AM receiver circuit diagrams

Bug Detector

This circuit can be used to "sweep" an area or room and will indicate if a surveillance device is operative. The problem in making a suitable detector is to get its sensitivity just right; too much and it will respond to radio broadcasts, too little sensitivity and nothing will be heard.

A Bipolar Regenerative Receiver

Schematic for the 530 kHz to 1650 kHz AM Broadcasting Band.

MK484 Radio with Loudspeaker

A complete AM radio set based on the MK484 IC (formerly ZN414).

ZN414 Portable Receiver

An AM portable radio receiver made from the ZN414 IC. The ZN414 ic has now been replaced by the MK484 which is identical in performance and pinout.

Simple Field Strength Meter

This Field Strength Meter is simple and also quite sensitive. It uses an ordinary digital voltmeter to measure RF signal strength up to a few hundred MHz.

Field Strength Meter

This is a wide band signal strength meter circuit which responds to small changes in RF energy, designed to be used for the VHF spectrum and will respond to AM or FM modulation or just a plain carrier wave.