Monday, December 30, 2013

FM Radio Station Shielding Part 22

Whenever a capacitive or conductive source such as a human hand is in proximity or touching the radio station transmitter board, it can alter the signal and cause the circuit to drift, shifting the frequency.

To remedy this effect, install ground shielding throughout the radio station's enclosure. Form a continuous sheet of tin foil from a roll of kitchen aluminum foil used for cooking. Cover the inside of the front face plate as well. Make sure it contacts the sides to make a firm electrical connection without movement. Inside the cabinet, attach a ground wire from the foil to the transmitter's board ground connection. An external ground may also be needed. Experiment for best results. 

Make sure all other internal cabinet components are insulated and cannot inadvertently short out to ground.