This sophisticated remote field strength meter circuit was found in a 73 magazine for radio amateurs from the1990s. The circuit measures signals in the 1650 kHz range.
This symmetrical 1.2 to 35 V source was found in a 1994 documentation. The integrated circuits are...
Found in a 90s Elektor, this mixer makes use of integrated circuits of the time. The supply must be...
This amplifier is specifically designed for portable radio and recorders with a 4 ohms load....