This circuit with an unusual configuration was found in the January 1974 issue of Radio Electronics magazine. The frequency is given by L1/C1, and the transistors admit equivalents.
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,...