Alan, W2AEW did an awesome complete video review of the RigExpert AA-55 ZOOM Antenna Analyzer, and showed how to use an open-short-load (OSL) calibration kit to calibrate the analyzer to the end of a transmission line. In other words, to remove the transmission line from the measurements. This video shows how to build your own OSL cal kit that is suitable for HF use (to basically the frequency limits of the SO-239 / PL-259 connectors).
Here’s a link to the AA-55 Zoom Review video:
https://www.youtube.com/watch?v=9QRpWjLFApA