HP 70951A optical spectrum analyzer repair

The HP 70951A installs in the HP 70004A mainframe to form the HP 71451A system. Its double-pass monochromator design combines single-monochromator sensitivity with double-monochromator dynamic range - 60 dB at ±1 nm from a signal - making it suitable for amplifier testing, laser characterization, and component evaluation. HP support has been discontinued for this module.

The 70951A has an analog rear-panel output for photocurrent measurement that’s unique in the 70950-series lineup. This analog output’s conditioning circuitry ages and can produce offset or noise on the output, which affects any test setups that rely on it. The double-pass monochromator’s grating and stepper assembly wear at the same rate as the 70950-family, producing wavelength drift and sweep irregularities. Interface contact wear from mainframe insertion cycles is also a common issue.

We test in a mainframe against calibrated references, check analog output accuracy, verify sensitivity and dynamic range. Board-level repair, optical cleaning and monochromator alignment, and NIST-traceable calibration with cal cert complete the service.

Flat-rate estimate: $100. Turnaround 1–3 days. Ships worldwide.