ArtsAutosBooksBusinessEducationEntertainmentFamilyFashionFoodGamesGenderHealthHolidaysHomeHubPagesPersonal FinancePetsPoliticsReligionSportsTechnologyTravel

How To Make a Crystal Radio

Updated on February 25, 2014

Building Your Own Vintage Radio

Building a crystal radio is a fun project to build with your kids or even by yourself. Crystal radios are beauty in simplicity - they receive and play radio signals without an external power supply. They're one of the most simple electronic circuits you can build. The simplest designs only have 4 parts: an antenna, tuning coil, crystal detector (usually a diode), and an ear phone. More sophisticated versions might add extra coils, tuning capacitors, etc.

(Image: CODE 3 MEDIA AND MOTORSPORTS under Creative Commons)

Crystal Radio Schematic - You only need a few parts to build one...

Crystal radio schematic
Crystal radio schematic

Crystal Radio Parts

You only need a few parts to build a crystal radio. In fact, the simplest designs can be built with only four parts - a coil (inductor), diode (detector), earphones, and antenna. Adding a capacitor makes the design easier (unless you're building a kit), so figure on five parts. Still, that's not to bad - when you consider you're getting a complete working radio with only five parts (and no external power source) it's pretty amazing...

Crystal Radio Kits - For young kids, a kit is probably the best option...

A crystal radio is really easy to build, and it's not difficult to build one from scratch. If it's a project for a child though, or if you're just starting out (or just in a hurry) a kit is probably your best option. A kit is more convenient because it includes everything you need in one box. You don't have to worry about winding the coil, calculating inductance, or building the base. A kit is also more likely to work the first time (especially compared to designing your own radio) and is usually cheaper than buying the parts to build your radio from scratch. For these reasons, I recommend a crystal radio kit for your first attempt. Save the scratch building for your second radio...

The Antenna

Often overlooked, the antenna is one of the most important parts of a crystal radio...

The antenna is what pulls radio waves out of the air. On a crystal radio, the antenna also supplies all the electrical power needed to operate the circuit.For best reception and performance, the antenna should be at least 100 feet long for best reception. If you don't have that much room, don't worry - you can get OK reception with an antenna as short as 10 feet as long as you're near a transmitter putting out a strong signal.

The Coil

Your crystal radio coil must be properly tuned to receive radio broadcasts...

The coil an a crystal radio resonates at different frequencies along its length. The detector is attached to the coil, with the station being received depending on the point of contact on the coil.

The Detector

The detector is the heart of the radio...

A crystal radio uses a diode to convert the AM radio signal (which is alternating current) to a varying DC voltage. This process - called demodulation - is how the audio signal is extracted from the radio wave. Early crystal radio designs used a semiconductor crystal as the cathode with a wire contacting the crystal as an anode. The radio was tuned by moving the wire to various points on the crystal. This design is unstable though, and most modern designs use a germanium diode as the detector. On these designs, the radio is tuned either by moving the contact point for the detector to different points on the coil or by placing a variable capacitor between the coil and detector.

The headphone on a crystal radio takes the varying voltage from the detector and converts it to sound. Since a crystal radio has no amplifying circuit, the headphone must be very sensitive. Normal radio headphones won't work - you need a high impedance set designed for crystal radios.

.

Please Sign my Guestbook - Have you ever built a crystal radio?

    0 of 8192 characters used
    Post Comment

    No comments yet.

    working

    This website uses cookies

    As a user in the EEA, your approval is needed on a few things. To provide a better website experience, hubpages.com uses cookies (and other similar technologies) and may collect, process, and share personal data. Please choose which areas of our service you consent to our doing so.

    For more information on managing or withdrawing consents and how we handle data, visit our Privacy Policy at: https://hubpages.com/privacy-policy#gdpr

    Show Details
    Necessary
    HubPages Device IDThis is used to identify particular browsers or devices when the access the service, and is used for security reasons.
    LoginThis is necessary to sign in to the HubPages Service.
    Google RecaptchaThis is used to prevent bots and spam. (Privacy Policy)
    AkismetThis is used to detect comment spam. (Privacy Policy)
    HubPages Google AnalyticsThis is used to provide data on traffic to our website, all personally identifyable data is anonymized. (Privacy Policy)
    HubPages Traffic PixelThis is used to collect data on traffic to articles and other pages on our site. Unless you are signed in to a HubPages account, all personally identifiable information is anonymized.
    Amazon Web ServicesThis is a cloud services platform that we used to host our service. (Privacy Policy)
    CloudflareThis is a cloud CDN service that we use to efficiently deliver files required for our service to operate such as javascript, cascading style sheets, images, and videos. (Privacy Policy)
    Google Hosted LibrariesJavascript software libraries such as jQuery are loaded at endpoints on the googleapis.com or gstatic.com domains, for performance and efficiency reasons. (Privacy Policy)
    Features
    Google Custom SearchThis is feature allows you to search the site. (Privacy Policy)
    Google MapsSome articles have Google Maps embedded in them. (Privacy Policy)
    Google ChartsThis is used to display charts and graphs on articles and the author center. (Privacy Policy)
    Google AdSense Host APIThis service allows you to sign up for or associate a Google AdSense account with HubPages, so that you can earn money from ads on your articles. No data is shared unless you engage with this feature. (Privacy Policy)
    Google YouTubeSome articles have YouTube videos embedded in them. (Privacy Policy)
    VimeoSome articles have Vimeo videos embedded in them. (Privacy Policy)
    PaypalThis is used for a registered author who enrolls in the HubPages Earnings program and requests to be paid via PayPal. No data is shared with Paypal unless you engage with this feature. (Privacy Policy)
    Facebook LoginYou can use this to streamline signing up for, or signing in to your Hubpages account. No data is shared with Facebook unless you engage with this feature. (Privacy Policy)
    MavenThis supports the Maven widget and search functionality. (Privacy Policy)
    Marketing
    Google AdSenseThis is an ad network. (Privacy Policy)
    Google DoubleClickGoogle provides ad serving technology and runs an ad network. (Privacy Policy)
    Index ExchangeThis is an ad network. (Privacy Policy)
    SovrnThis is an ad network. (Privacy Policy)
    Facebook AdsThis is an ad network. (Privacy Policy)
    Amazon Unified Ad MarketplaceThis is an ad network. (Privacy Policy)
    AppNexusThis is an ad network. (Privacy Policy)
    OpenxThis is an ad network. (Privacy Policy)
    Rubicon ProjectThis is an ad network. (Privacy Policy)
    TripleLiftThis is an ad network. (Privacy Policy)
    Say MediaWe partner with Say Media to deliver ad campaigns on our sites. (Privacy Policy)
    Remarketing PixelsWe may use remarketing pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to advertise the HubPages Service to people that have visited our sites.
    Conversion Tracking PixelsWe may use conversion tracking pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to identify when an advertisement has successfully resulted in the desired action, such as signing up for the HubPages Service or publishing an article on the HubPages Service.
    Statistics
    Author Google AnalyticsThis is used to provide traffic data and reports to the authors of articles on the HubPages Service. (Privacy Policy)
    ComscoreComScore is a media measurement and analytics company providing marketing data and analytics to enterprises, media and advertising agencies, and publishers. Non-consent will result in ComScore only processing obfuscated personal data. (Privacy Policy)
    Amazon Tracking PixelSome articles display amazon products as part of the Amazon Affiliate program, this pixel provides traffic statistics for those products (Privacy Policy)