For months I`ve been looking for a simple FM BUG project, the ones online require inductors which you either have to acquire or build, if you don`t have a LCR meter it becomes rather hard to get the circuit working, specially if you`re a beginner without an oscilloscope! Sometimes they don`t even tell you which inductance is required and you h
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ave to calculate an estimate, which is the main reason why many high frequency RF projects fail in the first place. From all the projects out there I`ve only seen one which didn`t require an external inductor since it simply used a pcb / trace inductor, however the board was big and the circuit itself had lots of stability issues, etc. I wasn`t going to waste my time with it. My first FM BUG was based on one of the many schematics out there, it seldom worked. It was microphonic (due to the air core inductor) but the electret capsule itself did not modulate the output at all, needless to say it was very unstable and it never worked properly. This circuit on the other hand performs pretty well, even if you`re manipulating the board or touching the coax it will stay within the tuned frequency (unless you touch the transistor or timing capacitor!). The power is very low, so don`t expect great distances, specially in populated areas! No surprises there, it`s very similar to other schematics so therefore I won`t go into the working details. Actually I might argue this one is a bit on the low efficiency side, but at the moment I don`t have the equipment to further improve it`s design. But let`s not focus on that and instead let`s talk about the inductor / antenna, it`s based on a 12cm long 50-75Ohms coaxial cable with one of it`s ends soldered (mesh and core are joined together) this is a big plus, we don`t have to use a flimsy...
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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