Since I experience trouble with HF interference in my shack, I needed to have a HF Current Meter to detect where the cause of the problem comes from. I came across a simple schematic of DJ4UF and decided to build that one. However, the challenge was to construct the clamp-on EMC ferrite for the current transformer. However, when I was abroad and doing some shopping in a department store, my eye catch over sized clothespins and I immediately saw the alternative use.
The trick is the split the ferrite ring without damaging it completely, but that turned out not too difficult. below you see the result of the clamp-on EMC ferrite and the uA meter. Simple and effective measurement tool for the shack.