RFPM2 – current probe – #2 exposed some of the build details.
This article reports the completed article.
Above the current probe with RFPM2, the display does not show well at this camera angle… it is actually a lot clearer when viewed from a higher angle.
The instrument noise floor is around -76dBA or 0.16mA. When coupled to a conductor the background noise level will raise that by some site dependent amount, at my home coupled to an antenna feed line it bounces between -75 and -65dBA.
Above is a log of the instrument noise floor.
The current probe was made primarily for measuring feed line common mode current and although this core is not split to clip onto a feed line, the centre hole is large enough to pass 7/16 DIN connectors through it.
Of course it can use all of the facility of the RFPM2 for configuration and remote measurement (eg the screen shot above).