Found in an old American publication, this circuit generates signals of various waveforms. The frequency depends on the components. Operational amplifiers are from the period.
I found this circuit in a 1986 English magazine. It can still be easily assembled, exchanging Q1...
We found this circuit in an Argentine publication from the 70s. The coil can be made with 80 turns...
Found in General Electric documentation from 1967, this circuit makes use of an unusual...