This circuit has a normally low output that is triggered by a high pulse. The circuit is from Radio Electronics from November 1984. The frequency is given by C1.
This circuit is from an article in the December 1988 issue of Radio Electronics magazine that...
This circuit was found in an American documentation from the 80's. The sensor is a special...
The FET can be a BF245, and the other transistors can be the BC548 and BC558 in this simple AM...