This low frequency oscillator circuit was found in an Electronic Design from the 90s. The transistors are common types, and the frequency is given by the crystal.
The LM11 operational amplifier is not common today. The circuit was obtained in the Linear...
Only one LED is turned on when S1 and S2 are pressed. The LED that will be on is just the...
This is one of the first transistorized receivers (2N107) published in the Radio Electronics...