March 2024

Radio Frequency In My Wah

It’s the nature of the beast – wahs and radio stations.

The inductor in a wah acts as an antenna.

This from Dunlop (who happens to make Vox wahs, btw):

“This is a common occurrence because the inductor in the Wah pedal acts as an antenna. When you are in an area with a lot of radio frequency, the pedal can and will pick up radio stations. It is not very easy to troubleshoot and fix, because it differs so greatly due to the different signals and the varying surroundings. What may work in one region might not work in another.

The first step in troubleshooting is to find out where in your rig the signal is coming from.

First check to see if it is coming in through the AC Adapter. Use the effect with a battery and see if it is coming in through the wall. If it is, discontinue the use of the AC Adapter. If this doesn’t work, then…

Second, check to see if it is coming in through the guitar. Turn the volume of the guitar down to zero and see if you still get the radio signal. If yes, you might want to try putting a .0068-microfarad capacitor on the input jack between the tip and the shaft. (The capacitor can be a ceramic or polyester type and voltage rating of any size works.) This will also kill the high end of your sound. If this doesn’t work, then…

Third, check the inductor. If you have a metal inductor, you can purchase a shield from us and place it over the inductor with a ground wire that is placed under one of the screws on the PC Board. This acts as both an AC Hum and RF shield. (It is part number ECB99 – and lists for $12.00) If this doesn’t work then…

Fourth, open up the pedal and unsolder the black wire from the pot. Slide some Ferrite beads onto the wire and re-solder it. The size, number and shape of the beads depends upon the signal that you are getting, and we have not found any rhyme or reason as to which beads work with which signals. If this doesn’t work then…

Fifth, wrap the entire wire harness in Mumetal foil, which comes in a tape format, and hope that that works, because after that who knows!

Getting radio stations on your wah pedal is unfortunately, the nature of the beast, and has been that way since its inception. In some areas it is worse than others. It is especially bad in the great lakes region because the lakes act as large antennas sending out the radio signals to all areas – and all wah pedals.”

More here


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