This circuit covers 400 kHz to 40 MHz in three bands according to the selected coil. The double MOSFET allows equivalent, since the original is not easy to obtain.
This circuit reinforces signals in a frequency range between 1500 and 2000 Hz for use in...
When a small air current reaches the piezoelectric sensor, a small audio signal is generated and...
This circuit is from a Poptronics, American magazine from August 2000. The circuit can be...