Making a Transistor Radio is a book written by George C. Dobbs, with illustrations by B. H Robinson, and published by Wills and Hepworth Ltd. This wonderful book is to introduce a novice beginner into the world of radio engineering and begins from simple steps. Most radio engineers today will remember seeing this book at their local lending library and making the radio when they were young, and if they did not, then they will want to make it today to relive their youth.

The book begins with building a simple crystal receiver set, and then additional transistor stages are included to build a one-transistor radio, two-transistor radio and finally a three-transistor radio capable of driving a loudspeaker. This complete introductory book explains the basic principles of radio engineering including what regeneration is and how it operates. Back when I was a young whippersnapper, I found it most helpful to understand. The radio uses germanium transistors, and the first regeneration stage uses an OC45, whilst the second and third stages use an OC71. The most wonderful thing about this book is that it explains the principles of regeneration and feedback in very simple terms.

Back when I was a carefree young whippersnapper, we did not have a wireless television receiver set -- as many of the rich folks had -- and we listened to the radio for entertainment. Of course, having my own personal radio was something I always dreamed of because my parents would not let us listen to any other stations or even touch the family radio. Therefore, when I found this book in the library, I had to build my own radio, and I was only twelve years old at that time. My plan was to build this radio and then install the tallest aerial so that it could detect all the signals from distant galaxies, as I was deeply into reading sci-fi, rockets, and space exploration. The fun of building a radio was not just in the construction of it, but also in the procurement of parts. It would often involve visiting electronics shops, of which there were several to choose from in Croydon.

Many of the shops were far away, however my little legs always had the energy to walk miles just to buy one transistor! I was an expert in cutting my journey time by using my skateboard and taking all the shortcuts. I would sometimes get 50-pence to buy sweets, but of course, I would rather buy components, and three hours later, I would return home with a bag of diodes, coils, and transistors.

Thanks to Rev George, here are the remaining pages digitally cleaned and mastered. I do not have time to do all of them; however some of this should help.

Making a Transistor Radio - Ladybird Book

Making A Radio Today

I was wondering how much it would cost to make one of these radio sets today. We live in the modern age now and it should be cheaper for young children to make this for educational purposes. However, after some research, I discovered that you would not be able to make this today, because it would be too expensive, and it would work out cheaper to buy a readymade transistor radio from China! The main problem is finding the OC75 and OC71 germanium transistors. They were expensive back in my time and they still are today as they are limited stock! There are some sellers on eBay; however, they want approximately a fiver for just one transistor, therefore, it would cost around £15 just for the transistors!

A 0.0005 µF tuning capacitor is also going to be hard to find, especially those old-fashioned ones with the open blades, and those who sell it will likely command a premium for it. A ferrite rod costs around two pounds, and the Eagle LT700 transformer is approximately £2.30 on eBay. The variable 10 pF trimmer capacitor is also going to be hard to find, and the ceramic ones with brass plates are very expensive.

The OA81 germanium diodes are also getting difficult to source. Germanium signal diodes are not so difficult to find though. There is the famous OA90, that is readily available for less than a pound. One can still buy a crystal earpiece and they cost approximately a fiver, and it still looks like grandma’s hearing aid with that awful tube that you have to stuff into your ear.