Published in an old Popular Electronics, this circuit makes use of components that are still current. The circuit must be powered with 9 V and eventually adapted to function as a shield.
The sensor of this circuit is a 2N3055 transistor from which the housing cover has been removed to...
The figure shows how to generate a 60 Hz clock signal for TTL circuits. The circuit is from Radio...
The circuit shown in the figure can generate signals of good intensity up to a frequency of 30...