This circuit was found in an old Popular Electronics. The integrated circuit is equivalent to a double 741. The source does not have to be symmetrical.
This circuit was found in the July 1969 issue of Radio Electronics magazine. It also appeared in...
We found this circuit in the August 1994 Electronics Now magazine. The circuit is based on the...
This 4.5 MHz oscillator, or according to the crystal, was found in American documentation from the...