## Measuring an RF inductor

This article walks through practical measurement of a ferrite toroidal inductor using an antenna analyser.

To be relevant practically, lets use an example from N4SPP’s end fed wire antenna on 3.6MHz. His coupling transformer uses a two turn winding on an FT240-43 core for the nominal 50Ω connection to the antenna system.

We could calculate the impedance of this winding using one of the plethora of online and desktop inductance calculators, but lets first fetch the data from the manufacturer.

A simple statistic that is widely used is Al, and above, Fair-rite gives Al=1075nH +/-20%. Note that although they give a tolerance of +/-20%, it is not uncommon that manufactured product has greater error, they may have optimistically quoted the standard deviation and it is easy to fall outside that (37% chance). Continue reading Exploiting your antenna analyser #10