Found in a 1988s Radio Electronics, this circuit uses transistors of general use to increase the intensity of signals up to about 30 MHz. The power can be done by battery because the consumption is low.
This circuit is from a Popular Electronics from the 90s. The circuit has a tone frequency...
This solar powered circuit was found in a 1991 documentation. The transistor is a general purpose...
This circuit is based on a common cathode 7-segment display. The circuit is based on CMOS...