This circuit was suggested by Motorola in a 1969 publication. It makes use of components of the time, but both the FET and the bipolar may be general purpose current types.
This circuit for some amps was found in a 90s Radio Electronics. The voltage can be between 6 and 25 V...
This circuit was obtained from an American 80's documentation. The balanced mixer can be shown in...
This powerful sound emitter used in defense to intimidate people was found in a 90s Popular...