Rearranging Radio is a book: a step-by-step formula guide for the UK amateur radio exams, covering the Foundation, Intermediate and Full Licence syllabus.
The thing most revision guides skip is the algebra. They give you the formula and they give you the answer, but not the journey between the two. So this book takes all 34 formulas on the syllabus and works through every useful rearrangement of each one, line by line.
Ohm's Law, power, decibels, reactance, resonance, time constants, transformers, voltage dividers, SWR, free-space path loss, Friis transmission, skin depth, FM modulation, Carson's rule, and the rest.
Each step is numbered and described in plain English — "divide both sides by R", "take the square root of both sides" — next to the maths. Terms are colour coded, arrows in the margin annotate each operation, and cancelled terms are struck through so you can see what drops out and why. Every formula gets a worked numerical example with realistic radio values, and there are practice problems with answers in the back.
It's written in LaTeX, and the arrows and annotations are drawn with TikZ. There's also an interactive HTML version of the Ohm's Law walkthrough with a quiz mode and a live number substitution calculator.
It's published under my pen name, Ezra Hinkley.
Buy it on Amazon: Rearranging Radio
