In just a few hours you can make a completely batteryless AM radio receiver with a range of around 25 miles. Built with a small assortment of components, some scrap wood, and a beverage bottle tightly wound with magnet wire, we call this project Bottle Radio. Similar to other “crystal radio” projects, the crystal in this build is contained inside a germanium diode, which rectifies incoming audio...
http://youtu.be/-td7YT-Pums
Video by MAKE
They electronically switch and amplify signals by harnessing the unique abilities of semiconductor materials. Their invention has transformed the world of electronics and accelerated our entry into the digital age. Behold - the Transistor!
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audio and video by Collin Cunningham
Description:
Commercial Geiger counters can cost hundreds of dollars. With this Geiger Counter Kit you can build your own at a fraction of the price! This easy to solder kit can be built in an evening and it works just like you think it would; clicking and blinking in the presence of radiation. Is grandma's dish collection radioactive? Do bananas give off radiation? Are your granite table tops...
As Kent was riding home one night, he wondered why his bike's headlight, meant to illuminate the road ahead of him, was mounted on the handlebars. Why couldn't the light be closer to the ground? He put his engineering mind to work, and Revolights were born.
httpvh://youtu.be/-UvO3QITwkU
The Revolights bike lighting system consists of two narrow rings of LEDs that mount directly to each wheel...
httpvh://youtu.be/rbDO1gdNRlo
Demo of the Mark Rodgers (KC8GRQ) Twitter to Pager setup. This uses a POCSAG pager on the Ham Radio bands to send specific tweets from his account.
Details
During World War II, GIs in the field built really amazing simple radios to listen too. These were made with materials that they could get their hands on and were small enough to carry around in a big pocket. You can modify this design if you want to set it up so that it's tuneable too!
httpvh://youtu.be/skKmwT0EccE
Get acquainted with the Digital Multimeter – an engineer’s best friend!
The ability to test resistance, voltage, current & continuity are vital to any electronics maker – even the freshest of newbies. In fact, having a reliable multimeter on hand is a huge help when learning the basics. Even before understanding what each value means, you’ll be able to establish reference points for applying...