This 5.1 MHz circuit was found in a 1980s documentation. The frequency is given by the crystal and general purpose transistors can be used.
With this circuit it is possible to monitor audio and RF signals in common devices such as...
We found this amplifier in a 90's manual. The integrated circuit is not easy to obtain today. The...
This circuit is an alternative to using Darlington power transistors in the previous amplifier. The...