What is OSL Calibration of NanoVNA?

OSL stands for Open-Short-Load. OSL calibration is used in NanoVNA and other vector network analyzers (VNAs). That gives a reference for the test port of the VNA. Open circuit, short circuit and a 50 ohms load are used for calibrating the test port of NanoVNA and other VNAs. Calibration is done prior to the first use as well as after any change in the system like cables and connectors. Open, short and load connectors come with the NanoVNA package when you purchase it. SMA barrel connector is needed while connecting adapters.

This PL259 calibration kit comes in handy when you need to terminate with SO239-PL259 rather than SMA-SMA. Corresponding PL259 open, short and load are used in this case. SMA to SO239 adapter will also be needed along with this kit.