A Bug Detector Circuit from H. Adams, a master designer of simple electronic circuits. This circuit uses a MC 34002 chip and a 9V DC battery for its supply. Simply adjust the 50K pot until the piezo sounds off and then back it off.
Once RF is encountered the piezo alert gos off. Keep backing down the sensitivity control and as you get closer the piezo will again go off. It will lead you straight to the source of the RF.
Two different LEDs are included, a red and a green. The green is for on and the red alerts with the piezo. D1 is a standard In34A Germanium Diode. Mr Adams - Contact me at me at my email address: email@example.com