During my FieldFox calibration I get an error message “Failure to compute calibration steps. Check for missing calibration standards or insufficient f

This error message can appear on a FieldFox due to various causes. A common occurrence is during Enhanced Response Calibration. An Enhanced Response Calibration includes four steps: open, short, load and thru. The “thru” has to be a “known thru”. A known thru can either be a zero-length thru (same as flush thru), where the male-female cables mate together (hence a zero length thru). Or a known thru can be a known thru standard, such as the female-female or male-male thru that is included in the 4-in-1 cal kits such as the 85518A, 85519A, 85520A, 85521A. Either way, the cal algorithm knows the thru.

Now what happens is a user has a non-insertable device such a male-male or female-female device and selects a 3-in-1 cal kit such as the 1250-3605 or 1250-3607 for the Enhanced Response Calibration, and then the Cal Wizard complains, because it cannot complete the calibration. It says, I cannot connect my two ports together because you have said the device is non-insertable and you have not given me a known thru standard.

So what are your options if you need to do a calibration a non-insertable device and want to perform an Enhanced Response calibration?

(1) Use a cal kit that has a known thru standard such as the 4-in-1s, or the ‘box’ cal kits that have a known thru standard.

(2) If you have a 3-in-1 cal kit, add a cal standard to it. You can use Keysight’s Cal Kit Editor and edit the cal kit and add a thru standard. You need mainly to know the delay of the standard and you can add it. After editing, you can load the cal kit back into the FieldFox.
(3) Pretend you have an insertable device. If your device is male-male or female-female, tell the Cal Wizard it’s male-female and ignore the error associated with the adapter. In this case, it is important to use a high-quality adapter, one with good match. This is not a metrology solution, and if absolute traceability is key, then this method should not be used. If measuring the delay or phase shift of your device is critical, and your adapter adds significant delay, then this needs to be considered. But for many users, simply pretending the device is insertable (male-female) is sufficient.

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