This receiver is from a 1924 Gernsback publication. The receiver has good efficiency when powered by the indicated voltages. Listening is through a high-impedance phone.
We can implement this filter with more modern equivalent operational amplifiers, since the LM110 is...
This circuit is from an October 1980 Radio Electronics magazine. The circuit indicates when the...
This circuit can be used as a shield when its supply is 5 V. in this case we can exchange the...