In this file is a schematic for a simple wiretap & instructions for hooking up a small tape recorder control relay to the phone line. First, I will discuss taps a little. There are many different types of taps. There are transmitters, wired taps, and induction taps to name a few. Wired and wireless transmitters mus
Click here to download the full size of the above Circuit.
t be physically connected to the line before they will do any good. Once a wireless tap is connected to the line, it can transmit all conversations over a limited reception range. The phones in the house can even be modifies to pick up conversations in the room and transmit them too! These taps are usually powered off of the phone line, but can have an external power source. You can get more information on these taps by getting an issue of Popular Communications and reading through the ads. Wired taps, on the other hand, need no power source, but a wire must be run from the line to the listener or to a transmitter. There are obvious advantages of wireless taps over wired ones. There is one type of wireless tap that looks like a normal telephone mike. All you have to do is replace the original mike with this and it will transmit all conversations! There is also an exotic type of wired tap known as the `Infinity Transmitter` or `Harmonica Bug`. In order to hook one of these, it must be installed inside the phone. When someone calls the tapped phone & *before* it rings and blows a whistle over the line, the transmitter picks up the phone via a relay. The mike on the phone is activated so that the caller can hear all of the conversations in the room. There is a sweep tone test at 415/BUG-1111 which can be used to detect one of these taps. If one of these is on your line & the test # sends the correct tone, you will hear a...
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.....
characters left: