HP TM 11-6625-2779-14&P manual Front, Side and Rear Pane

Page 15

Model 3555B

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Section III

 

 

 

 

 

 

 

 

Table 3-1. Front, Side and Rear Pane

 

 

 

 

 

 

 

 

 

 

 

(1)

S and G Jacks:

Binding posts accepting banana

 

Controls, Indicators and Connectors either the

 

plugs, spade lugs, phone tips or bare wires for

 

NOISE BRDG or the NOISE TERM before the

 

connection to the case ground (G) and sleeves (S)

 

NOISE WTG filters can be selected.

 

 

 

 

of all INPUT jacks (12) and DIAL/AC MON jacks

 

(9) FUNCTION

Switch:

A

series

of

interlocking

 

(10) and (11).

 

 

 

 

 

 

 

pushbutton switches (with the exception of the

(2)

Shorting

Strap:

A swing-away shorting strap

 

HOLD switch which is push-push type) with the

 

connecting the S and G terminals together which

 

following functions:

 

 

 

 

 

 

 

 

 

 

may be used to isolate the jack sleeves from case

 

a.

VF/Nm

 

 

 

 

 

 

 

 

 

 

 

ground. Not for use with type 347 plugs.

 

 

 

1. HOLD:

Applies

a

dc

holding bridge

(3)

WTG Switch:

Selects

weighting

filters for

noise

 

 

 

across the metallic line for the NG, 900

 

measurements.

These filters are selectable only

 

 

 

and

600

functions.

 

The

HOLD

 

when the INPUT switch is in one of the two NOISE

 

 

 

pushbutton is the push-push type, ie,

 

positions.

The 3kHz FLAT, C-MSG, 15kHz FLAT

 

 

 

push to make and push to break. The

 

and PROG filters all conform to the standards set

 

 

 

HOLD

 

function

 

cannot

be

 

up by the Bell System and Edison Institute for

 

 

 

accomplished when any one of the

 

measuring message circuit noise.

 

 

 

 

 

CARRIER pushbuttons is depressed.

(4)

RANGE SWITCH: Selects dBm or dBm ranges of

 

 

2. DIAL/BAT:

Connects

the

multiple

 

input sensitivity.

The

RANGE

switch markings

 

 

 

INPUT jacks in parallel with the

 

correspond to the 0 markings on the meter scale

 

 

 

DIAL/AC MON jacks for the dial and

 

(6). The black markings are dBm for transmission

 

 

 

talk operation.

The circuit is arranged

 

measurements and the blue markings are dBrn for

 

 

 

for loop dialing and the line under test

 

noise measurements.

 

 

 

 

 

 

 

must supply talk battery. Connects the

(5)

RESPONSE

Switch:

Selects

NORM

meter

 

 

 

meter circuit and a load to the internal

 

response for transmission level measurements or

 

 

 

power supply to check the condition of

 

DAMP for noise measurements where noise is

 

 

 

the battery, ac power or external office

 

impulsive in nature.

 

 

 

 

 

 

 

battery as indicated on the green meter

(6)

Meter:

A taut band individually calibrated meter

 

 

 

scale. POWER (7) must be ON for the

 

with shaped pole pieces to provide a linear dBm

 

 

 

battery test.

 

 

 

 

 

 

 

 

indication with equal accuracy and resolution over

 

 

3. NG:

Selects the noise-to-ground input

 

the entire meter scale.

The dBm scale is marked

 

 

 

circuits

for

measuring

longitudinal

 

in black and has 0.1dB resolution for transmission

 

 

 

noise.

Attenuation of 40dB is inserted

 

measurements.

The 0 marking at the right end of

 

 

 

by this circuit. Earth ground should be

 

the scale corresponds to the black RANGE switch

 

 

 

connected to the black G binding post

 

setting. The dBm scale is marked in blue for noise

 

 

 

(1)

 

 

 

 

 

 

 

 

 

 

 

measurements.

The 0 marking at the left end of

 

 

4. 900:

 

Selects

the

input

circuitry

for

 

the scale corresponds to the blue RANGE switch

 

 

 

balanced

900 ohm

circuits.

This

 

setting.

 

The

green

arc

marked BAT GOOD

 

 

 

function selects a low frequency

 

corresponds to the green DIAL BAT pushbutton for

 

 

 

transformer for

voice

frequencies.

 

checking the power source.

The left edge of the

 

 

 

Response of this transformer is 20Hz

 

arc corresponds to the battery cut-off voltage of 24

 

 

 

to 20kHz.

 

 

 

 

 

 

 

 

 

volts and the right edge (meter full-scale)

 

 

5.

600:

 

Selects

the

input

circuitry

for

 

represents 60 volts which is the maximum voltage

 

 

 

balanced

600

ohm

circuits.

A

low

 

that can be used to power the set without internal

 

 

 

frequency

transformer

is selected

for

 

damage.

 

 

 

 

 

 

 

 

 

 

this function.

 

 

 

 

 

 

 

(7)

POWER ON/OFF Switch: turns on all power to the

 

b.

Carrier

 

 

 

 

 

 

 

 

 

 

 

set. The set operates from either 115 volts or 230

 

 

1.

600:

 

Selects

the

input

circuitry

for

 

volts ac, the internal 45 volt dry cell battery or from

 

 

 

balanced

600

ohm

circuits.

A high

 

an external office battery supply.

 

 

 

 

 

frequency transformer is selected for

(8)

INPUT

Switch:

Selects TMS, either BRDG or

 

 

 

this

function.

 

Response

of

this

 

TERM for transmission measurements and NOISE,

 

 

 

transformer is 1kHz to 600kHz.

The

 

either BRDG or TERM for noise measurements.

 

 

 

HOLD function is not operative in any

 

For noise

measurements the switch must

be in

 

 

 

of the carrier functions.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

3-3

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Page 14 Page 16
Image 15
Page 14 Page 16
Contents HEADQUARTERS, Department of the Army NSN Reporting Errors and Recommending ImprovementsTM 11-6625-2779-14&P Technical Manual Headquarters Department of the ArmyReplaceable Parts List of Illustrations List of TablesIii Maintenance Forms, Records, and Reports Section IntroductionScope Administrative Storage Destruction of Army Electronics MaterielReporting Equipment Improvement Recommendations EIR Items Comprising an Operable Equipment Voice Frequency Level Measurements 20Hz to 20kHz SpecificationsSection General Information Introduction SectionBAL Modification Accessory Equipment SuppliedAccessory Equipment Supplied Instrument IdentificationBattery Section Installation InspectionWarranty Exception Power Requirements Cover Removal Installation and Removal of BatteryOperating Instructions Controls Connectors IndicatorsBattery SectionFront Panel Controls, Indicators, and Connectors Front, Side and Rear Pane Side Panel Controls and Connectors Level Measurements Level and Noise MeasurementsPage Noise Measurement Applications Recorder CompatibilityRecorder Compatibility Chart Crosstalk Correction Factor Identifying Noise CharacteristicsTransmission Loss Measurements Crosstalk MeasurementsMeasurements in DBC 135 BAL Reinstall the set in its case0dBm Input jacks are connected in parallel. If a 600 ohmLevel Measurement Noise Metallic Measurements Step ProcedureTransmission Loss Measurement Noise-to-Ground Measurements Balance MeasurementRecorder Calibration ExampleSection Theory of Operation Introduction Block Diagram DescriptionSimplified Dial BAT Function Detailed Circuit DescriptionRange Attenuator A2 Input Amplifier A3. Schematic NoPads Used Setting AttenuationFILTERS. Schematic No Range AttenuatorKHz Flat and Program Weighting Curves C-MSG and 1SkHz Flat Weighting Curves DETECTOR. Schematic No Meter AMPLIFIER. Schematic NoPower Supply and Series Regulator Schematic No BAL Conversion Section Maintenance IntroouctionInstrument Recommended Type Required Characteristics Model Factory Selected ValuesTMS, Term Performance ChecksLevel Accuracy Checks Function CARRIER, 75 Unbal30Hz to 1MHz 100Hz to 600kHz 1MHz to 3MHz Unbal Carrier Accuracy CheckRange Frequency20Hz to 20kHz 40Hz to 15kHz 100Hz to 20kHz 100Hz to 15kHz Return Loss CheckReturn Loss Test Set-Up Filter Response Checks Filter Response ChecksMSG dBm 3kHz Flat dBm 15kHz Flat dBm Program dBm Input TMS Brdg Input BalanceBridging Loss TMS BrdgAttenuator Calibration Adjustment and Calibration ProcedurePower Supply Check Unbal CalibrationFrequency Response Adjustment Common Mode AdjustmentBalance Check Assembly Removal Troubleshooting ProceduresFilter Calibration Troubleshooting Tree Dial BAT Front Panel Trouble AnalysisFront Panel Trouble Analysis Contd Front Panel TroubleshootingFunction Troubleshooting Range TroubleshootingDefective Function Troubleshooting Input AmplifierFilter Troubleshooting Troubleshooting the Meter Amplifier and DetectorBrdg Term Function Switch Resistance ValuesFunction Input Jacks DIAL/AC MON Jacks Tip to Ring Tip to Ground Ring to Ground11. Factory Selected Values 10. Resistance ChecksRange dBm Pin 1 to Pin 2 to Carrier 135 BAL Level Accuracy Check Performance Check Test CardDescription Check Carrier 75 Unbal Level Accuracy CheckCarrier 600 BAL Level Accuracy Check Performance Check Test Card ContdBridging Loss Check Return Loss CheckFilter Response Checks MSG ProgramOrdering Information Section Replaceable Parts Introduction03555-66507 PC Board Assy function Replaceable Parts03555-66508 Board Assy amplifier Replaceable Parts ContdA3 Contd 03555-66506 PC Board Assy filter A4 Contd Chassis Mounted Components Miscellaneous Chassis Mounted Components ContdMiscellaneous Contd National Stock Number Replacement National Part Stock Number FscmPart Number National Stock Number Cross Reference Index FscmPage Model 3555B Appendix a Code List of Manufacturers Reference Designations Circuit DiagramsFunctional Block Diagram Schematic DiagramsSection Model 3555B 7-4 Functional Block Diagram7-6 A1 Function Assembly Schematic and Component Location7-8 7-10 A4 Filter Schematic and Component Location11/7-12 References Appendix aColumn Entries Maintenance Allocation Section I. Introduction GeneralMaintenance Function Appendix BRemarks Sec Tool and Test Equipment Requiremen ts SecAudio Level Meter TA-885/U REF Code Number TM 11-7725-2779-14&PAppendix C Manual Backdating ChangesTransmission and Noise Measuring SET Government Printing Office 1980-603-128/66 Delete CR6 across M1Active Army General, United States ArmyChief of Staff Major General, United States Army Adjutant GeneralPage PIN
Top Page Image Contents