[SOLD] HP 8903B Audio Analyzer - Page 1
Forum section: electronics / general

author: macboy
author_rank: Super Contributor
timestamp: October 15, 2017, 07:45:06 pm
content: SOLDFor sale in Ottawa, Canada to Canada/USA*HP 8903B Audio AnalyzerI've bought a Panasonic/National audio analyzer and can't justify keeping two around, so I am selling this one.This instrument can measure THD+N (Total harmonic distortion plus noise), SNR (Signal to Noise ratio), frequency (using a reciprocal measurement), and basic measurements like AC and DC levels. The AC measurement can be True RMS, average responding (RMS calibrated) or quasi-peak. Measurements are fully automatic and the instrument can be controlled over GPIB.The 8903B Consists of a low distortion, low noise audio oscillator source, plus an analyzer. The source has frequency range of 20 Hz to 100 kHz, and amplitude of 0.6 mV to 6.0 V RMS, selectable 50 or 600 Ohm output impedance, and a differential/floating output (within limits w.r.t ground). The analyzer has fully differential input, 100 kohm input impedance. It accepts up to 300 VAC or will measure sub-millivolts True-RMS AC volts.Refer to the datasheet online for all the specifications and capabilities. The (two volume) service manual is freely downloadable and contains all the goodness you would expect from HP gear, including block diagrams, theory and description of circuits, troubleshooting information including waveforms and voltages, plus full schematics and parts lists. Construction is through-hole with many metal-can and ceramic packaged opamps and precision passives. For reference, the 8903A is similar but older, and the 8903E does not include the source (analyzer only).The residual distortion is specified at -80 dB (0.01%) but actually it does much better.With the source set to 1 kHz, 6 VRMS, single ended, and connected directly to the analyzer input with a single BNC cable, I measure 0.0018% (-95 dB) residual at 30 kHz BW, or 0.0019% at 80 kHz BW, or 0.0039% at full bandwidth of about 750 kHz.Using a separate ultra low distortion source at approximately 1 kHz at 2.7 VRMS, the analyzer section measures 0.0006% (-104 dB) THD+N at 30 Khz BW, and 0.0007% THD+N at 80 kHz BW. Photos of these measurements are below.This one is equipped with two filters in the option slots: A-weighting (human ear perceptual loudness curve), and C-message (perceptual and bandpass based on telecoms systems). For most HiFi measurements, you will simply use the 30 kHz low pass filter. It has front panel inputs/outputs (some units have them at the back only). Includes two BNC to single banana/binding post adapters for the inputs and two BNC to RCA jack adapters for the outputs. The pull-out quick reference cards are intact and come in quite handy. It is fully functional and in very good to excellent overall condition.SOLD

author: Zucca
author_rank: Unknown
timestamp: October 16, 2017, 01:48:24 pm
content: Nice one, but I am in Europe

author: tmarushak
author_rank: Newbie
timestamp: September 23, 2018, 10:32:14 pm
content: I know it's been 11 months since your post but I am wondering if you sold this unit or is it still for sale?

author: macboy
author_rank: Super Contributor
timestamp: September 24, 2018, 04:06:03 pm
content: I still have it and it is still available.

author: tmarushak
author_rank: Newbie
timestamp: September 24, 2018, 04:49:52 pm
content: Just sent you a PM.