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 adds a beep to turn on with car flashers that do not have this feature. A 47 ohm to...
Depending on the value of C1, this oscillator can produce signals of up to 1 MHz. For a capacitor of 10...
This commercial circuit, sold under the designation H531 in Japan in the 1960s, used three...