GW Instek GAD-201G User Manual
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GAD-201G user manual
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1. PRODUCTION INTRODUCTION
The model GAD-201G Automatic Distortion Meter is designed to
measure the total distortion down to 0.1% full scale at any frequency
between 20Hz and 20kHz.
The instrument provides the function of automatic tuning, auto ranging
and automatic level control circuit to save the time of adjustment,
frequency tuning control and input level setting control.
The instrument uses two meters allowing simultaneous level and
distortion measurements. The range selection for both distortion and level
measurements is automatically made with a reed relay.
The instrument also equips with a frequency holding selector to keep a
spot frequency in a suitable condition to measure distortion factor of audio
equipment, such as FM/AM radios, stereo amplifiers, tape recorders,…etc.
Besides, the instrument uses X axis and Y axis two outputs to observe
the waveforms of the input signal and the total harmonics. All these
features allow an easy measurement of Lissajous’ figure distortion and the
analysis of distortion accuracy.
GAD-201G user manual
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2.
SPECIFICATIONS
Distortion Measurements
Measure Range
0.1% to 10% full scale in 7 ranges by auto ranging
Fundamental Frequency
range
20Hz to 20kHz 3 ranges continuous fine adjustment,
3 spot frequency: 400Hz, 1kHz, and 10kHz±1% only
Input level
100mVrms to 300Vrms
Fundamental Harmonic
Rejection Ratio
80dB above
Secondary Harmonic
Accuracy
Within ±1dB at a basic frequency of 20Hz to 20kHz.
Residual Distortion
Less than 0.03% (including hum and noise)
Maximum Input
Voltage
DC +AC peak, 400V or less
AC Voltage Measurements
Level measurement on
AC voltage ranges
1mVrms to 300Vrms full scale in 12 ranges by auto
ranges
Decibel range
-60dB to +50dB in increments of 10dB
-60dBm to +50dBm in increments of 10dBm
Decibel scale
-20dB to +1dB (0dB=1V)
-20dBm to +3.2dBm (0dBm=1mW, 600Ω)
Accuracy
Within ±3% of full scale (at 1kHz)
Frequency response
Within ±0.5dB, 20Hz to 200kHz for 100mV to 300mV
ranges
Within ±1dBm, 20Hz to 200kHz for 1mV to 30mV
ranges
Residual noise
Less than 10μV with input short circuit
Input impedance
100kΩ±10%, 70pF or less (unbalance)