This sensitive bio-monitoring circuit was found in the December 1984 issue of Radio Electronics magazine. The circuit is powered by a 9 V battery and uses a low-impedance headphone output.
This transistor amplifier provides 35 W of power to an 8 ohms speaker and must be powered by a 59...
The input and output frequencies of this circuit depend on the coils and capacitors of the tuned...
The integrated circuit used in this configuration for noise reduction on FM radios is not common...