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.
A first circuit that uses a phototransistor as a detector and is suitable for covering short...
We found this circuit in recent English documentation. The circuit uses CMOS technology and can be...
We found this circuit in an old Mullard (Philips) documentation on the 555 and 556 integrated circuit...