Bird Technologies 4527 User Manual
RF Directional
Thruline® Wattmeter
Model 43
Also Covers Models 4431, 43P
And Series 4300 and 4520
OPERATING INSTRUCTIONS
©Copyright 2011
Instruction Book Part Number 920-43 Rev. K
Thruline® and Termaline® are registered trademarks
by Bird Electronic Corporation
of Bird Electronic Corporation
THIS PAGE INTENTIONALLY LEFT BLANK
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.
WARNING
Keep Away From Live Circuits
Operating Personnel must at all times observe general safety precautions. Do not
replace components or make adjustments to the inside of the test equipment with
the high voltage supply turned on. To avoid casualties, always remove power.
WARNING
Shock Hazard
Do not attempt to remove the RF transmission line while RF power is present.
WARNING
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.
WARNING
Safety Earth Ground
An uniterruptible 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.
WARNING
Resuscitation
Personnel working with or near high voltages should be familiar with modern
methods of resuscitation.
WARNING
Remove Power
Observe general safety precautions. Do not open the instrument with the
power on.
iii
Safety Symbols
WARNING
Warning notes call attention to a procedure, which if not correctly performed,
could result in personal injury.
CAUTION
Caution notes call attention to a procedure, which if not correctly performed,
could result in damage to the instrument.
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.
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.
WARNING
Leaking RF energy is a potential health hazard. Never attempt to connect or
disconnect equipment from the transmission line while RF power is being applied.
Severe burns, electrical shock, or death can occur.
On page 11.
WARNING
When working with RF powers of 200 watts or more, the potential of the
center conductor of the line section will be over 100 volts. Do not touch the
center conductor while RF power is on.
On page 13.
Caution Statements
The following equipment cautions appear in the text and are repeated here for
emphasis.
CAUTION
For low reflection measurements, do not rotate the reflected power element
to read forward power. Damage to the element or wattmeter could result.
On page 7.
iv
CAUTION
Handle elements with care. Calibration could be disturbed if they are
dropped.
On page 11.
CAUTION
Do not attempt to remove the RF center conductor. This will damage the line
section.
On page 20.
v
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
ELECTRIC SHOCK, DO NOT PERFORM ANY SERVICING
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.
vi
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 PRÉVENIR UN CHOC ÉLECTRIQUE
DANGEREUX, NE PAS EFFECTUER D’ENTRETIEN SI L’ON N’A
PAS ÉTÉ QUALIFIÉ POUR CE FAIRE.
ASSISTENZA TECNICA
LE ISTRUZIONI RELATIVE ALL’ASSISTENZA SONO PREVISTE
ESCLUSIVAMENTE PER IL PERSONALE OPPORTUNAMENTE
ADDESTRATO. PER EVITARE PERICOLOSE SCOSSE
ELETTRICHE NON EFFETTUARRE ALCUNA RIPARAZIONE A
MENO CHE QUALIFICATI A FARLA.
vii
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.
viii
About This Manual
This manual covers the operating and maintenance instructions for the following models:
43 43P 4301 4305A 4431 4527
4521 4522 4526
Changes to this Manual
We have made every effort to ensure this manual is accurate. If you discover any
errors, or if you have suggestions for improving this manual, please send your
comments to our Solon, Ohio factory. This manual may be periodically updated.
When inquiring about updates to this manual refer to the part number and revision on the title page.
Literature Contents
Chapter Layout
Introduction — Describes the features of the 43 Wattmeter, lists equipment
supplied and optional equipment, and provides power-up instructions.
Theory of Operation — Describes how the 43 Wattmeter works and
Installation — Describes how to set up and prepare the 43 Wattmeter for use.
Operation - All instructions necessary to operate the equipment appears in
this chapter.
Maintenance — Lists routine maintenance tasks as well as troubleshooting for
common problems.
Model Differences — Describes how each indivdual models vary from
each other.
Specifcations — Specifications and parts information are included in this
chapter.
ix
Table of Contents
Safety Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii
Safety Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iv
Warning Statements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iv
Caution Statements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iv
Safety Statements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vi
About This Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix
Changes to this Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix
Chapter Layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix
Chapter 1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Purpose and Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Performance Characteristics and Capabilities . . . . . . . . . . . . . . . . . . . . . . . . . 1
Chapter 2 Theory of Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Travelling Wave Viewpoint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Formulas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Forward . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Reflected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Coupling Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Load Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Standing Wave vs. Travelling Wave Viewpoint (ρ vs. φ) . . . . . . . . . . . . . . . . 5
Low Reflection Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Transmitter Monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Component Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Measuring Insertion Loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Frequency Response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Impedance Mismatch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Chapter 3 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Replacing Quick-Change Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Remote Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Chapter 4 Operating Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Normal Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Load Matching . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Chapter 5 Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Troublehshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Contact Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
xiii
Zero Adjust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Customer Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Bird 43 Replacement Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Bird 43 Replacement Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Available “QC” Type Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Chapter 6 Model Differences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Bird 43P Peak Wattmeter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Peak Detector Response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Rectangular Pulses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Peak Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Bird 4301 Thruline Wattmeter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Bird 4305A Thruline Wattmeter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Bird 4305A Replacement Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Bird 4431 Thruline Wattmeter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Bird 4431 Replacement Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Customer Replacement Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Service Only Replacement Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Bird 4520 Series Thruline Wattmeters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Bird 4520 Series Replacement Parts List . . . . . . . . . . . . . . . . . . . . . . . . . 34
4521 Replacement Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
4522 Replacement Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
4526/27 Replacement Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Service Only Replacement Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Chapter 7 Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Limited Warranty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
xiv
xv
Chapter 1 Introduction
Purpose and Function
The 43 is an insertion-type RF wattmeter, designed to measure RF power and
load match in 50 ohm coaxial transmission lines. It is intended for use with CW,
AM, FM, and TV modulation, but not pulse modulation. When used in 50 ohm
applications, the 43 has a maximum VSWR of 1.05 for frequencies up to 1000
MHz. The meter provides direct readings in watts with an expanded scale for
easy reading. The scale is graduated for 25, 50, and 100 full scale. Elements are
available in a variety of power and frequency ranges (see the Bird Electronic Corporation Catalog for details).
This manual covers the operation of the Bird 43 Thruline Wattmeter and its
descendants. Two models have RF sampler ports, while the Bird 43P can measure peak power. The Bird 4520 series comes ready for panel mounting. Differences are discussed in Chapter 6, on page 27. Except where indicated,
instructions and specifications for the 43 apply to other models also.
Performance Characteristics and Capabilities
The Bird 43 is portable, with an attached carrying strap. It has an aluminum
housing and an easily removed back cover, with bumpers on the base and back
that allow the meter to stand or lie flat. For additional protection, the
microammeter is specially shock mounted. A slotted screw on the lower front
face of the meter is used to zero the pointer. Below the meter face, the RF line
section protrudes slightly from the wattmeter housing with the element socket
in the center.
A shielded cable connects the RF line section to the rest of the wattmeter. This lets
you remove the line section from the wattmeter housing for custom installation and
still make measurements. The RF line section is precision machined to provide the
best possible impedance match to the transmission line under test. A formed phosphor-bronze spring finger protrudes into the element socket to make contact with
the element.
At each end of the line section are Bird Quick-Change RF connectors that may be
interchanged with any other Bird “QC” connector. The wattmeter housing does
not interfere with connector changes.
To make measurements, a Bird Plug-In Element is inserted into the line section
socket and rotated against one of the stops. A small catch in the corner of the
socket face presses on the shoulder of the element to keep it in proper alignment. This assures good contact between the spring finger and the element contact and between the lower edge of the element and the line section body (see
Figure 1).
1
Figure 1 Securing an element
Contacts on opposite sides of the element connect with the spring finger when
the element is in the forward or reverse position. This occurs when the stop pin
on the element is against either stop and the catch is in place.
Figure 2 Bird 43 Thruline Wattmeter Outline Drawing
2
Chapter 2 Theory of Operation
WfWattsForward E
f
2
Zo⁄ I
f
2
ZoEfL
f
====
WrWattsReflected E
r
2
Zo⁄ I
r
2
ZoErL
r
====
Travelling Wave Viewpoint
The easiest way to visualize Thruline operation is from a travelling wave viewpoint. In transmission lines the voltages, currents, standing waves, etc., on any
uniform line section result from the interaction of two travelling waves:
• Forward Wave (and its power) travels from the source to the load. It
has RF voltage E
• Reflected Wave (and its power) originates by reflection at the load and
travels from the load back to the source. It has an RF voltage E
rent I
in phase, with Er / Ir = Zo.
r
Formulas
Each wave is mathematically simple and has a constant power:
Forward
Reflected
and current If in phase, with Ef / If = Zo.
f
and cur-
r
Note: Z
useful lines it is usually a pure resistance of 50 ohms. The RF circuit of
the Bird 43 is a length of uniform air line with Z
Coupling Circuit
The coupling circuit that samples the travelling waves is in the Bird Plug-In Element. The element circuitry and its relationship to the rest of the Bird 43 are
illustrated in Figure 3.
is the characteristic impedance of a uniform line section. For
o
= 50 ohms.
o
3
Figure 3 Thruline Wattmeter Schematic
W1WattsIntoLoad WfWr–==
Current is produced in the coupling circuit by the travelling waves in the line
section. Both inductive and capacitive coupling contribute to this. The inductive current flows in the direction of the travelling wave. The capacitive current is independent of the direction of the travelling wave. Therefore, the
inductive current produced by one of the travelling waves will add in phase
with the corresponding capacitive current, while that produced by the wave
travelling in the opposite direction will subtract. The additive or “arrow” direction is assigned to the forward wave.
The electrical characteristics of the element are carefully adjusted so that, for the
reverse travelling wave, the inductive current will completely cancel the capacitive
current. The result is directivity greater than 25 dB. Thus, the element is sensitive
at either of its settings, but to only one of the two travelling waves. Thruline Wattmeter measurements are also independent of position along the transmission
line.
Like similar diode devices, the Bird 43 indicates the carrier component of amplitude modulation, with very little response to side band components added by
modulation.
Load Power
For loads with a VSWR of 1.2 or less, the power dissipated in a load (Wl) is
equivalent (with less than one percent error) to the forward power (W
appreciable power is reflected, as with an antenna, it is necessary to use the
exact load power which is given by:
Good load resistors, such as Bird Termaline loads, will give negligible reflected
power.
4
). When
f
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