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Signal build

FM Radio

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

Radio & soundBuildRadio

Watch on YouTube

How it works

What this project is testing.

FM radio is sound riding on a radio wave. Instead of making the wave taller and shorter, FM nudges the wave frequency back and forth, and a receiver turns those tiny shifts back into audio.

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This project demonstrates tuning: the radio is most sensitive when its resonant parts line up with one station carrier frequency.

f_{0} = \frac{1}{2 π L C}

A simple tuning relationship: changing inductance or capacitance changes the station the receiver favors.

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.

Amazon Basics 8-Pack 9V Long-Lasting Alkaline Batteries for Smoke Detector, Electronics & Audio, Reliable, 5-Year Shelf Life

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Amazon Basics 8-Pack 9V Long-Lasting Alkaline Batteries

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General electronics battery pick; choose AA/AAA variants when the circuit calls for them.

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

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

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

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

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

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

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

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BNTECHGO 30 AWG Magnet Wire - Enameled Copper Wire - Enameled Magnet Winding Wire - 4 oz - 0.0098" Diameter 1 Spool Coil Natu

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BOJACK 1000 Pcs 25 Values Resistor Kit 1 Ohm-1M Ohm with 5% 1/4W Carbon Film Resistors Assortment

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

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BOJACK 10 Values 250 Pcs A1015 BC327 BC337 C1815 S8050 S8550 2N2222 2N2907 2N3904 2N3906 PNP NPN Power General Purpose Transistors Assortment Kit

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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

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150 Pcs 15 Value 100 ohm- 2M ohm Trimpot Variable Resistor 6mm Potentiometer Assortment Kit

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

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

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

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

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Panasonic Portable AM/FM Radio, Battery Operated Analog Radio, AC Powered, Silver (RF-2400D)

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Panasonic RF-2400D Portable AM/FM Radio, Battery Operated or AC Powered

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E-outstanding 1 Pair AM FM Radio Universal Antenna, 62.5cm 24.6" Length 4 Section Telescopic Stainless Steel Replacement Antenna Aerial for Radio TV

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E-outstanding 1 Pair AM/FM Radio Universal Telescopic Stainless Steel Replacement Antenna

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ZENY 3.5CFM Single-Stage 5 Pa Rotary Vane Economy Vacuum Pump 3 CFM 1/4HP Air Conditioner Refrigerant HVAC Air Tool R410a 1/4" Flare Inlet Port, Blue

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Tegg 18PCS Adjustable Capacitor 5PF 10PF 20PF 30PF 40PF 50PF 60PF 70PF 120PF Trimmer Variable Capacitance Plastic for Arduino

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Tegg Adjustable Variable Capacitor Kit for Radio Projects

$9.99

Confirm capacitance range for the exact radio/transmitter circuit. Review requirements and safety guidance before buying.

Sand Paper, 48 PCS Sandpaper, 120 to 5000 Assorted Grit Sandpaper Sheets, 9 x 3.6 Inch Premium Wet Dry Sandpaper for Wood Fur

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Fandeli Assorted Grit Sandpaper Sheets

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Jesverty DC Power Supply Variable, 0-30V 0-10A Adjustable Switching DC Regulated Bench Power Supply with High Precision 4-Dig

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Variable DC Bench Power Supply, 30V 10A Adjustable Regulated Supply

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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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