The AM Tuned Radio Frequency (TRF) receiver, has a sensitivity of about 1 m V at tbe input for an audio output of `iz W. Capacitor C22 couples audio signals from the power line to the PC board-it must be rated at 600 Vdc. R8 will cause F1 to blow, if C22 shorts. The signal from C22 goes to a tuned network (C1 through C5, Ll, and L2) that has a 20-kHz bandwidth, which allows only the desired signal to pass through. IC1 is a gain block i-f chip that has AGC capability and approximately 60 dB of gain. Components C8, C9, and L3, which are placed across tbe output of IC1, are broadly resonant around 280kHz.
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C10 couples rf to detector -diode D 1, which is used as an envelope detector. The detector output is taken from C14, which sets the upper frequency limit at about 10kHz or so. By reducing tbe value of C14, high frequency response can be obtained. The detector output is connected to an external jack. Audio components are fed to audio-gain control R6, through C16 to IC2, an audio amplifier. C18 couples up to 1/z watt of audio to an external speaker. The kit is available from North Country Radio, P.O. Box 53, Wykagyl Station, NY 10804.
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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