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.
Found in old documentation, this circuit makes use of amplifiers of the time, uncommon today. Next...
Rumble is a low-frequency oscillation that occurs in turntables due to variations in motor speed....
This circuit was found in a Popular Electronics from the 90s. The circuit uses common components...