Found in a publication by Gernsback from 1960, this circuit uses germanium transistors of the time and commercial coils. It can be changed to operate with modern transistors and other wavebands.
This circuit was found in Ferranti's 1974 transistor manual. The circuit is for non-critical...
This circuit was found in a 1991’s PE Hobbyst Handbook. The circuit is based on altering the sound...
This circuit is based on the operational amplifier LM833 which is not a common component today. The...