This sophisticated remote field strength meter circuit was found in a 73 magazine for radio amateurs from the1990s. The circuit measures signals in the 1650 kHz range.
Bipolar transistors are types of general use like BC548, while the power MOSFET can be of any type...
We found this circuit in an old documentation. Its purpose is to turn on warning lights when the...
This simple humidity alarm circuit includes a timed warning oscillator whose time is set to R4....