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TRL multiport cal on PNA under Win 7

Question asked by observers on Sep 22, 2015
Latest reply on Sep 24, 2015 by observers

I am trying to perform a TRL calibration for ports 1, 2 and 3 on a PNA N5224 A with four ports, with a user-defined cal kit that contains only Through, Line and Reflect. Application code version is A.10.43.00. I did the same already on another PNA under Win XP, version A.09.80.20, with success. It seems that the arrangement of the dialogs has been changed substantially between the software versions and that a new checkmark "Virtual device" has been introduced. The first obstacle in the new version was the correct setting of this checkmark. According to Help, it influences only the way how the prompts appear when measuring two-port standards. (It was not clear to me for which application this could be useful). After quite a number of trials, it turned out that the checkmark must not be checked for the Line standard, as opposed to the Thru. Otherwise, one will not be prompted for all TRL standards in the cal wizard. 

After having resolved this issue, I tried to do a TRL cal with 2-port standards connected between all port combinations. This should be possible after checking "Modify Cal: Change cal method, standards" in one of the cal wizard dialogs. In the following dialog, however, a table appears that indicates "Unknown Through" for the existing port connections 1-2 and 1-3. Adding a Thru 2-3 in the table has the effect that the cal wizard now prompts for an Unknown Through between these ports. In version A.09 this worked properly. Here, a "Defined Through" appears in the table and the wizard prompts for the correct standards. Maybe I am doing something wrong with the new version? Or is this a bug?