Radio with amplifier (CB20486E)

We found this circuit in a publication of 1991. The audio amplifier is an operational that admits equivalent.

Memory sensor amplifier (CB6809E)
This circuit is from a 1967 documentation. It consists of a sensor for memories used at the time....
10W Amplifier LM1875 (CB25523E)
We found this circuit in the November 1992 issue of Radio Electronics magazine. The circuit has...
Flasher with two settings (CB6802E)
Found in EEE documentation, this circuit can have the duration and frequency adjusted separately....