The gain of this step is controlled by the feedback circuit depending on the strength of the input signal. The circuit will operate with modern general-purpose transistor.
We found this circuit in a 1965 magazine. The circuit can be assembled with current equivalent...
This is a typical circuit of a PROM programmer from the 70s. It appeared in the magazine Radio...
If there is an indispensable household appliance in our kitchen these days it is the microwave...