A Growing Concern
I describe here a simple RF current probe that can be used to directly measure RF currents in wires and cables using an oscilloscope. The probe features "clip-on" operation, using a common clip-on RFI suppression ferrite core for the sensor coil. This was "take two" for coming up with a suitable current sensor for measuring [...]
There are quite a few recipes for building a suitable transformer for an end fed half wave antenna (EFHW), but I was never sure I really understood the main principles. So, I wound a bunch of transformers, made measurements on them using my NanoVNA, learned how to get what I really wanted out of the [...]
I've been using a spool of RG-6 CATV cable of dubious quality for quite a while as my go-to source of antenna feed line because I happened to have the spool in my junk collection. Using the 75 Ω cable got me thinking about why we care what impedance the cable is and how matching [...]
You never know when you might need to measure the speed of light. When the time comes, this avalanche transistor pulse circuit will come in real handy. This is one of my favorite little bits of electronics because you get such great performance out of a single common 5¢ transistor that is abused for this purpose! [...]
Squash Practice 