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Bug "Electronic" Devices & Detectors
 

Last Updated: December 31, 2017 06:46 AM


Links to electronic circuits, electronic schematics, designs for engineers, hobbyists, students & inventors:

1 transistor FM transmitter / FM bugging Device -  This circuit is basically an oscillator which runs at around 100 MHz.   The most important parts of the oscillator are the transistor Q1 and the tuned circuit, which comprises the inductor Ll and the variable capacitor CV1.  When the battery is first connected, a brief surge of current flows from the collector to the emitter of Q1, causing an oscillating   (i.e: alternating) current to flow back and forth between Ll and CV1.___ CdS Electronic

2 transistor FM transmitter / FM bug -  VOYAGER is a super-sensitive FM Radio microphone developed by Talking  Electronics.  The components are all common types of resistors, capacitors and transistors matched so well in this circuit that  amazing  sensitivity and  distance  are obtained.  The name VOYAGER was given to it "because it  goes so far".  We have re-designed the Board and further matched some components  to  suit  the  needs  of  the  classroom.  The result is a superb bug which is compact but powerful, and quite easy to build___ CdS Electronic

3m 100 MHz small bug -  Zip File __ Designed by Rysanek Frantisek

A 'bug' receiver -  I have had several requests for a miniature, VHF FM   (wideband) transmitter of the type that are commonly refered to as BUG's.  I personally use one of these plugged into my HF rig headphone socket so I can "earwig" QSO's and nets when sitting on the toilet, washing the dishes, bringing in the coal, etc.  I know from experience that this project can be used to stimulate interest in Radio in older children, __ Designed by Harry Lythall-SM0VPO

Bug Detector (mini) -  This project is a handy piece of TEST EQUIPMENT.  You can never have enough assistance when designing FM bugs.  The first thing you need to know after putting a bug together is the fact it is transmitting. 
This project gives you this indication.  Once you know a bug is transmitting, you can work on getting the best output power and adjusting the frequency to a blank spot on the dial. __ Contact: Colin Mitchelltalking @ tpg.com.au

Bug Detector with Beep -  This circuit is not open for discussion.  Although working perfectly, it was experimental.  I will answer no emails in regards to this circuit.  If you are looking for a more serious and reliable bug detector, . __ Designed by Tony van Roon  VA3AVR

Bug Duster -  For cleaning out those pesky bugging devices:  The Bug Duster is a detector for uncovering RF-based video and audio bugging devices.  It has two modes of operation, an All-Band detector suitable for spotting many forms of analog and digital modulation and a "Pseudo-Sinitsa" mode of operation that can detect most forms of modulation, even dead carriers.  The Pseudo-Sinitsa mode is based on the Soviet Cold War transmitter hunter called the Sinitsa.  That machine used an RF diode to chop the incoming RF at an audio rate, imparting an AM modulation on the carrier.  Subsequent filters and an RF amplifier then fed an ordinary AM detector and audio amplifier.  The Bug Duster uses two diodes to accomplish nearly the same results.  Instead of turning the RF on and off, an analog switch selects the voltage from one of two detector diodes at an audio rate, one diode detecting incoming RF and the other acting as a reference.  The result is nearly identical to the old Sinitsa since the reference diode sits at the same voltage the detector diode would drop to if the RF were removed.  In fact, an offset voltage may be applied to the reference diode to "dial out" background RF, typically commercial broadcast signals   (the 5k potentiometer). __ Contact: Charles Wenzel of Wenzel Associates, Inc.

Countersurveillance Monitor -  Figure 1 shows a schematic diagram of the Countersurveillance Monitor.  The circuit, built around a single integrated circuit   (U1.  an MC3403P quad op-amp), three transistors   (Q1-Q3), and a few support components, receives its input from the antenna   (ANT1).  That signal is fed through a high-pass filter, formed by C1, C2, and R1, which eliminates bothersome 60-Hz pickup from any nearby power lines or line cords located in and around buildings and home. __ Designed by Vincent Vollono and Tony van Roon

Crystal Locked FM Bug -  Producing a crystal locked transmitter is a natural extension to our FM Bug series.  We have already produced a number of simple FM devices, (without the use of a crystal) and showed how the power and frequency depends on a number of factors including the voltage of the supply and the design of the stages.  (electronic circuits 04/09) __ Contact: Collin Mitchell

Electronic Eavesdropping Devices Detector -  Copyright of this circuit belongs to smart kit electronics.  In this page we will use this circuit to discuss for improvements and we will introduce some changes based on original schematic. __ Contact: IQ Technologies

FM bug 420-480 MHz -  How about getting that old Nokia phone out of your drawer and turning it into something freakishly cool? I will not lie to you, you will need a few tools and skills such as soldering/desoldering and making PCBs.  Here you can download Sprint-Layout __

FM Bug-transmitter -  The circuit consists of two separate stages.  The first is an audio pre-amplifier and the second is a 90MHz oscillator.  The first stage is very simple to explain.  It is a self-biasing common-emitter amplifier capable of amplifying minute signals picked up by the electret microphone __ Contact: Collin Mitchell

FM Telephone Bug -  Receive telephone conversations on any FM radio with this neat little device. __ Designed by Tony van Roon  VA3AVR

FM Telephone line Bug Transmitter -  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. __ Designed by Aaron Cake

FM Telephone Transmitter -  Receive telephone conversations on any FM radio with this neat little device. __ Designed by Tony van Roon  VA3AVR

FM Transmitter Bug -  The goal of this project is for me personally to learn a little more about fm transmitters and fm bug making (may the HAM radio gods bless me in this pursuit).  The ideal outcome of this project is a very small and full functional FM transmitter that we can stick into a plastic mint box.  In order to be able to build this, we'll have to learn a lot about amplifiers, LC oscillators, mixers, antennas and FM.  This project assumes you're already comfortable build your own PCB boards.  If you're not please take a look at the homemade pcb's tutorial before you continue.  It will help you out a lot. __

High Power FM Microphone FM Bug -  My FM Wireless Microphone has been a very popular project with beginners and experienced constructors alike.  It has been used inside guitars and as the basis of a remote control system. __ Designed by Harry Lythall-SM0VPO

Infinity Bug -  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 (circuit 02/07) __ Contact: Collin Mitchell

One transistor FM transmitter / FM bugging Device -  This circuit is basically an oscillator which runs at around 100 MHz.   The most important parts of the oscillator are the transistor Q1 and the tuned circuit, which comprises the inductor Ll and the variable capacitor CV1.  When the battery is first connected, a brief surge of current flows from the collector to the emitter of Q1, causing an oscillating   (i.e: alternating) current to flow back and forth between Ll and CV1.  An oscillating voltage therefore appears at the junction of Ll and CV1.  The frequency of the oscillation depends on the values of Ll and CV1, so that varying the value of CV1 tunes the oscillations to the exact frequency required.___ CdS Electronic

Pen FM Transmitter Bug -  Pen FM Transmitter bug projects have been very popular.  The idea of being able to hide a transmitter in a pen is very appealing.  In an effort to reduce the size of this design, we have used surface-mount components.  Firstly, the thought of using the coil in the tank circuit for transmitting RF was a little far fetched, but we used it as an example for those who were interested in experimenting with our circuits.  Now we have gone back to a conventional antenna, the whip.  The whip or straight-line antenna can be coiled, wound longitudinally or folded.  The way it is wound makes a big difference to its effectiveness, but when you are limited in space, you have to accept these limitations.  Even though we have used this antenna set up in our previous pen bugs we have considerably improved the circuit to the point were it has low battery consumption, but high RF output.  The size of this design has been reduced considerably by using surface-mount components. __

Phone Spy Transmitter -  Here is a very simple telephone broadcaster transmitter 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 phone transmitter 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. __

Phone Transmitter -  This small phone transmitter will transmit a phone conversation to an FM radio on the 88-108MHz band.  It uses energy from the phone line to transmit the signal about 100 meters away.  It uses the phone wire as the antenna and is activated when the phone is picked up.  Transmitter components are mounted on a small PC board.  PC layout is included. __

Simple Circuit Phone Tap -  Will record any conversation on any ph1-on same line, the circuit seems to be a bad design because it does not provide proper isolation and has too low DC impedance (can keep you line off-hook all the Time) __ Designed by Aaron Cake

Surveillance Transmitter Detector -  This circuit can be used to "sweep" an area or room and will indicate if a surveillance device is operative.  The problem in making a suitable a detector is to get its sensitivity just right, Too much sensitivity and it will respond to radio broadcasts, too little, and nothing will be heard. __ Designed by Andy Collison

Telephone Listening Bug -  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. __

The Bug Duster -  For cleaning out those pesky bugging devices. __ Contact: Charles Wenzel of Wenzel Associates, Inc.

Three Transistor FM Radio Bug -  My FM Wireless Microphone has been a very popular project with beginners and experienced constructors alike.  It has been used inside guitars and as the basis of a remote control system. __ Designed by Harry Lythall-SM0VPO

Two transistor FM transmitter / FM bug -  VOYAGER is a super-sensitive FM Radio microphone developed by Talking  Electronics.  The components are all common types of resistors, capacitors and transistors matched so well in this circuit that  amazing  sensitivity and  distance  are obtained.  The name VOYAGER was given to it "because it  goes so far".  We have re-designed the Board and further matched some components  to  suit  the  needs  of  the  classroom.  The result is a superb bug which is compact but powerful, and quite easy to build___ CdS Electronic

Vibrating pocket bug Detector -  Circuit Only __

Voyager 2 FM Radio Bug -  VOYAGER is a super-sensitive FM Radio microphone developed by Talking  Electronics.  The components are all common types of resistors, capacitors and transistors matched so well in this circuit that  amazing  sensitivity and  distance  are obtained.  The name VOYAGER was given to it "because it  goes so far".  We have re-designed the Board and further matched some components  to  suit  the  needs  of  the  classroom.  The result is a superb bug which is compact but powerful, and quite easy to build___ CdS Electronic

VXO FM Bug -  After constructing my Solar Powered FM Bug circuit, I decided to try building an FM bug with a more frequency-stable oscillator.  Numerous Variable Crystal Oscillator (VXO) circuits have been published for ham radio receivers and transmitters, these are normally used for fixed frequency CW applications.  I decided to see if it would be possible to use a varactor diode (voltage variable capacitor) to modulate the frequency of a crystal oscillator with an audio signal __ Designed by G. Forrest Cook

Wireless Telephone Bug -  Here's a neat little project that will allow you to monitor your phone line as soon as your phone is off hook.  You can use a regular FM broadcast band radio to monitor the conversation.  Just remember, it __

Wireless Telephone Eavesdropper Electronic -  The IR transmitter connects to a telephone circuit, and transmits both sides of all telephone conversations to any line-of-sight location, within 40 feet.  No power is taken from the central office, as long as all phones remain on-hook.  The current flows through the phone and back to the central office __


Surveilliance Devices & Detectors


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