Temperature and voltage variation of ceramic capacitors. Read the data sheet! This tutorial explains how ceramic capacitor type designations, such as X7R and Y5V, imply nothing about voltage coefficients. You must check the data sheet to really know, how a specific capacitor will perform under temperature and voltage.
Circuit measures capacitance or inductance. You don’t need a fancy LC meter to measure capacitance or inductance. This short article show you how to do it with a function generator, multimeter, frequency counter, and an oscilloscope. Hmmmmm. By the time you get that all lashed up, it might have been quicker to just buy one of these LC meters from China.
Understand Radio Architectures. This is the first in a series of excerpts from the book RF Circuit Design, 2e by Christopher Bowick. Even though this appears in an engineering trade magazine, some of this is pretty basic stuff. You even get a schematic for a crystal radio!