Found in a documentation from the 90's, this circuit uses only one integrated circuit. The resistors in series with the LEDs depend on the power that can be between 5 and 12 V.
We found this circuit in a 1989 publication. Its purpose is to produce noise in the VHF or UHF...
This short-range, medium-wave transmitter was found in a 1966 documentation. The transistors are...
This is the receiver circuit for the PFM (pulse rate modulation) transmitter of the previous...