This circuit was found in an American documentation from the 1980s. The sensitivity ranges from 100 mV to 1 V. The supply must be done with an excellent filtering source.
Found in an old publication, this is a transmitter with a spark coil. The high frequency...
This circuit was found in a 90s Hands-On Electronics. When a signal appears at the headphone...
In the figure we give a suggestion of a high-power stage to excite a speaker with the 2N3055. The...