We found this circuit in the Radio Electronics magazine of December 1972. It generates signals in 6 frequency bands, being indicated for experimental applications with TTL circuits.
Any operational amplifier, like the 741, can be used on this oscillator whose frequency depends on R1...
This old 4-channel circuit was found in the December 1994 Electronics Now magazine. The circuit uses...
This low power TTL circuit (Low Power Schottky) can generate rectangular signals on a 10 MHz...