This bargraph circuit using LM3914 was found in the October 1980 Radio Electronics magazine. Note the use of a transistor to modify the response.
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,...