This super regenerative detector circuit was found in an English documentation from 1963. The coil is frequency compliant. The transistors are germanium of the time.
January 2017 - STMicroelectronics' new TN4015H SCRs with 40 A currents and high temperature...
This circuit of the 70's uses transistors of the time. The circuit can amplify signals from 10 Hz...
This is a circuit suggested by Linear Technology in a 1980s documentation. The integrated circuit is from...