Found in a documentation from the 90's, this circuit already includes an amplification stage. The 12 V power supply allows its use in the car.
An old analog TV that is not in use can be turned into an oscilloscope for low frequencies...
This circuit can be used as a base for a UHF transmitter or even a test equipment. The circuit is...
Virtually any FET can be used on this voltmeter found in old documentation. The indicator is a...