Traditionally, high quality reception of VLF natural radio signals has involved driving or hiking out to remote locations far from civilisation, in order to find an environment free of pollution by artificial radio signals. I`ve lost count of the times I`ve hiked out into the countryside with a small portable VLF receiver in search of a quiet spot
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for a night`s listening. All I ever seemed to get is sferics and tweeks, . and hum, the ever-present signal radiating from the country`s power distribution system. Even in the best of spots this hum never goes away completely, in my part of the world at least. Now and again a whistler manages to surface above it, but I never contrived to be in the right place at the right time to hear anything spectacular. On the whole, it was quite a disappointing experience. The only course of action seemed to be to arrange the means of receiving VLF signals cleanly from home. Although I live in a rural location, the moorland around here is crisscrossed by big powerlines, as well as smaller ones leading out to the many farms. So when the receiver is switched on, most of what comes out of it is hum - a suffocating, mind numbing hum, which smothers everything but the loudest sferics. Just beneath the hum, there is another layer of noise - an unpleasant brew of signals produced by televisions and computers in the house. I`m glad to report that I`ve had a fair amount of success with setting up a home receiver, and I can now listen to a completely hum-free rendering of the earth`s natural VLF activity, more or less continuously. At times there is interference from machinery and so on, and although the antenna is now almost immune to wind and drizzle, it is still wiped out by driving rain or hail. But most of the time reception is first class,...
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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