Showing Results for Keysight Technologies (Agilent HP) 339A

The 339 distortion measurement set combines a low distortion signal source, a high resolution distortion analyzer, an rms responding voltmeter, and a VU (volume units) meter in one unit. This light-weight bench instrument lets you make THD measurements over the 10 Hz to 110 kHz frequency band, including harmonics to 330 kHz.

The signal source used in the 339A is a "bridged-T" oscillator that provides a low distortion sine-wave signal from 10 Hz to 110 kHz. The output amplitude is variable from 1 mVrms to 3 Vrms into a 600 Ω load and is maintained by an amplitude control circuit that minimizes amplitude variations even when changing frequency ranges.

The distortion analyzer section of the 339A contains a tracking notch filter that is tuned to the oscillator frequency. The analyzer measures total harmonic distortion (THD) from 100% full-scale to 0.01% full-scale in nine ranges and features both automatic "Set Level" and automatic "Nulling". Auto Set Level automatically sets the reference level over a 10 dB range. If the input signal is outside this range, a LED on the front panel indicates whether the INPUT RANGE control setting must be increased or decreased to be within the "pull-in" range of the Auto Set Level. The Auto Nulling features is fully automatic when the 339A internal oscillator is used as the signal source. When an external oscillator is used as the signal source, an LED on the front panel indicates which direction the FREQUENCY controls must be set to be within the Auto Nulling range. Distortion characteristics of the input signal can be monitored at the MONITOR OUTPUT terminals with external equipment to provide additional analysis of the distortion products.

The 339A is equipped with an amplitude modulation (AM) detector that has a frequency response from 550 kHz to 1.6 MHz.

The 339A contains three active filters, one high-pass and two low-pass, which enable the user to eliminate unwanted frequencies and noise to permit higher resolution measurements.

The ac voltmeter section of the 339A measures the rms value of input voltage from 1 mV full-scale to 300 V full-scale in twelve ranges. In the VU meter mode, the meter response characteristics are changed to those of a volume units meter.

• Distortion
  • Fundamental frequency range: 10 Hz to 110 kHz
  • Distortion measurement range: 0.01% full scale to 100% full scale (-80 dB to 0 dB) in nine ranges
  • Fundamental rejection: 10 Hz to 20 kHz: >100 dB; 20 kHz to 50 kHz: >90 dB; 50 kHz to 110 kHz: >86 dB
  • Distortion introduced by instrument: 10 Hz to 20 kHz: <-95 dB, 20 kHz to 30 kHz: <-90 dB, 30 kHz to 50 kHz: <-85 dB, 50 kHz to 110 kHz: <-70 dB
  • Residual noise (fundamental frequency setting <20 kHz, 80 kHz filter in, source resistance ≤1 kΩ shielded): <-92 dB reference to 1 V
  • Input level for distortion measurements: 30 mV to 300 Vrms (100 mV range minimum)
  • Input impedance: 100 kΩ
  • DC isolation: Input low can be connected to chassis ground or floated 30 V
• Voltmeter
  • Voltage range: 1 mVrms full scale to 300 Vrms full scale
  • Frequency range: 10 Hz to 110 kHz
  • Input impedance: 100 kΩ
• Relative Input Level provides a ratio measurement relative to an operator selected reference level with readout directly in dBV or dBm (600 Ω)
• Oscillator
  • Frequency range: 10 Hz to 110 kHz in four overlapping decade ranges
  • Output level: Variable from <1 mV to >3 Vrms into 600 Ω
  • Level flatness: 20 Hz to 20 kHz: ±0.1 dB, 20 Hz to 110 kHz: ±0.2 dB
  • Distortion: 10 Hz to 20 kHz: <-95 dB (0.0018%) THD, 20 kHz to 30 kHz: <-85 dB (0.0056%) THD, 30 kHz to 50 kHz: <-80 dB (0.01%) THD, 50 kHz to 110 kHz: <-70 dB (0.032%) THD
• AM detector
  • Frequency range: Carrier frequencies at 550 kHz to 1.6 MHz; Modulation frequencies at 20 Hz to 20 kHz
  • Distortion introduced by AM detector: Up to 85% modulation: <-36 dB (1.6%) THD, 85% to 95% modulation: <-30 dB (3%) THD
  • Maximum input level: 60 V peak
  • Modulation signal level: 2.0 Vrms minimum; 10 Vrms maximum