Bug

The Circuit shown can transmit voice to exceptionally good range. Tune trimmer to hear the signal to your near radio. Frequency range is 88-108 MHz. Max current consumption is 30mA. You can power the bug with a 9Volt Battery, or you can plug a power supply to feed in 9-12 Volts. http://www.next.gr/security/bugs/..

Views: 2957 | Votes: 1 | Comments: 4 | Rating: 10 | Rank: 10 | Added: Dec 25, 2012 |

This bug can be attached to anything from a glider to a pot plant and you can track it with a radio. Why track a pot plant? The Beeper is the result of many requests for a mini tracking device and introduces a new world of tracking. The circuit is very compact and consumes very little power. It is small enough to be hidden in anything you suspect will be lost or stolen. By using a mercury switch or "grasshopper" the bug can be "primed" for the time when it is moved.....

Is a 100 to 200 metre (100 to 200yds) device having a very stable performance. It can be used as a hand held microphone or left on a shelf to pick up the sounds in a room. It has many interesting features. These will be fully described in the article. One of the most important features of this project is the use of standard components. This gives it universal appeal as the parts can be obtained from almost any electronics store. It has been designed, not only for.....

This project is a miniature, VHF FM (wideband) Wireless Microphone transmitter of the type that are commonly refered to as BUG's. Note that "BUGS" are illegal but "Wide-Band Frequency Modulation Wireless Microphones" (WBFMWMs) are not, as so many people have told me (including the RSGB!). Besides, the AF sensitivity of this transmitter prevents it from being an effective bug for eaves-dropping! I personally use one of these WBFMWMs plugged into my HF rig headphone socket.....

Power supply: 12-14 V stab., 100 mA. RF power: 400 mW. Impedance: 50-75 ohm. Frequency range: 87,5-108 MHz. Modulation: wideband FM. Connect the 6 V / 0,1 A bulb to the output and use R1 to tune the right frequency. Maybe you might stretch coils of the L1. Then use C14 and C15 to adjust the highest power (the highest light of the bulb). Then you can connect antenna and audio signal. Adjust R2 until the audio sounds as loud as the other stations. With good antenna (dipole.....

This project requires a high degree of soldering. It uses surface-mount resistors, capacitors transistors and diodes. It can only be assembled on the PC board supplied in the kit as the Latching Circuit is already soldered to the board and the project will not work with substitute components. The Infinity Bug connects across the phone line and takes very little current as most of the circuit is not active when in the "waiting" state. This is called "leeching" and the.....

This fairly simple circuit makes it possible to place such a wall as a conduit to locate. It is a conduit for power, no water or gas-seeker. The only requirement is that there is tension on the line. The antenna in the table can consist of a simple piece of copper wire. The correct adjustment is done through R7, in order to prevent the buzzer and LEDs still light up even though there is no leadership in the area. ..

This Mini FM Bug Detector is basically a broad-band receiver. It picks up the complete band from below 80Mhz to 150MHz and almost anything that transmits in that band will be detected. If a bug with a sensitive microphone is transmitting nearby, the result will be a feedback whistle. The Bug Detector will not determine the output power of a bug as it is detecting the sensitivity of the microphone. However it will prove the carrier section is working (this is the.....

The circuit consists of three stages, an electret microphone, an audio amplifier and an RF oscillator. The electret microphone consists of only two parts - a FET transistor and a plastic diaphragm. There is nothing else inside the case. The 3-leaded FET has an input, output and earth lead. The mylar diaphragm has been permanently charged with a static charge and this is one of the secrets of the operation of the microphone...

The circuit is basically a radio frequency (RF) oscillator that operates around 100 MHz. Audio picked up and amplified by the electret microphone is fed into the audio amplifier stage built around the first transistor. Output from the collector is fed into the base of the second transistor where it modulates the resonant frequency of the tank circuit (the 5 turn coil and the trimcap) by varying the junction capacitance of the transistor. Junction capacitance is a.....

Here is a simple yet very useful circuit which can be used to eavesdrop on a telephone conversation. The circuit can also be used as a wireless telephone amplifier. One important feature of this circuit is that the circuit derives its power directly from the active telephone lines, and thus avoids use of any external battery or other power supplies. This not only saves a lot of space but also money. It consumes very low current from telephone lines without disturbing its.....

Here is the schematic, PC board pattern, and parts placement for a low powered FM transmitter. The range of the transmitter when running at 9V is about 300 feet. Running it from 12V increases the range to about 400 feet. This transmitter should not be used as a room or telephone bug...

This bugg is based on my previous 3-transistor transmitter. This bugg unit has many advantage. The transmitter use a crystal 46.515MHz to hold a steady frequency. The frequency can be fine-tuned by some 100kHz. The transmitter can send data and audio-signal with +/- 10kHz FM modulation. The output power is about 10mW into 50 ohm. The crystal I used is a 3:th overtone crystal. The coil L1 is a slug tuned coil. The primary winding is 8 turns and the second winding is 2 turn......

Many Cordless phones are still analogue and use the frequency from 30-50MHz. The signal is FM-modulated and can easy be picked up with any FM-receiver. I will present a FM-receiver wich can be adjusted within this frequency range. The cordless phones can have different number of channels. In the oldest type you will find a single crystall (one channel). The multi-channel phones uses a synthesizer chip to set a frequency wich is not occupied. The receiver I present is not.....

This is just one of the many bugging devices available on the eaves-dropping market. The range includes pen and pencil holders, trophies, framed pictures and office furniture with false bottom drawers. These products are readily sold to fledgling companies, eager to nestle into big brother's market. And for a while these bugging devices worked. Few firms knew of their existence, and even less on how to sniff them out. But that has all changed now. If a corporation.....

This implementation is adapted to rebroadcast the output of a CD player, television receiver, or radio receiver. I use it so that I can move about the house and listen to my favorite programs without disturbing others. Within and the house, I find that I can get 10 to 20 meters away from the transmitter with the small pocket FM receiver I carry in my shirt pocket. Your mileage may vary. The transmitter as built and pictured below (the transmitter is in the blob of hot melt.....

Views: 1732 | Votes: 63 | Comments: 0 | Rating: 7 | Rank: 2 | Added: Jun 19, 2012 |

Today they have moved up to 900MHz. It is not easy to build stuff for 900MHz so in this project I will re-use an old cordless 900MHz phone I found in a container. Since you wont have the same phone as I have, you might think this is not a project for you, Wrong! Read this and you will learn how do identify parts in cordless phones and you can rebuild almost any model. This is a block diagram of an analogue 900MHz cordless phone. The transmitter part is not interesting.....

Here is a simple transmitter that when connected to a phone line, will transmit anything on that line (execpt the dial tone) to any FM radio. The frequency can be tuned from 88 to about 94Mhz and the range is about 200 feet. It is extremely easy to build and is therefore a good, useful beginner project...

This circuit uses a small microphone to capture the sound and some transistors to generate radio waves that can be picked up by a FM receiver like a car stereo. The first part is the microphone and some resistors to get it working. Next we have a capacitor and the first transistor, this amplifies the sound from the microphone so that it can be loud enough to work with. The last part, there is a transistor, a coil and some capacitors. This part generates the radio waves and.....

This is the basic fm trasmitter that I built. In theory, according to electronics, it shouldn't work but works fine and is very sensitive. It can transmit the signal up to 45 yards (about 40 meters) . A sensitive FM radio can pick up the signal up to 100 yards (80 meters) but I can't see any reason for it. This kind of microphones are also called "spy microphones" but knowing that the battery is bigger than the actual circuit, I can't see any application like that, anyway,.....