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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What this article brings back most strongly is the use of wood for my early circuits. In Eastern Europe ex-communist countries there are such books for sale at open markets, except they are the translated versions of their Russian Soviet Union sources.
Ravio symptom in my set was very low audio level which could only just be heard when the r. There are some places where you could trip up. Wore a tie to private school, it was part of the uniform, but transisttor at home. I also found that the first audio amplifier stage was fully saturated with the 0C81 transistors that came out of my drawer.
Books You Should Read: Making A Transistor Radio
Like so many others this book was my introduction to electronics, I built this radio screws and cup washers into wood and all with my Dad over many great binding evenings. If the feedback is loo great, the circuit will produce a howling sound, so C3 is an adjustable capacitor to control the transjstor of feedback.
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 via the loudspeaker. There follows a guide to using the radio, and finally a page on finishing its case with a mounting for both speaker and battery. Mount the screws and screwoups, used for connections, at one inch intervals in two rows of eight. The centre tag is joined to a movable contact which slides over the track when the shaft is rotated.
Full out a 3 inch loop and twist the wire until it is tight up to the rod Fig. I only have one that has survived since my youth. Not realising that in this design, the ‘improved’ transistor parameters could leave the target audience in heaps of trouble. Any excuse to blow out the dust from the s germanium transistors drawer.
A loudspeaker changes electrical waves into sound waves in the same way that an earpiece does, but it has a large cardboard cone so that several people can hear the sound. Join the emitter to screw 5, the base to E and the collector to F. This is prevented by the lOOpF capacitor which takes any stray signals to earth without affecting Lhe battery voltage. So, as I happened to have all of the parts available I thought that I would have a go at it in these enlightened times of the 21st century.
Books You Should Read: Making A Transistor Radio | Hackaday
Sometimes this is not obvious, but follow ladyird circuit and layout diagrams with care to avoid mistakes. Plywood, assorted nails and screws, tinfoil and a small box of precious components pulled from dead radios. Two diodes are needed to provide the feedback path from the 50GpF capacitor.
The final receiver might not have trxnsistor as good as its commercial superhetrodyne equivalent, but it would have provided acceptable performance to receive most strong AM stations. As founder of the G-QRP Clubhe has been very active in furthering the cause of low-power amateur radio.
The next stage is the detection stage, in which i lie electro-magnetic boook frequency rdaio is detected from the carrier wave. The reader is introduced to these, and the tools the might have to master, before being shown the measurements for the board.
DO NOT apply the solder to the bit the heat of the joint should do the melting. I saved 20p a each week for a couple of months to buy it. Woolworths produced a series of these, I found a mention of them here: A circuit diagram is like a map.
You can buy one from your local radio dealer and you should ask for a pF solid dielectric type. Two smart plastic pointer knobs and a tuning scale complete the front panel.
Despite the introduction to soldering inside the cover, the signature construction method used in the book is the use of woodscrews and screwcups on a wooden baseboard. Dobbs designed his circuit and used cheap basic parts with the minimum of extras and simplest layout. For a more detailed explanation of this, you might like to read pages of the Ladybird book: 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.
Re member to leave about 3 inches of spare wire at both ends and at the twisted wire the Tapping’ point.
To make construction easier we will use both circuit and layout diagrams. The accuracy of the measurements is not vitally important, but it would be helpful to follow those given as closely as possible. We transistod lOgF al a working voltage of [6-volts. If the connection is good, the bulb will light up, 16 1 t. I think that this is due to them having higher Ft, basically more gain at high frequency, and coupling around the loose layout involved with the screwcup design results in unwanted high frequency oscillations.
It consists of two plates which arc separated by insulating material; the circuit symbol shows this.
The diagram shows one simple method of improvising a diode. 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. The general method for receiving any station is to tune it in with the tuning capacitor and to adjust the trasistor back trimmer until the howling just disappears.
Usually ferrite rods are rradio inches long, so cut a notch all round the centre and smartly snap the rod in half Figs, 3 and 2. I suspect the problem with transistor beta mentioned above may have played a part, but I never even got mine to whistle. For those who wish to solder the connections, the technique mking explained on the inside back covers of this book, A simple method of connecting the components uses wood screws and washers. Poten- tiometers are often used, as ladyvird his case, as volume controls, A capacitor is a component which allows the signal to pass but not he fixed voltages used to power a circuit.
The illustrations opposite will guide you through each stage. Remove the K resistor from F and G and connect in the new components carefully, following the layout diagram facing this page. I’ve tested the transistors supplied in the kit and you can use them without these problems. The drawing shows how to place these three wires.
There are many bare wires which come close to each other and great care must be taken to ensure they do not touch each other.