Donor challenge: Your generous donation will be matched 2-to-1 right now. Your $5 becomes $15! Dear Internet Archive Supporter,. I ask only. Making a Transistor Radio [G.C. Dobbs, B.H. Robinson] on Hardcover: 52 pages; Publisher: Ladybird Books Ltd (January 27, ); Language. Making a Transistor Radio – Ladybird Book. Making a Transistor Radio Book Cover. Making a transistor radio is a book written by G.C. Dobbs, with illustrations .

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The Ladybird Radio

If you have followed these pages carefully, you will now f have a useful working radio. The idea is to suspend as much of this wire as possible, as high as possible.

The final signal is taken from R. This frequency, which is imposed on the carrier wave, is known as an audio frequency, ft is this electro-magnetic audio frequency that a radio receiver translates into sound ladybidr the loudspeaker. Electronic engineers have developed a ‘shorthand” method of showing the various components and their joining wires. There are many bare wires which come close to each makung and great care must be taken to ensure they do not touch each other.

By moving the shaft, which is usually fitted with a plastic knob, any part of the resistance can be used and tapped off through the centre tag. For those who wish to solder the connections, the technique is explained on the inside back covers of this book, A ladyhird method of connecting the components uses wood screws and washers.

Now I spend time with my sons building things with the Raspberry Pi, I hope they are inspired by the experience as I was.


It is possible to replace ihe nook cups of the radio with small copper nails Arid Solder the components onto these. This book was certainly pretty key in driving my early interest in electronics and later amateur radioalong with the various computer books that Usborne lacybird released as PDFs. But we need only signals of a certain frequency those sent out by a particular transmitter. Dobbs designed his circuit and used cheap basic parts with the minimum of extras and simplest layout.


Fill in your details below or click an icon to log in: The selectivity is very good indeed, though the whole set is rather ‘live’ and detunes a little when you move it or the short wire antenna. The final receiver might not have been as good as its commercial superhetrodyne equivalent, but it would have provided acceptable performance to receive most strong AM stations. The wire should be fastened onto a large screw eye or hook.

O yrigb if cmw making a Transistor Radio by G. The simple solution is to fit a 1k Ohm emitter resistor in parallel with a 22uF bypass capacitor to ground, instead of a direct connection to ground.

This would probably not have been the case with a scabby old low beta 0C71 in that position, but the transistor that I had there was quite good and so would not work correctly. This section is radi than simply the stages of amplifier construction though, because while it takes the reader through those steps it is also a very basic primer on electronic components and transistor circuits. InI think I assumed the boys in the UK did wear white shirts and ties.

The circuit shows how the transistor is biased with two resistors, 33K il — orange, orange, orange, and I50K, fl— brown, green, yellow. I ladybied the radio and being a stickler for detail, the bored was as exact a copy of the one in th book as myself and my father could manage.



The diagram shows one simple method of improvising a diode. The negative — wire is connected to the metal can which forms ihe body of the capacitor, and which may be marked with a black band.

If tftrs is transistod, remake the joint.

The wire should now be slightly springy. The setting of the reaction trimmer is, as stated in the book, a boik tricky but neither of these phenomena stop the radio being usable, especially if you prefer one station.

Take care to connect up the circuit as shown in the drawing. You are rransistor using your Twitter account. The little tubes are filled with a carbon composition, and the coloured bands give the Value of the resistor. Again, the reader is not talked down to, being introduced to all the useful things you need to know if you are to maintain an interest in radio.

I suspect the problem with transistor beta mentioned above may have played a part, but I never even got mine to whistle. The transistors in question are the now-archaic germanium PNP devices that had probably already been superseded by the early s, but the principles of biasing and transistor circuitry are universal to all bipolar circuits. Every school day… I can still tie my tie asleep, hungover, you name it.