This may be an elimentary question ,but what is the most accurate way to measure the electrical length of an adapter when it is necessary to use it to measure phase.(ie port extention using an 8722d vna). I am using an s11 reflective cal in the transform mode(real time format) and attaching a known short(cal standard short), setting marker to min, reading the value , taking half of that and subtracting the value of the short. This method is supposed to eliminate fringing at the end of the adapter and give an accurate result. Any comments or sugestions? Thank you.