTAM PLUG BANTAM PLUG

BANTAM PLUG

CABLE 48-0047, 6 Ft

CABLE 48-0048, 6 Ft

310 PLUG

2.5 mm JACK

PRINTER CABLE 48-0079, 6 Ft

4-WIDE

MODULAR

2.5 mm PLUG

2.5 mm PLUG

PRINTER CABLE 48-0078, 6 Ft

DB25 PLUG

Figure 3-4. Optional AM-48 Cables

3.5 Switches

Figure 3-5 shows the location of the AM-48 switches. The functional

descriptions of the switches in this paragraph follows the same

numbering scheme as Figure 3-5.

Note: Throughout this manual, a switch position indicated on the

front panel is referred to with angular brackets, <>. For

example, <ABS> refers to the absolute measurement position

of Switch 2.

Switches are referred to by number throughout this manual.

See Figure 3-5 for ease of reference of switch numbers.

0015-S03

Unit Description (18-0015) AM-48 Test Set

Ameritec

PERSONAL TRANSMISSION TEST SET

MODEL AM-48

ON

ON/
OFF

∇

•

∇

1

15

14

13

12

11

10

QUIET 1004 VAR

VOL

∇

MON RCV
MON SND

•

∇

TALK

∇

TERM

∇

BRDG

∇

TONE
PULSE

•

∇

ON HK

∇

900Ω
600Ω

∇

PAR

SEND MEASURE FILTER

HOLD

L/F

NOISE NOISE S/N

TONE

PAR3 TONE SWEEP

IMPLS ØJTR JTR TRANS

21 A3

54 B6

∇

2W
4W

•

4W REV

∇

MIC

PRT EARDC9V

*

87 C9

0

4W/2W

SND4WRCV

STOPSTART

∇

∇

∆
∇

ETR/NEXT

ETR/PREV

CANCEL

D#

+/-

3K C-MSG

15K PROG

RCL/STO

ABS

REL

SEND

DAMP

OFF

SEL

SEL

SEL

DTMF

SHIFT

SF SKP

NOR

X TONE

PRINT

MF

Figure 3-5. AM-48 Switch Identification Numbers

∇

•

∇

∇

∇

∇

∇

∇

∇

∇

∇

∇

•

∇

∇

•

∇

∇

∇

2

3

4

5

6

7

8

9

0015-S033-6

AM-48 Test Set (18-0015) Unit Description

3

There are three (3) types of switches:

Thumb Wheel : "Switch" 15 is the only thumb wheel. It is a

volume control. Push up (toward the front panel) on <VOL> to

increase the volume of the monitor speaker. Push down on

<VOL> to decrease the monitor speaker volume.

Slide Switches : Switches 10 and 11 are slide switches. Push

these switches toward the top or the bottom in the direction

indicated by the arrows on the front panel to select the desired

line parameter.

Rocker Switches : The other 12 switches are rocker switches.

The action of these switches is rather like a rocking chair. Rock

the appropriate switch toward or away from the front panel as

indicated by the arrows to activate the desired function. There

are various combinations between toggle and/or momentary

switching action as explained in the functional descriptions

which follow (reference Figure 3-5).

1

Power . Combination toggle and momentary rocker switch.

• Set to <ON> position for power to be on continuously.

• To allow the AM-48 to power down by itself, turn the

power on by momentarily pressing the switch toward

the <ON/OFF> position. The power will shut off

automatically after the TIME OFF setting, if the unit is

left unattended. (See ¶7.12 for instructions to set the

time).

• To turn the power off, momentarily press the switch

toward the <ON/OFF> position.

0015-S03

-7

Unit Description (18-0015) AM-48 Test Set

2

Display Select . Three-position toggle switch. This

determines what is being viewed on the display.

• Set <ABS> to view MEASUREMENT mode in

reference.

• Set <REL> to view MEASUREMENT mode in

reference.

• Set <SEND> to view the SEND mode.

See ¶7.22 and 8.2 for explanation of absolute and relative

measurements.

3

Two-position toggle switch. This switch has a dual

function:

A. Controls the display damping. <DAMP> gives a

display update of two times per second (used with

widely fluctuating signals to update the display more

often for better sampling of the measurement).

<OFF> gives a display update of four times per

second.

absolute

relative

B. Controls the monitoring point of the receive monitor

speaker (<MON RCV> position of Switch 14).

<DAMP> gives a monitoring point at the output of the

auto-range amplifier, significantly increasing the

spaeker level.. See Figure 9-1 for a block diagram

showing how this switch interacts with Switch 14.

0015-S033-8

AM-48 Test Set (18-0015) Unit Description

3-9

4

Filter Select . Dual momentary switch. Rock up or down

to move FILTER menu cursor left or right to select desired

noise-weighting filter. See Table 7-5 for a list of

measurements that require a noise-weighting filter. See

Figure 3-8 for the FILTER menu.

5

Measure Select . Dual momentary switch. Rock up or

down to move MEASURE menu cursor left or right to

select desired measure mode. See Figure 3-8 for the

MEASURE menu.

6

Send Select . Dual momentary switch. Rock up or down

to move SEND menu cursor left or right to select desired

send (generator) mode. See Figure 3-8 for the SEND

menu.

7

Three-position toggle switch. See Table 7-6 for

interaction of this switch with Switch 12 for dialing.

• Set <MF> to dial multi-frequency tones from the

keyboard.

• Set <DTMF> to dial DTMF (Touch Tone) from the

keyboard.

• Set <SHIFT> to enable the auxiliary functions on the

keyboard. See ¶3.6 for details.

0015-S03

Unit Description (18-0015) AM-48 Test Set

8

Two-position toggle plus momentary switch.

• Set <SF SKP> to skip the signaling frequency band of

2450 Hz to 2750 Hz (2130 Hz to 2430 Hz for

AM-48E), avoiding the accidental transmission of

signaling frequencies.

• Set <NOR> to allow the internal signal generator to be

stepped through all frequencies within its range while

in the SWEEP and VAR

• Press <X TONE> to momentarily send a 2713 Hz tone,

overriding the internal signal generator. This feature

is useful for actuating loopback devices. See ¶6.6

Loopback Testing " for the procedure to use the

under "

Western Electric Model 829 loopback device.

9

Dual momentary switch.

• Press <RCL/STO> to recall and/or store up to 10 test

setups. See ¶7.36 for details.

• Press <PRINT> to send unit setup and measurement

results to the printer port, <PRT>. See ¶3.9 and 7.39

for details.

SEND modes.

10

Three-position slide switch. See Figure 6-1 and 6-2 for

2-wire and 4-wire line connections associted with this

switch.

• Set <2W> to connect the internal measurement

circuitry and signal generator across the 2-wire line at

the <SND> jack. The signal generator source

impedance of 600 or 900 ohms terminates the line in

all signal generator modes except QUIET.

0015-S033-10

AM-48 Test Set (18-0015) Unit Description

3

In QUIET mode, the line will be terminated only if

Switch 13 is set to <TERM>. See Figure 6-1.

Note: The <RCV> jack is not used when connecting

to 2-wire circuits.

• Set <4W> to connect the internal measurement

circuitry to the <RCV> pair, and the internal signal

generator to the <SND> pair. See the upper half of

Figure 6-2.

• Set <4W REV> to reverse the send and receive pairs.

See the lower half of Figure 6-2.

11

Two-position slide switch.

• Set <600 Ω> (usual position for 4-wire) to

A. apply 600 ohms across the receive pair when

Switch 13 is set to <TERM> and,

B. set the send pair source impedance at 600 ohms.

• Set <900 Ω> (usual position for 2-wire) to

A. apply 900 ohms across the receive pair when

Switch 13 is set to <TERM> and,

B. set the send pair source impedance at 900 ohms.

12

Three-position toggle switch. See Table 7-6 for

interaction of this switch with Switch 7 for dialing.

• Set <TONE> to come off-hook to dial either MF or

DTMF (set Switch 7 to <MF> or <DTMF>

accordingly). <TONE> causes a 200 ohm DC short

across T& R of the send pair to simulate a telephone

off-hook condition on 2-wire dial access lines.

0015-S03

-11

Unit Description (18-0015) AM-48 Test Set

Press a button on the 16-button keypad to generate the

appropriate DTMF or MF tone pair, depending on the

setting of Switch 7. See Table 7-7 for a list of MF and

DTMF tone pairs generated by pressing the keys.

• Set <PULSE> to dial pulse. Switch 7 must be set at

either <MF> or <DTMF>. <PULSE> causes a 200 ohm

DC short across T & R of the send pair to simulate a

telephone

off-hook condition on 2-wire dial access

lines. Press a button on the 16-button keypad while in

this mode to cause the DC short to make and break at

10 PPS, 60% break, creating dial pulses in accordance

with the button pressed.

• Set <ON HK> to

pair to simulate a telephone

open the DC across T & R of the send

on-hook condition on

2-wire dial access lines. The 16-button keypad stays

operational, and if pressed, will send out DTMF or

MF tones (see Table 7-7) as selected by Switch 7.

13

Two-position toggle switch.

• Set <TERM> to terminate the

receive (<RCV>) line

with a resistive impedance as elected by Switch 11.

• Set <BRDG> unterminate the receive line and bridge it

only with the impedance of the measurement circuitry

(>25 kohms) across the receive pair.

0015-S033-12

AM-48 Test Set (18-0015) Unit Description

3-13

Note: In 2-wire mode, the signal generator source

impedance will terminate the line with 600 or

900 ohms, regardless of the position of

<TERM> / <BRDG>. If the "QUIET" send

mode is selected while in 2-wire bridge mode,

the signal generator will be disconnected from

the send pair, and the send pair source

impedance will be >25 kohms. This will

allow the <TERM> / <BRDG> switch to

function.

14

Speaker Control . Two-position toggle and momentary

switch. See Figure 9-1 for a block diagram showing how

this switch interacts with Switch 3.

• Set <MON RCV> to connect the internal speaker to

audibly monitor the

• Set <MON SND> to connect the internal speaker to

audibly monitor the

receive pair.

send pair.

0015-S03

• Push <TALK> to mute the speaker and connect the

internal microphone to allow "talking" over the send pair.

This feature is useful in voice communication with an

assistant technician at the distant end of the transmission

line being tested. It also allows the AM-48 to be used as a

conventional push-to-talk telephone set on 2-wire dial

networks. See ¶7.38 for more details.

15

Volume Control . This controls the gain of the internal

speaker amplifier. Use this to set the speaker or earphone

loudness to a comfortable level.

Unit Description (18-0015) AM-48 Test Set

Note: Switch 3 and Switch 14 control the speaker/

earphone monitoring point. See Figure 9-1 for a

block diagram showing the interaction of these

switches. When Switch 3 is set to <DAMP>, the

monitor point is after the auto-range amplifier,

which significantly increases the speaker level.

WARNING

For a given volume setting, the earphone audio level

sounds much higher than the speaker level. Be careful

to adjust the audio volume down before inserting the

earphone into the ear.

3.6 Keyboard

See Figure 3-6 for the AM-48 keyboard with identification numbers

which are referenced in the descriptions of this paragraph.

Auxiliary Functions . The AM-48 is equipped with auxiliary keypad

functions which are identified in Figure 3-6 with reference numbers 2

thru 9. The keys and their auxiliary functions are:

[*] START

[#] STOP

[A] ETR/NEXT

[B] ETR/PREV

[C] CANCEL

[D] ±

Note: To enable the auxiliary functions, set Switch 7 to <SHIFT>.

0015-S033-14

AM-48 Test Set (18-0015) Unit Description

3-15

1

2

21 A3

ETR/NEXT

54 B6

ETR/PREV

87 C9

CANCEL

0

*

∇

9

Figure 3-6. AM-48 Keyboard Identification Numbers

1

16-Key Array. The function of the keys depends on the

positions of Switch 7 and Switch 12 (Figure 3-5). See Table

7-1.

To use the keys to dial MF, DTMF, or pulse, set Switches 7

and 12 as shown in Table 7-6. See Table 7-7 for a list of the

dual tones for the different keys.

With Switch 7 in <SHIFT>, the number keys can enter new

parameter values (¶7.8), or momentarily send user-

programmed tones from the QUIET SEND display (¶7.13). The

auxiliary functions of the other keys are described next.

8

STOPSTART

∇

7

D#

+/-

6

3

4

5

0015-S03

Unit Description (18-0015) AM-48 Test Set

2

3

[ETR/NEXT], [ETR/PREV]. These keys have a dual

function:

A. To enter new parameter values into memory.

B. To scroll through multiple displays.

After using the number keys to input a new parameter value:

1) Press either [ETR/NEXT] or [ETR/PREV] to enter the

new value into memory.

2) Then press [ETR/NEXT] to step to the next display, or

press [ETR/PREV] to step to the previous display.

If no change was made to the display, or a change was made

with the [∆] or [∇] keys, press [ETR/NEXT or [ETR/PREV] once

to go immediately to the next/previous display. See ¶7.8 for

complete details.

4

[CANCEL]. Press [CANCEL] to erase a value input with the

number keys. The display defaults to the previous value. To

erase an input, press [CANCEL] before pressing [ETR/NEXT] or
[ETR/PREV]. [CANCEL] does not operate after pressing [∆] or

[∇] to change a value. See ¶7.8 for complete details.

5

[±]. This key is used to designate a positive or negative

polarity for a new parameter value input with the number keys.

See ¶7.8 for complete details.

0015-S033-16

AM-48 Test Set (18-0015) Unit Description

3

6

9

[START], [STOP]. These keys are used in the IMPLS

(impulse noise) and TRANS (transients, i.e., impulse noise,

phase hits, gain hits, and dropouts) modes to stop/start the

timed test. See ¶7.24 for information on timed tests. The

[START][STOP] functions are in operation only when data is

displayed, i.e., not when a user-entered parameter is displayed.

With a user-entered parameter displayed, these same keys take

on the functions explained for number 7 and 8.

8

7

[∆∆∆∆] / [∇]. Press [∆] or [∇] to step the value of any variable

number displayed either up or down. Hold down [∆] or [∇] for

one (1) second to enable auto-repeat mode and step in

increments ten (10) times the normal increments. See Table

7-2 for the values of the increments, depending on the

parameter.

3.7 Display

Figure 3-7 shows the AM-48 liquid crystal display:

1. The top line in Figure 3-7 shows all the possible units of

measurement. The units of measurement appear as appropriate

to label the value(s) displayed in the main display field. Time

and Count parameters do not show the units on the display.

2. The main display field has nine (9) 7-segmented characters with

decimal points. The prompts that appear on the display are

"pseudo-alpha" because of the limitations of the 7-segmented

characters. There are three (3) possible types of display fields,

as explained in ¶7.4.

3. Below the main display field are the menus for the three (3)

cursors, shown in detail in Table 3-2.

0015-S03

-17

Unit Description (18-0015) AM-48 Test Set

UNITS OF

MEASUREMENT

9-CHARACTER
DISPLAY FIELD

MENUS

FOR AM-48E

PSHO
SWTD

AM-48E

SLOPE

QUIET

DBRN

DBM DB REL

1004 VAR

L/F

PAR

PAR3 TONE SWEEP

DEFAULT CURSOR POSITIONS WHEN POWER TURNED ON

HOLD

NOISE NOISE S/N

TONE

IMPLS ØJTR JTR TRANS

∆
∇

HZ PAR

3K C-MSG

15K PROG

Figure 3-7. AM-48 Liquid Crystal Display

Menus . Table 3-2 defines each possible cursor position for the three

(3) menus. The positions of the three (3) cursors identify the present

SEND mode, MEASURE mode, and FILTER selected. Switches 4, 5,

and 6 move the cursors to select the desired mode of operation.

Menu Color Coding and Framing .

1. All send modes on the SEND menu are yellow .

2. All noise-weighting filter options on the FILTER menu are

orange .

3. On the MEASURE menu, both NOISE modes, IMPLS, S/N, and

TRANS are orange , indicating that these measurements require a

noise-weighting filter.

4. All MEASURE modes

holding tone. The HOLD TONE indicator in the corner of

1004 Hz

within the pink rectangle require a nominal

the rectangle darkens when a valid holding tone is present at the

receive port.

See Table 7-5 for a summary of measurement requirements.

Note: Throughout this manual cursor positions are referred to with

ALL CAPITAL LETTERS, underlined . For example, QUIET

always refers to the Quiet SEND menu cursor position and

associated Quiet mode.

0015-S033-18

AM-48 Test Set (18-0015) Unit Description

3-19

The SEND menu is yellow , the MEASURE menu is pink and orange ,

and the FILTER menu is

orange .

Table 3-2. AM-48 SEND, MEASURE, and FILTER Menus

MEASURE MODES

Level/Frequency

L/F

Idle Channel

NOISE

Noise

PAR

Peak-to-Average
Ratio with
Receive Level

IMPLS

Impulse Noise
(Timed Test)

MEASURE MODES LISTED BELOW

NEED 1004 HZ HOLD TONE

Notched Noise

NOISE

S/N

Signal-to-Noise
Ratio

Phase Jitter

∅ JTR

∆

JTR Amplitude Jitter

∇

TRANS

Transients
(Timed Tests):
Impulse Noise,
Phase Hits,
Gain Hits,
Dropouts

FILTER OPTIONS

3K

15K

AM-48 ONLY:

C-MSG

PROG

AM-48E ONLY:

PSHO

SWTD

3 kHZ

15 kHZ

C-Message

Program

Psophometric

Sound­Weighted

QUIET

1004

VAR

3TONE

SLOPE

SWEEP

PAR

SEND MODES

Passive Resistor
Termination

1004 Hz Tone
@ Selelcted Level

Variable Continuous
Frequency & Level

AM-48 ONLY:

404 Hz, 1004 Hz,
2804 Hz for 5 sec.
Cyclic @ Selected
Level

AM-48E ONLY:

404 Hz, 1004 Hz,
2004 Hz, 3004 Hz
for 5 sec. Cyclic
@ Selected Level

Tones Stepped
per Selected
Level, Start/Stop
Frequencies,
Step Size and
Sweep Rate

Peak-to-Average
Ratio Waveform
@ Selected Level

3.8 Microphone/Speaker

The speaker is for "listening" on the send or receive pairs, and the

microphone is for "talking" on the send pair. See ¶7.38.

Pressing Switch 14 to <TALK> (momentary position) activates the

microphone.

0015-S03

Unit Description (18-0015) AM-48 Test Set

Switches 3 and 14 control the speaker/earphone monitoring point.

See Figure 9-1 for a block diagram showing the interaction of these

switches. When Switch 3 is set to <DAMP>, the monitor point is

after the auto-range amplifier which significantly increases the

speaker level. This is particularly useful for audibly monitoring the

residual noise in notched noise and S/N Ratio measurements.

3.9 Hand-Held Printer

The AM-47 Hand-Held Printer is designed to be used exclusively

with the AM-48 to produce a hard copy of measurements and setups.

Table 3-3 lists technical specifications, Figures 3-8 and 3-9 provide

component locations, Figure 6-3 shows the connectors, and ¶7.39

contains the operating instructions.

Connectors . The connectors are used with the AC Adapter (70-0029)

and the Printer Cable (48-0079) as shown in Figure 6-3. The AC

Adapter is supplied with the AM-48, and the 48-0079 Printer Cable is

supplied with the AM-47 Hand-Held Printer. The input is a special

serial ASCII current loop compatible with the AM-48.

Power . Power is provided by an internal NiCad battery pack. When

the printer is connected, power to the AM-48 comes from the printer

battery pack, prolonging the life of the AM-48 batteries. There is an

internal recharging circuit in the printer that operates when the AC

Adapter is plugged in.

Power Switch . The slide switch to the left of the connectors is for

POWER ON/OFF.

LEDs . The LEDs light as described below:

1. The POWER LED lights continuously when the AC Adapter is

connected and the battery pack is charging (starts charge cycle

each time power is turned ON).

0015-S033-20

AM-48 Test Set (18-0015) Unit Description

3

2. The POWER LED

blinks when power is ON and the battery pack

has been charged.

3. The SIGNAL LED lights when data is being received from the

AM-48.

Printing Mechanism . The printing mechanism is a dot matrix impact

type with a replaceable ribbon cartridge. It uses standard-width

adding machine paper. The ribbon cartridge and paper supply are

housed within the case (see Figure 3-9). The printout is in a

24-column format (see Figure 7-11 thru 7-13 for example printouts).

In order to conserve paper, no automatic space is made after a

printout. The paper can be advanced manually with the PAPER

ADVANCE button.

Table 3-3. AM-47 Hand-Held Printer Technical Specifications

CHARACTERISTICS SPECIFICATIONS

Input Signal Serial ASCII Code with 2-Wire Proprietary

Current Loop

Input Connector 4-Wide Modular Jack
Input Speed 300 Baud with 1500 Character FIFO Buffer
Print Type 6 x 8 Impact Dot Matrix
Paper 2.25”W x 1.8” Dia. Adding Machine Paper
Ink Supply Replaceable Inked Ribbon Cartridge
Characters per Line 24
Print Speed 0.7 Lines per Second
Power Internal NiCad Battery Pack with Built-In

Charger

Battery Life Approximately 10,000 Lines
Charge Time 8 to 14 Hours
Size 7.6”L x 3.4”W x 1.9”D
Weight 1.5 lbs.
Cables Printer Cable (48-0079), Supplied AC Adapter

(70-0029) (cables shown in Figures 3-3 & 3-4).

0015-S03

-21

Unit Description (18-0015) AM-48 Test Set

PUSH UP HERE

TO REMOVE COVER

PAPER ROLL

COMPARTMENT

(See Figure 3-9)

PAPER CUTTER

BATTERY CHARGE/

PAPER FEED

BUTTON

POWER LED

Ameritec

HAND-HELD PRINTER • Model AM-47

PAPER

ADVANCE

POWER

OFF ON

DATA RECEIVE LED

POWER

9VDCINSIGNAL

IN

SIGNAL

TOP VIEW

POWER SWITCH

AC ADAPTER PLUG

END VIEW

Figure 3-8. Hand-Held Printer, External View

0015-S033-22

AM-48 Test Set (18-0015) Unit Description

3-23

PAPER ROLL

RIBBON

MANUAL
RIBBON
TAKE-UP

RIBBON CARTRIDGE

PAPER CUTTER

PAPER ROLL COMPARTMENT

PUSH (PAPER ADVANCE)

BUTTON TO ROUTE

PAPER THROUGH

3

2

PAPER ROLL INSTALLATION

Figure 3-9. Hand-Held Printer, Internal View

FEED PAPER

INTO SLOT

PUSH DOWN

HERE TO

EJECT RIBBON

CARTRIDGE

INSTALL

PAPER

1

ROLL

0015-S03

Unit Description (18-0015) AM-48 Test Set

3.10 Impedance Adapter

The Impedance Adapter (24-0005) is illustrated in Figure 3-10. It is

used to match the AM-48 to:

1. Line impedance

2. 4-Wire

split impedances

The Impedance Adapter has settings for five (5) different impedances

to match the AM-48 to the user interface. It plugs into the RJ11

modular connector of the AM-48. See ¶6.5 for installation, and ¶7.41

for measurement corrections when the Impedance Adapter is used.

The schematic of the Impedance Adapter is shown in Figure 9-2.

UPPER

KNOB

LOWER

KNOB

other than 600 Ohms or 900 Ohms

RJ11 PLUG

IMPEDANCE ADAPTER

MODEL 240005

THRU

1200 Ω

900 Ω

150 Ω

135 Ω

75 Ω

THRU

1200 Ω

900 Ω

150 Ω

135 Ω

75 Ω

SET AM4 SERIES TEST SET FOR 600 Ω

Ameritec

CORPORATION

Figure 3-10. Impedance Adapter

COVINA, CA. U S A

RJ11 JACK

4W/2W

SEND

4W

RCV

0015-S033-24

AM-48 Test Set (18-0015) Power Considerations

4 POWER CONSIDERATIONS

4.1 General

This section covers AM-48 power considerations, including battery

installation, AC Adapter connection, and the power on/off switch.

The AM-48 runs on internal battery or external AC power. Flashing

display decimal points indicate low batteries; alkaline batteries need

replacing, and NiCad batteries need recharging.

Low-Level Noise Measurements . Power the AM-48 with batteries

when making a low-level noise measurement. Do

AM-48 with the AC Adapter for this test, because interference from

the AC source can affect the measurement.

4.2 Battery Compartment

The battery compartment under the rear panel is accessed through a

removable slide door. The compartment takes four (4) AA 1.5-volt

alkaline or NiCad batteries. The battery compartment also serves as a

recharger for NiCad batteries when the AM-48 is connected to 115

VAC with the AC Adapter.

not power the

4.3 Battery-Selector Switch

The Battery-Selector Switch is on the inside edge of the battery

compartment as shown in Figure 4-1.

0015-S04

4-1

Power Considerations (18-0015) AM-48 Test Set

SELECTOR SWITCH
FOR BATTERY TYPE

NICAD

+

+

+

+

ALKALINE

CAUTION

SET SELECTOR SWITCH
FOR BATTERY TYPE USED

Figure 4-1. Battery Installation and Selector Switch

Using a pointed instrument, such as a pencil, set the Battery-Selector

Switch to “NICAD” or “ALKALINE” position to match the type of

battery used.

NICAD Position . This position connects the internal battery charge

circuitry to charge the NiCad batteries when the AC Adapter is

connected.

Never set the switch to this position when using alkaline

batteries.

ALKALINE Position . The internal battery charge circuitry is

disconnected because alkaline batteries are

not rechargeable.

WARNING: The Battery-Selector Switch MUST be in the

“ALKALINE” position when using alkaline batteries.

Alkaline batteries can explode if the AC Adapter is

used with alkaline batteries with the Battery-Selector

Switch in the “NICAD” position; warranty is voided if

this happens.

\ 0015-S044-2

AM-48 Test Set (18-0015) Power Considerations

3

4.4 Battery Installation

To install the batteries:

1. Slide off the battery compartment cover.

2. Set the Battery-Selector Switch per ¶4.3.

3. Lay the ribbon in the base of the compartment (to be able to pull

up on the ribbon for easy removal of the batteries).

4. Install four (4) 1.5-volt AA NiCad or Alkaline batteries as

shown in Figure 4-1.

5. Replace the battery compartment cover.

4.5 Battery Information

General . When new, each battery will furnish approximately 1.5

Volts. The batteries are wired in series, supplying 6 VDC nominal.

An internal DC-to-DC Converter allows operation until the batteries

have discharged to approximately 3 Volts.

To avoid battery chemical leakage :

1. Use only first quality batteries

2. Do not subject the AM-48 to excessively high temperatures.

The warranty does

Alkaline Batteries . The AM-48 is shipped with four (4) high-quality

alkaline batteries, which give approximately 6-7 hours of service.

When the batteries have discharged to approximately 3.5 volts, the

display decimal points will flash. The flashing indicates

approximately 30 minutes of remaining operating life.

0015-S04

not cover damage resulting from battery leakage.

4-

Power Considerations (18-0015) AM-48 Test Set

NiCad Batteries . Commercially available AA size Nickel Cadmium

(rechargeable) batteries can be used, but operating life will be

reduced to approximately 3 to 4 hours because of the limited energy

storage capacity of rechargeable batteries. Due to the abrupt end-of-

life discharge curve of Nickel Cadmium batteries, the flashing

decimal points low-battery indication will only provide a few minutes

of warning before the end of operation.

4.6 AC Power

To power the AM-48 with 115 VAC, plug one end of the AC Adapter

(70-0029) into the <DC 9V> connector on the bottom of the unit, and

the other end into an AC wall jack. See Figure 3-3 for the AC

Adapter, and Figure 3-2 for the AC Adapter plug on the AM-48.

The AC Adapter supplies 9 VDC to the AM-48. The locations of the

+ and – DC voltage contacts on the 2.5 mm jack of the AC Adapter

are illustrated on the transformer housing of the AC Adapter itself.

When using the AM-47 Hand-Held Printer, the AC Adapter can be

used to maintain the charge of the printer batteries that power the

AM-48. See Figure 6-3 for connections.

4.7 Power On/Off Switch

The Power On/Off Switch is a combination toggle switch and

momentary switch located at the top right-hand side of the AM-48

(Switch 1 in Figure 3-5).

Automatic Power Shutdown . To allow the AM-48 to power down by

itself, momentarily press the switch toward the <ON/OFF> position to

turn the power on. If the unit is left unattended, the power will shut

off automatically after the TIME OFF setting (see ¶7.12.4 for

instructions to set the time).

\ 0015-S044-4

AM-48 Test Set (18-0015) Power Considerations

5

Continuous Power On . Set the switch to the <ON> position for power

to be on continuously.

Note: To turn power on continuously when battery voltage is less

than about 5 VDC, first turn power ON in momentary

<ON/OFF> position, then set switch to <ON>.

Power Off . To turn the power off, momentarily press the switch

toward the <ON/OFF> position.

The position of Switch 2 determines the initial display. The default

power-up cursor positions are shown in Figure 3-7.

0015-S04

4-

AM-48 Test Set (18-0015) Self-Test Instructions

5

5 SELF-TEST INSTRUCTIONS

5.1 General

Purpose . This section has two (2) objectives:

1. To practice the main AM-48 operating procedures.

2. To verify that the AM-48 is working properly.

General . Each test in this section is described and illustrated. In the

figures, circled

description; circled

Note: Power is ON for the tests in this section. See Section 4

5.2 Self-Test Setup

Self-Test Setup is depicted in Figures 5-1 and 5-2.

Cable Connection . The tests in this section are done with the AM-48

looped back on itself, not connected to any external equipment. Plug

in the Modular-to-Minigator Cable (48-0049) (supplied with the

AM-48), and connect the minigator clips as shown in Figure 5-1.

The signals sent (generated) through the send port are routed directly

back to the receive port.

letters correspond to the steps of the written

numbers identify the switches.

concerning connecting and turning on power to the AM-48.

0015-S05

-1

Self-Test Instructions (18-0015) AM-48 Test Set

Ameritec

PERSONAL TRANSMISSION TEST SET

QUIET 1004 VAR

VOL

MIC

PRT EAR

3 TONE SWEEP

SEND

PAR

A

X TONE

∇

SF SKP

NOR

∇

SHIFT

•

∇

DTMF

PAR

MF

•

∇

∇

L/F

NOISE

IMPLS ØJTR

TONE

MEASURE

SEL

∇

SEL

∇

∇

∇

MON RCV

•

∇

MON SND

TALK

∇

TERM

∇

BRDG

∇

TONE

•

∇

PULSE

ON HK

∇

∇

900Ω

600Ω

∇

2W

•

4W

∇

4W REV

START

*

∇

DC

9V

1

4

2

7

5

3

8

6

ETR/NEXT

4W/2W
SND

0

#

STOP

∇

4W

RCV

B

ETR/PREV

9

C

CANCEL

RCL/STO

PRINT

D

+

/

-

HOLD

∇

∇

∇

NOISE

∆

JTR TRANS

OFF

SEL

∇

FILTER

DAMP

∇

S/N

SEND

∇

15K

REL

∇

MODEL AM-48

3K

C-MSG

PROG

ABS

∇

•

∇

ON

∇

•

ON/

∇

OFF

Red (R)

Black (R1)

Yellow (T1)

Figure 5-1. AM-48 Setup for Self-Test (Looped Back)

Green (T)

0015-S055-2

AM-48 Test Set (18-0015) Self-Test Instructions

5-3

General Switch Setup . Figure 5-2 shows the initial positions of the

switches for the tests in this section. Leave these switches in the

positions indicated unless otherwise directed in the instructions for

the individual tests. Switches are referenced by the circled numbers.

Ameritec

PERSONAL TRANSMISSION TEST SET

MODEL AM-48

ON

∇

•

1

∇

ON/
OFF

(MON SND)

(TERM)

(ON HK)

(600 Ω)

(4W)

15

14

12

13

11

10

QUIET 1004 VAR

VOL

∇

MON RCV
MON SND

•

∇

TALK

∇

TERM

∇

BRDG

∇

TONE
PULSE

•

∇

ON HK

∇

900Ω

∇

600Ω

PAR

SEND MEASURE FILTER

HOLD

L/F

NOISE NOISE S/N

TONE

PAR3 TONE SWEEP

IMPLS ØJTR JTR TRANS

21 A3

54 B6

∇

2W

4W

•

4W REV

∇

MIC

PRT EARDC9V

87 C9

0

*

∇

4W/2W

SND4WRCV

STOPSTART

3K C-MSG

∆

15K PROG

∇

∇

ABS

REL

•

SEND

∇

∇

DAMP

OFF

∇

∇

SEL

∇

∇

SEL

∇

∇

SEL

∇

∇

MF

DTMF

•

SHIFT

SF SKP

NOR

X TONE

RCL/STO

PRINT

∇

∇

•

∇

∇

∇

ETR/NEXT

ETR/PREV

CANCEL

D#

+/-

∇

3

4

5

7

8

2

6

9

(ABS)

(DAMP)

(SHIFT)

(NOR)

Figure 5-2. General Switch Setup for Self Test

Switches 4, 5, 6, and 9 do not have a set position because they are all

dual momentary switches. The instructions for each test will indicate

when to rock switches 5 and 6 to move the cursors to desired

positions on the display menus.

0015-S05

Self-Test Instructions (18-0015) AM-48 Test Set

The FILTER menu cursor (controlled by Switch 4) will default to

C-MSG (PSHO

for AM-48E) when power is turned on. Leave the

cursor in this position for all the tests in this section.

5.3 Quiet Send Mode

Quiet Send Mode switch settings and display are depicted in Figure

5-3.

A. Verify that the SEND menu cursor is in QUIET (default position

when power is first turned on). Rock Switch 6 if necessary to

move cursor to QUIET.

B. Verify that the MEASURE menu cursor is in L/F (default position

when power is first turned on). Rock Switch 5 if necessary to

move cursor to L/F (level/frequency).

C. Display should read “UNDR” with units “DBM” and “HZ”.

D. Rock Switch 5 to move cursor to NOISE (to the right of L/F

E. Display should read “UNDR” with units of “DBRN” (“DBM” for

AM-48E).

QUIET

QUIET

DBM

1004 VAR

QUIET

darkened

DBRN

1004 VAR

QUIET

darkened

L/F

NOISE NOISE S/N

IMPLS ØJTR JTR TRANS

PAR

PAR3 TONE SWEEP

A

L/F

NOISE NOISE S/N

PAR

PAR3 TONE SWEEP

IMPLS ØJTR JTR TRANS

A

C

L/F darkened

E

HOLD
TONE

∆
∇

HOLD
TONE

∆
∇

NOISE darkened

HZ

Ameritec

PERSONAL TRANSMISSION TEST SET

MODEL AM-48

3K C-MSG

15K PROG

B

3K C-MSG

15K PROG

QUIET 1004 VAR

L/F

NOISE NOISE S/N

PAR

PAR3 TONESWEEP

IMPLS ØJTR JTR TRANS

SEND MEASURE FILTER

VOL

∇

MON RCV
MON SND

•

∇

TALK

∇

TERM

∇

BRDG

∇

TONE
PULSE

•

∇

ON HK

∇

900Ω

21 A3

600Ω

∇

54 B6

∇

2W
4W

•

87 C9

4W REV

∇

0*D#

∇

MIC

4W/2W

PRT EARDC9V

SND4WRCV

HOLD
TONE

∆
∇

ETR/NEXT

ETR/PREV

CANCEL

STOPSTART

∇

D

Figure 5-3. Quiet Send Mode Self Test

).

ON

∇

•

∇

ON/
OFF

3K C-MSG

15K PROG

∇

ABS

REL

•

SEND

∇

∇

DAMP

OFF

∇

∇

SEL

Set L/F

∇

∇

SEL

∇

SEL

∇

MF

DTMF

•

SHIFT

∇

SF SKP

NOR

•

X TONE

∇

RCL/STO

∇

PRINT

+/-

B

∇

Set NOISE

5

∇

Set QUIET

6

∇

∇

D

A

0015-S055-4

AM-48 Test Set (18-0015) Self-Test Instructions

5-5

5.4 Send 1004 Hz

Send 1004 Hz switch settings are depicted in Figure 5-4, while the

displays are depicted in Figure 5-5.

A. Rock Switch 6 to move SEND menu cursor to 1004.

Note: Turn volume control (“Switch” 15) up or down as desired to

increase or decrease the volume of the speaker sound. With

Switch 14 in <MON SND>, the speaker is monitoring the

1004 Hz tone being sent.

B. Rock Switch 5 if needed to move MEASURE menu cursor to L/F.

C. Read “00.0 ±0.1 DBM” and “1004 HZ” on display.

D. Rock Switch 5 to move MEASURE menu cursor to NOISE.

E. Read “90.0 ±1.0 DBRN” (“00.0 ±1.0 DBM” for AM-48E) on

display.

F. Rock Switch 5 to move MEASURE menu cursor to NOISE (to the

right of HOLD TONE ).

Note: HOLD TONE will be darkened for the remaining steps in this

paragraph.

G. Read typically “32.0 DBRN” (must be <40.0 dBrn) and “1004 HZ”

on display; for AM-48E, “-58.0 DBM” (must be <–50.0 dBm).

H. Rock Switch 5 to move MEASURE menu cursor to S/N (signal-to-

noise ratio).

I. Read typically “58.0 DB” (must be >50.0 dB) and “1004 HZ” on

display.

J. Rock Switch 5 to move MEASURE menu cursor to Ø JTR

K. Read “JITR 00.0 ±0.2˚” on display.

L. Rock Switch 5 to move MEASURE menu cursor to ∆ JTR

M. Read “JITR 00.0 ±0.2” on display.

0015-S05

.

.

Self-Test Instructions (18-0015) AM-48 Test Set

Ameritec

PERSONAL TRANSMISSION TEST SET

MODEL AM-48

ON

∇

•

∇

ON/
OFF

14

15

QUIET 1004 VAR

PAR

SEND MEASURE FILTER

VOL

∇

MON RCV
MON SND

•

∇

TALK

∇

TERM

∇

BRDG

∇

TONE

PULSE

•

∇

ON HK

∇

900Ω
600Ω

∇

HOLD

L/F

NOISE NOISE S/N

TONE

PAR3 TONE SWEEP

IMPLS ØJTR JTR TRANS

21 A3

54 B6

∇

2W

4W

•

4W REV

∇

MIC

PRT EARDC9V

87 C9

0

*

∇

STOPSTART

4W/2W

SND4WRCV

3K C-MSG

∆

15K PROG

∇

∇

ABS

REL

•

SEND

∇

∇

DAMP

OFF

∇

∇

SEL

∇

∇

SEL

∇

5

∇

SEL

∇

6

∇

MF

DTMF

•

SHIFT

SF SKP

NOR

X TONE

RCL/STO

PRINT

∇

∇

•

∇

∇

∇

ETR/NEXT

ETR/PREV

CANCEL

D#

+/-

∇

Figure 5-4. Send 1004 Hz Self Test, Switch Settings

Set L/F

NOISE
NOISE
S/N

Set 1004

Ø

JTR

∆

JTR

∇

B

D

F

H

J

L

A

0015-S055-6

AM-48 Test Set (18-0015) Self-Test Instructions

5

DBM

•

QUIET

1004 VAR

L/F

NOISE NOISE S/N

PAR

PAR3 TONE SWEEP

1004 darkened L/F darkened

DBRN

IMPLS ØJTR JTR TRANS

A

•

QUIET

1004 VAR

L/F

NOISE NOISE S/N

PAR

PAR3 TONE SWEEP

IMPLS ØJTR JTR TRANS

See Note Below

QUIET 1004 VAR

L/F

NOISE NOISE S/N

PAR

PAR3 TONE SWEEP

IMPLS ØJTR JTR TRANS

See Note Below

C

HOLD
TONE

G

HOLD
TONE

K

HOLD
TONE

∆
∇

B

∆
∇

NOISE darkened

∆
∇

ØJTR darkened

HZ

3K C-MSG

15K PROG

HZ

3K C-MSG

15K PROG

F

•

3K C-MSG

15K PROG

J

DBRN

QUIET

1004 VAR

DB

QUIET

1004 VAR

QUIET 1004 VAR

•

L/F

NOISE NOISE S/N

PAR

PAR3 TONE SWEEP

IMPLS ØJTR JTR TRANS

NOISE darkened

•

L/F

NOISE NOISE S/N

PAR

PAR3 TONE SWEEP

IMPLS ØJTR JTR TRANS

See Note Below

L/F

NOISE NOISE S/N

PAR

PAR3 TONE SWEEP

IMPLS ØJTR JTR TRANS

See Note Below

E

HOLD
TONE

∆
∇

D

HZ

I

HOLD
TONE

∆
∇

S/N darkened

M

HOLD
TONE

∆
∇

∆

JTR darkened

∇

Figure 5-5. Send 1004 Hz Self Test, Displays

Note: HOLD TONE is darkened for all measurements with

MEASURE menu cursor inside the pink rectangle.

1004 is darkened for all tests in Figure 5-5.

5.5 Send PAR (Peak-to-Average Ratio)

Send PAR switch settings and display are depicted in Figure 5-6.

A. Rock Switch 6 to move SEND menu cursor to PAR.

Note: Turn volume control (“Switch” 15) up or down as desired to

increase or decrease the volume of the speaker sound. With

Switch 14 in <MON SND>, the speaker is monitoring the PAR

waveform being sent.

3K C-MSG

15K PROG

3K C-MSG

15K PROG

H

3K C-MSG

15K PROG

•

L

B. Rock Switch 5 to move MEASURE menu cursor to PAR.

C. Read “00.0 ±1.0 DBM 100 ±2 PAR” on display.

0015-S05

-7

Self-Test Instructions (18-0015) AM-48 Test Set

Ameritec

PERSONAL TRANSMISSION TEST SET

QUIET 1004 VAR

VOL

SEND MEASURE FILTER

∇

MON RCV
MON SND

•

∇

TALK

∇

TERM

∇

BRDG

∇

TONE
PULSE

•

∇

ON HK

∇

900Ω

∇

600Ω

∇

2W

4W

•

4W REV

∇

*

∇

MIC

PRT EARDC9V

L/F

PAR

PAR3 TONE SWEEP

MODEL AM-48

HOLD

NOISE NOISE S/N

TONE

∆

IMPLS ØJTR JTR TRANS

∇

21 A3

54 B6

87 C9

0

STOPSTART

∇

4W/2W

SND4WRCV

ETR/NEXT

ETR/PREV

CANCEL

ON

∇

•

∇

ON/
OFF

3K C-MSG

15K PROG

∇

ABS

REL

•

SEND

∇

∇

DAMP

OFF

∇

∇

SEL

∇

∇

SEL

∇

Set PAR

5 B

∇

SEL

∇

Set PAR

6

∇

MF

DTMF

•

SHIFT

∇

∇

SF SKP

NOR

•

X TONE

∇

∇

RCL/STO

∇

PRINT

D#

+/-

A

DBM

C

PAR

•

QUIET

PAR darkened

1004 VAR

PAR

L/F

PAR3 TONE SWEEP

A B

HOLD

NOISE NOISE S/N

TONE

IMPLS ØJTR JTR TRANS

∆
∇

Figure 5-6. Send PAR (Peak-to-Average Ratio)

5.6 Dialing

Dialing switch settings and display are depicted in Figure 5-7.

A. Rock Switch 6 to move SEND menu cursor to QUIET.

B. Rock Switch 5 to move MEASURE menu cursor to L/F.

C. Set Switch 2 (display select) to <SEND>.

D. Set Switch 7 to <MF>.

E. Set Switch 12 to <TONE>.

3K C-MSG

15K PROG

0015-S055-8

AM-48 Test Set (18-0015) Self-Test Instructions

5-9

F. Turn volume control (“Switch” 15) all the way up for maximum

speaker volume.

G. Press various keys on the keypad to dial MF (multiple

frequency) tones. Listen to the dual tones coming from the

speaker. The speaker will emit the tones as long as the key is

held down. Note that key [D] has no MF tones.

Note: See Table 7-7 for list of dual frequencies transmitted in tone

dialing.

H. When doing step G., the display will read “DIAL -10.0 DBM”.

This indicates that –10.0 dBm (factory setting) is the send level.

Tone dialing send level can be changed. See ¶7.12.3 and Figure

7-1 for “TTLEV” (Touch Tone Level) display.

I. Set Switch 7 to <DTMF>.

J. Press various keys on the keypad to dial DTMF (Dual Tone

Multiple Frequency) tones. Listen to the dual tones coming

from the speaker. The speaker will emit the tones as long as the

key is held down.

K. The display will read as in step H.

L. Set Switch 12 to <PULSE>.

M. Press the keys on the keypad and note that no sound is heard.

No battery is connected to the line and line battery voltage is

required for pulse dialing.

0015-S05

Self-Test Instructions (18-0015) AM-48 Test Set

Ameritec

PERSONAL TRANSMISSION TEST SET

QUIET 1004 VAR

VOL

15

12

SEND MEASURE FILTER

∇

MON RCV
MON SND

•

∇

TALK

∇

TERM

∇

BRDG

∇

TONE
PULSE

•

∇

ON HK

∇

900Ω

∇

600Ω

∇

2W

4W

•

4W REV

∇

*

MIC

PRT EARDC9V

PAR

∇

HOLD

L/F

NOISE NOISE S/N

TONE

PAR3 TONE SWEEP

IMPLS ØJTR JTR TRANS

21 A3

54 B6

87 C9

0

STOPSTART

4W/2W

SND4WRCV

MODEL AM-48

∆
∇

∇

ETR/NEXT

ETR/PREV

CANCEL

ON

∇

•

∇

ON/
OFF

3K C-MSG

15K PROG

∇

ABS

REL

•

SEND

2

(SEND)

∇

∇

DAMP

OFF

∇

∇

SEL

∇

∇

SEL

∇

5

∇

SEL

∇

6

∇

MF

DTMF

•

SHIFT

∇

7

∇

SF SKP

NOR

•

X TONE

∇

∇

RCL/STO

∇

PRINT

D#

+/-

G J M

Set L/F

Set QUIET

C

B

A

DBM

H K

•

QUIET

1004 VAR

PAR

QUIET darkened

A B

L/F

PAR3 TONE SWEEP

L/F darkened

HOLD

NOISE NOISE S/N

TONE

IMPLS ØJTR JTR TRANS

∆
∇

Figure 5-7. Dialing

5.7 Parameter Values for Send Sweep

Parameter Values for Send Sweep settings and display are depicted in

Figure 5-8.

A. Set Switch 2 to <SEND>.

B. Set Switch 7 to <SHIFT>.

C. Rock Switch 6 to move SEND menu cursor to SWEEP.

3K C-MSG

15K PROG

0015-S055-10

AM-48 Test Set (18-0015) Self-Test Instructions

5

Note: The MEASURE menu cursor can be in any mode.

Turn volume control (“Switch” 15) up or down as desired to

increase or decrease the volume of the speaker sound. With

Switch 14 in <MON SND>, the speaker is monitoring the

frequencies being swept.

D. Display will read “00.0 DBM” and frequencies which start at “204

HZ” and increase in 100 Hz steps every second up to 19,904 Hz,

at which time the sweep starts again at 204 Hz.

E. Rock Switch 6 once to momentarily exit SWEEP mode. Rock

Switch 6 once in the opposite direction to re-enter SWEEP mode

(SEND menu cursor back to SWEEP). Note that the sweep starts

again at 204 Hz.

F. Press [ETR/NEXT] on the keypad ([A] key).

G. Display will change to “LEVL 00.0 DBM”. This is the first of

the five (5) default parameter settings shown in Figure 5-8.

H. Repeat Step F. four (4) more times and observe the NEXT

displays in sequence:

I. “STRT 204 HZ”

J. “STOP 19904 HZ”

K. “STEP 100 HZ”

L. “RATE 1.0”

M. Press [ETR/PREV] on the keypad ([B] key) five (5) times and

observe the PREVIOUS displays appear in reverse sequence.

Note: In the remaining steps, an example will be given of setting

new parameter values for the SWEEP mode. Carefully note

the procedure, because the same procedure is used for setting

all AM-48 parameter values.

0015-S05

-11

Self-Test Instructions (18-0015) AM-48 Test Set

N. Repeat Step E. to start with the first SWEEP display.

O. Press [ETR/NEXT] to go to the NEXT display (sweep frequency

LEVEL).

P. Press [±], same as [D] key. Then press [5] and [0]. Display now

reads “LEVL -5.0 DBM”. Press [±] several times and notice the

“-“ sign appear and disappear. Leave display with the “-“.

Q. Press [ETR/NEXT] again. This enters the new LEVEL, -5.0 dBm.

R. Press [ETR/NEXT] to go to the NEXT display (START frequency

setting).

S. Press [4], [0], [0]. Display now reads “STRT 400 HZ”.

T. Press [ETR/NEXT] again. This enters the new START frequency,

400 Hz.

U. Press [ETR/NEXT] to go to the NEXT display (STOP frequency

setting).

V. Press [1], [6], [0], [0]. Display now reads “STOP 1600 HZ”.

W. Press [ETR/NEXT] again. This enters the new STOP frequency,

1600 Hz.

X. Press [ETR/NEXT] to go to the NEXT display (frequency STEP

setting).

Y. Display now reads “STEP 100 HZ”.

Note: In the next step, a “mistake” will be made when entering a

new parameter value to show how it can be corrected.

Z. Press [2], [0], [0]. Display now reads “STEP 200 HZ”. This is

a mistake; desired step is actually 300 Hz.

AA. Press [CANCEL], same as [C] key. The incorrect value is gone

and the display now reads as in Step Y.

BB. Press [3], [0], [0]. Display now reads “STEP 300 HZ”, the

desired value.

0015-S055-12

AM-48 Test Set (18-0015) Self-Test Instructions

5-13

CC. Press [ETR/NEXT] again. This enters the new frequency STEP,

300 Hz.

DD. Press [ETR/NEXT] to go to the NEXT display (RATE, i.e. duration

of each frequency in the sweep).

EE. Display now reads “RATE 1.0”.

FF. Press [∆] momentarily repeatedly and notice the time

increase

0.1 sec at a time: 1.1, 1.2, 1.3. ….sec. Hold [∆] down

continuously and notice that the time starts increasing in steps of

1.0 sec; 2.0, 3.0, 4.0, ….sec. Press momentarily and/or hold

down [∇] and note that the time

decreases in steps of 0.1 and/or

1.0 sec. Use [∆] and [∇] as necessary to step the time (rate) to

2.0 sec.

GG. Display now reads “RATE 2.0”.

HH. Press [ETR/NEXT] to return to the original display. Instead of the

sweep that was seen in Step D., there is now a new sweep that

reflects the settings just entered. Display now reads “-05.0 DBM”

and shows frequencies which start at “400 HZ” and increase in

300 Hz steps every 2 seconds up to 1600 Hz, at which time the

sweep starts again at 400 Hz.

Note: The new parameter settings will remain until (1) they are

changed, or (2) power is turned off. If power is turned off,

the settings will revert back to the default settings as shown

in Figure 5-8.

This completes the self test. See Section 7 for complete operating

instructions and details of other tests and parameter settings not

covered here.

0015-S05

Self-Test Instructions (18-0015) AM-48 Test Set

DBM

DBM

D

•

G

J

HZ

Ameritec

PERSONAL TRANSMISSION TEST SET

•

HZ

I

HZ

HZ

K

VOL

15

∇

MON RCV
MON SND

•

∇

14

TALK

∇

TERM

∇

BRDG

∇

TONE
PULSE

•

∇

ON HK

∇

900Ω
600Ω

∇

∇

2W
4W

•

4W REV

∇

MIC

PRT EARDC9V

L

MODEL AM-48

HOLD

QUIET 1004 VAR

L/F

NOISE NOISE S/N

TONE

∆

PAR

PAR3 TONE SWEEP

IMPLS ØJTR JTR TRANS

∇

SEND MEASURE FILTER

21 A3

54 B6

87 C9

0*D#

STOPSTART

∇

∇

4W/2W

SND4WRCV

3K C-MSG

15K PROG

ETR/NEXT

SF SKP

X TONE

ETR/PREV

RCL/STO

PRINT

CANCEL

+/-

FFFF

•

QUIET 1004 VAR

L/F

NOISE NOISE S/N

PAR

PAR3 TONE SWEEP

IMPLS ØJTR JTR TRANS

SWEEP darkened

HOLD
TONE

C

3K C-MSG

∆

15K PROG

∇

Figure 5-8. Default Parameter Settings for SWEEP Send Mode

ON

∇

•

∇

ON/
OFF

∇

ABS
REL

•

SEND

∇

∇

DAMP

OFF

∇

∇

SEL

∇

∇

SEL

∇

∇

SEL

∇

∇

MF

DTMF

•

SHIFT

∇

∇

NOR

•

∇
∇

∇

(SEND)

2 A

Set SWEEP

6 C

Set SHIFT

7

F

M

AA

P

B

0015-S055-14

AM-48 Test Set (18-0015) Connection & Configuration

6

6. CONNECTION AND CONFIGURATION

6.1 Introduction

This section describes the AM-48 connections and configurations

made in preparation for testing. It is divided into the following

paragraphs:

6.2 General

6.3 Connectors and Cables

6.4 600 Ohm/900 Ohm Line Termination Impedances

6.5 Impedance Adapter

6.6 Configurations

In ¶6.6, basic operating instructions are given for testing with the

Western Electric 829 loopback device, as well as with Ameritec

responders.

Note: Section 7 gives detailed AM-48 operating instructions and

Section 8 explains the meaning of the measurements.

6.2 General

Low-Level Noise Measurements . Power the AM-48 with batteries

when making a low-level noise measurement. Do

AM-48 with the AC Adapter for this test because interference from

the AC source can affect the measurement.

“Dry” Circuit Measurements . Set Switch 12 (Figure 3-5) to <ON HK>

when making measurements on “dry” (4-wire only) circuits. “Dry”

circuits have no loop current.

not power the

0015-S06

-1

Connection & Configuration (18-0015) AM-48 Test Set

Independent Send and Measure Modes . The Send, Measure, and

Filter modes of the AM-48 operate

combination of Send, Measure, or Filter can be selected. However,

depending on the setup, the resulting measurements may or may not

be valid.

For example, a 1004 Hz holding tone must be sent for various measure

modes and a PAR waveform must be sent when PAR is measured. If

the 1004 Hz tone or PAR waveform were not present in the

corresponding measurement, the measurement would no be valid.

The AM-48 configuration (see ¶6.6) determines in what part of the

system the signals need to be sent and measured.

The correct Send, Measure, and Filter modes are indicated for each

test described in the operating instructions of Sections 5 and 7.

completely independently. Any

6.3 Connectors and Cables

See Figures 3-2 thru 3-4 for illustrations of the AM-48 connectors

and cables. Note that some cables are standard and others are

optional. Connect the appropriate cable(s) described in this

paragraph according to the desired application.

AC Adapter . Connect the circular connector of the AC Adapter to

the <DC 9V> AC Adapter Plug. Plug the two (2) prongs on the other

end into a standard 115 VAC wall socket. Observe the WARNING

in ¶4.3.

Earphone . The earphone can be used in place of the speaker. Use the

earphone to hear better in noisy environments or to listen without

disturbing other people in the area. See the WARNING in ¶3.5.15

before connecting the earphone. Plug the earphone into the <EAR>

Earphone Jack. Note that the internal speaker is disconnected when

the Earphone is plugged in.

0015-S066-2

AM-48 Test Set (18-0015) Connection & Configuration

6-3

Printer Cables . There are two (2) types of cables used with printers.

The 48-0079 is used with the AM-47 Hand-Held Printer. The

48-0078 is used to connect with most other 25-pin female serial EIA

printers. The pin assignments of the male connector are:

2 = RCV

3 = XMIT

7 = GND

20 = Data Terminal Ready (+12V typical)

Figure 6-3 shows the connections for the AM-47 Hand-Held Printer.

See ¶7.39 for operating instructions for printing.

Line Connection Cables . The RJ-11 (modular) and three (3) Bantam

cables illustrated in Figures 3-4 and 3-5 are used for line connections.

Use these cables as required to connect the AM-48 to 2-wire or

4-wire lines. Figures 6-1 and 6-2 illustrate and define Modular and

Bantam line connections. Be sure to set Switch 10 (Figure 3-5) to the

appropriate position as indicated in the Figures.

Ameritec

2-WIRE
Set Switch 10 to <2W>

BANTAM-TO-BANTAM

DO NOT USE <RCV>
FOR 2-WIRE

PERSONAL TRANSMISSION TEST SET

QUIET

VOL

3 TONESWEEP

1004

SEND

VAR

PAR

L/F

∇

MON RCV

•

∇

PAR

NOISE

MON SND

TALK

IMPLS ØJTR

HOLD

∇

TERM

∇

BRDG

∇

TONE

•

∇

PULSE

ON HK

∇

∇

MODULAR

∇

2W

•

4W

∇

4W REV

7

MIC

8

PRT EAR

START

*

∇

DC

0

9

9V

C

#

CANCEL

STOP

4W/2W

∇

SND

4W

D

RCV

+

/

-

900Ω

600Ω

1

∇

2W

•

4W

∇

4W REV

4

7

5

MIC

8

PRT EAR

START

*

∇

DC

0

9

9V

#

STOP

4W/2W

∇

SND

4W

D

RCV

+

/

-

TONE

MEASURE

NOISE

∆

∇

JTR TRANS

FILTER

DAMP

2

6

C

CANCEL

OFF

∇

SEL

∇

3

∇

SEL

∇

A

ETR/NEXT

∇

SEL

∇

DTMF

MF

B

∇

ETR/PREV

SHIFT

•

SF SKP

∇

X TONE

NOR

∇

RCL/STO

•

∇

∇

PRINT

∇

S/N

15K

REL

SEND

∇

∇

MODEL AM-48

3K

C-MSG

PROG

ABS

∇

•

∇

T = Tip
R = Ring

ON

∇

•

ON/

∇

OFF

Green (T)

Red (R)

Yellow (T1)

NOT USED

Black (R1)

T

R

Black (R1)

Figure 6-1. 2-Wire AM-48 Line Connections

0015-S06

Connection & Configuration (18-0015) AM-48 Test Set

Ameritec

4-WIRE
Set Switch 10 to <4W>

BANTAM-TO-BANTAM

∇

2W

•

4W

∇

4W REV

7

MIC

8

PRT EAR

START

*

∇

DC

0

9

9V

#

CANCEL

STOP

4W/2W

∇

SND

4W

D

RCV

+

/

-

RECEIVE, <RCV>

SEND , <SND>

4-WIRE REVERSED (Frogged)
Set Switch 10 to <4W REV>

BANTAM-TO-BANTAM

∇

2W

•

4W

∇

4W REV

7

MIC

PRT EAR

8

START

*

∇

DC

0

9

9V

#

STOP

4W/2W

∇

SND

4W

D

RCV

+

/

-

C

C

CANCEL

MODULAR

R1

R

PERSONAL TRANSMISSION TEST SET

QUIET 1004 VAR

VOL

3 TONE SWEEP

SEND

PAR

L/F

∇

MON RCV

•

∇

PAR

MON SND

TALK

∇

TERM

∇

BRDG

∇

TONE

•

∇

PULSE

ON HK

∇

∇

900Ω

600Ω

1

∇

2W

•

4W

∇

4W REV

4

2

7

MIC

PRT EAR

5

8

START

*

∇

DC

0

9

9V

#

CANCEL

STOP

4W/2W

∇

SND

4W

D

RCV

+

/

-

NOISE

IMPLS ØJTR

HOLD

TONE

MEASURE

NOISE S/N

∆

∇

JTR

TRANS

15K

FILTER

ABS

REL

SEND

DAMP

∇

OFF

∇

∇

SEL

3

6

B

ETR/PREV

C

∇

∇

SEL

∇

A

ETR/NEXT

∇

SEL

∇

DTMF

MF

∇

SHIFT

•

SF SKP

∇

X TONE

NOR

∇

RCL/STO

•

∇

∇

PRINT

∇

T1

T

∇

2W

•

4W

∇

4W REV

4

MODULAR

7

MIC

8

PRT EAR

START

*

∇

DC

0

9

9V

#

STOP

4W/2W

∇

SND

4W

D

RCV

+

/

-

MODEL AM-48

3K

C-MSG

PROG

∇

•

∇

T = Tip
R = Ring
T1 = TIP 1
R1 = Ring1

T = Tip
R = Ring
T1 = TIP 1
R1 = Ring1

ON

∇

•

ON/

∇

OFF

Green (T1)

SEND , <SND>

Red (R1)

Yellow (T)

RECEIVE, <RCV>

Black (R)

SEND , <SND>

R

T

RECEIVE, <RCV>

T1

R1

Figure 6-2. 4-Wire AM-48 Line Connections

Green (T1)

RECEIVE, <RCV>

Red (R1)

Yellow (T)

SEND , <SND>

Black (R)

0015-S066-4

AM-48 Test Set (18-0015) Connection & Configuration

6-5

115 VAC
WALL JACK

AM-47
HAND-HELD PRINTER

AC ADAPTER
(70-0029)

Ameritec

HAND-HELD PRINTER • Model AM-47

PAPER

ADVANCE

OFF ON

POWER

POWER

9VDC
IN

SIGNAL

IN

PRINTER CABLE
(48-0079)

PAPER CUTTER

Am

eritec

VOL

∇

MON RCV

•

∇

MON SND

TALK

2

3

6

ETR/NEXT

B

ETR/PREV

C

CANCEL

D

PERSONAL TRANSMISSION TEST SET

QUIET 1004 VAR

3 TONE SWEEP

SEND

PAR

L/F

PAR

NOISE

IMPLS ØJTR

HOLD

TONE

MEASURE

SEL

∇

A

∇

SEL

∇

DTMF

MF

∇

SHIFT

•

SF SKP

∇

X TONE

NOR

∇

RCL/STO

•

∇

∇

PRINT

∇

AM-48

MODEL AM-48

ON

∇

NOISE S/N

∆

∇

•

JTR TRANS

ON/

∇

OFF

3K

15K PROG

C-MSG

FILTER

ABS

∇

REL

SEND

•

DAMP

∇

∇

OFF

∇

∇

SEL

∇

∇

SIGNAL

∇

TERM

∇

BRDG

∇

TONE

•

∇

PULSE

ON HK

∇

∇

900Ω

600Ω

1

∇

2W

•

4W

∇

4W REV

4

7

5

8

START

*

∇

DC

0

9

9V

#

STOP

4W/2W

∇

SND

4W

RCV

+

/

-

<PRT>

MIC

PRT EAR

<DC 9V>

LINE CONNECTION
CABLE(S) NOT SHOWN

Figure 6-3. AM-47 Hand-Held Printer Connection with AC Power

Note: The RJ-11 and Bantam jacks are wired in parallel, resulting

in an identical connection when either type of plug is used.

Do not use the <RCV> jack to connect 2-wire lines.

0015-S06

Connection & Configuration (18-0015) AM-48 Test Set

AM-48 Interface with Line Connections . The position of Switch 10

(Figure 3-5) determines the connection of the AM-48 internal

circuitry to the 2-wire or 4-wire lines. The connections for the

different settings of Switch 10 are listed below:

<2W> Connects the internal measurement circuitry to the

signal generator across the 2-wire line at the <SND>

jack. The signal generator source impedance 600Ω or

900Ω (determined by Switch 11) terminates the line in

all signal generator modes except QUIET. In QUIET

mode, the line will be terminated only if Switch 13 is

set to <TERM>. Note that the

< RCV > jack is not used

to connect to 2-wire lines .

<4W> Connects the internal measurement circuitry to the

<RCV> pair, and the internal signal generator to the

<SND> pair.

<4W REV> Send and receive pairs (as defined above) are reversed.

See ¶6.4 and 6.5 for details about line termination impedance.

AM-48 is Polarity Insensitive . It does not matter which way the Send

pair or Receive pair of contacts are connected. The Send <SND> T

and R can be interchanged without affecting the measurement. The

Receive <RCV> T1 and R1 may also be switched without changing

the measurement.

For example, in Figure 5-1, which shows the loopback connections

for self-test, the connections could be changed as indicated below:

Figure 5-1 Connections Alternate Connections

RED (R) to BLACK (R1)
GREEN (T) to YELLOW (T1)

RED (R) to YELLOW (T1)
GREEN (T) to BLACK (R1)

0015-S066-6

AM-48 Test Set (18-0015) Connection & Configuration

6

In general:

1. For 4-wire

a) Use the <SND> T and R (connecting either way) for

the Send contacts

b) Use the <RCV> T1 and R1 (connecting either way) for

the Receive contacts

2. For 2-wire, use <2W> T and R (connected either way). These

contacts are the same as <SND> for 4-wire.

6.4 600Ω/900Ω Line Termination Impedances

It is important that the line(s) be properly terminated with a matching

impedance. This paragraph gives instructions for terminating lines

with 600Ω or 900Ω impedance. To terminate lines with impedance

other than 600Ω or 900Ω connect the Ameritec Impedance Adapter

as per ¶6.5.

To terminate the line(s) correctly with 600Ω or 900Ω:

1. Choose either terminate or bridge mode:

a) Set Switch 13 to <TERM>, terminate mode, or

b) Set Switch 13 to <BRDG>, bridge mode, and terminate

the line with some other device (such as a modem) of

proper impedance.

2. Regardless of the method of termination, set Switch 11 to

<600Ω> or <900Ω> to match the impedance of the line.

Note: An incorrect Switch 11 setting results in about 1.8 dB error

in level and noise readings.

0015-S06

-7

Connection & Configuration (18-0015) AM-48 Test Set

Switch 13 Settings . The connections for the settings of Switch 13 are

listed below:

<TERM>

Receive line terminated with a resistive impedance as

selected by Switch 11.

<BRDG> Receive line unterminated and bridged only with the

impedance of the measurement circuitry (>25KΩ) across

the receive pair.

Note: In 2-wire mode, the signal generator source impedance will

terminate the line with 600Ω or 900Ω with Switch 13 in

either <TERM> or <BRDG>. However, if SEND is in QUIET

mode, Switch 13 will be able to function. In 2-wire QUIET

send mode, setting Switch 13 to <BRDG> will disconnect the

signal generator from the send pair and the send pair source

impedance will be >25KΩ. There will be an error of 6 dB if

<BRDG> is incorrectly selected when the line should be

terminated with <TERM>.

Switch 11 Settings . The connections for the settings of Switch 11 are

listed below:

<600Ω> 600Ω applied across the Receive pair when Switch 13 is

set to <TERM>.

Send pair source impedance set at 600Ω.

<900Ω> 900Ω applied across the Receive pair when Switch 13 is

set to <TERM>.

Send pair source impedance set at 900Ω.

0015-S066-8

AM-48 Test Set (18-0015) Connection & Configuration

6-9

6.5 Impedance Adapter

The Impedance Adapter (24-0005) is used:

1. To match the AM-48 to a user interface of

600Ω or 900Ω .

2. To match 4-wire split impedances .

See Figure 3-10 for an illustration of the Impedance Adapter; Figure

9-2 is the schematic diagram of the Impedance Adapter.

The Impedance Adapter is used to adapt the AM-48 to impedances of

75Ω, 135Ω, 150Ω, or 1200Ω. For example, high speed digital lines

typically have impedances of 75Ω, 135Ω, or 150Ω. A “THRU”

setting on the Impedance Adapter makes a straight through

connection resulting in a 600Ω or 900Ω termination inside the

AM-48.

To use the AM-48 with the Impedance Adapter:

1. Set AM-48 Switch 11 to <600Ω> and Switch 13 to <BRDG>.

2. Plug the Impedance Adapter into the AM-48 modular jack.

3. Plug a modular line cable into the jack on the Impedance

Adapter.

impedance other than

4. Connect the line cable to the 2-wire or 4-wire line per Figure 6-1

or 6-2.

5. Turn knob(s) on the Impedance Adapter to match the impedance

of the line:

a) For 2-wire, use only the upper knob.

b) For 4-wire, set the upper knob to match the Send pair

impedance and the lower knob to match the Receive

pair impedance.

0015-S06

Connection & Configuration (18-0015) AM-48 Test Set

Note: The reading on the AM-48 display needs to be corrected

when the Impedance Adapter is used; see ¶7.41 for

instructions.

6.6 Configurations

There are three (3) basic AM-48 configurations to test 2-wire and 4-

wire telephone and data communication lines:

1. End-to-end - requiring two (2) AM-48’s

2. Loopback

3. Testing with responders

This paragraph describes the different configurations, explains how

they are used, and discusses the advantages and disadvantages.

Note: End-to-end and responder testing applies to either 2-wire or

4-wire. Loopback testing only applies to 4-wire.

End-to-end Testing . Measurements on telephone transmission lines

are usually made by applying an appropriate signal at one end of the

transmission line and then measuring the results at the other end of

the line. This configuration requires a test set at each end of the line

and is called “end-to-end” testing.

Figure 6-4 shows a 4-wire end-to-end configuration, making

measurements over a telephone network that normally connects two

(2) modems. Each AM-48 both sends and receives signals, sending a

signal over the <SND> pair of lines and measuring the signal received

over the <RCV> pair of lines.

End-to-end testing can also be done over 2-wire lines. The AM-48

on one end sends a signal, and the AM-48 on the other end measures

the received signal.

0015-S066-10

AM-48 Test Set (18-0015) Connection & Configuration

6

End-to-end testing is the most reliable for characterizing the near-to-

far and far-to-near impairments, but it has the disadvantage of

requiring two (2) test sets and an operator at each test site.

CPU

MODEM

AM-48

RCV

Telephone

Network

<RCV> <SND>

<SND>

<RCV>

AM-48

XMIT

RCVXMIT

MODEM

DTE

Figure 6-4. 4-Wire End-to-End Testing

Loopback Testing . The distant end of a 4-wire transmission line can

be looped back (1) manually, or (2) with a commandable loopback

device such as a Western Electric Model 829. The AM-48 at the near

end sends a signal which travels to the distant end where it makes a

U-turn and travels back to the AM-48, which measures the received

signal.

The advantage of this configuration is that it requires only one (1)

operator and test set at a central site. Although this method is more

convenient and less costly than end-to-end testing, it is also less

reliable. The disadvantage is that it does not characterize

transmission impairments in each direction. Instead of detecting

impairments, a loopback measurement could actually cover them up.

An apparently satisfactory loopback measurement may contain

impairments in each direction which cancel each other. Loopback

testing may be useful, providing its limitations are recognized.

Note: A loopback test can not be done on 2-wire because signals

can not be sent and measured simultaneously on the same

pair of lines.

To do a loopback test with a Western Electric Model 829:

1. Connect the AM-48 at the near end of the 4-wire line under test.

0015-S06

-11

Connection & Configuration (18-0015) AM-48 Test Set

2. With Switch 8 (Figure 3-5), momentarily press <X TONE> to

send a 2713 Hz tone over the <SND> line. This will trip the

distant Model 829 into loopback.

3. Send the desired test signal with the AM-48 and make the

desired measurement of the looped-back signal.

4. After testing is finished, momentarily press <X TONE> to restore

the Model 829 to its normal, transparent state.

Testing with Responders . The use of multi-function responders

supplies most of the advantages of end-to-end testing with the added

advantage of not requiring an AM-48 at the far end of the system.

This configuration is similar to loopback testing except that the

responder can generate signals in addition to looping back. Unlike a

dedicated loopback device, responders can be used in 2-wire far-to-

near testing.

On 4-wire circuits, a DTMF commandable responder, such as the

Ameritec Model AM3-4, may be placed permanently at the distant

modem where it remains transparent until commanded by DTMF

signals sent from the AM-48 at the central site. In addition to

performing loopback, the responder can send various tones, allowing

for far-to –near tests as well as loopback tests.

EXAMPLE: 4-wire far-to-near and loopback tests for level and

frequency with an Ameritec AM3-4A or AM3-4B Responder:

1. Connect an AM-48 to the near end of a 4-wire facility and an

Ameritec Model AM3-4A or AM3-4B Responder at the far end.

A typical configuration is illustrated in Figure 6-5.

2. Use the AM-48 keypad to send the appropriate DTMF command

sequence to command the responder into milliwatt mode

(responder will generate 1004 Hz, 0 dBm signal). Measure the

received signal and note the level and frequency.

0015-S066-12

AM-48 Test Set (18-0015) Connection & Configuration

6-13

3. Use the AM-48 keypad to send a DTMF sequence to command

the responder into loopback.

4. Use the AM-48 to send a 1004 Hz tone @ 0 dBm. Measure the

loopback received level and frequency.

5. Use the AM-48 keypad to send a DTMF command sequence to

restore the responder to normal.

On a 2-wire network, dial access responders are very useful in

measuring far-to-near characteristics. An Ameritec AM3-2C

Responder (automatic milliwatt) or AM3-2A Responder can be

dialed up over the network path under test using the AM-48 keypad.

It can then be commanded with touch tone from the AM-48 to make

level measurements or send tones. The AM3-2C can perform far-to-

near level and frequency, idle channel noise, and noise with tone. In

addition to the AM3-2C functions, the AM3-2A can also perform far-

to-near gain slope and near-to-far level. A typical configuration is

illustrated in Figure 6-6.

Loopback Quiet

Send Tones

CPU

MODEM

AM-48

RCV

<RCV>

<SND>

Telephone

Network

Amputate

AM3-4A

Responder

XMIT

RCVXMIT

MODEM

DTE

Figure 6-5. 4-Wire Testing with Responder

0015-S06

Connection & Configuration (18-0015) AM-48 Test Set

MW

AM-48

<SND>

AM3-2

2W RESPONDER

PBX

CO

FX

MW

TIE

TELEPHONE NETWORK

DISTANT

CO

LOCAL

CO

Figure 6-6. 2-Wire Network Testing with Responders

AM3-2

2W RESPONDER

PBX

AM-48

<SND>

0015-S066-14

AM-48 Test Set (18-0015) Operating Instructions

7. OPERATING INSTRUCTIONS

Note: Set up the AM-48 per Section 6 before performing

operations in this section.

7.1 Introduction

The AM-48 operating instructions in this section are divided into five

(5) major subjects and associated paragraphs as listed below:

7.2 General Instructions and Notes

7.3 General Operating Notes

7.4 Figure Format

7.5 General Switch Setup

7.6 Multiple Use of Keys

7.7 Memory

7.8 General Procedure to Set New Parameter Values

7.9 Send (Generator) Modes and Parameter Settings

7.10 Type of Send Signals

7.11 Send Quiet

7.12 Set Parameters from Quiet Display

7.13 Send Momentary Variable Tones

7.14 Send 1004 Hz

7.15 Send Continuous Variable Tone

7.16 Send 3-Tone Slope

7.17 Send Variable Sweep

7.18 Send PAR Waveform

7.19 Send Momentary 2713 Hz Tone

7.20 General Measure Mode Notes

7.21 Accuracy of Measurements

7.22 Absolute and Relative Measurements

7.23 Special Measurement Requirements

7.24 Timed Tests

0015-S07

7-1

Operating Instructions (18-0015) AM-48 Test Set

7.25 Measure Modes and Parameter Settings

7.26 Measure Level and Frequency

7.27 Measure Noise

7.28 Measure PAR

7.29 Measure Impulse Noise

7.30 Measure Notched Noise

7.31 Measure S.N Ratio

7.32 Measure Phase Jitter

7.33 Measure Amplitude Jitter

7.34 Measure Transients (Impulse Noise, Notched Noise,

Phase Hits, Gain Hits, and Dropouts)

7.35 Miscellaneous Operations

7.36 Store and Recall

7.37 Dialing

7.38 Talking

7.39 Printing

7.40 Auto Study Result Save

7.41 Impedance Adapter Measurement Corrections

7.42 Auto Calibrate

It is assumed in this section that the user is familiar with basic

AM-48 operation, having followed the self-test instructions of

Section 5. Instead of step-by-step procedures with full details, the

instructions refer to the figures, which summarize the information

needed to perform a test.

Read the general notes in ¶7.2 thru 7.10 and 7.20 thru 7.24 before

going to specific operating instructions.

0015-S077-2

AM-48 Test Set (18-0015) Operating Instructions

3

7.2 General Instructions and Notes

¶7.3 thru 7.8 cover general instructions and notes. These paragraphs

should be read before doing a specific test or operation.

7.3 General Operating Notes

Keys . Do not be afraid to experiment with the keys. The AM-48 will

not accept an “illegal” or meaningless keystroke. If an out-of-

tolerance value is entered in a user-programmable variable field, the

display will default to an acceptable value.

Displays .

1. The units of measurement appear at the top of the display, above

the value. Time and count units are not shown, but are given in

the table associated with the corresponding display.

2. Display decimal points will flash when batteries are low.

3. Displays of “OVER” or “UNDR” indicate the signal being

monitored is too high or low to be read.

4. Depending on the mode, there may be multiple displays through

which one can scroll. All displays accessible form each mode

are shown in the figures.

5. To quickly go to the initial display from another display in a

scroll, momentarily exit and then re-enter the same mode by

moving the cursor. See the example in ¶5.7.

Check List . Go through the following check list to cover important

points while performing any operation:

1. Look at the cursor positions on the menus. These indicate what

SEND and MEASURE mode is selected and what noise-weighting

filter is selected.

0015-S07

7-

Operating Instructions (18-0015) AM-48 Test Set

2. Note the color-coding and framing of the cursor menus and use

these to determine if a filter is needed (orange functions) or a

holding tone is needed (within the rectangle) for the present

position of the cursors. See ¶3.7 and 7.23 for explanation of

menu framing.

3. Note the setting of Switch 2, the Display Select Switch. This

will indicate what is being viewed on the display. <ABS> or

<REL> indicate that the display is viewing the MEASURE mode;

while <SEND> indicates the display is viewing the SEND mode.

4. Note the setting of Switch 7. This indicates whether the

keyboard is connected to dial (<DTMF> or <MF>) or to operate

the auxiliary functions (<SHIFT>).

7.4 Figure Format

Figures 7-1 thru 7-9 show the display(s) which can be accessed from

the indicated SEND or MEASURE mode. The position of the menu

cursor, the necessary switch settings, and other pertinent information

is indicated in each figure. A detailed description of the arrangement

of the figures is listed below.

1. The

display fields are shown with three (3) types of characters.

The characters are illustrated at the bottom of some figures in a

table labeled “DISPLAY CHARACTER CODE”. The meanings of

the characters are:

Solid : These letters and numbers are fixed and will

a)

always appear just as they are shown. They are

abbreviations for the names of the parameters.

0015-S077-4

AM-48 Test Set (18-0015) Operating Instructions

5

b) Cross-hatched : These characters represent values that

variable but cannot be changed by the user from

are

the display in which they are shown. In the SEND

modes these indicate the level and frequency being

sent; in the MEASURE mode, they give the measured

values.

c)

Plain : These characters represent parameter values

variable and can be changed by the user from

that are

the display in which they are shown.

2. Next to each display is a

table of information and instructions

which apply to the adjacent display. The middle column of the

table gives the range of acceptable values to enter for a variable

parameter or the range of values that can be measured.

3. The SEND or MEASURE

cursor setting is shown darkened on the

menu just as it appears at the bottom of the AM-48 display.

There are always three (3) cursors in view, although only one (1)

is shown in each of the figures. The positions of the other two

(2) cursors will depend upon the test configuration and setup.

4. The

switch settings are indicated next to the location of the

switches in the illustration of the AM-48 at the bottom of the

figure. Only the necessary switch settings for the test under

consideration are shown. Set the other switches as appropriate,

according to the test configuration and setup.

5. The

notes on the left at the bottom of the figures relate to the

displays. The notes on the right relate to the switches and

keyboard.

0015-S07

7-

Operating Instructions (18-0015) AM-48 Test Set

6. At the bottom of some figures, an alternate display(s) is

illustrated, e.g., “OVER” or “UNDR”, which may be displayed to

call attention to an out-of-tolerance condition.

7.5 General Switch Setup

See ¶3.5 for a summary of the use of each switch. Refer to Figure

3-5 for switch identification number (see ¶3.2). Follow the

guidelines below for proper switch setup.

1. Make connections and set Switches 10, 11, and 13 per the line

interface. See ¶6.3 thru 6.5 for details.

2. Connect and turn on power with Switch 1 per Section 4.

3. Switch 2, Display Select, determines what appears on the

display. Set Switch 2 to the desired position:

a) <ABS> to view MEASURE display (see ¶7.22 for use of

<REL> position).

b) <SEND> to view SEND display

4. Use Switches 5 and 6 to set the display cursor to the desired

SEND and MEASURE modes, and Switch 4 to select a noise-

weighting filter, if required (see Table 7-5).

5. Set Switch 7 to <SHIFT> to enable auxiliary keyboard functions

to:

a) Scroll through multiple displays

b) Use keyboard to change a parameter value

c) Send momentary user-programmed tone from

keyboard in

d) Do Store/Recall

e) Run a transient test

f) Do auto calibrate

Leave Switch 7 in <SHIFT> except when dialing.

QUIET mode

0015-S077-6

AM-48 Test Set (18-0015) Operating Instructions

6. Use Switches 3, 14, and 15 to connect a speaker or earphone to

the desired monitoring point and adjust volume. As a rule, leave

Switch 3 <OFF>.

7. Leave Switch 8 in <NOR> unless it is desired to avoid

transmission of tones in the signaling frequency band (in which

case, set to <SF SKIP>).

8. Use Switch 9 as required to Store and Recall setups or output

information to the Printer port. See ¶7.36 and 7.39.

9. Leave Switch 12 in <ON HK> except to go

dial access lines. <TONE> and <PULSE> are

off-hook on 2-wire

off-hook positions

and connect a 200Ω DC short across T and R.

Display Damping Switch . Set Switch 3 to <OFF> for a normal

display update of four (4) times per second, or to <DAMP> to slow the

display update to two (2) times per second.

Switch 3 also affects the monitor point of the speaker. Refer to the

upper part of Figure 9-1 with the descriptions below:

1. With Switch 14 set to <MON RCV> and Switch 3 set to <OFF>,

the speaker monitors the signal on the <RCV> jack (T1, R1) for

4-wire operation.

2. With Switch 14 set to <MON RCV> and Switch 3 set to <DAMP>,

the speaker monitors the received signal (from T1, R1 in 4-wire

operation, or T, R in 2-wire operation) at a point following the

noise weighting filter, notch filter (if in use), and auto-ranging

amplifiers. This is particularly useful for audibly monitoring the

residual noise in notched noise and S/N ratio measurements.

0015-S07

7-7

Operating Instructions (18-0015) AM-48 Test Set

7.6 Multiple Use of Keys

Multi-Function Keyboard . See Table 7-1 for different uses of the

keyboard, per the setup (switch numbers per Figure 3-5).

Table 7-1. Setup Requirements for Different Keyboard Applications

SWITCH 12 POSITION

KEYBOARD

USE

Dial DTMF <DTMF> <TONE> <ON HK>
Dial MF <MF> <TONE> <ON HK>
Dial PULSE <DTMF> or

Send Momentary
Variable Tone

Set Parameter
Values

Keys with Two (2) Auxiliary Functions . The (*) and (#) key each

have two (2) auxiliary functions. The [START]/[∆], on the (*) key,

and [STOP]/[∇], on the (#) key, are enabled per the setup.

SWITCH 7
POSITION

<MF>

<SHIFT> From QUIET SEND Display

<SHIFT> Displays in Figures 7-1 thru 7-8 with

2-WIRE

OFF-HOOK

(loop current)

<PULSE> _ _ _ _ _

DISPLAY REQUIREMENTS

plain (not cross-hatched) characters

2-WIRE

ON-HOOK

OR 4-WIRE

The [START] and [STOP] functions only operate from certain displays

in a timed test; see ¶7.24.3.

See ¶7.8.2 and .3 for explanation of the use of the [∆] and [∇]

functions. When the [∆] or [∇] key is pressed continuously, the

“auto-repeat” feature is enabled and repeatedly steps a parameter

value at 10 times the normal step. Table 7-2 lists the momentary and

continuous press steps.

0015-S077-8

AM-48 Test Set (18-0015) Operating Instructions

9

Table 7-2. Steps for [∆] and [∇] Keys

PARAMETER MOMENTARY

PRESS STEP

Frequency 10 Hz 100 Hz

Level 0.1 dB 1.0 dB

Time 0.1 minute 1.0 minute

Note that in changing a level, the [∆] key steps mathematically more

positive and the [∇] key steps mathematically more negative . Foe

example, if a negative level is stepped down with the [∇] key, the

value of the number itself will become larger.

CONTINUOUS

PRESS STEP

7.7 Memory

Parameter Values Stored in Memory . Some user-programmable

parameter values are stored in

non-volatile memory . Table 7-3 lists the variable parameters and

in

indicates in which memory they are stored. General information

about the two (2) types of memory is given below:

Volatile Memory . User-set values stored here will be stored as

1.

long as the AM-48 power is on or until changed by the user.

When power is turned off or times out (after turning on with the

momentary power switch), the user-set volatile memory values

will be lost and revert to the

volatile memory and others are stored

default values.

2. Non-Volatile Memory . Values stored here will stay stored even

if AM-48 power is turned off. They will remain until changed

to another value by the user. Also stored in non-volatile

memory are the results and the parameter settings of the last

timed impulse noise or transient test. Note that the timed test

information is not stored in non-volatile memory unless the test

is actually run.

0015-S07

7-

Operating Instructions (18-0015) AM-48 Test Set

In order to allow the transfer of timed test information into non-

volatile memory, the AM-48 power will not time-out during a

timed study. The time-out timer restarts at the end of a timed

study.

Level Display . There is only one level setting and it is stored in

volatile memory. For convenience, the level display that shows this

value can be accessed from any SEND display. The level display is

always the second display in the scroll. To access the level display:

1. Set Switch 2 to <SEND>.

2. Set Switch 7 to <SHIFT>.

3. Rock Switch 6 to select any SEND mode.

4. Press [ETR/NEXT]

5. Level display will appear.

Remember that when the level value is changed, it changes the level

for all SEND signals, except for dialed tones (see ¶7.12.3 for

instructions to set touch tone level). When power is turned off, the

send level always defaults to 00.0 dBm. The level for dialed tones,

however, is stored in non-volatile memory.

Store/Recall . Up to 10 test setups, including parameter values, can be

stored in non-volatile memory. A stored test setup can be recalled,

avoiding the need to set cursors and re-enter parameter values for a

routine test. See ¶7.36 for instructions.

0015-S077-10

AM-48 Test Set (18-0015) Operating Instructions

Table 7-3. User-Programmable Parameter Values Stored in Memory

VOLATILE MEMORY

PARAMETER DEFAULT LEVEL

Level 00.0 dBm
Variable Frequency 1004 Hz
Variable Sweep Start Frequency 204 Hz
Stop Frequency 19,904 Hz
Step 100 Hz
Rate 1.0 sec
Jitter Bandpass Range 20 Hz – 300 Hz

NON-VOLATILE MEMORY

PARAMETER FACTORY SETTINGS

Dial Level (DTMF and MF) -10.0 dBm
Blanking Interval 125 ms
Time Off with Momentary Power 16 minutes
10 Momentary Frequencies

Not Applicable

(with Volatile Memory Level)
10 Test Setups

Not Applicable
(Stored on Number Keys
using <RCL/STO>)

Timed Test Parameters

Not Applicable

Duration of Timed Test
Impulse Noise Delta
Impulse Noise Threshold
Phase Hit Threshold
Gain Hit Threshold

Timed Test Results

Not Applicable

Time Elapsed
Low Impulse Count
Middle Impulse Count
High Impulse Count
Noise
Phase Hit Count
Gain Hit Count
Dropouts
Phase Locked Loop Frequency

0015-S07

7-11

Operating Instructions (18-0015) AM-48 Test Set

7.8 General Procedure to Set New Parameter Values

Note: Set Switch 7 to <SHIFT> to enable the keys to perform the

auxiliary functions.

See ¶7.36 for instructions to store new parameter values for future
use.

Items 2, 3, 4, 5, 7, and 8 shown in Figure 3-6 are the auxiliary

keyboard functions that are used together with the number keys to set

new parameter values. ¶3.6 explains how these keys are used.

See ¶5.7, Steps N thru HH, for an example of setting new parameter

values. To summarize, there are three (3) procedures used to set new

parameter values (confirm Switch 7 in <SHIFT>).

Scroll Through the Displays . To view the displays without

1.

making any changes in parameter values:

(a) Press [ETR/NEXT] to go to the next display.

(b) Press [ETR/PREV] to go to the previous display.

2. Set a New Parameter Value Using the Number Keys.

(a) Press any number key or the [±] key to clear the

display of the old parameter value and start writing a

new value on the display.

Note: Now the [∆] and [∇] keys will not work.

Finish writing the new value with the number keys.

b) If a mistake is made in Step a), press [CANCEL] to

clear the display and view the old value.

c) After using the number keys to write a new value in

Step a), press either [ETR/NEXT] or [ETR/PREV] to

enter the new value into memory, replacing the old

value.

0015-S077-12

AM-48 Test Set (18-0015) Operating Instructions

3

Note: Now [CANCEL] will not work.

d) Use Step1 to go to another display.

3. Set a New Parameter Value Using the [∆] and [∇] Keys.

a) Press [∆] and/or [∇] to step the displayed parameter

value up or down to a new value. To step in

increments 10 times the normal increment, hold the

key down continuously. See Table 7-2 for step values.

The new value displayed is entered directly into

memory, replacing the old value.

b) The [CANCEL] key will

value directly replaces the old value in memory.

c) [±] can

d) Use Step1 to go to another display.

not be used to change the sign because it will

clear the display (see Step 2a).

not work here because the new

7.9 Send (Generator) Modes and Parameter Settings

Paragraphs 7.10 thru 7.19 discuss the SEND modes.

Note: For all SEND modes, set Switch 8 to <SF SKIP> to prevent

sending tones in the signaling band of 2450 Hz to 2750 Hz

(2130 Hz to 2430 Hz for AM-48E). Set Switch 8 to

<NOR> to allow all frequencies to be sent.

7.10 Types of Send Signals

The AM-48 Send signals can be classified according to their

duration. The three (3) types of Send signals are:

1. Momentary

2. Continuous

3. Stepped (Slope and Sweep)

0015-S07

7-1

Operating Instructions (18-0015) AM-48 Test Set

To send a variable

set the level and frequency per instructions in ¶7.12.1 and 7.12.2.

Send the frequency from the QUIET SEND display by pressing the

number to which the tone is assigned. Momentarily press Switch 8 to

<X TONE> to send

To send a variable continuous tone, set the SEND cursor to VAR and

set the desired level and frequency per ¶7.15.

To send

send continuous PAR, set the SEND cursor to PAR (¶7.18).

To send a pre-programmed set of slope frequencies, set the SEND

cursor to 3TONE (SLOPE

To send variable sweep set the SEND cursor to SWEEP (¶7.17).

continuous 1004 Hz, set the SEND cursor to 1004 (¶7.14). To

momentary tone, set the SEND cursor to QUIET and

momentary 2713 Hz tone (¶7.19).

for the AM-48E) (see ¶7.16).

7.11 Send Quiet

1. See Figure 7-1. Set switches per the SWITCH SETUP illustration

and the SEND cursor per the menu illustration.

2. A Quiet termination display will appear, “_ _ _ _ _ _ _ _”,

confirming that the AM-48 is quiet terminated.

0015-S077-14

AM-48 Test Set (18-0015) Operating Instructions

5

DBM

QUIET DISPLAYS

•

HZ

TOUCH TONE
LEVEL "TTLEV"

NAME

QUIET

TERMINATION

LEVEL

"LEVL"

FREQUENCY

"FR"

ACCEPTABLE VALUES

10.0 to -50.0 dBm

200 to 19,999 Hz

7.0 to -50.0* dBm

TIME OFF

QUIET 1004 VAR

QUIET darkened

PAR

HOLD

L/F

NOISE NOISE S/N

TONE

PAR3 TONE SWEEP

IMPLS ØJTR JTR TRANS

∆
∇

DISPLAY CHARACTER CODE

Parameter Name (Fixed)

•

Key from which Programmed
Tone is Sent

User-Entered Value

See ¶7.11, 7.12, and 7.13 for instructions.

See ¶7.8 for general procedure to set new parameter values.

3K C-MSG

15K PROG

with momentary power

switch on "TMOFF"

BLANKING INTERVAL

"BLANC"

1 to 255* minutes

1 to 255* millisec (ms)

Ameritec

PERSONAL TRANSMISSION TEST SET

HOLD

QUIET 1004 VAR

L/F

NOISE NOISE S/N

TONE

PAR

PAR3 TONESWEEP

IMPLS ØJTR JTR TRANS

SEND MEASURE FILTER

VOL

∇

MON RCV
MON SND

•

∇

TALK

∇

TERM

∇

BRDG

∇

TONE
PULSE

•

∇

ON HK

∇

900Ω

21 A3

600Ω

∇

54 B6

∇

2W
4W

•

87 C9

4W REV

∇

0*D#

STOPSTART

∇

∇

MIC

4W/2W

SND4WRCV

PRT EARDC9V

SWITCH SETUP

Figure 7-1. Parameter Settings from QUIET SEND Display

0

MODEL AM-48

∆
∇

ETR/NEXT

ETR/PREV

CANCEL

+/-

ON/
OFF

3K C-MSG

15K PROG

ABS

REL

SEND

DAMP

OFF

SEL

SEL

SEL

MF

DTMF

SHIFT

SF SKP

NOR

X TONE

RCL/STO

PRINT

NOTES

Press key ([0] to [9]) to momentarily
send user-programmed tone.

Set level for all tones sent (except
dialed tones.

10 displays.
Set frequencies for tones on keys
[0] to [9].

Set level for DTMF or MF
tones dialed.

Power stays on.

Unused AM-48 powers down
after this time.

For Impulse and Transient tests
Standards:

143ms Bell 41009
125ms IEEE

FACTORY SETTINGS

*

TTLEV

ON

TMOFF

∇

•

BLANC

∇

∇

•

<SEND>

∇

∇

∇

∇

∇

∇

∇

∇

∇

Set QUIET

∇

•

<SHIFT>

∇

∇

•

∇
∇

∇

-10.0 dBm
16 minutes
125 ms

7.12 Set Parameters from Quiet Display

There are a total of 15 displays in the QUIET SEND mode. The third

display in Figure 7-1, “FR 8 18888”, represents 10 different displays,

from “FR 0 18888” to “FR 9 18888”.

See Figure 7-1 for all parameter settings in this paragraph. Set

switches per the SWITCH SETUP

per the menu illustration.

0015-S07

illustration, and set the SEND cursor

7-1

Operating Instructions (18-0015) AM-48 Test Set

1. Set Level (see Figure 7-1 and ¶7.8).

a) Go to “LEVL” display.

b) Set desired level value (default value is 00.0 dBm).

c) New level value is stored in volatile memory.

Set Up to 10 Frequencies , sent with number keys from QUIET

2.

display (see Figure 7-1 and ¶7.8).

a) Go to desired “FR” display - - one (1) of 10.

b) The number after “FR” identifies the number key onto

which the frequency is programmed.

c) Set desired frequency value.

d) This value is stored in non-volatile memory.

e) Repeat Steps a) and c) for other frequencies as desired.

Set Touch Tone Level (see Figure 7-1 and ¶7.8).

3.

a) Go to “TTLEV” display.

b) Set desired level value for DTMF and MF dialing.

c) Recommended level (factory setting) is –10.0 dBm.

d) This value is stored in non-volatile memory.

Set Time Off : operates when power is turned on with the

4.

momentary power switch (see Figure 7-1 and ¶7.8).

a) Go to “TMOFF” display.

b) Set desired time value.

c) This value is stored in non-volatile memory (factory

setting is 16 minutes).

d) This time is when the AM-48 will turn off after the

last key or switch activity, if the unit has been turned

on with the momentary power switch.

0015-S077-16

AM-48 Test Set (18-0015) Operating Instructions

e) Note that the AM-48 will

“0” is set. A time of “0” is not a desirable setting

when using batteries.

5.

Set Blanking Interval (see Figure 7-1 and ¶7.8).

a) Go to “BLANC” display.

b) Set desired blanking interval value.

c) This value is stored in non-volatile memory (factory

setting is 125 ms).

d) The meaning of the blanking interval for timed tests is

explained in ¶8.9.

e) Note the Bell and IEEE standard settings listed in

Figure 7-1.

not turn itself off if a time of

7.13 Send Momentary Variable Tones

1. With the switches and cursor set per Figure 7-1, program desired

frequencies on the number keys per ¶7.12.2.

2. The level of the tone sent is the value in the “LEVL” display,

stored in volatile memory (factory setting is 125 ms).

3. Go to the QUIET termination display, “_ _ _ _ _ _ _ _”.

Note: First select “SEND 1004” and then step backwards to select

QUIET termination.

4. Press the appropriate number key; [0], [1], [2], . . . . [9], to send

the desired frequency.

5. The tone will be sent for as long as the key is held down.

0015-S07

7-17

Operating Instructions (18-0015) AM-48 Test Set

7.14 Send 1004 Hz

1. See Figure 7-2. Set switches per the SWITCH SETUP illustration,

and set the SEND cursor per the lower menu illustration.

2. Go to the “LEVL” display and set the desired level value.

DBM

DBM

QUIET 1004 VAR

1004 HZ TONE DISPLAYS

•

L/F

NOISE NOISE S/N

PAR

PAR3 TONE SWEEP

IMPLS ØJTR JTR TRANS

1004 darkened

TONE

HOLD

HZ

•

3K C-MSG

∆

15K PROG

∇

VARIABLE TONE DISPLAYS

DBM

DBM

•

HZ

•

HZ

QUIET 1004 VAR

L/F

NOISE NOISE S/N

PAR

PAR3 TONE SWEEP

IMPLS ØJTR JTR TRANS

HOLD
TONE

VAR darkened

DISPLAY CHARACTER CODE

Parameter Name (Fixed)

•

Key from which Programmed
Tone is Sent

User-Entered Value

See ¶7.8 for general procedure to set new parameter values.

3K C-MSG

∆

15K PROG

∇

Figure 7-2. Parameter Settings from 1004 Hz and VAR Tone Send Displays

NAME

"1004" HZ

TONE

LEVEL

"LEVL"

NAME

VARIABLE

TONE

LEVEL

"LEVL"

FREQUENCY

"FREQ"

Ameritec

PERSONAL TRANSMISSION TEST SET

QUIET 1004 VAR

VOL

∇

MON RCV
MON SND

•

∇

TALK

∇

TERM

∇

BRDG

∇

TONE
PULSE

•

∇

ON HK

∇

900Ω
600Ω

∇

∇

2W
4W

•

4W REV

∇

MIC

PRT EARDC9V

ACCEPTABLE VALUES

10.0 to -50.0 dBm

ACCEPTABLE VALUES

10.0 to -50.0 dBm

200 to 19,999 Hz

SWITCH SETUP

MODEL AM-48

HOLD

L/F

NOISE NOISE S/N

TONE

∆

PAR

PAR3 TONESWEEP

IMPLS ØJTR JTR TRANS

∇

SEND MEASURE FILTER

21 A3

ETR/NEXT

54 B6

ETR/PREV

87 C9

CANCEL

0*D#

STOPSTART

+/-

∇

∇

4W/2W

SND4WRCV

Send Level of 1004 Hz
constant tone.

Set level for all tones sent (except
dialed tones).

Send Level and Frequency of
variable constant tone.

Set level for all tones sent (except
dialed tones).

Set frequency for variable

constant tones.

ON

∇

•

∇

ON/
OFF

3K C-MSG

15K PROG

∇

ABS

REL

•

<SEND>

SEND

∇

∇

DAMP

OFF

∇

∇

SEL

∇

∇

SEL

∇

∇

SEL

∇

Set 1004 or VAR

∇

MF

DTMF

•

<SHIFT>

SHIFT

∇

∇

SF SKP

NOR

•

X TONE

∇

∇

RCL/STO

∇

PRINT

NOTES

NOTES

0015-S077-18

AM-48 Test Set (18-0015) Operating Instructions

9

7.15 Send Continuous Variable Tone

1. See Figure 7-2. Set switches per the SWITCH SETUP illustration,

and set the SEND cursor per the lower menu illustration.

2. Go to the “LEVL” display and set the desired level value.

3. Go to the “FREQ” display and set the desired frequency value.

7.16 Send Set of Slope Tones

1. See Figure 7-3. Set switches per the SWITCH SETUP illustration,

and set the SEND cursor per the upper menu illustration.

2. Go to the “LEVL” display and set the desired level value.

3. Go to the initial display and note that the frequencies 404 Hz,

1004 Hz, and 2804 Hz (404 Hz, 1004 Hz, 2004 Hz, and 3004 Hz

for AM-48E) are sent in a cycle @ 5 seconds.

0015-S07

7-1