Distortion Measurement - HP 333A Operating And Service Manual

Model 333A/334A
Section I
SECTION |
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 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 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 0. 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 atthe
OUTPUT connectors with an oscilloscope, a true rms
voltmeter, ог 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 b Hz to 3 MHz (20 Hz to 500 kHz
for 300 uV range) and а voltage range of 300uV to
300 V rms full scale,
1-5. The AM detector included in the Model 334A is
a broadband дс restoring peak detector consisting of
@ semiconductor diode and filter circuit. AM distor-
. tion levels as low as 0. 3% can be measured on a 3 V
to8 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 0. 1964-1009 are measured
full scale in 7 ranges.
DISTORTION MEASUREMENT ACCURACY
Harmonic measurement accuracy (full scale)
Fundamental Input Less Than 30 V
100%-0. 3%
0.1%
1-6. ACCESSORY FEATURES.
1-7. The accessory available with the 333A and334A
Distortion Analyzers is a voltage divider probe, -hp-
Model Ко. 10001A. The features of the probe are:
a. 10 megohms shunted by 10 pF, giving 10:1
attenuation.
b, DC to 30 MHz bandwidth.
2% division accuracy.
d. 600 V peak input.
e. 5 ns rise-time.
1-8. OPTION.
1-9, Option 01іѕа 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. На letter is
included with the serial number, it identifies the coun-
try in which the instrument was manufactured. Н 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 Арреп-
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
100%-0. 3%
10 На
300 ЕН?
30 Hz
300 ЕН?
10 Hz
3 MHz
10 Hz
1.2 MHz
0.1%
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