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.
The TBA810 integrated circuit used in this 1982 project is not very common today, but if found it...
Based on operational amplifiers of the time, this circuit from the 1980s has high input impedance. The...
Found in a 90s Popular Electronics, this mixer can be expanded to more channels. Transistors can be...