This third-order filter was found in a 1975 publication. The circuit must be powered by a symmetrical source. The components can be changed for operation on other frequencies.
This circuit was found in Motorola documentation from 1968, using high power transistors and...
Also able to use the LM291, this circuit was found in a Radio Electronics magazine from October 1977....
This circuit generates a linear sawtooth signal. The circuit was found in the December 1992 issue...