Natural Radio` is simply radio noise with natural origins, mainly lightning, but also clouds of ions interacting with the earth`s magnetic field. Nearby lightning sounds like the familiar crackle heard on an ordinary AM radio but distant lightning produces distinctive `chirps. ` The frequencies of the original pulse can be spread out in time (a process called `dispersion)
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because the higher frequencies travel a little faster than the lower. The result is that the short impulse from a lightning strike in South America can sound like a chirp in Texas. Slower sweeping tones are called "whistlers" and they are a bit of a mystery. Allyson`s explanation is the best I`ve heard. When conditions are just right, numerous lightning strikes combine with numerous reflections to give an eerie chorus that sounds a bit like a flock of geese. One can also hear interesting man-made signals in the urban environment. Latitudes away from the equator are best for whistlers and urban areas are often awash in man-made signals, but they can be interesting, too. Before launching into the construction of sophisticated receivers it`s a good idea to throw together a few simple projects to get a feel for the hobby, and to see just how big a challenge the local interference poses. Portable designs will have relatively short antennas and the input impedance of the amplifier needs to be quite high to avoid attenuating the lower audio frequencies. Also, it`s a good idea to give the amplifier an inverting sense from input to output. Otherwise positive feedback from the headphone cable to the antenna can cause squealing and instability. These two requirements usually mean that either a grounded-source FET preamplifer or a dual op-amp is needed. It`s difficult to make a single op-amp inverting design with sufficient input...
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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