ARLA/CLUSTER: Circuito simples para detectar Ondas Radioelectricas

[João Costa > CT1FBF]

 How to detect radio waves

Sandeep Baruah VU2MUE has released a video showing a simple circuit
which can be used to demonstrate electromagnetic radiation to young
people

Take 30 cm of copper wire to form a loop with one OA85 point contact
germanium diode and a Light Emitting Diode (LED) in series in series.
This simple passive device detects the electromagnetic radiation from
the mobile phone.

When the radio waves from the mobile phone passed through the copper
loop, the free electrons in the copper wire starts oscillating at the
frequency of the mobile phone. This oscillating current of electrons
are converted to DC current by the Germanium diode and the LED (Light
Emitting Diode). Only a single LED without the diode should also work
but due to very high internal capacitance of the LED, the copper loop
de-tunes.

Full details are given at
http://www.creative-science.org.uk/mobile_LED.html

Watch How to detect radio wave (Radio Wave Detector)!
 http://www.youtube.com/embed/2vimFkG1gvk?rel=0