Published in an old Popular Electronics, this circuit makes use of components that are still current. The circuit must be powered with 9 V and eventually adapted to function as a shield.
This integrated amplifier was used in televisions from the 70s, with good sensitivity...
In the figure we have the use of one of the four existing amplifiers in the LM2900 and LM3900 as a...
This small FM transmitter for clandestine listening has a good range and should be powered by a 9...