This circuit is from an American transistor book from the 60's. The transistor is germanium of the time.
We found this automatic traffic light circuit with 6 LEDs in a 1983 publication. The circuit can...
This is another one of the many preamp configurations with operationals that can be found on this...
This circuit covers 400 kHz to 40 MHz in three bands according to the selected coil. The double...