- on RF (radio)
- Published in issue 7/2010 on page 56
Mobile Phone TX Demo
(Summer Circuits 2010 article)
This is a very simple and cheap device that demonstrates mobile phones (US: 'cell phones') generate RF energy (radio waves) strong enough to light an LED.
We have a 30 cm (7.5 cm per side) full-wavelength loop antenna (a 'Quad' to radio amateurs) connected to a germanium diode and a hyper-bright LED.