This circuit has an automatic dynamic gain control in a range of 6 dB to 40 dB. We found it in documentation from the 90s. The bipolar transistor is a general purpose type.
This circuit was found in a Popular Electronics from the 90s. The components used are all common...
This circuit was found in a Popular Electronics from the 80s. With it we can make a 100 W...
This circuit interferes with the operation of infrared remote controls. Your radiation should be...