Agilent 86140B optical spectrum analyzer repair

The Agilent 86140B is the B-revision of the 86140 series - tighter RBW floor (0.06 nm), improved dynamic range, and optimized for 50 GHz WDM channel characterization. The double-pass monochromator gives it simultaneous high sensitivity and high dynamic range, which is why these units stayed in DWDM component test lines long after newer instruments became available. Keysight’s support window for the 86140B is closed.

Grating assembly wear is the dominant hardware failure on the 86140B. The stepper motor and grating positioning system lose accuracy over time, producing wavelength errors that can’t be calibrated away - only fixed. Sensitivity degradation (usually optical path contamination or detector aging) is the second most common issue. Board-level capacitor failures on the analog front-end cause noise floor increases and intermittent measurement errors. Boot issues on 15+ year old units are almost always power supply or capacitor-related.

We bench-test each incoming 86140B against calibrated DFB references at 1310, 1550, and 1625 nm. Grating and monochromator are adjusted to factory tolerances after optical cleaning. Component-level board repair addresses electronics failures. Final NIST-traceable calibration with cal cert.

Estimate: $100 flat-rate. Turnaround 1–3 days. International shipping supported.