We found this small audio amplifier in the November 1999 issue of Electronics Now magazine. The integrated circuit used is not very common today.
This Japanese radio is from the 60s, presenting excellent sensitivity and an output power of 100mW...
Found in a Popular Electronics from the 90s, this circuit uses components that are still current....
This circuit consists of a simple capacitance bridge. The handset can be high impedance from 500...