This circuit controls the passage of the signal from one speaker to another. The potentiometers must be of wire 50 to 100 ohms with dissipation according to the power of the sound system.
This voltmeter has an input resistance of 200 M ohms (47 M ohms resistors can be used in series to...
This transmitter for the 2-meter range with a power of 1.5 W was found in a magazine 73 for radio...
High-brightness LEDs of various colors and even white can be obtained easily in specialized...