Radio with amplifier (CB20486E)

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

Changeover switch with PIN diode (CB21256E)
The resistor of this circuit has typical values between 470 ohms and 2k2. We found this circuit in a...
Flip Flop 4027 (CB25120E)
This circuit was suggested by an article in the April 1988 Radio Electronics magazine. The...
5 V to 400 V Converter (CB1478E)
This circuit converts voltages from 5 to 12 V at voltages of 100 to 400 V. The transformer has a...