Removing RFI from Audio Inputs

The majority of RFI problems evolve around grounding systems of the stations. Several of the transceiver manufacturers do NOT ground the microphone shield. Here's a simple fix you can try. It just may the ticket to removing your RFI.

Remove the two small #4 Phillips head screws and the cable clamp they hold. Then remove the tiny Phillips head screw that holds the rest of the metal sleeve. Slide that back onto the mic cable. Now...cut off the end of a resistor or get a #20 solid tinned wire about 3" long. Locate the mic pin that has the shield of the mic cable soldered to it. With a small iron, carefully solder this solid wire to that shield and pin. Bring the sleeve back up the cable and attach to the connector with the small screw. This leaves the solid wire coming out the back of the connector. Replace the cable clamp and as you do that, tightly wrap that solid wire around one of the #4 Phillips head screws and tighten the clamp assembly very well.

What you have accomplished is grounded the shield to the transceivers chassis ground through the ring on the mic connector. (Make sure that ring is tight). This has been a big help to many stations with RFI problems and should help you clean up your signal.