What does Error Code 27 on the 8970B Noise Figure Analyzer indicate?
The Keysight 8970B/71B/71C Noise Figure Measurement Operating Manual specifies the error code as: “Overflow while calibrating”.
This error is generated when excessive loss exists between the noise source and the noise figure analyzer´s input during calibration. This condition could exist due to several conditions as outlined below:
- High insertion loss in the calibration path due to external high loss devices such as an: isolator, attenuator, cable, etc
- Noise source not attached to the analyzer’s input
- A failed noise source
- Improper switching of the noise source +28V dc control voltage
- Other service failures
If excessive insertion loss is the culprit, remove the path loss from the calibration path, utilize Special Function 34.x, "Loss Compensation", to account for the pre and/or post DUT insertion loss, and re-calibrate directly between the noise source and analyzer input. Another alternative is to implement Special Function 32.x, and force the Calibration, Input Gain Selection, to a specific mode or range.
If a service failure is suspect, the following manuals may be of assistance in troubleshooting the 8970B analyzer.
Operating Manuals
- 8970B /8971B /8971C Operating Manual (08970-90118 - see link)
- Option H18 Operating Guide Special Supplement (08970-90042 – see link)
Service Manuals
- 8970B Service Manual. For Standard instrument only. (08970-90054)
- 8970B Option 020 Service Manual Supplement (08970-90115 - see link)
- 8971C Service Manual (08971-90011)
Manuals that are listed without a link indicate an electronic version of the manual is not available. Visit Keysight "Find-a-Part" to arrange for purchase of these manuals.