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Signal build

Electro-Magnetic EavesDropper

Start with the video, then use the science notes and recommended parts below to follow the idea behind the build.

Radio & soundBuild

Watch on YouTube

How it works

What this project is testing.

Changing currents create changing magnetic fields, and those fields can leak tiny copies of the original signal into nearby space.

Read more

The experiment demonstrates electromagnetic induction: a pickup coil can turn motion or audio-frequency magnetic changes back into a small voltage.

E = - N \frac{d Φ _{B}}{d t}

Faraday law: a changing magnetic flux through a coil induces a voltage.

Recommended parts

Products used in this project.

Affiliate links may earn Keystone Science a commission. Match ratings, values, sizes, polarity, and safety requirements to your own build before buying.

Rigol Digital Oscilloscope DS1054Z 50 MHz 4-Ch 1 GSa/s 24 Mpts 30,000 wfms/s UltraVision 7" 800x480 Intensity Display, 60,000-Frame Record/Playback, Serial Decode UART I2C SPI for Debug & Education

oscilloscopetest equipment

Rigol DS1054Z Digital Oscilloscope, 50 MHz, 4 Channel, 1 GSa/s

$349.004.7(724)

Good bench choice; budget scope alternatives may be cheaper but less durable.

YIHUA 926 III 60W Digital Display Soldering Iron Station Kit w 2 Helping Hands, 6 Extra Iron Tips, Lead-Free Solder, Solder Sucker, S/S Tweezers, °C/ºF Conversion, Auto Sleep & Calibration Support

soldering ironfabrication

YIHUA 926 III 60W Digital Display Soldering Iron Station Kit

$39.994.4(6,900)

BOJACK 3 Values 130 Pcs Solderless Breadboard 4 Pcs 830 Tie Points & 400 Tie Points & 126 Pcs Flexible Breadboard Jumper Wires

breadboardprototyping

BOJACK Solderless Breadboard Kit with 830/400 Tie-Point Boards and Flexible Jumper Wires

$9.994.4(692)

EDGELEC 120pcs Breadboard Jumper Wires 20cm Wire Length Optional Dupont Cable Assorted Kit Male to Female Multicolored Ribbon Cables

jumper wires / hookup wirewiring

120pcs Breadboard Jumper Wires, 20cm Dupont Cable Assorted Kit, Male to Female

$6.984.7(4,500)

BOJACK 24Value 630pcs Aluminum Electrolytic Capacitor Assortment Box Kit Range 0.1uF－1000uF

capacitorpassive electronics

BOJACK 24-Value 630pcs Aluminum Electrolytic Capacitor Assortment Box Kit, 0.1uF-1000uF

$16.994.7(953)

BOJACK 12 Values 120 Pcs Opamp Timer Darlington Phototcoupler LM324 LM339 ULN2003AN ULN2803APG LM358P LM386 LM393 NE5532P NE555P UA741CN JRC4558D PC817 IC Assortment Kit

integrated circuit / ICsemiconductor

BOJACK 12 Values 120 Pcs Opamp Timer Darlington Phototcoupler LM324 LM339 ULN2003AN ULN2803APG LM358P LM386 LM393 NE5532P NE555P UA741CN JRC4558D PC817 IC Assortment Kit

$18.994.8(511)

BOJACK 20 Values 200 Pcs Inductor 10 uH to 10 mH 1 W Color Ring Inductor 1 Watt Assortment Kit

inductor / coilpassive electronics

20 Values 200 Pcs Inductor Assortment Kit, 1uH to 4.7mH, 0.5W Color Ring Inductors

$13.994.8(182)

Tolako 5v Relay Module 5V Indicator Light LED 1 Channel Relay Module for Arduino ARM PIC AVR MCU

relay / switchcontrol

5V 1-Channel Relay Module with Indicator LED for Arduino, ARM, PIC, AVR, and MCU Projects

$5.694.6(381)

EUDAX 6 Set DC Motors Kit, Mini Electric Hobby Motor 3V -12V 25000 RPM Strong Magnetic with Shaft Propeller, 2 x AA Battery Holder,9V Battery Clip Connector,Plastic Wheels for DIY Science Projects

electric motorelectromechanical

EUDAX 6 Set Mini DC Motors Kit, 3V-12V, with Propellers, Wheels, Battery Holders, and Connectors

$11.994.5(1,500)

CQRobot Speaker 3 Watt 8 Ohm Compatible with Arduino Motherboard, JST-PH2.0 Interface. It is Ideal for a Variety of Small Electronic Projects.

speakeraudio

CQRobot 3 Watt 8 Ohm Speaker for Arduino and Small Electronics Projects

$7.994.5(457)

TOSHIBA EM131A5C-BS Countertop Microwave Ovens 1.2 Cu Ft, 12.4" Removable Turntable Smart Humidity Sensor 12 Auto Menus Mute Function ECO Mode Easy Clean Interior Black Color 1000W

microwave ovensalvage

Toshiba EM131A5C-BS Countertop Microwave Oven, 1.2 Cu Ft, 1000W

$148.994.4(32K)

Recommend only as an appliance; do not encourage buying a working microwave for disassembly. Review requirements and safety guidance before buying.

ElectroCookie Large PCB Prototype Board Kit Solderable Breadboards for Electronics Projects Compatible for DIY Arduino Soldering Projects, Gold-Plated (6 Multi-Pack, Blue)

printed circuit board / PCBprototyping

ElectroCookie Large PCB Prototype Board Kit, Solderable Breadboards for Electronics Projects

4.8(111)

Tugermoola 72PCS 5mm/0.2inch 2Pin 3Pin 4Pin Pitch PCB Mount Screw Terminal Block Connector Assortment Kit PCB Board Wire Connectors Green

terminal blockwiring

72PCS 5mm/0.2inch 2Pin 3Pin 4Pin Pitch PCB Mount Screw Terminal Block Connector Assortment Kit PCB Board Wire Connectors Green

$8.954.8(90)

Sparse or missing rating evidence from Amazon search result. Review requirements and safety guidance before buying.

ShillehTek Pre-soldered 3.5mm Stereo Audio Jack Breakout Board – TRRS Headphone/Video Jack Module for Arduino, Raspberry Pi,

3.5mm audio jackaudio

3.5mm Stereo Audio Jack Breakout Board with Screw Terminal

$8.39

Functional breakout pick; verify mono/stereo wiring and connector style. Review requirements and safety guidance before buying.

Project files

Prints, kits, and downloads.

Diagrams, printable files, kits, or companion downloads will appear here when they are ready to use.

Coming soon

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