The theory of operation has already been covered either in the Simple Superhet or the All American Five. Building this radio is really not hard especially if you have been working along through the circuits in the order I have presented them. The variable capacitor is one I happened to have on hand but there is one like it listed in the Antique El
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ectronics Supply catalog and on their web site. It is a 3 section 30 to 470 picofarad per section. This is not the best for the AM band but it`s all I have. The ideal capacitor would have one section smaller than the other two. If you have or can get one by all means get it and use it. Some variable capacitors have what look like screws on the side; one for each section. People who are not knowledgeable about electronics will sometimes tighten up these screws because they in fact are loose. These screws are small adjustable capacitors. As the screws are tightened the metal plates, which are separated by the insulating mica, are pressed closer together thus increasing the capacitance. These are shown in the schematic diagram as variable capacitors in parallel with the sections of the main tuning capacitor. If you have one of those tuning capacitors with one small section and it has three trimmer capacitors on it you can skip the rest of this section and the entire section on the padder capacitor. If you are still reading you have a tuning capacitor like the one I have. Mine has only one trimmer built in and it is on the center section. If yours has three trimmers you will need one less external trimmer than I did. Use the front section (closest to where the shaft comes out) as the oscillator tuner. Loosen this screw until the trimmer has expanded as much as it will. If you need to add one or two trimmers use 7 to 45 or 10 to...
This project fits more for custom made battery casing that can have more space to hide things inside. This switch with few alterations can be used for any other project as well but is designed based on e-bike needs! This project use a clever functionality of....
The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is....
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to....
Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This....
The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the....
The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound,....
In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the....
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power....
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower.....
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