Bird Brain 4391A User Manual

INSTRUCTION BOOK

OPERATING INSTRUCTIONS

MULTI-PURPOSE

THRULINE

® WATTMETER

RF POWER ANALYST

MODEL 4391A

©Copyright 2008 by Bird Electronic Corporation

Instruction Book Part Number 920-4391A Rev. H

Thruline® and Power Analyst® are Registered Trademark of

®

Bird Electronic Corporation

Safety Precautions

The following are general safety precautions that are not necessarily
related to any specific part or procedure, and do not necessarily appear
elsewhere in this publication. These precautions must be thoroughly
understood and apply to all phases of operation and maintenance.

Keep Away From Live Circuits

Operating personnel must at all times observe normal safety regulations.
Do not replace components or make adjustments inside the equipment
with high voltage turned on. To avoid casualties, always remove power.

Shock Hazard

Do not attempt to remove the RF transmission line while RF power is
present. Radiated RF power is a potential health hazard. Observe general
safety precautions for handling high voltage equipment. Always
disconnect power before attempting any repairs.

Do Not Service or Adjust Alone

Under no circumstances should any person reach into an enclosure for the
purpose of service or adjustment of equipment except in the presence of
someone who is capable of rendering aid.

Chemical Hazard

Dry cleaning solvents for cleaning parts may be potentially dangerous.
Avoid inhalation of fumes or prolonged contact with skin.

Safety Earth Ground

An uninterruptible earth safety ground must be supplied from the main
power source to test instruments. Grounding one conductor of a two
conductor power cable is not sufficient protection. Serious injury or death
can occur if this grounding is not properly supplied.

Resuscitation

Personnel working with or near high voltages should be familiar with
modern methods of resuscitation.

Safety Symbols

WARNING

Warning notes call attention to a procedure which, if not correctly

performed, could result in personal injury.

i

Bird Model 4391M Power Analyst

Caution notes call attention to a procedure which, if not correctly

performed, could result in damage to the instrument.

CAUTION

The caution symbol appears on the equipment
indicating there is important information in the
instruction manual regarding that particular area.

 NOTE: Calls attention to supplemental information

Fuse Replacement

Always use the same type and rating of fuse when replacing the fuse.
Fuse information can be found in the parts list on page 30.

Warning Statements

The following safety warnings appear in the text where there is danger to
operating and maintenance personnel, and are repeated here for emphasis.

Use only NIckel Metal Hydride (NiMH) batteries that have a minimum

capacity of 4600 milliamper hours (mAh). Do not install batteries that are

not Nickel Metal Hydride. Do not install NiMH batteries that have less

than 4600 mAh capacity. Failure to comply may result in damage to the

batteries, damage to the instrument, and injury to personnel from battery

WARNING

chemicals.

WARNING

Use dry cleaning solvents in a well ventilated area. Avoid excessive

inhalation of solvent fumes, since they can be toxic in heavy concentrations.

Always wear eye protection and avoid skin contact with the solvent.

Be sure that the power cable is unplugged before opening the wattmeter

case. The power supply capacitor, C1, can retain a dangerous charge that

must be removed before touching. Always have another person standing by

who is trained in electric shock first aid.

WARNING

ii

Caution Statements

The following equipment cautions appear in the text whenever the
equipment is in danger of damage, and are repeated here for emphasis.

Long-term storage of this instrument can affect battery performance and

reduce battery life. Do not store the instrument for long periods of time

without recharging the batteries (refer to page 19). Failure to comply may

result in reduced battery charge and shortened battery life.

CAUTION

CAUTION

If the element cannot be fully inserted into the socket, do not force

it. You might damage the element.

Internal batteries are connected. Remove one of the battery tubes before

unsoldering wires connected to the Main PCB. Failure to comply may result

in permanent equipment damage and severe shock to individuals.

Never apply RF power to the Model 4391A Wattmeter unless both line

section sockets are filled with either an element or a dust plug. If an

element is used it is advisable to place the element with the arrow at a 90°

Always be certain the 115/230 voltage selector is set to the proper voltage

before ac power is applied.

CAUTION

CAUTION

angle to the coaxial line.

CAUTION

CAUTION

Always disconnect AC power before opening the Model 4391 enclosure.

Removal of at least one battery cell is also recommended when servicing the

instrument.

CAUTION

This instrument contains static sensitive electronic components. Before

opening or servicing the unit, make sure that you understand and practice

electrostatic discharge component handling. Failure to comply may result

in permanent damage to sensitive components.

iii

Bird Model 4391M Power Analyst

Safety Statements

USAGE
ANY USE OF THIS INSTRUMENT IN A MANNER NOT

SPECIFIED BY THE MANUFACTURER MAY IMPAIR THE

INSTRUMENT’S SAFETY PROTECTION.
USO
EL USO DE ESTE INSTRUMENTO DE MANERA NO ESPECIFICADA POR

EL FABRICANTE, PUEDE ANULAR LA PROTECCIÓN DE SEGURIDAD
DEL INSTRUMENTO.

BENUTZUNG
WIRD DAS GERÄT AUF ANDERE WEISE VERWENDET ALS VOM

HERSTELLER BESCHRIEBEN, KANN DIE GERÄTESICHERHEIT
BEEINTRÄCHTIGT WERDEN.

UTILISATION
TOUTE UTILISATION DE CET INSTRUMENT QUI N’EST PAS

EXPLICITEMENT PRÉVUE PAR LE FABRICANT PEUT ENDOMMAGER
LE DISPOSITIF DE PROTECTION DE L’INSTRUMENT.

IMPIEGO
QUALORA QUESTO STRUMENTO VENISSE UTILIZZATO IN MODO

DIVERSO DA COME SPECIFICATO DAL PRODUTTORE LA PROZIONE
DI SICUREZZA POTREBBE VENIRNE COMPROMESSA.

SERVICE

SERVICING INSTRUCTIONS ARE FOR USE BY SERVICE -

TRAINED PERSONNEL ONLY. TO AVOID DANGEROUS

UNLESS QUALIFIED TO DO SO.
SERVICIO
LAS INSTRUCCIONES DE SERVICIO SON PARA USO EXCLUSIVO DEL

PERSONAL DE SERVICIO CAPACITADO. PARA EVITAR EL PELIGRO DE
DESCARGAS ELÉCTRICAS, NO REALICE NINGÚN SERVICIO A MENOS
QUE ESTÉ CAPACITADO PARA HACERIO.

WARTUNG
ANWEISUNGEN FÜR DIE WARTUNG DES GERÄTES GELTEN NUR FÜR

GESCHULTES FACHPERSONAL.
ZUR VERMEIDUNG GEFÄHRLICHE, ELEKTRISCHE SCHOCKS, SIND

WARTUNGSARBEITEN AUSSCHLIEßLICH VON QUALIFIZIERTEM
SERVICEPERSONAL DURCHZUFÜHREN.

ENTRENTIEN
L’EMPLOI DES INSTRUCTIONS D’ENTRETIEN DOIT ÊTRE RÉSERVÉ

AU PERSONNEL FORMÉ AUX OPÉRATIONS D’ENTRETIEN. POUR

ELECTRIC SHOCK, DO NOT PERFORM ANY SERVICING

iv

PRÉVENIR UN CHOC ÉLECTRIQUE DANGEREUX, NE PAS EFFECTUER
D’ENTRETIEN SI L’ON N’A PAS ÉTÉ QUALIFIÉ POUR CE FAIRE.

UNITS ARE EQUIPPED WITH RECHAREABLE BATTERIES.

THESE ARE TO BE REPLACED BY AUTHORIZED SERVICE

PERSONNEL ONLY!!!

RECARGABLES. ¡¡¡Y SOLAMENTE EL PERSONAL DE SERVICIO
AUTORIZADO PUEDE REEMPLAZARLAS!!!

GERÄTE SIND MIT WIEDER AUFLADBAREN BATTERIEN BESTÜCKT.
BATTERIEN SIND NUR VON QUALIFIZIERTEM SERICE PERSONAL
AUSZUWECHSELN!!!

CES DISPOSITIFS SONT ÉQUIPÉS DE BATTERIES RECHARGEABLES.
SEUL LE PERSONNEL D’ENTRETIEN AUTORISÉ EST HABILITÉ À LES
REMPLACER!

LE UNITÀ SONO DOTATE DI BATTERIE RICARICABILI, CHE DEVONO
DA COME SPECIFICATO DAL PRODUTTORE LA PROTEZIONE DI
SICUREZZA POTREBBE VENIRNE COMPROMESSA.

USE LA INSTALACION Y FUSIBLE DE VOLTAJE CORRECTO - VEA EL
MANUAL.

AUSSCHLIESSLICH VORSCHRIFTSMÄSSIGE WECHSELSPANNUNGS­EINSTELLUNG UND SICHERUNG BENUTZEN - SIEHE DAZU
HANDBUCH.

UTILLIZZARE TENSIONE E FUSIBLE ADATTI - FARE RIFERIMENTO AL
MANUALE.

EST BIEN RÉGLÉ POUR LA TENSION DU RÉSEAU ET QUE LE FUSIBLE
DE LIGNE C.A. CORRECT EST EN PLACE AVANT DE METTRE SOUS
TENSION C.A.

CERCIORESE QUE EL SELECTOR DE VOLTAJE DE 115/230V CA ESTE
COLOCADO A LA LINEA DE VOLTAJE APROPIADA Y QUE EL FUSIBLE
ESTE INSTALADO A LA LINEA CA ANTES DE APLICAR LA CORRIENTE
ALTERNA.

VOR EINSCHALTEN DER WECHSELSTROMZUFUHR SICHERSTELLEN,
DASS DER 115/230V WECHSELSPANNUNGS-SELEKTOR AUF DIE
VORSCHRIFTSMÄSSIGE LEITUNGSSPANNUNG EINGESTELLT UND
DIE RICHTIGE WECHSELSTROM-HAUPTSICHERUNG EINGESETZT
IST.

LAS UNIDADES VIENEN EQUIPADAS CON BATERIAS

USE CORRECT VOLTAGE SETTING AND FUSE - SEE

MANUAL.

UTILISER UNE TENSION ET UN FUSIBLE CORRECTS -

CONSULTER LE MODE D’EMPLOI.

BE SURE THE 115/230V AC VOLTAGE SELECTOR IS SET TO

THE PROPER LINE VOLTAGE, AND THE CORRECT AC LINE

FUSE IS INSTALLED BEFORE AC POWER IS APPLIED.

S’ASSURER QUE LE SÉLECTEUR DE TENSION 115/230V C.A.

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Bird Model 4391M Power Analyst

PRIMA DI EROGARE CORRENTE, ASSICURARSI CHE IL SELETTORE DI
VOLTAGGIO 115/230 V.C.A. SIA REGOLATO CORRETTAMENTE E CHE
IL FUSIBLE ADATTO ALLA LINEA DI ALIMENTAZIONE C.A. SIA
INSTALLATO.

RF VOLTAGE MAY BE PRESENT IN RF ELEMENT SOCKET -

KEEP ELEMENT IN SOCKET DURING OPERATION.

DE LA TENSION H.F. PEAT ÊTRE PRÉSENTE DANS LA PRISE

DE L’ÉLÉMENT H.F. - CONSERVER L’ÉLÉMENT DANS LA
PRISE LORS DE L’EMPLOI.

HF-SPANNUNG KANN IN DER HF-ELEMENT-BUCHSE ANSTEHEN ­ELEMENT WÄHREND DES BETRIEBS EINGESTÖPSELT LASSEN.

PUEDE HABER VOLTAJE RF EN EL ENCHUFE DEL ELEMENTO RF ­MANTENGA EL ELEMENTO EN EL ENCHUFE DURANTE LA
OPERACION.

IL PORTAELEMENTO RF PUÒ PRESENTARE VOLTAGGIO RF - TENERE
L’ELEMENTO NELLA PRESA DURANTE IL FUNZIONAMENTO.

vi

About This Manual

This instruction book is arranged so that essential information on safety
is contained in the front of the book. Reading the Safety Precautions
Section before operating the equipment is strongly advised.

The remainder of this manual is divided into Chapters and Sections.
Figures and tables are numbered sequentially within each chapter.

Chapter Layout

Introduction

Introduces the external features and and functions of the unit, equipment
provided, and optons available.

Theory of Operation

Describes the overall operation of the circuitry and the instrument
functions.

Installation

Provides information about connecting the instrument to your equipment.

Operation

First time operators should read Chapter 1 - Introduction, Chapter 2 ­Theory of Operation, and Chapter 3 - Installation, to get an overview of
equipment capabilities and how to install it. Experienced operators can
refer to Chapter 4 - Operating Instructions. All instructions necessary to
operate the equipment, are contained in this section.

Maintenance

All personnel should be familiar with calibration and repair information
found in Chapter 5 - Maintenance. If a failure should occur, the
troubleshooting section will aid in isolating and repairing the failure.

Parts

For location of major assemblies or parts refer to the part lists and
associated drawings.

Changes to this Manual

We have made every effort to ensure this manual is accurate at the time of
publication. If you should discover any errors or if you have suggestions for
improving this manual, please send your comments to our factory. This
manual may be periodically updated, when inquiring about updates to this
manual refer to the part number and revision level on the title page.

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Bird Model 4391M Power Analyst

viii

Table of Contents

Safety Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . i

About This Manual . . . . . . . . . . . . . . . . . . . . . . . . . . vii

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Purpose and Function . . . . . . . . . . . . . . . . . . . 1

Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Theory of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Description of Operation . . . . . . . . . . . . . . . . . . 3

Keyboard, Range Switches, and Display Group 3
Elements, Analog Circuitry, and A/D Converter 3

Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Operating on AC Power . . . . . . . . . . . . . . . . . . 7

Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Operating Instructions . . . . . . . . . . . . . . . . . . . . . . . 11

Operating Modes . . . . . . . . . . . . . . . . . . . . . . 11

Reading Forward CW Power . . . . . . . . . . . . . 11

Reading Reflected CW Power . . . . . . . . . . . . 12

Reading SWR. . . . . . . . . . . . . . . . . . . . . . . . . 12

Measuring Peak Envelope Power . . . . . . . . . 13

Measuring Amplitude Modulation . . . . . . . . . . 14

Measuring Power in dBm . . . . . . . . . . . . . . . . 15

Measuring Return Loss . . . . . . . . . . . . . . . . . 15

Insertion Loss or Attenuation . . . . . . . . . . . . . 16

Monitoring Maximum and Minimum Readings 16

Using the Peaking Aid . . . . . . . . . . . . . . . . . . 17

Battery Care . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Maintenance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Preventive Maintenance . . . . . . . . . . . . . . . . . . . . 19

Cleaning and Inspection . . . . . . . . . . . . . . . . . 19

Long-term Storage . . . . . . . . . . . . . . . . . . . . . 19

Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Required Equipment. . . . . . . . . . . . . . . . . . . . 20

Initial Setup. . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Element Wiper Contact Adjustment . . . . . . . . . . . 21

ix

Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . 23

General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Disassembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Front Panel Removal . . . . . . . . . . . . . . . . . . . 24

Main Printed Circuit (PC) Board Removal . . . 25

QC Connectors Removal . . . . . . . . . . . . . . . . 26

Line Section Removal. . . . . . . . . . . . . . . . . . . 27

Battery Replacement . . . . . . . . . . . . . . . . . . . 28

Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Customer Service . . . . . . . . . . . . . . . . . . . . . . . . . 33

Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

x

Purpose and

Function

Chapter 1 Introduction

The Model 4391A is a multi-purpose Radio Frequency

wattmeter designed around a microcomputer. A program

stored in permanent memory controls the operation of the

instrument at all times, permitting the detection and

correction of various error sources and the refinement of the

raw data produced by the directional detectors. The

instrument can compute VSWR, amplitude modulation, and

various decibel variables reducing the odds of error and

making such measurements consistent or repeatable

regardless of who makes the measurement.

Other benefits include extended range using standard

elements in some modes of operation, continuous monitoring

of maximum and minimum readings, a peaking aid, and

error messages.

Because of its complexity, the proper use of the 4391A is not

always obvious. For this reason it is strongly advised that

this manual be read in its entirety before using the device.

The 4391A RF Power Analyst is an insertion type digital RF

Directional Thruline® Wattmeter designed to measure peak

or average power flow, load match, and amplitude

modulation in 50 ohm coaxial transmission lines. It is

intended for use with CW, AM, FM, SSB, TV, and Pulse

modulation envelopes. The instrument directly reads PEP or

CW power in watts, milliwatts, or kilowatts in 9 ranges from

2.5 to 1000 full scale forward power and 0.25 to 100 full scale

reflected power depending on the Plug-in Element. In

addition it reads SWR directly over the range of 1.00 to

99.99, percent modulation directly over the range of 0.0 to

99.9, and return loss over the range of 0 to 36.1 dB. For

convenience, forward and reflected CW power can be

displayed in dBm (dB above 1 milliwatt) from 6 dB above to

24 dB below nominal element range.

Power range and frequency band are determined by the

Plug-in Elements used. Two switches on the front panel of

the instrument are set by the user to correspond to the

nominal power range of the forward element. The reflected

element is assumed to have a nominal range one tenth that

of the forward element.

In any mode of operation, the instrument can recall from

memory the lowest or highest reading taken or tell the

operator whether the newest reading is less than, equal to,

or greater than the previous reading.

1

Bird Model 4391A Power Analyst

Description The instrument is housed in an aluminum case

approximately 4-3/8 inches high by 9-5/8 inches deep by 6-1/

4 inches wide (111 mm x 244 mm x 159 mm) including

connections, see Figure 1. At each end of the line section are

Bird Quick-Change type RF connectors which may be easily

interchanged with any other Bird QC connector. See Bird

Catalog for types available.

Operating power is derived from rechargeable nickel metal

hydride batteries inside the unit or from a 115/230 VAC

power source connected to the unit through the power cord

supplied with the unit.

Figure 1

Outline

Drawing

2

Chapter 2 Theory of Operation

Description of

Operation

Figure 2

Circuit Block

Diagram

Keyboard,

Range

Switches, and

Display

Group

Elements,

Analog

Circuitry, and

A/D Converter

Figure 2 is a block diagram of the major functional parts of

the Model 4391A RF Wattmeter. The Microcomputer

integrated circuit shown, controls all the other portions of

the instrument, which fall into two major groups.

The keyboard and range switches serve only to pass

information to the computer. The display, of course, returns

information from the computer to the operator. The display,

which is comprised of four seven-segment LED digits, is

strobed digit by digit left to right at a rate of approximately

one digit per millisecond. This serves to conserve battery

power and drive circuitry while providing scanning for the

columns of the keyboard. Each time a digit is strobed, the

corresponding column of the keyboard is read and if a key is

pressed, the computer puts the code for that key into a

memory cell. The nine mode keys select which parameter is

to be measured. The three modifier keys simply modify the

way in which the result is displayed. The range selector

switches identify to the computer the nominal full scale

values of the elements used. They have no effect on input

sensitivity, which is determined by the elements.

These components are controlled by the computer. The Plug-

in Elements in the line section provide low level positive

voltages related to the instantaneous value of power (see

Figure 3). The first group of solid state switches selects the

forward element, the reflected element, or ground as the

input to the preamplifier which boosts these signals to 0.1 to

2.0 volt range. The remaining switches shown as two groups

direct the output of the preamp to the analog-to-digital

converter either directly or through a peak or negative peak

detector. The analog-to-digital converter converts the voltage

to a 15 digit binary number.

3