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Agilent Technologies. Inc www agilent corn
24001 E Mission
Liberty take, WA 99019
. .
.':tis:. . AgiI ent Technologies
..
,
.* .
*e
:: Innovating the HP Way
June 8,2000
Dear Customer,
As of November 1,1999, four of Hewlett-Packard's businesses, test and measurement,
semiconductor products, health care solutions, and chemical analysis became a new company,
Agilent Technologies. Now, many of your Hewlett-Packard products and services are in the care of
Agilent Technologies.
At Agilent Technologies, we are working diligently to make this transition as smooth as possible for
you. However, as a result of this transition, the products and related documentation contained in this
shipment may be labeled with either the Hewlett-Packard name and logo, the Agilent Technologies
name and logo, or a combination of both. Information in this package may refer to Hewlett-Packard
(HP), but applies to your Agilent Technologies product. Hewlett-Packard and Agiient branded
products with the same model number are interchangeable.
Whatever logo you see, the information, products, and services come from the same reliable source.
If you have questions about Agilent Technologies products and services, please visit our website at
http://www.anilent.com.
Sincerely,
Rebranding Team
HP 8903B
AUDIO ANALYZER
(Including Option 001)
Operation and Calibration Manual
SERIAL NUMBERS
This manual applies directly to instruments with
serial numbers prefixed
2450A to 2922A and all Mqior changes that apply t o your instrument.
rev.ZOJUN91
For additional important information about serial
numbers, refer t o "INSTRUMENTS COVERED BY
THIS MANUAL'' Section 1.
in
Fourth Edition
T i material may be reproduced by or for the US.
hs
Government pursuant to the Copyright License un-
der the clause at DFARS 52.227-7013(AF'R 1988).
Copyright GHEWLETT-PACKARD COMPANY 1985
EAST 24001 MISSION AVENUE, TAF C-34, SPOKANE, WASHINGTON, U.S.A. 99220
Operation and Calibration Manual HP Part 08903-90079
Other Documents Available:
Service Manual (Volume 1, 2) HP Part 08903-90062
Microfiche Operation and Service Manual HP Part 08903-90080 Printed in U.S.A. : November 1989
H E WLETT@
PACKARD
1 Regulatory Information
(Updated March 1999)
1
Regulatory Information (Updated March 1999)
Safety Considerations
GENEFtAL
This product and related documentation must be reviewed for familiarization with safety
markings and instructions before operation.
This product has been designed and tested in accordance with IEC Publication 1010,
"Safety Requirements for Electronic Measuring Apparatus," and has been supplied in a
safe condition. This instruction documentation contains information and warnings which
must be followed by the user to ensure safe operation and to maintain the product in a safe
condition.
SAFETY EARTH GROUND
A uninterruptible safety earth ground must be provided from the main power source to the
product input wiring terminals, power cord, or supplied power cord set.
SAFETY SYMBOLS
A Indicates instrument damage can occur if indicated operating limits are exceeded.
A Indicates hazardous voltages.
-
& Indicates earth (ground) terminal
A WARNING note denotes a hazard. It calls attention to a procedure,
~~~~ ~ ~ ~
WARNING
practice, or the like, which, if not correctly performed or adhered to,
could result in personal injury. Do not proceed beyond a WARNING
sign until the indicated conditions are fully understood and met.
~
CAUTION A CAUTION note denotes a hazard. It calls attention to an operation
procedure, practice, or the like, which, if not correctly performed or adhered
to, could result in damage t o or destruction of part or all of the product. Do
not proceed beyond an CAUTION note until the indicated conditions are hlly
understood and met.
2 Chapter 1
Regulatory Information (Updated March 1999)
Safety Considerations for this Instrument
WARNING This product is a Safety Class I instrument (provided with a
protective earthing ground incorporated in the power cord). The
mains plug shall only be inserted in a socket outlet provided with a
protective earth contact. Any interruption of the protective
conductor inside or outside of the product is likely to make the
product dangerous. Intentional interruption is prohibited.
Whenever it is likely that the protection has been impaired, the
instrument must be made inoperative and be secured against any
unintended operation.
If this instrument is to be energized via an auto transformer (for
voltage reduction), make sure the common terminal is connected to
the earth terminal of the power source.
If this product is not used as specified, the protection provided by
the equipment could be impaired. This product must be used in a
normal condition (in which a l means for protection are intact) only.
l
No operator serviceable parts in this product. Refer servicing to
qualified personnel. To prevent electrical shock, do not remove
covers.
Servicing instructions are for use by qualified personnel only. To
avoid electrical shock,do not perform any servicing unless you are
qualified to do so.
The opening of covers or removal of parts is likely to expose
dangerous voltages. Disconnect the product from all voltage sources
while it is being opened.
The power cord is connected to internal capacitors that my remain
live for 5 seconds after disconnecting the plug from its power supply.
For Continued protection against fire hazard, replace the line fuse(s)
only with 250 V fuse(s)or the same current rating and type (for
example, normal blow or time delay). Do not use repaired fuses or
short circuited fuseholders.
Always use the three-prong ac power cord supplied with this
product. Failure to ensure adequate earth grounding by not using
this cord may cause product damage.
This product is designed for use in Installation Category I1 and
Pollution Degree 2 per IEC 1010 and IEC 664 respectively. FOR
INDOOR USE ONLY.
This product has autoranging line voltage input, be sure the supply
voltage is within the specified range.
3
~~~~
Chapter 1
Regulatory Information(Updated March 1999)
To prevent electrical shock, disconnect instrument from mains (line)
before cleaning. Use a dry cloth or one slightly dampened with water
to clean the external case parts. Do not attempt to clean internally.
Ventilation Requirements: When installing the product in a cabinet,
the convection into and out of the product must not be restricted.
The ambient temperature (outside the cabinet) must be less than the
maximum operating temperature of the product by 4" C for every 100
watts dissipated in the cabinet. If the total power dissipated in the
cabinet is greater than 800 watts, then forced convection must be
used.
Product Markings
CE - the CE mark is a registered trademark of the European Community. A CE mark
accompanied by a year indicated the year the design was proven.
CSA - the CSA mark is a registered trademark of the Canadian Standards Association.
4 Chapter 1
CERTIFICATION
Hewlett-Packard Company certifies that this product met its published specifications at the time of shipment
from the factom. Hewlett-Packard further certifies that its calibration measurements are traceable to the
United States National Bureau of Standards, to the extent allowed by the Bureau's calibration facility, and
to the calibration facilities of other International Standards Organization members.
WARRANTY
This Hewlett-Packard instrument product is warranted against defects in material and workmanship for a
period of one year from date of shipment. During the warranty period, Hewlett-Packard Company will at its
option, either repair or replace products which prove to be defective.
For warranty senrice or repair, this product must be returned to a service facility designated by HP. Buyer
shall prepay shipping charges to HP and H P shall pay shipping charges to return the product to the Buyer.
However, Buyer shall pay all shipping charges, duties, and taxes for products returned to HP from another
country.
HP warrants that its software and firmware designated by H P for use with an instrument will execute
its programming instructions when properly installed on that instrument. H P does not warrant that the
operation of the instrument, or s o h a r e , or firmware will be uninterrupted or error free.
LIMITATION OF WARRANTY
The foregoing warranty shall not apply to defects resulting from improper or inadequate maintenance by
Buyer, Buyer-supplied software or interfacing, unauthorized modification or misuse, operation outside of the
environmental specifications for the product, or improper site preparation or maintenance.
NO OTHER WARRANTY IS EXPRESSED OR IMPLIED. HP SPECIFICALLY DISCLAIMS THE
IMPLIED WARRANTIES OF MERCHANTABILITYAND FITNESS FOR A PAWICULAR PURPOSE.
EXCLUSIVE REMEDIES
THE REMEDIES PROVIDED HEREIN ARE BUYERS SOLE AND EXCLUSIVE REMEDIES.
HP SHALL NOT BE LIABLE FOR ANY DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR
CONSEQUENTIAL DAMAGES, WHETHER BASED ON CONTRACT, TOFU', OR ANY OTHER
LEGAL THEORY.
ASSISTANCE
Product maintenance agreements and other customer assistance agreements are available for Hewlett-
Packard products.
For any assistance, contact your nearest Hewlett-Packard Sales and Service Office.Addresses are provided
at the back of this manual.
Safety Considerations Model 8903B
SAFETY CONSIDERATIONS
GENERAL
This product and related documentation must be re-
(WARNING I
viewed for familiarization with safety markings and
A n y interruption of the protective (ground-
instructions before operation.
ing) conductor (inside or outside the instru-
This product is a Safety Class I instrument (provided ment) or disconnecting the protective earth
with a protective earth terminal). terminal will cause a potential shock hazard
that could result in personal injury. (Ground-
BEFORE APPLYING POWER ing one conductor of a two conductor outlet
Verify that the product is set to match the available is not sufficient protection).
line voltage and the correct fuse is installed.
Whenever it is likely that the protection has
SAFETY EARTH GROUND been impaired, the instrument must be made
An uninterruptible safety earth ground must be pro- inoperative and be secured against any unin-
vided from the main power source to the product input tended operation.
wiring terminals, power cord, or supplied power cord
set. I f this instrument is to be energized via an
autotransformer (for voltage reduction) make
SAFETY SYMBOLS sure the common terminal is connected to the
earth terminal of the power source.
/I\ Instruction manual symbol: the product will
be marked with t h i s symbol when it
is necessary for the user to refer to the instruction Servicing instructions are for use by service-
manual (refer to Table of Contents). trained personnel only. To avoid dangerous
electric shock, do not perform any servicing
unless qualified to do so.
Indicates hazardous voltages.
Adjustments described in the manual are per-
Indicates earth (ground) terminal.
formed with power supplied to the instrument
while protective covers are removed. Energy
The WARNING sign denotes a available at manypoints may, if contacted, re-
hazard. I t calls attention to a sult i n personal injury.
procedure, practice, or the like, which, if not correctly
performed or adhered to, could result in personal in-
jury. Do not proceed beyond a WARNING sign until Capacitors inside the instrument may still be
the indicated conditions are fully understood and met. charged even if the instrument has been dis-
connected from its source of supply.
The CAUTION sign denotes a haz-
a r d . I t calls a t t e n t i o n t o a n For continued protection against fire hazard,
operating procedure, practice, or the like, which, if not replace the line fuse(s) only with 250V fuse(s)
correctly performed or adhered to, could result in dam- of the same current rating and type (for exam-
age to or destruction of part or all of the product. Do ple, normal blow, time delay, etc.). Do not use
not proceed beyond a CAUTION sign until the indi- r e p a ired f u s e s o r s h o r t c irc u i t ed
cated conditions are fully understood and met. fuseholders.
Model 8903B Safety Considerations
ATTENTION
Static Sensitive
Devices
This instrument was constructed i n an E S D (electro-static dis-
charge) protected environment. This is because most of the semi-
conductor devices used in this instrument are susceptible to damage
by static discharge.
Depending o n the magnitude of the charge, device substrates can
be punctured or destroyed by contact or mere proximity of a static
charge. The results can cause degradation of device performance,
early failure, or immediate destruction.
These charges are generated in numerous ways such as simple con-
tact, separation of materials, and normal motions of persons
working with static sensitive devices.
W h e n handling or servicing equipment containing static sensitive
devices, adequate precautions must be taken to prevent device dam-
age or destruction.
Only those who are thoroughly familiar with industry accepted
techniques for handling static sensitive devices should attempt to
service circuitry with these devices.
I n all instances, measures must be taken to prevent static charge
build-up o n work surfaces and persons handling the devices.
For further information on E S D precautions, refer to "SPECIAL
HANDLING CONSIDERATIONS FOR STATIC S E N S I T I V E
DEVICES,' in Section VIII Service Section.
H P 8903B Table of Contents
TABLE OF CONTENTS
Section +General Information
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.
1
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
Safety Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
.
Instruments Covered By Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
.
Manualchanges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
Audio Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
Transceiver Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4
Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5
Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6
Electrical Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6
Mechanical Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6
Hewlett-Packard Interface Bus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8
Compatibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8
Selecting the HP-IB Address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8
Accessories Supplied . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8
Electrical Equipment Available . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8
HP-IB Controllers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8
Front-to-Rear-Panel Connectors Retrofit Kit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8
Rear-to-Front-Panel Connectors Retrofit Kit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8
Mechanical Equipment Available . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9
Chassis Slide Mount Kit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9
Chassis Tilt Slide Mount Kit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9
Recommended Test Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9
Principles of Operation for Simplified Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9
Voltmeter and Notch Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-10
Counter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11
Source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11
Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-12
Basics of Audio Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-12
ACLevel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-12
Frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-13
DCLevel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-13
Signal Impurities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-13
Distortion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-13
SINAD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-15
Signal-to-Noise Ratio . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-15
Internal Source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-16
Plotting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-16
Table of Contents H P 8903B
Section 2-Installation
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1
Initial Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1
Preparation for Use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1
Power Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1
Line Voltage and Fuse Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
Power Cables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2
HP-IB Address Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3
Interconnections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.5
Mating Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.5
Operating Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.6
Bench Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.6
Rack Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.6
Storage and Shipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.8
Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
8
.
Packaging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.8
Section %Operation
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -3-1
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
Operating Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
"urn-On Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
Local Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2
Remote Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3
Operator's Checks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3
Operator's Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4
Front-Panel Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-6
Basic Functional Checks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-12
Simplified Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-8
Rear-Panel Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-11
Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-12
Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-12
Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-12
Preliminary Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-12
AC Level and Output Level Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-12
Filter Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-13
Distortion Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-15
SINAD Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-15
Signal-to-Noise Ratio Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-15
Sweep, X Axis, Y Axis, Pen Lift, and DC Level Check . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-15
HP-IB Functional Checks ............................................. 3-16
Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-16
Initial Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-16
Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-16
Address Recognition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-16
Remote and Local Messages and the LCL Key . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-17
Sending the Data Message . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-17
Receiving the Data Message . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-18
Local Lockout and Clear Lockout/Set Local Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-18
H P 8903B Table of Contents
ClearMessage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-18
AbortMessage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-19
Status Byte Message . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-20
Require Service Message . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-21
Trigger Message and Clear Key Triggering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-22
Remote Operation. Hewlett-Packard Interface Bus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-22
HP-IB Compatibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-23
Remote Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-23
LocalMode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-23
Addressing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-23
Data Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-26
Receiving the Data Message . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-26
Sending the Data Message . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-30
Receiving the Clear Message . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-31
Receiving the Trigger Message . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-32
Receiving the Remote Message . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-32
Receiving the Local Message . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-33
Receiving the Local Lockout Message . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-33
Receiving the Clear Lockout/Set Local Message . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-33
Receiving the Pass Control Message . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-33
Sending the Require Service Message . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-33
Selecting the Service Request Condition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-34
Sending the Status Byte Message . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-34
Sending the Status Bit Message . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-35
Receiving the Abort Message . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-35
HP-IB Syntax and Characteristics Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-35
ACLevel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-42
Amplitude . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-44
Automatic Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-46
CommonMode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-47
DCLevel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-50
Default Conditions and Power-up Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-52
Detector Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-53
Display Level in Watts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-55
Display Source Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-57
Distortion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-58
Distortion Level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-60
Error Disable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-62
Error Message Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-64
Filters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-68
Float . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-72
Frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-74
Hold Decimal Point . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-76
Hold Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-78
HP-IB Address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-79
Increment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-82
Input Level Range (DC Level) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-84
Input Level Range (Except DC Level) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-86
Monitor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-88
Notch~ne . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. 3-91
Output Impedance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-93
Plot Limit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-96
Post-Notch Detector Filtering (Except SINAD) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-98
Table of Contents H P 8903B
Post-Notch Gain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-100
Rapid Frequency Count . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-102
Rapidsource . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-105
RATIO and LOG/LIN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-109
Read Display to HP-IB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-112
Service Request Condition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-114
Signal-to-Noise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-116
Special Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-121
Sweep . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-128
Sweep Resolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-131
Time Between Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-134
X-YRecording . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-135
Section 4-Performance
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.1
Equipment Required . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
.
TestRecord . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
Calibration Cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
.
Abbreviated Performance Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.1
Performance Test 1 AC Level Accuracy and Output Level Accuracy and Flatness . . . . . . . . . . . . . . . 4-2
Performance Test 2 DC Level Accuracy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-12
Performance Test 3 Distortion and Noise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-14
Performance Test 4 Distortion, SINAD, and Signal-to-Noise Accuracy . . . . . . . . . . . . . . . . . . . . 4-16
Performance Test 5 Frequency Accuracy and Sensitivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-19
Performance Test 6 Audio Filters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-21
Performance Test 7 Input and Output Impedance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-28
Performance Test 8 Common-Mode Rejection Ratio . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-29
Section 5-Adjustments
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.1
Safety Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.1
Equipment Required . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.1
Factory-Selected Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.1
Post-Repair Tests, Adjustments, and Checks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
.
Related Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
.
Adjustment 1 Internal Reference Frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
.
Adjustment 2 Input Flatness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
.
Adjustment 3 Common Mode Rejection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
.
Adjustment 4 Input DC Offset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
.
Adjustment 5 400 Hz High-Pass and Weighting Bandpass Filters . . . . . . . . . . . . . . . . . . . . . . . 5-10
Adjustment 6 Notch Filter Tune and Balance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-12
Adjustment 7 Voltmeter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-13
Adjustment 8 SINAD Meter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-15
Adjustment 9 Oscillator and Output Attenuator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-16
Model 8903B General Information
Section 1
GENERAL INFORMATION
1-1. INTRODUCTION
This manual contains information required to install, operate, test, adjust, and service the Hewlett-
Packard Model 8903B Audio Analyzer. This manual documents options installed in the Audio Analyzer
such as rear-panel connections and internal plug-in filters.
This section of the manual describes the instruments documented by the manual and covers
instrument description, options, accessories, specifications, and other basic information. This section
also contains principles of operation on a simplified block diagram level and basic information on audio
measurements. The other sections contain the following information:
Section 2, Installation: provides information about initial inspection, preparation for use (including
address selection for remote operation), and storage and shipment.
Section 3, Operation: provides information about panel features, and includes operating checks,
operating instructions for both local and remote operation, and maintenance information.
Section 4, Performance Tests: provides the information required to check performance of the
instrument against the critical specifications in Table 1-1.
Section 5, Adjustments: provides the information required to properly adjust the instrument.
Section 6, Replaceable Parts: provides ordering information for all replaceable parts and assemblies.
Section 7, Instrument Changes: provides instrument modification recommendationsand procedures.
Section 8, Service: provides the information required to repair the instrument.
Sections 1through 5 are bound in this volume, the Operation and Calibration Manual. One copy of the
Operation and Calibration Manual is supplied with the instrument. Sections 6 through 8 are bound
in two separate volumes, the Service Manual. Copies of the Service Manual are not supplied with the
instrument unless specifically requested (as Option 915) at time of instrument order. Copies of all
volumes can be ordered separately through your nearest Hewlett-Packard office. The part numbers are
listed on the title page of this manual.
Also listed on the title page of this manual, below the manual part number, is a microfiche part number.
This number may be used to order 100 x 150 mm (4x 6 inch) microfilm transparencies of this manual.
Each microfiche contains up to 96 photo-duplicates of the manual's pages. The microfiche package also
includes the latest MANUAL UPDATES packet, as well as all pertinent Service Notes.
1-2. SPECIFICATIONS
Instrument specifications are listed in Table 1-1. These are the performance standards, or limits against
which the instrument may be tested. Characteristics listed under Supplemental Information, Table 1-2,
are not warranted specifications but are typical characteristics included as additional information for
the user.
1-1
General Information Model 8903B
1-3. SAFETY CONSIDERATIONS
This product is a Safety C a s I instrument (that is, provided with a protective earth terminal). The
ls
Audio Analyzer and all related documentation must be reviewed for familiarization with safety markings
and instructions before operation. Refer to the Safety Considerations page found at the beginning of
this manual for a summary of the safety information. Safety information pertinent to the task at hand
(installation, performance testing, adjustment, or service) is found throughout the manual.
1-4. INSTRUMENTS COVERED BY MANUAL
Serial Numbers. This instrument has a two-part serial number in the form OOOOAOOOOO which is
stamped on the serial number plate attached to the rear of the instrument. The first four digits and the
letter constitute the serial number prefix, and the last five digits form the suffix. The prefix is the same
for all identical instruments. It changes only when a change is made to the instrument. The suffix,
however, is assigned sequentially and is different for each instrument. The contents of this manual
apply directly to instruments having the same serial prefix(es) as listed under SERIAL NUMBERS
on the title page.
Options. Electrical Option 001, internal plug-in filter options, and various mechanical options are
documented in this manual. The differences are noted under the appropriate paragraph such as Options
in Section 1, the Replaceable Parts List, and the schematic diagrams.
1-5. MANUAL UPDATES
An instrument manufactured after the printing of this manual may have a serial prefix that is not
listed on the title page. Having a serial number prefix that is greater than that shown on the title page
indicates that the instrument is slightly different from those documented in the manual. In this case,
your manual is provided with updating information to make it as current as possible. This updating
information includes any hardware or software changes that have occurred as well as corrections to the
manual.
A Description of the Manual Update Packet
A "MANUAL UPDATES" packet is shipped with the Operation and Calibration Manual when
necessary to provide you with the most current information available at the time of shipment. These
packets consist of replacement and addition pages which should be incorporated into the manual to
bring it up to date.
Signing Up for the Documentation Update Service
Hewlett-Packard offers a Documentation Update Service that will provide you with further updates
and changes as they become available. If you have not received update information that matches the
serial number of your instrument, you can receive this information through the Update Service.
If you operate or service instruments with different serial prefixes, we strongly recommend that you
join this service immediately to ensure that your manual is kept current. For more information, refer
to the Documentation Update Service reply card included in this manual or contact:
Hewlett-Packard Company
Technical Writing Department
24001 E. Mission-TAF C-34
Spokane, WA. 99220
(509) 922-4001
1-2
Model 8903B General Information
1-6. DESCRIPTION
General
The H P Model 8903B Audio Analyzer is a complete audio measurement system covering the frequency
range of 20 Hz to 100 kHz. It combines a low-distortion signal source with a signal analyzer. The
source has a maximum open-circuit output of 6 Vrms and a selectable output impedance of either 50 or
6000. The analyzer can perform distortion analysis, frequency count, and ac level, dc level, SINAD, and
signal-to-noise ratio measurements. The Audio Analyzer reduces the number of instruments required
in many applications involving audio signal characterization.
The Audio Analyzer is easy to use. All measurements are selected by one or two keystrokes. For
distortion measurements, the Audio Analyzer automatically tunes to and levels the input signal.
Measurement and output ranges are automatically selected for maximum resolution and accuracy.
firthermore, tuning is independent of the source. Thus, the source can be set to one frequency while
the analyzer is measuring the distortion on a signal at another frequency (that is, there is no need to
tune the analyzer to the source).
The combined capabilities of the instrument are enhanced by microprocessor control, resulting in more
capability than would be available from separate instruments. For example, when making signal-to-noise
ratio measurements, the Audio Analyzer monitors the ac level while turning the source on and off. The
microprocessor then computes and displays the ratio of the on and off levels. The ratio can be displayed
in either 5% or dB.
In addition, the source can be swept. This makes measurements such as frequency response or complete
distortion characterization simple to perform. Microprocessor control allows flexible entry of source
parameters and versatile display formats. For example, ac level can be displayed in V, mV, dBm into
6000, watts, or as a ratio (in % or dB) referenced to an entered or measured value.
Virtually all functions are remotely programmable through the Hewlett-Packard Interface Bus
(HP-IB'). Programming is easy and straightforward; all measurements are made through a single
input. This eliminates the need to switch between multiple inputs under remote control and reduces
software development time and hardware costs. The Audio Analyzer measures the true rms level
on all ac measurements. True rms measurements assure greater accuracy when measuring complex
waveforms and noise. For those applications where average detection is required, the analyzer can
be switched to average-responding (rms calibrated) detection through special functions. Accurate
distortion measurements typically can be made to less than 0.003% (-90 dB) between 20 Hz and
20 kHz at a 1.5V level. For those applications where quasi-peak detection is required, the analyzer
(Serial Prefix 2730A and above) can be switched to this type of detection through special functions.
This detector is designed to meet the requirements specified by CCIR 468-3.
Audio Testing
The Audio Analyzer has numerous features which make audio testing simple and convenient.
These features include flexible data entry and display formats, convenient source control, and swept
measurements capability. For example, distortion results can be displayed in % or dB. AC level
measurements can be displayed in volts, dBm into 600R, or watts. Measurement results can be displayed
in % or dB relative to a measured or entered value. Finding the 3 dB points of filters and amplifiers
is simplified by using the source frequency increment and decrement keys together with the relative
display feature. A major contribution of the Audio Analyzer is its ability to make swept measurements.
When sweeping, the Audio Analyzer tuning steps its source frequency in logarithmic increments. With
an x-y recorder, hard copy measurement results can be obtained. X-axis scaling is determined by the
entered start and stop frequencies. Y-axis scaling is determined by the measurement units selected and
the plot limits entered through the keyboard. Any valid display units (except mV) are allowed when
plotting. To change the scaling from frequency response to swept distortion plots, simply key in new
HP-IB: Not just IEEE-488, but the hardware, documentation and support that delivers the shortest path to a
measurement system.
1-3
General Information Model 8903B
values for the plot limits. No adjustment of the x-y recorder is necessary. The Audio Analyzer also
features high accuracy. The instrument can typically measure flatness to 0.5% (0.05 dE3) over the range
of 20 Hz to 20 kHz and swept distortion over the same range to 0.003% (-90 dB).See Figures 1-1
and 1-2.
+0.2, I , , I 1
Figure 1-1. npical Combined Source and AC Level Flatness
-70
9
w -75
v,
p -80
'0
g -80
'-
?o -85
!
I-
9 -95
D
2 -100
3
0 -105
v)
-110
20Hz 5OHz 2OOHz 500Hz PkHr 5kHz 20kHz
FREQUENCY
Figure 1-2. Typical Combined Source and Analyzer Residual Distortion
With Vsource Set to 1.5V (80 kHz BW)
Balanced Input. The Audio Analyzer has a selectable balanced input configuration for testing balanced
devices. For example, in the quest for higher output power, many audio amplifiers use bridged output
stages. Such amplifiers can be difficult to characterize because their outputs cannot be grounded. To
test these devices, the usual approach has been to use a balanced, calibrated isolation transformer
connected to an analyzer with an unbalanced input. Balanced inputs on the Audio Analyzer make
transformers unnecessary. With the analyzer input in the float position, connect the bridged device
directly to the Audio Analyzer to make measurements.
Transceiver Testing
The Audio Analyzer has several measurements and features specifically designed for transceiver testing.
It has SINAD and signal-to-noise ratio measurements for receiver testing, optional internal plug-in
weighting filters for testing to international standards, a reciprocal counter for measuring squelch tones,
and an optional internal plug-in 400 Hz high-pass filter for eliminating squelch tones when measuring
transmitter audio distortion.
SINAD is one of the most basic receiver measurements. It must be made repeatedly when performing
sensitivity or adjacent-channel sensitivity tests. In the Audio Analyzer, the SINAD measurement is
more heavily filtered than the distortion measurement in order to smooth the noisy signals encountered
in receiver testing. The filtering is optimized for excellent repeatability and speed (2 readings/second
typical). Some automatic distortion analyzers have a tendency to become untuned when measuring
SINAD on noisy signals. The Audio Analyzer overcomes this problem by tuning the notch filter to
1-4
Model 8903B General Information
the source frequency when measuring SINAD. SINAD measurement results are indicated both by the
digital display and a front-panel analog meter. The meter is specifically marked for EIA and CEPT
sensitivity and selectivity. For SINAD ratios less than 25 dB,the digital display is automatically
rounded to the nearest 0.5 dB to reduce digit flicker.
Signal-to-noise ratio measurements are also filtered for improved repeatability and speed (1 read-
ing/second typical), and automatic display rounding is provided. For accurate noise measurements, the
Audio Analyzer uses true rms detection for both SINAD and signal-to-noise measurements. Most older
instruments employ average detection which reads low for noise. The discrepancy can be 1.5 dB or
greater and varies with the ratio being measured. For correlating results with past test data, the Audio
Analyzer's detector can be switched via special functions to an average responding configuration.
For those applications where quasi-peak detection is required, the analyzer (Serial Prefix 2730A and
above) can be switched to this type of detection through special functions. This detector is designed
to meet the requirements specified by CCIR 468-3.
For transceivers, the Audio Analyzer has an optional, internal plug-in seven-pole 400 Hz high-pass filter
for rejecting squelch tones. Rejection of squelch tones up to 250 H is greater than 40 dB. Therefore,
z
audio distortion measurements to 1%residual distortion can be made without disabling the transmitter
squelch tones.
Under remote control, the Audio Analyzer can generate or count burst tone sequences. Typically the
maximum count rate is 8 ms/reading and the minimum tone duration is 12 ms. This is fast enough for
applications such as unsquelching pagers (see Figure 1-3).
Figure 1-3. Two-Tone Burst Sequence (15 ms Duration)
Systems
The Audio Analyzer features capabilities for general systems applications. The audio source is
programmable in frequency, level, and output impedance has very low distortion. The distortion
measurements are fully automatic, programmable, and fast. The typical time to tune and return the
first distortion measurement is 1.5 seconds with a measurement rate of 2 readings/second thereafter.
The combined distortion of the internal source together with the measurement section is typically
0.003% (-90 dB) between 20 Hz and 20 kHz at a 1.5V level.
Often systems applications involve measuring low level ac signals. The Audio Analyzer features a full
range ac level display of 0.3000 mV with an accuracy of 4% of reading (2%of reading for levels >50 mV
and from 20 Hz to 20 kHz). The ac detector is switchable between true rms, average-responding, and
Quasi-peak detection. The 3 dB measurement bandwidth for each detector is greater than 500 kHz.
Since many systems have noise problems, the Audio Analyzer has both 30 and 80 kHz low-pass filters to
reject high frequency noise. In addition, the optional internal plug-in 400 H high-pass filter attenuates
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line-related hum and noise by more than 68 dB.
Two special binary programming modes are available in remote operation. A rapid frequency count
mode provides a packed, four-byte output for fast counting. Also, a rapid source binary programming
mode is available which allows the internal oscillator tuning to be programmed directly with five bytes
of data.
1-5
General Information Model 8903B
1-7. OPTIONS
Electrical Options
Electrical Option 001. This option provides rear-panel (instead of front-panel) connections for both
the INPUT and OUTPUT HIGH and LOW BNC connectors.
Internal Plug-in Filter Options. The Audio Analyzer has two plug-in filter positions; each position
can be loaded with any one of six optional filters. Each filter is referenced to its corresponding filter
position by one of two option numbers. For example, the 400 Hz high-pass filter option can be ordered
as Option 010 which corresponds to the left-most filter position, or as Option 050 which corresponds
to the right-most filter position. These optional plug-in filters can be configured in any combination
desired. (If there is no filter ordered for a position, a jumper is loaded and a label marked "No Filter"
is placed above the filter key on the front panel.) The following list includes the name and option
numbers for each available filter.
0400 Hz High-Pass Filter (Option 010,050)
0CCITT Weighting Filter (Option 011, 051)
0 CCIR Weighting Filter (Option 012, 052)
0 C-MESSAGE Weighting Filter (Option 013, 053)
0 CCIR/ARM Weighting Filter (Option 014, 054)
0 "A" Weighting Filter (Option 015, 055)
Specific information on each plug-in filter option can be found in the Detailed Operating Instructions
in Section 3 under "Filters".
Mechanical Options
The following options may have been ordered and received with the Audio Analyzer. If they were not
ordered with the original shipment and are now desired, they can be ordered from the nearest Hewlett-
Packard office using the