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 A3906 integrated circuit from Allegro Microsystems (www.allegromicro.com) consists of a PWM...
This analog TV circuit can be used on a small transmitter. The circuit is from an 80's American...
This circuit is from an Electronics Now from the 90s. It applies to almost any operational...