AMERITEC AM-48 Instruction Manual
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AMERITEC AM-48 Instruction Manual

Personal transmission test sets
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Models AM-48 and AM-48E
Personal Transmission
Test Set
INSTRUCTION MANUAL

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  • Page 1 Models AM-48 and AM-48E Personal Transmission Test Set INSTRUCTION MANUAL...

  • Page 2: 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 626.915.5441 FAX 626.915.7181 www.ameritec.com For extra copies of this manual, order Part No.
  • Page 3 Record of Revisions September 1992 Initial Release. January 28, 1998 Minor Update Changes. October 2, 1998 Changed Generator Accuracy Specs. October 9, 1999 Changed Distortion specification on 1-6. February 4, 2000 Reformatted Manual to provide new soft copy. January 19, 2004 Made a Better PDF April 19, 2004 Option...

  • Page 4: 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 ..............
  • Page 5 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.
  • Page 6 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............
  • Page 7 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................
  • Page 8 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.
  • Page 9 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 0015-TOC...
  • Page 10 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.

  • Page 11: Introduction

    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.

  • Page 12: General Description

    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.
  • Page 13 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: •...

  • Page 14: Technical Specifications

    • 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: End-to-end -- requiring two (2) AM-48 units Loopback Testing with responders 1.3 AM-48 Technical Specifications...

  • Page 15: Table 1-1. Am-48 General Technical Specifications

    AM-48 Test Set (18-0015) Introduction 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...

  • Page 16: Table 1-2. Am-48 Generator (Send) Technical Specifications

    Touch Tone/MF Dial Level Power Down Time with momentary power switch Blanking interval for impulse and transient tests 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.
  • Page 17 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.

  • Page 18: Table 1-3. Am-48 Receiver (Measure) Technical Specifications

    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: 15 kHz 20 kHz 200 Hz ±0.2...
  • Page 19 AM-48 Test Set (18-0015) Introduction Characteristic Specification Amplitude Jitter Displays the incidental amplitude modulation of a holding 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.
  • Page 20 Introduction (18-0015) AM-48 Test Set Characteristic Specification Transients Gain hit threshold can be 2, 3, 4, or 6 dB. A gain hit will be (cont.) 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.

  • Page 21: Am-48E Technical Specifications

    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: Instead of the C-Message (CMSG) noise-weighting filter, the AM-48E has the Psophometric (PSHO) noise-weighting filter .
  • Page 22 Introduction (18-0015) AM-48 Test Set Instead of Signal Frequency (SF) Skip 2450 Hz to 2750 Hz, the AM-48E has SF SKIP from 2130 Hz to 2430 Hz . On all noise displays, instead of units of dBrn , the AM-48E displays the noise in units of dBm .

  • Page 23: Receiving And Unpacking

    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.

  • Page 24: Table 2-1. Am-48 Standard Equipment

    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.

  • Page 25: Physical & Functional Description

    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.

  • Page 26: Component Location

    Table 3-1. Front Panel/Switches Color Coding Color Description Black & Blue Line controls. Associated with configuring the AM-48 for the type of line to be measured. Yellow Send controls. Associated with selecting the desired signal generator (send) function and controlling the signal generator.

  • Page 27: Connectors And Cables

    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.

  • Page 28: Figure 3-2. Am-48 Connectors

    EARPHONE JACK 4-WIRE SEND, RJ11 MODULAR 2-WIRE JACK <EAR> BANTAM JACK Figure 3-2. AM-48 Connectors YELLOW GREEN CABLE 48-0049, 7 Ft RJ-11 BLACK AC ADAPTER 70-0029, 6 Ft 2.5 mm JACK EARPHONE 82-0005, 3 Ft Figure 3-3. Standard AM-48 Cables 0015-S03...

  • Page 29: Switches

    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, <>.

  • Page 30: Figure 3-5. Am-48 Switch Identification Numbers

    TERM BRDG TONE • PULSE ON HK 900Ω • DTMF ∇ 600Ω SHIFT ETR/NEXT SF SKP • X TONE ETR/PREV RCL/STO • PRINT ∇ 4W REV CANCEL START STOP ∇ 4W/2W PRT EAR Figure 3-5. AM-48 Switch Identification Numbers 0015-S03...
  • Page 31 • 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.
  • Page 32 Unit Description (18-0015) AM-48 Test Set Display Select . Three-position toggle switch. This determines what is being viewed on the display. Set <ABS> to view MEASUREMENT mode in absolute • reference. Set <REL> to view MEASUREMENT mode in relative •...
  • Page 33 AM-48 Test Set (18-0015) Unit Description 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.
  • Page 34 Unit Description (18-0015) AM-48 Test Set 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.
  • Page 35 AM-48 Test Set (18-0015) Unit Description 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>...
  • Page 36 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.
  • Page 37 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.

  • Page 38: Keyboard

    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.

  • Page 39: Figure 3-6. Am-48 Keyboard Identification Numbers

    CANCEL START STOP ∇ Figure 3-6. AM-48 Keyboard Identification Numbers 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.
  • Page 40 Unit Description (18-0015) AM-48 Test Set [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.

  • Page 41: Display

    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: 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.

  • Page 42: Figure 3-7. Am-48 Liquid Crystal Display

    PSHO SLOPE SWTD 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.

  • Page 43: Microphone/Speaker

    AM-48 Test Set (18-0015) Unit Description 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 SEND MODES MEASURE MODES FILTER OPTIONS Level/Frequency...

  • Page 44: Hand-Held Printer

    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.

  • Page 45: Table 3-3. Am-47 Hand-Held Printer Technical Specifications

    AM-48 Test Set (18-0015) Unit Description The POWER LED blinks when power is ON and the battery pack has been charged. 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.

  • Page 46: Figure 3-8. Hand-Held Printer, External View

    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/ POWER LED DATA RECEIVE LED Ameritec HAND-HELD PRINTER • Model AM-47 PAPER FEED BUTTON PAPER POWER SIGNAL ADVANCE...

  • Page 47: Figure 3-9. Hand-Held Printer, Internal View

    AM-48 Test Set (18-0015) Unit Description PAPER ROLL RIBBON MANUAL PUSH DOWN RIBBON HERE TO RIBBON CARTRIDGE TAKE-UP EJECT RIBBON CARTRIDGE PAPER CUTTER PAPER ROLL COMPARTMENT PUSH (PAPER ADVANCE) FEED PAPER BUTTON TO ROUTE INTO SLOT PAPER THROUGH INSTALL PAPER...

  • Page 48: Impedance Adapter

    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.

  • Page 49: Power Considerations

    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.

  • Page 50: Figure 4-1. Battery Installation And Selector Switch

    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.

  • Page 51: Battery Installation

    Do not subject the AM-48 to excessively high temperatures. The warranty does not cover damage resulting from battery leakage. 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.

  • Page 52: Ac Power

    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.
  • Page 53 AM-48 Test Set (18-0015) Power Considerations 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>...

  • Page 54: Self-Test Instructions

    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.

  • Page 55: Figure 5-1. Am-48 Setup For Self-Test (Looped Back)

    Self-Test Instructions (18-0015) AM-48 Test Set Figure 5-1. AM-48 Setup for Self-Test (Looped Back) 0015-S05...

  • Page 56: Figure 5-2. General Switch Setup For Self Test

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

  • Page 57: Quiet Send Mode

    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.

  • Page 58: Send 1004 Hz

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

  • Page 59: Figure 5-4. Send 1004 Hz Self Test, Switch Settings

    Self-Test Instructions (18-0015) AM-48 Test Set Ameritec PERSONAL TRANSMISSION TEST SET MODEL AM-48 • HOLD QUIET 1004 NOISE NOISE 3K C-MSG TONE ∆ 3 TONE SWEEP IMPLS ØJTR ∇ TRANS 15K PROG SEND MEASURE FILTER • SEND Set L/F DAMP...

  • Page 60: Send Par (Peak-To-Average Ratio)

    AM-48 Test Set (18-0015) Self-Test Instructions DBRN • • HOLD HOLD QUIET 1004 NOISE NOISE 3K C-MSG QUIET 1004 NOISE NOISE 3K C-MSG TONE TONE ∆ ∆ 3 TONE SWEEP IMPLS ØJTR ∇ TRANS 15K PROG 3 TONE SWEEP IMPLS ØJTR ∇...

  • Page 61: Dialing

    Self-Test Instructions (18-0015) AM-48 Test Set Ameritec PERSONAL TRANSMISSION TEST SET MODEL AM-48 • HOLD QUIET 1004 NOISE NOISE 3K C-MSG TONE ∆ 3 TONE SWEEP IMPLS ØJTR ∇ TRANS 15K PROG SEND MEASURE FILTER • SEND DAMP MON RCV •...
  • Page 62 AM-48 Test Set (18-0015) Self-Test Instructions 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.

  • Page 63: Parameter Values For Send Sweep

    Self-Test Instructions (18-0015) AM-48 Test Set Ameritec PERSONAL TRANSMISSION TEST SET MODEL AM-48 • HOLD QUIET 1004 NOISE NOISE 3K C-MSG TONE ∆ 3 TONE SWEEP IMPLS ØJTR ∇ TRANS 15K PROG SEND MEASURE FILTER • (SEND) SEND DAMP MON RCV •...
  • Page 64 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. 5-11 0015-S05...
  • Page 65 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). Press [±], same as [D] key. Then press [5] and [0]. Display now reads “LEVL -5.0 DBM”.
  • Page 66 AM-48 Test Set (18-0015) Self-Test Instructions 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”.

  • Page 67: Figure 5-8. Default Parameter Settings For Sweep Send Mode

    Self-Test Instructions (18-0015) AM-48 Test Set Ameritec • PERSONAL TRANSMISSION TEST SET MODEL AM-48 • HOLD QUIET 1004 NOISE NOISE 3K C-MSG • TONE ∆ 3 TONE SWEEP IMPLS ØJTR ∇ TRANS 15K PROG SEND MEASURE FILTER (SEND) • SEND...

  • Page 68: Connection And Configuration

    Low-Level Noise Measurements . Power the AM-48 with batteries when making a low-level noise measurement. Do not power the 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>...

  • Page 69: Connectors And Cables

    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.

  • Page 70: Figure 6-1. 2-Wire Am-48 Line Connections

    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.

  • Page 71: Figure 6-2. 4-Wire Am-48 Line Connections

    BANTAM-TO-BANTAM MODULAR T = Tip R = Ring T1 = TIP 1 R1 = Ring1 Green (T1) RECEIVE, <RCV> Red (R1) SEND , <SND> Yellow (T) SEND , <SND> Black (R) RECEIVE, <RCV> Figure 6-2. 4-Wire AM-48 Line Connections 0015-S06...

  • Page 72: Figure 6-3. Am-47 Hand-Held Printer Connection With Ac Power

    AM-48 Test Set (18-0015) Connection & Configuration 115 VAC WALL JACK AM-47 HAND-HELD PRINTER AC ADAPTER (70-0029) AM-48 PRINTER CABLE (48-0079) <PRT> <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.
  • Page 73 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.

  • Page 74: 900Ω Line Termination Impedances

    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: Choose either terminate or bridge mode: Set Switch 13 to <TERM>, terminate mode, or...
  • Page 75 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...

  • Page 76: Impedance Adapter

    Connection & Configuration 6.5 Impedance Adapter The Impedance Adapter (24-0005) is used: To match the AM-48 to a user interface of impedance other than 600Ω or 900Ω . 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.

  • Page 77: Configurations

    <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. 6-10...

  • Page 78: 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.
  • Page 79 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.

  • Page 80: Figure 6-5. 4-Wire Testing With Responder

    Use the AM-48 keypad to send a DTMF sequence to command the responder into loopback. Use the AM-48 to send a 1004 Hz tone @ 0 dBm. Measure the loopback received level and frequency. Use the AM-48 keypad to send a DTMF command sequence to restore the responder to normal.

  • Page 81: Figure 6-6. 2-Wire Network Testing With Responders

    Connection & Configuration (18-0015) AM-48 Test Set AM3-2 AM3-2 AM-48 LOCAL 2W RESPONDER 2W RESPONDER <SND> AM-48 <SND> TELEPHONE NETWORK DISTANT Figure 6-6. 2-Wire Network Testing with Responders 6-14 0015-S06...

  • Page 82: 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...
  • Page 83 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.

  • Page 84: General Instructions And Notes

    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.

  • Page 85: Figure Format

    Operating Instructions (18-0015) AM-48 Test Set 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.
  • Page 86 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.

  • Page 87: General Switch Setup

    Operating Instructions (18-0015) AM-48 Test Set 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).
  • Page 88 AM-48 Test Set (18-0015) Operating Instructions 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>. 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>).

  • Page 89: Multiple Use Of Keys

    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...

  • Page 90: Memory

    (2) types of memory is given below: Volatile Memory . User-set values stored here will be stored as 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 default values.
  • Page 91 (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.

  • Page 92: Table 7-3. User-Programmable Parameter Values Stored In Memory

    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...

  • Page 93: General Procedure To Set New Parameter Values

    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.

  • Page 94: Send (Generator) Modes And Parameter Settings

    (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: Momentary...

  • Page 95: Send Quiet

    See Figure 7-1. Set switches per the SWITCH SETUP illustration and the SEND cursor per the menu illustration. A Quiet termination display will appear, “_ _ _ _ _ _ _ _”, confirming that the AM-48 is quiet terminated. 7-14 0015-S07...

  • Page 96: Set Parameters From Quiet Display

    TOUCH TONE 7.0 to -50.0* dBm LEVEL "TTLEV" Power stays on. TIME OFF with momentary power Unused AM-48 powers down 1 to 255* minutes switch on "TMOFF" after this time. For Impulse and Transient tests Standards: BLANKING INTERVAL...
  • Page 97 This value is stored in non-volatile memory (factory setting is 16 minutes). 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.

  • Page 98: Send Momentary Variable Tones

    AM-48 Test Set (18-0015) Operating Instructions Note that the AM-48 will not turn itself off if a time of “0” is set. A time of “0” is not a desirable setting when using batteries. Set Blanking Interval (see Figure 7-1 and ¶7.8).

  • Page 99: Send 1004 Hz

    Operating Instructions (18-0015) AM-48 Test Set 7.14 Send 1004 Hz See Figure 7-2. Set switches per the SWITCH SETUP illustration, and set the SEND cursor per the lower menu illustration. Go to the “LEVL” display and set the desired level value.

  • Page 100: Send Continuous Variable Tone

    AM-48 Test Set (18-0015) Operating Instructions 7.15 Send Continuous Variable Tone See Figure 7-2. Set switches per the SWITCH SETUP illustration, and set the SEND cursor per the lower menu illustration. Go to the “LEVL” display and set the desired level value.

  • Page 101: Send Variable Sweep

    Operating Instructions (18-0015) AM-48 Test Set SLOPE DISPLAYS NAME ACCEPTABLE VALUES NOTES Send Level and Frequency (404, 1004, 2804 Hz* for 5 sec., cyclical). SLOPE TONES • Set level for all tones sent (except dialed tones). LEVEL 10.0 to -50.0 dBm "LEVL"...

  • Page 102: Figure 7-4. Parameter Settings From Sweep Send Display

    TOUCH TONE 7.0 to -50.0* dBm LEVEL "TTLEV" Power stays on. TIME OFF with momentary power Unused AM-48 powers down 1 to 255* minutes switch on "TMOFF" after this time. For Impulse and Transient tests Standards: BLANKING INTERVAL...

  • Page 103: Send Par Waveform

    Operating Instructions (18-0015) AM-48 Test Set 7.18 Send PAR Waveform See Figure 7-3. Set switches per the SWITCH SETUP illustration, and set the SEND cursor per the lower menu illustration. Go to the “LEVL” display and set the desired level value.

  • Page 104: Absolute And Relative Measurements

    Use batteries when making low-level noise measurements. For 2-wire measurements (Switch 2 in <ABS> or <REL>), set the SEND Cursor to QUIET mode; if not, the AM-48 will be measuring its own generator output in addition to the signal received from the far end of the line.

  • Page 105: Special Measurement Requirements

    Operating Instructions (18-0015) AM-48 Test Set When the desired reference point is established, set Switch 2 to <REL>. When <REL> is first selected, the display will read “00.0 dB REL”, meaning that the level or noise reading is now referenced to the reading that was on the display when <REL>...

  • Page 106: Table 7-4. Acceptable Holding Tone Ranges

    (18-0015) Operating Instructions PAR waveform The AM-48 can send 1004 Hz and PAR waveform (¶7.14 and 7.18). To select a noise-weighting filter, rock Switch 4, Filter Select, to set the FILTER menu cursor to the desired filter. Table 7-5 defines which measurements require special conditions.

  • Page 107: Timed Tests

    7.24 Timed Tests A timed study is made with the Impulse Noise and Transient tests. See ¶7.29 and 7.34. In general, for AM-48 timed tests: The time over which the study is to be made and the constraints (thresholds and blanking interval) are programmed before the test.

  • Page 108: Measure Modes

    AM-48 Test Set (18-0015) Operating Instructions A test may be started or stopped from any display showing a measurement, indicated in Figures 7-6 and 7-9 by a cross- hatched character variable field. These displays are also labeled on the left side with “S/S”, meaning “start/stop”. A test may not be started from a display used to set a parameter, because the [∆]...

  • Page 109: Measure Noise

    Operating Instructions (18-0015) AM-48 Test Set Read the level and frequency on the display. L/F DISPLAY MEASURABLE RANGE NAME NOTES -65 to 10.9 dBm Level and Frequency of tone 0 to 19,999 Hz being received. 0.1 dBm resolution LEVEL/ FREQUENCY •...

  • Page 110: Measure Par

    AM-48 Test Set (18-0015) Operating Instructions Read the noise on the display. Note that the reading will always be a whole number. 7.28 Measure PAR See ¶8.7 for information on this measurement. A PAR waveform must be sent from the far end for this measurement to be valid.
  • Page 111 Operating Instructions (18-0015) AM-48 Test Set If a run is left to continue until the duration time that was set is reached, both the “DUR” and “TIME” displays will read the same at the end of the run. A blanking interval is set, during which time the noise pulse counter does not count.
  • Page 112 AM-48 Test Set (18-0015) Operating Instructions At any time, go to the “NOISE” display and read the real time noise (always a whole number). To stop the run before the duration time has elapsed, press [STOP]. The IMPLS cursor will stop flashing.

  • Page 113: Measure Notched Noise

    Operating Instructions (18-0015) AM-48 Test Set IMPULSE NOISE DISPLAYS NAME RANGE NOTES No time-out STUDY DURATION Set duration for timed studies. .1 to 1999.9 minutes "DUR" • Elapsed time of last timed study. .1 to 1999.9 minutes "TIME" • DBRN Set Low Threshold for impulse noise.

  • Page 114: Figure 7-7. Notched Noise And S/N Ratio Measure Displays

    AM-48 Test Set (18-0015) Operating Instructions Display indicates frequency of received holding tone, which must be from 995 Hz to 1025 Hz to be valid. Be sure HOLD TONE cursor is darkened, indicating a valid holding tone is being received.

  • Page 115: Measure S/N Ratio

    Operating Instructions (18-0015) AM-48 Test Set 7.31 Measure S/N Ratio See ¶8.6 for explanation of S/N Ratio measurement. See Figure 7-7. Set switches per the SWITCH SETUP illustration, and set the MEASURE cursor per the bottom menu illustration (SIGNAL-TO-NOISE RATIO DISPLAY).

  • Page 116: Measure Amplitude Jitter

    AM-48 Test Set (18-0015) Operating Instructions Go to “JITR” display and read the peak-to-peak phase jitter. PHASE JITTER DISPLAYS RANGE NAME NOTES 0.0 to 25.0 degrees Peak-to-peak phase jitter displayed. PHASE JITTER "JITR°" • Phase-locked-loop frequency 0.0 to 1999.9 Hz PHASE LOCKED displayed.

  • Page 117: Measure Transients

    Operating Instructions (18-0015) AM-48 Test Set Go to “RANGE” display. Press [4] or [2] for desired bandwidth (4 Hz to 300 Hz or 20 Hz to 300 Hz). Go to “JITR” display and read the peak-to-peak amplitude jitter. 7.34 Measure Transients These are timed tests, any or all of which can be performed at the same time.
  • Page 118 AM-48 Test Set (18-0015) Operating Instructions Measure Phase Hits . See ¶8.13 for explanation of phase hit measurement. See Figure 7-9. Be sure HOLD TONE cursor is darkened. Go to “DUR” display and set the desired duration for the test.
  • Page 119 Operating Instructions (18-0015) AM-48 Test Set To stop the run before the duration time has elapsed, press [STOP]. The TRANS cursor will stop flashing. When the run is stopped before the duration (“DUR”) time is up, read the “TIME” display for the actual time of the run.
  • Page 120 AM-48 Test Set (18-0015) Operating Instructions TRANSIENT DISPLAYS (first 7 of 14) NAME RANGE NOTES No time-out STUDY DURATION Set duration for timed studies. .1 to 1999.9 minutes "DUR" • Elapsed time of last timed study. .1 to 1999.9 minutes "TIME"...

  • Page 121: Miscellaneous Operations

    REL measurable level. Figure 7-9. TRANS MEASURE Displays, Page 2 of 2 MISCELLANEOUS OPERATIONS 7.35 ¶7.36 thru 7.42 cover miscellaneous AM-48 operations. 7.36 Store and Recall The Store and Recall feature is very useful to quickly set up a test that was previously set up.
  • Page 122 Press a number key [0] thru [9] to recall a setup previously stored on that key, or press [CANCEL] to abort. Store . To store: Adjust the AM-48 to the test setup and parameter settings to be stored. Press and hold Switch 9 to <RCL/STO> for about five (5) seconds.

  • Page 123: Figure 7-10. Recall And Store Operations

    Operating Instructions (18-0015) AM-48 Test Set Ameritec PERSONAL TRANSMISSION TEST SET • MODEL AM-48 • • HOLD QUIET 1004 NOISE NOISE 3K C-MSG TONE ∆ 3 TONE SWEEP IMPLS ØJTR ∇ TRANS 15K PROG SEND MEASURE FILTER QUESTION MARKS •...

  • Page 124: Dialing

    Set Switches 7 and 12 for dialing mode per Table 7-6. The line connected to the AM-48 should provide dial tone. Adjust speaker volume to a comfortable level. Table 7-7 lists the MF and DTMF dual tones on each of the keys.

  • Page 125: Table 7-6. Setup Requirements For Dialing

    Operating Instructions (18-0015) AM-48 Test Set Table 7-6. Setup Requirements for Dialing SWITCH 12 POSITION DIAL MODE SWITCH 7 2-WIRE OFF-HOOK 2-WIRE ON-HOOK or POSITION (loop current) 4-WIRE Dial DTMF <DTMF> <TONE> <ON HK> Dial MF <MF> <TONE> <ON HK>...

  • Page 126: Talking

    (18-0015) Operating Instructions 7.38 Talking The AM-48 can be used as a telephone “butt-set” (also see ¶3.5.14). To talk , hold down Switch 14 in <TALK> position and speak into the microphone (labeled MIC). See Figure 3-1 for microphone location.
  • Page 127 Operating Instructions (18-0015) AM-48 Test Set As illustrated in Figure 3-9: Install Paper Roll. Feed paper into slot. Push [PAPER ADVANCE] button to route paper through. Re-install compartment cover. Self Test . For a printout of all possible characters: Simultaneously hold down the [PAPER ADVANCE] button and set the Power Switch ON.
  • Page 128 AM-48 Test Set (18-0015) Operating Instructions Note: The AC Adapter is only for charging the batteries. If batteries are dead, the AC Adapter will not power the unit. Carefully observe that the AM-47 is normally charged with the Power ON, even though many other devices are typically charged with the power OFF.
  • Page 129 Operating Instructions (18-0015) AM-48 Test Set Note: Each time power is turned ON with the AC Adapter connected, the AM-47 will go through a complete charging cycle, regardless of the charge of the battery pack. Charging Procedure When Battery Pack Completely Discharged Connect the AC Adapter (70-0029) as shown in Figure 6-3.
  • Page 130 Re-install the Compartment Cover. B. AM-48 PRINTOUTS Connect the AM-47 Hand-Held Printer or other printer to the AM-48 per ¶6.3 and Figure 6-3. There are two (2) methods to obtain an AM-48 printout: Momentarily press Switch 9 to <PRINT> to get a printout on demand .
  • Page 131 Noise levels and thresholds are in “dBrn”, which applies to the AM-48 only; units would be “dBm” for the AM-48E. “OVER” or “UNDER” readings could appear for any level measurement – only some samples are shown. These out-of- range indications are based on the Absolute reading, even for Relative printouts.
  • Page 132 AM-48 Test Set (18-0015) Operating Instructions 10. In Figure 7-13, Relative noise printouts are possible for IMPLS and TRANS cursor settings. These are the same as the Relative noise measurements shown in Figure 7-13 printouts which start with “HZ” and “NN”.

  • Page 133: Figure 7-11. Send Printouts

    Operating Instructions (18-0015) AM-48 Test Set SEND SAMPLE PRINTOUT NOTES (variable parameters CURSOR defined in parentheses) SND PAR –20.5dBm Send Peak-to-Average Waveform (Level) Figure 7-11. SEND Printouts Ameritec PERSONAL TRANSMISSION TEST SET MODEL AM-48 • HOLD QUIET 1004 NOISE NOISE...
  • Page 134 AM-48 Test Set (18-0015) Operating Instructions MEASURE SAMPLE PRINTOUT NOTES (variable parameters CURSOR defined in parentheses) NOISE NN +12.0dBrn CMSG* Measure Notched Noise 1020HT=ON** (Level) *Filter selected **Valid Measurement NOISE NN +12.0dBrn CMSG* Measure Notched Noise (Level) 980HT=OFF** *Filter selected **Invalid Measurement SN +50.0dB...

  • Page 135: Figure 7-12. Measure Printouts, Absolute Measure Mode

    Operating Instructions (18-0015) AM-48 Test Set MEASURE SAMPLE PRINTOUT NOTES (variable parameters CURSOR defined in parentheses) TRANS TRAN 60.0DUR 45.0TIM Transient Test Run THLD 100dBrn DELTA 4dB Duration/Elapsed Time, minutes BLANKING 125ms CMSG* (Low Threshold/Threshold Diff.) 7645LO 5113MID 1538HI (Blanking Interval)

  • Page 136: Figure 7-13. Measure Printouts, Relative Measure Mode

    AM-48 Test Set (18-0015) Operating Instructions MEASURE SAMPLE PRINTOUT NOTES (variable parameters CURSOR defined in parentheses) NOISE NZ + 4.0rel+67.0 CMSG* Measure Relative Idle Channel Noise (Relative Level,dB/Reference Level,dBrn) *Filter selected NOISE NN – 3.0rel+54.0 CMSG* Measure Relative Notched Noise...

  • Page 137: Auto Study Result Save

    (18-0015) AM-48 Test Set 7.40 Auto Study Result Save At the end of timed study (impulse or transient test), the AM-48 automatically stores the results and associated setup parameters in non-volatile memory. Whenever the AM-48 is turned on, the results of the last impulse or transient study are automatically recalled.

  • Page 138: Table 7-8. Impedance Adapter Correction Values

    Impedance Adapter is thus less than the signal into it. Refer to Figure 7-14. For an AM-48 SEND mode, the signal actually sent on the line (beyond the Impedance Adapter) is less than the signal sent from the AM-48 (as indicated on the display).

  • Page 139: Figure 7-14. Impedance Adapter Correction Value Memory Aid

    EXAMPLES . Refer to Table 7-8 for correction values (given in parentheses in the examples below). Impedance Adapter set to 135 Ohms. For AM-48 only : Switch 2 in <ABS> and MEASURE cursor at (idle channel) NOISE. The display reads 60.0 dBrn.

  • Page 140: Auto Calibrate

    Figure 7-15. Answer each prompt with “yes” or “no”. Press [ETR/NEXT] for “yes”. Press [CANCEL] for “no”, which aborts the auto calibrate sequence. After the last prompt, the AM-48 will proceed with an auto calibrate of the measurement circuits. 7-59 0015-S07...

  • Page 141: Figure 7-15. Am-48 Auto Calibrate Prompts

    PULSE ON HK Set QUIET 900Ω <SHIFT> • DTMF ∇ 600Ω SHIFT ETR/NEXT SF SKP • X TONE ETR/PREV RCL/STO • PRINT ∇ 4W REV CANCEL START STOP ∇ 4W/2W PRT EAR Figure 7-15. AM-48 Auto Calibrate Prompts 7-60 0015-S07...

  • Page 142: Explanation And Application Of Measurements

    AM-48 Test Set (18-0015) Measurements 8. EXPLANATION AND APPLICATION OF MEASUREMENTS 8.1 Introduction This section gives the theory behind the measurements whose operating instructions are described in Section 7. The meaning of the measurements and how they are used is discussed. This section is...

  • Page 143: Figure 8-1. Level And Noise Units Of Measurement

    Measurements (18-0015) AM-48 Test Set intensity of 1 milliwatt of power relative zero reference can be established at any point dBrn +100 arbitrary zero reference for noise measurements Figure 8-1. Level and Noise Units of Measurement dB . The decibel (dB) is a logarithmic (base 10) electrical unit used to compare or indicate changes in level of intensity.
  • Page 144 “noise”. In real life, however, noise is measured on an idle line, or after notching out a holding tone. Voltage to dB Conversion . The AM-48 makes level and frequency measurements by measuring the voltage appearing on the line.

  • Page 145: Level (Loss Or Gain) And Frequency

    Measurements (18-0015) AM-48 Test Set 8.3 Level (Loss or Gain) and Frequency Level or frequency measurements are made by applying a tone of a known frequency and amplitude (normally 1004Hz @ 0.0 dBm) to the distant end of the transmission line being tested, and then measuring the received level and frequency at the near end.

  • Page 146: Signal-To-Noise (S/N) Ratio

    AM-48 Test Set (18-0015) Measurements Near End . At the near end of the line, the AM-48 test set removes the holding tone by routing the received signal through a notch filter, and then passes the remaining noise through the selected noise- weighting filter before measuring its level.

  • Page 147: Table 8-1. P/Ar Requirements Of Telephone Lines

    Definition of P/AR . P/AR (Peak to Average Ratio) measurements are made by applying a special 16 tone (PAR) signal at the distant end of the line under test. At the near end, the AM-48 simultaneously measures the peak value and average value of the received test signal.
  • Page 148 AM-48 Test Set (18-0015) Measurements The constant K is derived by giving an undistorted signal a nominal value of 100. Therefore: K = 2Safwo/Po Where: Po = Peak voltage of the undistorted (original) signal Afwo = full-wave average of the undistorted (original)

  • Page 149: Gain Slope

    Because it is desirable to express the difference in loss at different frequencies, this measurement is usually done on a relative level basis. The two (2) methods that can be used with the AM-48 to measure gain slope are outlined below: Gain Slope Using <ABS>...

  • Page 150: Idle Channel Impulse Noise

    (18-0015) Measurements Gain Slope Using <REL> Measure . Start with Switch 2 of near end AM-48 to <ABS>. Read the level at the near end of the line while the far end AM-48 is in SEND 3TONE (SLOPE for AM-48E).

  • Page 151: Figure 8-2. Impulse Noise Thresholds And Blanking Intervals

    Measurements (18-0015) AM-48 Test Set Blanking Interval . The blanking interval for a threshold is started when a pulse exceeds the threshold for the first time. The noise pulse counter does not count during the blanking interval. The purpose of the blanking interval is to minimize the affect of ringing on the count.

  • Page 152: Phase Jitter

    AM-48 Test Set (18-0015) Measurements See the tables in Figure 7-6 for information on the ranges of the parameters. A typical duration time for the study is 15 minutes, although a study of up to 33 hours could be made. Note that only values for the low level and the delta are set, which determines all three (3) levels.

  • Page 153: Notched Impulse Noise

    Measurements (18-0015) AM-48 Test Set 8.12 Notched Impulse Noise This test is the same as the Idle Channel Impulse Noise Test, ¶8.9, except that it is made over an active line with a holding tone which is notched out before the measurements are performed.

  • Page 154: Circuit Diagrams

    Circuit Diagrams 9. CIRCUIT DIAGRAMS 9.1 Introduction This section covers a block diagram of the AM-48 and a schematic diagram of the Impedance Adapter. 9.2 AM-48 Simplified Block Diagram Figure 9-1 is a simplified block diagram of the AM-48. Note that continuous lines connecting the blocks indicate signal paths, while broken lines indicate control paths.

  • Page 155: Figure 9-1. Simplified Block Diagram Of The Am-48

    AUTO INPUT/OUTPUT RANGE GENERATOR MICROPROCESSOR CMSG 3 LEVEL IMPLS DET NTCH FREQUENCY PROG COUNTER NOISE-WEIGHTING FILTERS GAIN HIT DET DROPOUT DETECTOR PHASE HIT DET 20HZ 300HZ PHASE LOCKED LOOP 4/20 HZ Figure 9-1. Simplified Block Diagram of the AM-48 0015-S09...

  • Page 156: Impedance Adapter Schematic

    Impedance Adapter switch positions (THRU, 1200, 900, 150, 135, and 75) are indicated on the upper poles of S1 and S2. The internal impedance of the AM-48 is set for 600 Ohms. Therefore, for impedance greater than 600 Ohms , the Impedance Adapter adds resistance in series to give the correct impedance.

  • Page 157: Figure 9-2. Schematic Diagram Of The Impedance Adapter

    MODULAR JACK MODULAR PLUG (connect to line) (connect to AM-48) THRU 1200 S2, Lower Knob YELLOW BLACK 301Ω 301Ω 4W RECEIVE BLACK YELLOW Set Switch 11 of the AM-48 to <600Ω> Figure 9-2. Schematic Diagram of the Impedance Adapter 0015-S09...

  • Page 158: Warranty, Service, And Calibration

    For a period of one (1) year from shipment, AMERITEC will repair, without charge to the original purchaser, any unit which upon inspection by AMERITEC proves to be defective.

  • Page 159: Return Of Unit

    AMERITEC. 10.4 Return of Unit In the event of a malfunction, call or write to the AMERITEC factory and obtain a return authorization number. Return the unit to AMERITEC, freight prepaid, with a note (in- warranty repair) or a Purchase Order for the repair (out-of-warranty repair) listing the following information: •...

  • Page 160: Glossary

    Nomenclature . This manual uses consistent nomenclature to refer to the cursor settings, switches, jacks, keys, and displays. The writing of the reference is exactly the same as it appears on the AM-48. The different components are distinguished by underlining, or enclosing in angular brackets, square brackets, or quotation marks.
  • Page 161 Glossary (18-0015) AM-48 Test Set ACRONYM COMPLETE TERM or DEFINITION Central (telephone) Office Central Processing Unit Depth <DAMP> This switch setting slows down the display update to 2 times per second (instead of 4 times per second for <OFF> setting).
  • Page 162 AM-48 Test Set (18-0015) Glossary ACRONYM COMPLETE TERM or DEFINITION High Impulse noise count “ILO” Low Impulse noise count “IMID” MIDdle Impulse noise count IMPLS IMPuLSe Noise (timed test) “ITHLD” Impulse THreshoLD Jack Female connector “JITR” Jitter I JTR Amplitude Jitter Ø...
  • Page 163 Glossary (18-0015) AM-48 Test Set ACRONYM COMPLETE TERM or DEFINITION <OFF> This is the normal switch setting to give a display update of 4 times per second. <ON HK> Switch position for ON HooK. “OVER” Level is OVER maximum measurable level.
  • Page 164 Switch position to enable auxiliary keyboard functions. SLOPE For AM-48E only, pre-programmed set of tones (304 Hz, 1004 Hz, 2004 Hz, 3004 Hz) which are sent in a cycle for 5 second intervals. See 3TONE for AM-48. Signal-to-Noise ratio <SND> SeND jack Starting and Stopping of a timed test.
  • Page 165 Glossary (18-0015) AM-48 Test Set ACRONYM COMPLETE TERM or DEFINITION TRANS TRANSient test, i.e., a timed test measuring impulse noise, gain hits, phase hits, dropouts. “TTLEV” Touch Tone LEVel “UNDR” Level is UNDeR minimum measurable level. Volts DC Variable (level and frequency) tone <VOL>...
  • Page 166 (18-0015) Index INDEX ± .................3-16 1004 Hz ..............1-6 16-Key Array ............3-15 2-Wire AM-48 Line Connections ........6-3 2-Wire Measurements ..........7-23 2-Wire Network Testing with Responders......6-14 2W..............3-10, 6-6 3-Tone ..............1-7 4-Wire AM-48 Line Connections ........6-4 4-Wire End-to-End Testing .........6-11 4-Wire Testing with Responder........6-13...
  • Page 167 AM-47 Hand-Held Printer Technical Specifications..3-21 AM-48 Auto Calibrate Prompts ........7-60 AM-48 Connectors............. 3-4 AM-48 General Technical Specifications......1-5 AM-48 Generator (Send) Technical Specifications ... 1-6 AM-48 Interface with Line Connections ......6-6 AM-48 Keyboard Identification Numbers ......3-15 AM-48 Liquid Crystal Display ........3-18 AM-48 Location of Components........
  • Page 168 AM-48 Test Set (18-0015) Index Battery Compartment..........7-17 Battery Information ............ 4-3 Battery Installation ............. 4-3 Battery Installation and Selector Switch......4-2 Battery-Selector Switch..........4-1 Blanking Interval ............8-10 BRDG ............. 3-12, 6-8 Butt Set..............1-3 Cable Connection............5-1 Calibration Policy .............10-1 CANCEL ..............3-16...
  • Page 169 Index (18-0015) AM-48 Test Set DAMP ..............3-8 Damping ..............1-10 dB................8-2 dBm ................ 8-2 dBrn ................ 8-3 Default Parameter Settings for SWEEP Send Mode ..5-14 Definition and Purpose..........1-2 Dial ................. 1-5 Dialing............5-8, 5-10, 7-43 Dimensions............... 3-1 Display ............3-17, 7-3 Display Damping Switch ..........
  • Page 170 AM-48 Test Set (18-0015) Index ETR/PREV ..............3-16 Explanation and Application of Measurements ....8-1 Far End ..............8-4 Figure Format............7-4 Filter Select Switch ............ 3-9 Front Panel/Switches Color Coding ....... 3-2 Functional Overview ..........1-3 Gain Hits..............8-12 Gain Slope..............8-8 General ..........
  • Page 171 Index (18-0015) AM-48 Test Set Holding Tone Ranges ..........7-25 Idle Channel Impulse Noise ......... 8-9 Idle Channel Noise ............. 8-4 Impedance Adapter ..........3-24, 6-9 Impedance Adapter Correction Value Memory Aid ..7-58 Impedance Adapter Correction Values ......7-57 Impedance Adapter Measurement Corrections ....7-56 Impedance Adapter Schematic........
  • Page 172 AM-48 Test Set (18-0015) Index Level/Freq..............1-8 Line Connection Cables ..........6-3 Listen ..............7-45 Loopback Testing............6-11 Low-Level Noise Measurements ......4-1, 6-1 Main Display Field............3-17 Manual Overview............1-1 Measure Amplitude Jitter..........7-35 Measure Dropouts .............7-38 Measure Gain Hits ............7-37 Measure Impulse Noise ..........7-29 Measure Level and Frequency ........7-27...
  • Page 173 Index (18-0015) AM-48 Test Set Menu Color Coding and Framing .........3-18 Menu Framing............7-25 Menus..............3-18 MF................3-9 MF and DTMF Tone Pairs ..........7-44 Microphone/Speaker..........3-19 Miscellaneous Operations ...........7-40 Momentary Tone ............7-14 MON RCV ..............3-13 MON SND ..............3-13 Multi-Function Keyboard ..........7-8 Multiple Use of Keys..........7-8 Near End ..............
  • Page 174 AM-48 Test Set (18-0015) Index ON HK ..............3-12 Operating Instructions..........7-1 Optional AM-48 Cables ..........3-5 P/AR Measurements ........... 8-6 P/AR Requirements of Telephone Lines ......8-6 Paper Roll Compartment ..........3-23 Paper Roll Installation........3-23, 7-45 PAR ..............1-7, 1-8 Parameter Settings from 1004 Hz and VAR Tone Displays..........7-18...
  • Page 175 Index (18-0015) AM-48 Test Set Printer..............1-6 Printer Cables............6-3 Printer Connectors.............3-20 Printer LEDs............3-20 Printer Power ............3-20 Printer Power Switch ..........3-20 Printer Self Test............7-46 Printing ..............7-45 Printing Mechanism...........3-21 PULSE ..............3-12 Quiet ............... 1-7 Quiet Send Mode ............5-4 Quiet Send Mode Self Test .......... 5-4 RCL/STO ..............3-10...
  • Page 176 AM-48 Test Set (18-0015) Index Scroll Through Displays..........7-12 Self-Test Instructions..........5-1 Self-Test Setup ............5-1 SEND ..............3-8 Send (Generator) Modes and Parameter Settings .....7-13 Send 1004 Hz............ 5-5, 7-18 Send 1004 Hz Self Test, Displays........5-7 Send 1004 Hz Self Test, Switch Settings......5-6 Send Continuous Variable Tone........7-19...
  • Page 177 Index (18-0015) AM-48 Test Set Signal-to-Noise (S/N) Ratio ......... 8-5 Simplified Block Diagram of the AM-48 ......9-2 Slide Switches ............3-7 Speaker Control............3-13 Special Measurement Requirements......7-24, 7-26 Standard AM-48 Cables ..........3-4 START ..............3-17 Steps for Up and Down Arrow Keys ......7-9 STOP..............3-17...

  • Page 178: Warranty, Service, And Calibration

    AM-48 Test Set (18-0015) Index Transient Measurements..........1-5 Transients............1-9, 1-10 Transmission Test Set ..........1-2 Types of Send Signals..........7-13 Units of Measurement..........8-1 Up Arrow ..............3-17 User-Programmable Parameter Values Stored in Memory .7-11 Variable ..............1-6 Verification of Contents ..........2-1 Volatile Memory..........
  • Page 179 Ameritec is dedicated to serving the worldwide telecommunications community by providing competitively priced, state-of-the-art test equipment that is supported by the finest in marketing, engineering development and customer service. 760 Arrow Grand Circle Covina, CA 91722 USA TEL 626.915.5441 FAX 626.915.7181...

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