Model 333A/334A 
RANGE 
100%-0.3% 
0.1% 
Section 
I 
*3% 
*ts% 
*12% 
1MHz 
3MHz 
10 
HZ 
10H~ 
30 
Hz 
20 
Hz 
10 Hz 
300 
kHz 
500 
Wz 
1.2 
MHz 
SECTION 
I 
GENERAL  INFORMATION 
1-1. 
DESCRIPTION. 
1-2. 
The Hewlett-Packard  Models  333A 
and 
334A 
Distortion 
Analyzers axe solid 
state 
instruments for 
measuring distortion  on  ac voltages.  The 
Models 
333A and 334A include 
two 
control  loops 
that 
auto- 
maticdy 
tune 
both 
legs of 
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 
Mz 
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 
0.1% to 100% full scale 
are 
measured in seven ranges for any fundamental frequen- 
cy of 
5 
Hz 
to 
600 
Wz. 
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 atthe 
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 
Mz 
for 300  pV 
range) 
and 
a 
voltage  range  of  300pV to 
300 
V 
rms full scale. 
1-5.  The 
AM 
detector included in the Model 334A 
is 
a 
broadband dc restoring peak detector consisting of 
a 
semiconductor diode and 
filter 
circuit. 
AM 
distor- 
tion levels 
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 8ame level of  the carrier up to 
65 
Mc. 
1-6.  ACCESSORY  FEATURES. 
1-7.  The accessory available with the 333Aand334A 
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 
1O:l 
b. 
c. 
2% 
division accuracy. 
d. 
600Vpeakinput. 
e. 
5 
ns rise-time. 
attenuation. 
DC 
to 30  MHz  bandwidth. 
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 
W 
(volume 
units) 
character istic 
8. 
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 (suffjx) 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 cornpatable 
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. 
Table 
1-1. 
Specifications 
MODEL 333A 
Fundamental 
Input 
Greater Than 30 
V 
DISTORTION MEASUREMENT RANGE 
Any  fundamental frequency, 
5 
Hz  to 
600 
kHz. 
Distortion levels of 
0. 
1%-100% are measured 
full scale 
in 
7 
ranges. 
Harmonic measurement accuracy 
(full 
scale) 
Fundamental Input Less Than 30 
V 
DISTORTION MEASUREMENT 
ACCURACY 
RANGE 
I 
*3% 
1 
*6% 
I 
*12% 
50  Hz 
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 
Wz: 
better than 
4.6 
dB 
20 
kHz 
to 100 
kHz: 
better 
than 
-1 
dB 
100 
Wz 
to 300 
kHz: 
better than -2  dB 
300 
kHz 
to 
600 
kHz: 
better 
than -3 dB 
1-1