This circuit for signals up to 30 MHz can improve your reception in the medium and short-wave band. We found it in the Radio Electronics magazine of February 1989.
The audio signal generated by the oscillator stage is amplified by an LM380 and reproduced with...
This old integrated amplifier is from a Japanese publication from 1972. The integrated circuit is...
This second-order low-pass Salen-Key filter was obtained from an American 1980s documentation. Formulas...