How Your Radio Works

Radio collecting, preservation and restoration are becoming more and more interesting and more and more challenging.

The interest comes from the increasing variety and complexity of domestic and military equipment available to collectors through informal exchange, swap meets, auctions and online marketplaces.

The complexity comes from two sources: understanding older and often poorly-described equipment designs and their actual performance, and acquiring or hand-manufacturing replacements for parts that may be nearing a century in age.

This book aims to explain the common types of circuitry used in radio receivers, and concentrates on valve radios.

Crystal sets, despite their basic simplicity, derive from such an early stage of the radio art that it's difficult to offer definitive advice.

It's not uncommon to see an extensive collection with no two sets the same!

This book is compiled from 'speaker to aerial'. While this may seem a 'backwards' way of describing radios, it's the recommended method for most fault-finding. If the set is making no sound at all due to a faulty power supply rectifier, there's not much point attacking the aerial circuit.

Accordingly, Chapter 1 begins with the power supply.

Within the topic of valve radios, batteries are another field of confusion and complexity for the fastidious restorer.

The sheer mass of manufacturers, technologies and packaging make it hard to do justice to this topic.

Interested readers might well contact HRSA members and professional restorers for detailed advice on batteries.

Transistor radios are becoming increasingly sought after, and increasingly expensive.

And, as available examples are 'swept up' into collections, early and rare types are becoming rarer and more expensive in top condition.

Transistors, and their radios, are a topic for another book which the Society may publish in the near future.

The articles in this book were originally published in Radio Waves, the quarterly magazine of the Historical Radio Society of Australia, from April 2010 to April 2012.

A special thankyou to the HRSA's Bill Smith, our Radio Waves editor, for suggesting compilation and publication of the articles herein.

I have used notes sparingly.

They appear thus 0, and are collected at the end of this work.

Special thanks as well to online collections and other sources of some illustrations, including Ernst Erb of

This article contains several original drawings. For electronic copies in .PNG format, e-mail me at:

Usage of Drawings
You may use original drawings carrying my name as originator for any non-profit purpose but you may not remove the text that identifies me as the originator of such drawing or drawings.

Ian Batty