This assembly is from 1957 from a Raytheon manual, but can be modernized using a BC548, 6 V power supply and common 100 mA relays.
This audio amplifier for modulation of AM radio transmitters is from an American publication from...
This nonlinear gain circuit was found in a 1965 Electronic Design. The configuration can be used...
This circuit was found in an old 1970s telecommunication documentation. It is suitable for...