AN ANALOG SINE WAVE SIGNAL GENERATOR
by Paul Florian
A sine wave signal generator can be used to measure the frequency response of filters and amplifiers. Simply connect the signal generator to the input of the circuit under test and adjust the output of the generator to an appropriate amplitude. Next, measure the output voltage of the circuit at various frequencies with an oscilloscope. A frequency response graph can then be plotted with this data. Page 0
BUILD A SIMPLE SYNTHESIZER
by Tom Napier
The output frequencies from audio signal generators are not always either stable or accurately specified. An alternative is Direct Digital Synthesis (DDS). This process creates the desired output from numerical samples and generates any frequency you set with crystal accuracy. Page 0
THE ENIGMA MACHINE - PART 1
by Gerard Fonte
This is one of those things that seems just a little interesting at the start, but, as you look closer, it gets stranger and stranger. It’s a simple, plain, plastic box. It has a knob, LED, and power connector. When you turn it on, it doesn’t seem to do anything at all. It just sits there. However, put an empty soda can on the machine and lightly rub it with a dry finger. The can vibrates. Yet, this does not happen with a stationary finger or a damp finger. Page 0