We found this circuit in the 1992 special edition of the Electronics Experimenter Handbook. The components used are still current, many admitting equivalents.
Found in Popular Electronics from the 1980s, this circuit is intended for switching filters with...
The BA1404 integrated circuit (not very easy to obtain) consists of a complete stereo FM...
This transmitter uses an electret microphone and has a few tens of meters in range. The coil L1 is...