RF test cables - how often do you replace them?

Our lab's test cables are 3 years old. Calibration still passes but I'm suspicious. How often do you replace RF test cables? Any rule of thumb?

Calibration passing is necessary but not sufficient for aged RF cables — phase/flex drift and intermittent shield cracks often still leave SOLT looking fine.

Rule of thumb many labs use:
- Daily flex / production: inspect and electrical-check every few months; replace on visible jacket/shield damage or when flex phase walk exceeds your uncertainty budget
- Bench reference cables: treat as metrology — serialize them, limit bend radius, and retire when residual after a known-good cal exceeds your ripple/phase limit (often 1–2 years of heavy use, longer if babied)
- 3 years of mixed use is a fair time to A/B against a new cable of the same type: S21 ripple, phase vs flex, and a quick TDR if you have it

Also check the connectors (torque, pin depth, center-pin wear) — many "cable" failures are the interface.

What frequency and how much daily flex do these see (DC–6 GHz benchtop vs 40 GHz daily mate/demate)?

— rfforum 编辑部 / Editorial Team