HP 333A Service manual

Errata
Title & Document Type: 333A/334A Distortion Analyzer Operating & Service Manual
Manual Part Number: N/A
Revision Date: October 1985
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Hewlett-Packard's former test and measurement, semiconductor products and chemical
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this manual copy. The HP XXXX referred to in this document is now the Agilent XXXX.
For example, model number HP8648A is now model number Agilent 8648A.
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I.
•
•
c,:
~
..,
..,
c
..,
..,
..,
ca.
.,;:
OPERATING
AND
SERVICE MANUAL
DISTORTION
ANALYZER
333A/334A
F/,o'I HEWLETT
a!/!111 PACKARD

•
•
•
________
F/,°oW
HEWLETT
______
_
~~
PACKARD
OPERATING
AND
SERVICE
MANUAL
MODEL
333A/334A
D
ISTO
RTIO
N
ANALYZER
Serial
Numbers:
333A:
1137A03146
and greater
334A:
1140A05641
and greater
Appendix
C, Manual
Backdating
Changes, adapts this
manual
to
lower
serial
numbers.
WARNING
I
To
help minimize the
possibility
of
electrical fire
or
shock
hazards, do
not
expose this
instrument
to
rain
or
excessive moisture.
Manual Part No. 00333-90008
Microfiche Part No. 00333-90058
©Copyright Hewlett-Packard Company
1966
P.O.
Box
301,
Loveland, Colorado,
80537
U.S.A
.
Printed: October 1975, 1985

•
•
•
Model 333A/334A
Table of Contents
TABLE OF CONTENTS
Section
I GENERAL INFORMATION •
1-1. Description •••..
1-6. Accessory Features.
1-8. Option •••••..•
1-10. Instrument Identification
Section
II INSTALLATION.
2-1. Introduction •
2-3. Inspection ••
2-5. Power Requirements
2-7. Three-Conductor Power Cable
2-10. Installation ••..•.
2-12. Bench Installation •.•
2-14. Rack Installation ••••
2-16. Repackaging For Shipment
Section
III OPERATING INSTRUCTIONS
3-1. Introduction • . • • . •
3-4. Controls and Indicators •
3-6. General Operating Information •
3-7. Input Connections •••.•
3-9. Voltmeter Characteristici:
3-12. Output Terminals ••
3-14. Operating Procedures ••
3-15. Instrument Turn-On •
3-16. Adjustment of Meter
3-18.
3-21.
3-22.
3-23.
3-27.
3-30.
Mechanical Zero. •
Distortion Measurement
Distortion Measurement of AM
RF Carriers (334A only).
Voltage
Measurement •••
Meter Indication • • • • •
Use of Output
Terminals .
333A/334A with Option 01
3-32. Manual Nulling •
Section
IV THEORY
OF OPERATION •
4-1. Overall Description.
4-3. Block Diagram Description .
4-4. Distortion Measuring
Operation •.••••.
4-8. Distortion Measurement in AM
4-10.
4-12.
4-13.
4-17.
4-39.
4-41.
4-49.
4-54.
Section
Carriers •••••..••
Voltmeter Operation .•••.
Detailed Circuit Description • • .
Impedance Converter Circuit .
Rejection Amplifier Circuit.
High Pass Filter . • • . • • •
Meter Amplifier ••.•••.
Power Supply Circuit • • • • .
RF Detector Circuit (334A only)
V MAINTENANCE • . • • • • . • •
5-1. Introduction •••••..•
5-3. Required Test Equipment •
Page
1-3
1-3
1-3
1-3
1-3
Page
2-1
2-1
2-1
2-1
2-1
2-1
2-1
2-1
2-1
Page
3-1
3-1
3-1
3-1
3-1
3-1
3-2
3-2
3-2
3-2
3-2
3-3
3-3
3-4
3-4
3-4
3-4
Page
4-1
4-1
4-1
4-1
4-1
4-1
4-1
4-1
4-2
4-5
4-5
4-7
4-7
Page
5-1
5-1
5-1
Section
V MAINTENANCE (Cont'd) •.••••.•.
5-5, Performance Checks •.....•
5-9. Fundamental Rejection Check
5-10. Second Harmonic Accuracy ..
5-11. Instrument Induced
5-12.
5-13.
5-14.
5-17.
5-18.
5-19.
5-20.
5-21.
5-22.
Distortion Check. . . . . . .
Frequency Calibration Accuracy
Check •..•..•......
Automatic Nulling Mode Check
Input Impedance Check . . .
Minimum Input Level Check. •
DC Isolation Check . . . . . .
Voltmeter Accuracy and
Frequency Response Check.
High Pass Filter Check • •
Residual Noise Check . • . . •
AM Detector Check (Model
334A only)
.••••..
5-23. Adjustment and Calibration
5-26.
5-27.
5-28.
Procedure .......••
Power Supply and Bias
Adjustments • • • . • • . • .
Voltmeter Gain Adjustments .
Voltmeter Frequency Response
Adjustment • • • • • • • • .
5-29. Bridge Balance Adjustment ••
5-30. Sensitivity SwitchCalibration.
5-31. Adjustment of Factory Selected
Components . • • • • • •
5-33. Troubleshooting Procedure .•
5-38. Troubleshooting Voltmeter
Function •.•...•..
5-40. Troubleshooting Distortion
Function .•.....•••
5-45. Photoresistor Check and
Adjustment (A6Vl thruA6V5).
5-49. Servicing Etched Circuit
Boards •••.....•
5-52. Servicing Rotary Switches.
5-54. Isolating the Impedance
Converter . . . ...
Section
VI REPLACEABLE PARTS ..
6-1. Introduction •.••.
6-4. Ordering Information •
6-6. Non-Listed Parts .•.
Section
VII CIRCUIT DIAGRAMS .
7
-1. Introduction • . •
Appendix
A CODE LIST
OF MANUFACTURERS
B
C
SALES AND SERVICE OFFICES
MANUAL BACKDATING CHANGES
Page
5-1
5-1
5-1
5-2
5-2
5-3
5-4
5-4
5-5
5-5
5-6
5-7
5-7
5-7
5-8
5-8
5-8
5-10
5-10
5-11
5-11
5-11
5-12
5-14
5-15
5-16
5-16
5-16
Page
6-1
6-1
6-1
6-1
Page
7-1
7-1
iii

-----
-
-------
- -
----------
Table
of
Contents
Model
333A/334A
LIST
OF
TABLES
Number
Page
Number
1-1.
Specifications.
. • . . . . . . .
1-1
5-5.
Power
Supply
and
Bias
Adjustments
.
3-1.
Effect
of
Harmonics
on Voltage
5-6.
Sensitivity
Switch
Calibration
Measurements.
. . . . . . .
3-1
5-7.
Factory
Selected
Components
5-1.
Required
Test
Equipment.
. . •
5-0
5-2. Second
Harmonic
Accuracy
Check
•
5-2
5-8.
Troubleshooting
Aid .
5-3.
Frequency
Calibration
Accuracy
Check
5-4
5-9.
Photoresistor
Check
•
5-4.
Voltmeter
Frequency
Response
Check
5-6
6-1.
Replaceable
Parts
..
Page
5-8
5-12
5-12
5-13
5-15
6-6
LIST
OF
ILLUSTRATIONS
Number
1-1. Model 333A
Distortion
Analyzer
3-1.
Front
and
Rear
Panel
Description
.
3-2.
Manual Nulling
Test
Setup
3-3.
Impedance
Correction
Graph
• . .
4-1.
Block
Diagram
. • . • • . • . .
4-2.
Bridge
Waveforms
. . .
•.•
4-3. Wien
Bridge
Circuit
and
Rejection
Characteristics
. . . • . • . .
4-4. Auto
Control
Loop
Detector.
.
•..
4-5.
Reference
and
Error
Phase
Relationship
• . • • • . .
•...
4-6.
Rejection
Amplifier
Block
Diagram
and
Typical
Frequency
Rejection
Characteristic
. . • • •
4-7.
Bandwidth
Versus
Null Depth
.•
4-8.
Simplified
Metering
Circuit
..•
5-1.
Fundamental
Rejection
Check
5-2.
Instrument
Induced
Distortion
Check
.•
5-3.
Frequency
Calibration
Accuracy
Check
iv
Page
1-1
3-0
3-5
3-5
4-0
4-2
4-3
4-3
4-4
4-5
4-6
4-7
5-1
5-2
5-3
Number
Page
5-4.
5-5.
5-6.
5-7.
5-8.
6-1.
6-2.
6-3.
7-1.
7-2.
7-3.
7-4.
7-5.
7-6.
Capacitance
Check
. • • • •
DC
Isolation
Check
. . . • .
Voltmeter
Accuracy
and
Frequency
Response
Check
. .
Shielded
Load
Assembly
.
Adjustment
and
Chassis
Mounted
5-5
5-6
5-7
5-8
Component
Location.
. .
5-9
Mechanical
Parts
. .
6-2
Modular
Cabinet
Parts
• .
6-4
Frequency
Tuning
Assembly
6-5
Internal
Wiring
Data.
. . .
7-3/7-4
Impedance
Converter
(P/0
A2)
and
RF
Detector
(A4) . . • . . . .
7-5/7-6
Rejection
Amplifier
(A3),
Bridge
Balance
(P/OA6)
and
High
Pass
Filter
(A7)
7-7/7-8
Meter
Amplifier
(P/0
A2)
......
7-9/7-10
Control
Circuit
(A5)
and
Bridge
Balance
(P/0
A6)
.
Power
Supply (Al) . . . . . •
7-11/7-12
7-13/7-14
t)

•
•
•
-------
F/ip'9
HEWLETT
~~
PACKARD
SAFETY
SUMM°ARY
The
following
general
safety
precautions
must
be
observed
during
all
phases
of
operation,
service,
and
repair
of
this
instrument.
Failure
to
comply
with
thasa
precautions
or
with
specific
warnings
alsawhara
in
this
manual
violates
safety
standards
of
design,
manufacture,
and
intended
use
of
the
instrument.
Hewlett-Packard
Company
assumes
no
liability
for
the
customer's
failure
to
comply
with
these
requirements.
This
is
a
Safety
Class
1
instrument.
GROUND
THE
INSTRUMENT
To
minimize shock hazard,
the
instrument
chassis and
cabinet
must
be
connected
to
an elec-
trical ground. The
instrument
is equipped
with
a
three-conductor
ac
power
cable. The
power
cable
must
either
be plugged
into
an approved
three-contact
electrical
outlet
or
used
with
a
three-contact
to
two-contact
adapter
with
the
grounding
wire
(green)
firmly
connected
to
an
electrical
ground
(safety
ground)
at
the
power
outlet.
The
power
jack
and
mating
plug
of
the
power
cable
meet
International
Electrotechnical
Commission
(IEC)
safety
standards.
DO
NOT
OPERATE
IN
AN
EXPLOSIVE
ATMOSPHERE
Do
not
operate
the
instrument
in
the
presence
of
flammable
gases
or
fumes.
Operation
of
any
electrical
instrument
in such an
environment
constitutes
a
definite
safety
hazard.
KEEP
AWAY
FROM
LIVE
CIRCUITS
Operating personnel
must
not
remove
instrument
covers.
Component
replacement
and
internal
adjustments
must
be made
by
qualified
maintenance
personnel. Do
not
replace
components
with
power
cable connected.
Under
certain
conditions,
dangerous
voltages
may
exist
even
with
the
power
cable removed.
To
avoid injuries,
always
disconnect
power
and
discharge
circuits
before
touching
them.
DO
NOT
SERVICE
OR
ADJUST
ALONE
Do
not
attempt
internal service
or
adjustment
unless
another
person, capable
of
rendering
first
aid and resuscitation, is present.
DO
NOT
SUBSTITUTE
PARTS
OR
MODIFY
INSTRUMENT
Because
of
the
danger
of
introducing
additional hazards,
do
not
install
substitute
parts
or
per-
form
any
unauthorized
modification
to
the
instrument.
Return
the
instrument
to
a
Hewlett-
Packard Sales and Service
Office
for
service and repair
to
ensure
that
safety
features
are
main-
tained.
DANGEROUS
PROCEDURE
WARNINGS
Warnings, such
as
the
example
below,
precede
potentially
dangerous
procedures
throughout
this
manual.
Instructions
containec;t
in
the
warnings
must
be
followed.
I-
WARNING
I
Dangerous
voltages,
capable
of
causing
death,
are
present
in
this
instrument
Use
ex-
trema
caution
when
handling,
tasting,
and
adjusting
.
A

SAFETY SYMBOLS
General Definitions of Safety Symbols Used On Equipment or In Manuals.
,,
Instruction manual symbol: the product will be marked with this
symbol when it
is necessary for the user to refer to the instruction
manual in order to protect against damage to the instrument.
Indicates dangerous voltage (terminals fed from the interior by
voltage exceeding
1000 volts must be so marked).
Protective conductor terminal. For protection against electrical
-1-
OR ~ shock in case of a fault. Used with field wiring terminals to in-
-
~ dicate the terminal which must be connected to ground before
177 OR .L
operating equipment.
Low-noise
or noiseless, clean ground (earth) terminal. Used for a
signal common, as well
as providing protection against electrical
shock in case
of a fault. A terminal marked with this symbol must
be connected
to ground in the manner described in the installation
(operating) manual, and before operating the equipment.
Frame
or chassis terminal. A connection to the frame (chassis) of
the equipment which normally includes all exposed metal struc-
tures.
Alternating current (power line).
Direct current (power line).
Alternating
or direct current (power line).
WARNING
IThe WARNING sign denotes a hazard. It calls attention
to a pro-
cedure, practice, condition
or the like, which, if not correctly per-
•-----•- formed or adhered to, could result in injury or death to personnel.
NOTE:
The CAUTION sign denotes a hazard. It calls attention to an
operating procedure, practice, condition or the like, which,if not
correctly performed
or adhered to, could result in damage to or
destruction of part or all of the product.
The NOTE sign denotes important information. It calls attention
to procedure, practice, condition
or the like, which is essential to
highlight.
0
tJ

•
•
•
Model
333A/334A
Section
I
SECTION
I
GENERAL
INFORMATION
1-1.
DESCRIPTION.
1-2.
The
Hewlett-Packard
Models
333A
and
334A
Distortion
Analyzers
are
solid
state
instruments
for
measuring
distortion
on
ac
voltages.
The
Models
333A
and
334A
include
two
control
loops
that
auto-
matically
tune
both
legs
pf
a
bridge
circuit
which
re-
jects
the
fundamental
when
the
rejection
circuit
is
initially
set
within
the
range
of
the
loops.
The
334A
has
a
high
impedance
detector
which
operates
from
550
kHz
to
greater
than
65 MHz
and
provides
the
ca-
pability
of
monitoring
the
distortion
of
the
amplitude
modulation
on
an
rf
carrier.
1-3.
Distortion
levels
of
O.
1%
to
100%
full
scale
are
measured
in
seven
ranges
for
any
fundamental
frequen-
cy
of
5
Hz
to
600 kHz.
Harmonics
are
indicated
upto
3 MHz.
The
high
sensitivity
of
these
instruments
re-
quires
only
0.
3V
rms
for
the
100%
set
level
reference.
The
distortion
characteristics
can
be
monitored
at
the
OUTPUT
connectors
with
an
oscilloscope,
a
true
rms
voltmeter,
or
a
wave
analyzer.
The
instruments
are
capable
of
an
isolation
voltage
of
400
volts
above
chassis
ground.
1-4.
The
voltmeter
can
be
used
separately
for
general
purpose
voltage
and
gain
measurements.
It
has
a
frequency
range
of 5 Hz
to
3 MHz (20 Hz
to
500 kHz
for
300
µ
V
range)
and
a
voltage
range
of 300
µ
V
to
300 V
rms
full
scale.
1-5.
The
AM
detector
included
in
the
Model
334A
is
a
broadband
de
restoring
peak
detector
consisting
of
a
semiconductor
diode
and
filter
circuit.
AM
distor-
tion
ievels
as
low
as
0.
3%
can
be
measured
on
a 3 V
to
8 V
rms
carrier
modulated
30%
in
the
standard
broadcast
band.
Distortion
less
than
1%
can
be
measured
at
the
same
level
of
the
carrier
up
to
65
Mc.
Table
1-1.
MODEL
333A
DISTORTION MEASUREMENT RANGE
Any
fundamental
frequency,
5 Hz
to
600 kHz.
Distortion
levels
of
O.
1%-100%
are
measured
full
scale
in
7
ranges.
DISTORTION MEASUREMENT ACCURACY
Harmonic
measurement
accuracy
(full
scale)
Fundamental
Input
Less
Than
30 V
RANGE
±3%
±6%
±12%
100%-0.
3%
10 Hz
10
Hz
1 MHz 3 MHz
0.1%
30
Hz
20 Hz
10
Hz
300 kHz 500 kHz
1.2
MHz
1-6.
ACCESSORY FEATURES.
1-7.
The
accessory
available
with
the333Aand334A
Distortion
Analyzers
is
a
voltage
divider
probe,
-hp-
Model
No. 10001A.
The
features
of
the
probe
are:
a.
10
megohms
shunted
by 10
pF,
giving
10:1
attenuation.
b.
DC
to
30 MHz bandwidth.
c.
2%
division
accuracy.
d. 600 V
peak
input.
e.
5
ns
rise-time.
1-8.
OPTION.
1-9.
Option
01
is
a
standard-hp-
Model
333A
or
334A
with
a
special
meter
and
meter
amplifier,
compen-
sated
to
permit
response
to
VU
(volume
units)
characteristics.
1-10
INSTRUMENT IDENTICATION.
1-11.
Hewlett-Packard
uses
a
two-section
serial
number.
The
first
section
(prefix)
identifies
a
series
of
instruments.
The
last
section
(suffix)
identifies
a
particular
instrument
within
the
series.
If a
letter
is
included
with
the
serial
number,
it
identifies
the
coun-
try
in
which
the
instrument
was
manufactured.
If
the
serial
prefix
of
your
instrument
differs
from
the
one
on
the
title
page
of
this
manual,
a
change
sheet
will
be
supplied
to
make
this
manual
compatable
with
new-
er
instruments
or
the
backdating
information
in
Appen-
dix
C
will
adapt
this
manual
to
earlier
instruments.
All
correspondence
with
Hewlett-Packard
should
in-
clude
the
complete
serial
number.
Specifications
Fundamental
Input
Greater
Than
30 V
RANGE
±3% ±6%
±12%
100%-0.
3%
10
Hz
10Hz
10 Hz
300 kHz 500 kHz 3 MHz
0.1%
30
Hz
20
Hz
10
Hz
300 kHz 500 kHz
1.2
MHz
Elimination
Characteristics:
Fundamental
Rejection
> 80
dB
Second
Harmonic
Accuracy
for
a
fundamental
of:
5 Hz
to
20
Hz:
better
than
+
1 dB
20 Hz
to
20 kHz:
better
than
±0.
6 dB
20
kHz
to
100 kHz:
better
than
-1
dB
·
100 kHz
to
300
kHz:
better
than
-2
dB
300 kHz
to
600 kHz:
better
than
-3
dB
1-1

Section I Model 333A/334A
Table 1-1. Specifications (Cont'd)
Distortion Introduced by Instrument:
> -70 dB from 5 Hz to 200 kHz
> -64 dB from 200 kHz to 600 kHz
Meter indication is proportional to the aver-
age value of a waveform.
FREQUENCY CALIBRATION ACCURACY
Better than ±5% from 5 Hz to 300 kHz
Better than± 10% from 300 kHz to 600 kHz
INPUT IMPEDANCE
Distortion Mode: 1 Mn ±5% shunted by <70 pF.
Voltmeter Mode:
1
Mn ±5% shunted by <30 pF (333A only),
1
Mn ±5% shunted by <35 pF (334A only),
1
to 300 V ranges; 1 Mn ±5% shunted by<70pF,
300 µ V to O. 3 V ranges.
INPUT LEVEL FOR DISTORTIONMEASUREMENTS
0. 3 V
rms for 100% set level (up to 300 V may
be attenuated to set level reference). The
minimum measurable distortion for floating
operation on the Xl frequency range is 50dB
below the fundamental.
DC ISOLATION
Signal
ground may be ±400 Vdc from external
chassis.
VOLTMETER RANGE
300 µ V
to 300 V rms full scale (13 ranges),
10 dB per range.
VOLTMETER FREQUENCY RANGE
5 Hz
to 3 MHz (300 µ V range: 20 Hz-500 kHz).
VOLTMETER ACCURACY:
RANGE
±2% ±5%
300 µV 30 Hz-300 kHz 20 Hz-500kHz
1 mV-30 V 10 Hz-1 MHz 5 Hz-3 MHz
100V-300V 10 Hz-300 kHz 5 Hz-500 kHz
NOISE MEASUREMENTS
Voltmeter residual noise on the 300 µ V range:
< 25 µ V rms terminated in shielded 600n; <30
µ V
rms terminated in shielded 100 kn.
OUTPUT
For input frequencies from 20 Hz to 600 kHz,
0. 1 V
rms ± 0. 01 V open circuit for full scale
meter deflection; 0.05 V rms ± 0. 005 V into
2
kn for full scale meter deflection.
AUTOMATIC NULLING MODE
Set Level: At least O. 2 V rms.
Frequency Ranges:
Xl, manual null tuned to less than 3% of set
level; total frequency hold-in ±0. 5% about
true manual null.
XlO through XlO K, manual null tuned to
less than 10% of set level; total frequency
hold-in± 1% about true manual-null.
AUTOMATIC NULL ACCURACY
5 Hz
to 100 Hz: Meter reading within Oto +3
dB of manual null.
100 Hz
to 600 kHz: Meter reading within O to
+1. 5 dB of manual null.
HIGH-PASS
FILTER
3 dB point at 400 Hz with 18 dB per octave roll
off. 60 Hz rejection > 40 dB. Normally used
only with fundamental frequencies greater than
1 kHz. ·
POWER
SUPPLY
100 V /120 V /220 V /240 V + 5% -10%, 48 -
66 Hz,
approximately 4 watts.
r------------------------------------------
MODEL 334A
Same
as Model 333A except as indicated below:
AM DETECTOR
High
impedance de restoring peak detector with
semi-conductor diode operates from 550kHz to
greater than 65 MHz. Broadband input.
Maximum input; 40 V
p-p ac or 40 V peak
transient.
CARRIER FREQUENCY
1-2
550kHz to 1. 6 MHz: Distortion introduced by
detector is < O. 3% for 3 to 8 volt carriers
modulated 30%.
1. 6 MHz to 65 MHz: Distortion introduced by
detector is < 1% for 3 to 8 volts rms carriers
modulated 30%.
-------NOTE-------
Distortion measurement at carrier levels
as low as 1 volt may be made with reduced
accuracy.
OPTION: 01
Indicating meter has VU characteristics con-
forming to FCC Requirements for AM, FM,
and TV broadcasting.
0i

.
•
•
•
Model 333A/334A Section II
SECTION
II
INSTALLATION
2-1.
INTRODUCTION.
2-2.
This
section
contains
information
and
instruc-
tions
necessary
for
the
installation
and
shipping
of the
Models
333A/334A
Distortion
Analyzers.
Included
are
~itial
inspection
procedures,
power
and
grounding
requirements,
installation
information,
and
instruc-
tions
for
repackaging
for
shipment.
2-3.
INSPECTION.
2-4.
This
instrument
was
carefully
inspected
both
mechanically
and
electrically
before
shipment.
It
should
be
physically
free
of
mars
or
scratches
and in
perfect
electrical
order
upon
receipt.
To
confirm
this,
the
instrument
should be
inspected
for
physical
damage
in
transit.
Also
check
for
supplied
accessories
and
test
the
electrical
performance
of the
instrument'
using
the
procedure
outlined in
Paragraph
5-5.
If
!he7e
is
damage
or
deficiency,
see
the
warranty
on
the
ms1de
front
cover
of
this
manual.
2-5.
POWER
REQUIREMENTS.
2-6.
The
Model 333A/334A
can
be
operated
from
any
ac
source
of 100 V
/120
V
/220
V
/240
V
+
5%
-
10%,
48 -66 Hz. With
the
instrument
disconnected
from
the
ac
power
source,
move
the
slide
(located
on
the
rear
panel)
until
the
desired
line
voltage
appears.
Power
dissipation
is
approximately
4
watts.
2-7.
THREE-CONDUCTOR
POWER
CABLE.
2-8.
To
protect
operating
personnel,
the
National
Electrical
Manufacturers'
Association
(NEMA)
recom-
mends
that
the
instrument
panel
and
cabinet
be
grounded.
All
Hewlett-Packard
instruments
are
equipped
with
a
three-conductor
power
cable,
which, when plugged
in-
to
an
appropriate
receptacle,
grounds
the
instrument.
The~ffsetpinon
the
power
cable
three-prong
connec-
tor
1s
the
ground
wire.
2.9
.INSTALLATION.
2-10.
The
Model 333A/334A
is
fully
transistorized;
therefore,
no
special
cooling
is
required.
However,
the
instrument
should not be
gperated
where
the
am-
bient
temperature
exceeds
55
C (131°
F).
2-11.
BENCH INSTALLATION.
2-12.
The
Model 333A/334A
is
shipped
with
plastic
feet
and
tilt
stand
in
place,
ready
for
use
as
a
bench
instrument.
2-13.
RACK INSTALLATION..
2-14.
The
Model 333A/334A
may
be
rack
mounted
by
using the 5"
Rack
Mount Kit
(-hp-
Part
No. 5060-0775).
Instructions
for
the
conversion
are
included with
the
kit.
The
rack
mount
for
the
Model
333A/334A
is
an
EIA
standard
width
of
19
inches.
When mounted in a
rack
using
the
rack
mount
kit,
additional
support
at
the
rear
of
the
instrument
should
be
provided
if
vibra-
tion
or
similar
stress
is
likely.
2-15.
REPACKAGING
FOR
SHIPMENT.
2-16.
The
following
paragraphs
contain
a
general
guide
for
repackaging
of
the
instrument
for
shipment.
Refer
to
Paragraph
2-17
if
the
original
container
is
to
be
used;
2-18
if
it
is
not.
If
you
have
any
questions,
con-
tact
your
local
-
hp
-
Sales
and
Service
Office. (See
Appendix
B
for
office
locations.)
If
the
instrument
is
to
be
shipped·
to
Hewlett-Packard
for
service
or
repair,
attach
a
tag
to
the
instrument
identify-
ing the
owner
and
indicate
the
service
or
repair
to
be
accomplished.
Include
the
model
number
and
full
serial
num-
ber
of the
instrument.
In
any
corres-
pondence, identify
the
instrument
by
model
number,
serial
number,
and
serial
number
prefix.
2-17.
If
original
container
is
to
be
used,
proceed
as
follows:
a.
Place
instrument
in
original
container
if
avail-
able.
If
original
container
is
not
available,
a.suitable
one
can
be
purchased
from
your
nearest
-hp-
Sales
and
Service
Office. .
b.
Ensure
that
container
is
well
sealed
with
strong
tape
or
metal
bands,
2-18.
If
original
container
is
not
to
be
used,
proceed
as
follows:
a.
Wrap
instrument
in heavy
paper
or
plastic
be-
fore
placing
in
an
inner
container.
b.
Place
packing
material
around
all
sides
of
in-
strument
and
protect
panel
face
with
cardboard
strips.
c.
Place
instrument
and
inner
container
in a heavy
carton
or
wooden box
and
seal
with
strong
tape
or
metal
bands.
d,
Mark
shipping
container
with "DELICATE
INSTRUMENT,"
"FRAGILE,"
etc.
2-1