The resistors R1 and R2 consist of 8 220 ohms x 2 W resistors connected in parallel. The dissipation must be higher for high transmitter power. The indicator can be the multimeter.
This circuit is a kind of Hertz Loop that can be used to check the operation of transmitters and...
This high-impedance headphone circuit was found in a 1990s William Sheets. The power is low, but...
Based on the 555, this circuit was obtained from Internet documentation, serving to generate a...