This circuit was obtained from the July 1970 issue of Radio Electronics magazine. Zeners are power types that can provide a good current to the circuit. Selection is made by rotary switch.
This circuit uses two Raytheon RC4558 operational amplifiers that are similar to the 741. The...
This small stereo amplifier for headphones was found in a documentation on integrated circuits from...
This is a MOSFET version of a grid dip meter for frequencies between 1.8 MHz and 150 MHz,...