This circuit was obtained from a 1980's QST magazine. The circuit can generate 1 to 15 MHz signals with 1 Vpp at 50 ohms load. Used transistors are still common today.
This circuit is self-powered, that is, the sinusoidal signal that must be converted into a square is...
Originally this circuit excites an incandescent lamp, but it also serves for LEDs, if they use a...
In this circuit of 1987 the player has to briefly press one of the keys trying to hit which LED...