I made the “RF Sniffer Clip” as described in the 198th issue of SPRAT. This little guy has come in handy more times than i can count. With it, I’ve troubleshot radios, ignition systems, slayer exciters, florescent lighting, and quite a few other systems. It is a quick-to-make and extremely cheap tool. I will talk to anyone who will listen about how great this thing is.

The original design used a wooden clothes pin so it could be physically attached to whatever thing it was measuring. I find that design pretty useful, don’t get me wrong, but after iterating a bit I’ve settled on this “Probe” form factor. My prototyping and troubleshooting workflow has jumped in efficiency since switching the design and adding it to my toolset.