This 50 Hz rejector or notch filter was found in a 1975 documentation. Other frequencies can be obtained by changing components. The filter uses a Wien network and must use a symmetrical power supply.
This 80's Motorola circuit can generate 100 MHz signals, but they can reach 200 MHz with the...
Of course, the current is extremely small, but a voltage of 300 V can be obtained from 9 V of a...
We found this solid-state relay circuit that can function as a shield in a Radio Electronics...