Based on the TCA6600 or TCA5500 this circuit was found in a 90’s European documentation. The integrated circuit used is not very common today.
This circuit was found in an American documentation. Its purpose is to modify the tuning range of a...
We found this circuit in the October 1987 Radio Electronics magazine. The circuit uses a 1-to-1...
In the figure we have a variation of the previous circuit with only one transistor, using the...