|
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.
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…..(design
idea circuit)
FM Telephone Bug - Would you like to be able to amplify a
phone call so everybody can hear it? Or perhaps you'd like a way
to record phone calls for record-keeping purposes. If either
idea sounds good to you, then you might want to build the FM
Telephone Transmitter describe in this article. It's a simple,
yet ingenious device that connects in series with a phone line,
"reals" power from the latter, and transmits both sides of a
conversation to an FM radio tuned to between 90 and 95 MHz.….
[Tony van Roon's circuit]
FM Telephone line Bug Transmitter (Aaron Cake) - (circuit /
schematic)
FM Transmitter Bug - This small transmitter uses a hartley
type oscillator. Normally the capacitor in the tank circuit
would connect at the base of the transistor, but at VHF the base
emitter capacitance of the transistor acts as a short circuit,
so in effect, it still is.
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. …. [from Harry Lythall's
website]
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)
Miniature FM Spy Mic - This spy mic works from single 1.5
volts AA type battery cell. It is highly sensitive and has a
range of 300 meters. You can use any HF transistor with cut-off
freq. >300 MHz for Q. Use electrets mic.
Simple 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) [Aaron
Cake's design]
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. [Andy Collison]
Telephone Listening Bug - Here is a simple transmitter that
when connected to a phone line, will transmit anything on that
line (except 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.
Three Transistor FM Radio Bug - Electronic circuit design….
[from Harry Lythall's website]
Vibrating pocket bug detector - (schematic / circuit)
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.... [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
Wireless Telephone Eavesdropper Electronic Circuit - 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
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)
3 Transistor FM Radio Bug - Electronic circuit design….
[from Harry Lythall's website]
3m 100 MHz small bug - (circuit)
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.
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, …. [Tony
van Roon's circuit] |
