- there are now essentially "Do It Yourself" sensors thanks in part to Moore's law.
- improvement based on these technologies, such as more discriminate detectors, are in fact, already mainstream detectors. One wonders however, how revisiting these 1-bit detectors with some rapid prototyping and the 1-bit or n-bit compressive sensing approach, could yield newer and cheaper detectors that would be in competition with current mainstream and more advanced detectors.
From the video description: "Visit www.MadScientistHut.com and go to the blog for full details on how to make this DIY $30.00 Geiger counter."
The basic BFO (Beat Frequency Oscillator) employs two radio frequency (RF) oscillators which are tuned to very nearly the same frequency. The frequency of each oscillator is usually determined by an L-C resonant circuit, that is, an inductor and a capacitor. One is called the search oscillator and uses the search coil as its inductor; the other is called the reference oscillator and uses an internal inductor. The outputs of the two oscillators are fed into a mixer which produces a signal that contains the sum and difference frequency components (plus other intermodulation components) of the two input signals. As we will see shortly, the difference frequency is what we are interested in, and a low-pass filter at the output of the mixer will remove the other components.Note: No responsibility accepted due to injury or damage that may be caused in building or using this Metal Detector.
 Resources on Quantization
 Nuit Blanche blog entries on quantization
Liked this entry ? subscribe to Nuit Blanche's feed, there's more where that came from. You can also subscribe to Nuit Blanche by Email, explore the Big Picture in Compressive Sensing or the Matrix Factorization Jungle and join the conversations on compressive sensing, advanced matrix factorization and calibration issues on Linkedin.