Radio/Electronics Theory


It’s not my intention to repeat information that has been well presented elsewhere. However there appear to be a few gaps that I can hopefully fill in here. For some excellent sources of radio/electronics theory, please refer to the appropriate sections on my links page. My goal has been to keep discussions as non-technical as possible, and I’ve also tried to limit the mathematics to fairly simple formulae, and use words rather than equations. I have attempted to limit my use of equations to Ohm’s law, the basic LC resonance formula and standard series/parallel formulae for resistance/capacitance. The notable exception to this is the section: Numerical Methods for Inductance Calculation. In that discussion, there is some calculus involved, and I've attempted to provide some explanatory background material. However, it is not necessary to fully understand the mathematics in order to follow the computer algorithms.

Numerical Methods for Inductance calculation

A discussion of some practical computer methods for calculation of inductance for various types of coils.

Variable Capacitor Bandspread Calculations

This is an elementary discussion of how to design tuning circuits using a given tuning capacitor to give specific tuning range.

Part 1 Part 2 Part 3 Part 4

Negative Resistance Devices - A Graphical Approach

A discussion and analysis of negative resistance devices using graphical load line analysis, Most discussions of these devices emphasize oscillator applications. This discussion emphasizes their use as amplifiers.

Broadcast Band Tuned Loop Antennas

This is a compilation of miscellaneous information I dug up during the construction of my own tuned loop antenna.

Low Power AM Antenna Matching

A discussion of the practical issues involved in matching a very short antenna to a low power (FCC Part 15) AM broadcast band transmitter.


Online Bandspread Calculator

Online Inductance Calculator (Circular Coils)

Online Inductance Calculator (Rectangular Coils)

Online Inductance Calculator (Multi-Layer Coils)

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This page last updated: April 6, 2017

Copyright 2009, 2015, Robert Weaver