Can be used as a shield, this old American documentation circuit offers digitally selected attenuation values from 1 to 0.0001. The component used is uncommon today.
The sound produced by this circuit, from a 1978 publication, depends on the humidity between the...
In a September 1992 Radio Electronics article, we found this basic 555 circuit used to generate fixed...
This circuit is suggested by Motorola, using a 4N26 type coupler and an MC1733 type operational....