This circuit is from a Hands-On Electronics from the 90s. The integrated amplifiers used are well known. The range is a few tens of meters depending on the resistance of the cables.
This is an application circuit of the Texas Instruments (2019) component datasheet itself. The...
This conventional 12 V power supply stabilized with 2 A current was found in a 1995 documentation. Its...
This simple oscillator with two general-purpose transistors has its frequency given by capacitor...