Pedal Pickup Up Radio Stations

[PedalSouldier]

I have a DS-1 that I modified with the keely Method and some Germanium Diodes. Ever since the modification the pedal sounds good but picks

up radio stations and it is very annoying. What could I have done that could make it do this.

I would appreciate any help. Thank you.

[R.G.]

There is a serious handbook available on Amazon about RF circuit design techniques for practicing engineers. It's somewhat whimsical title is "Handbook of Black Magic".

First, the DS-1 is prone to noise pickup just as it sits. If you do anything to it that happens to give it a bit of RF resonance near a strong station, you're going to get radio pickup. Nature of the beast.

For a first pass at a fixup, be sure your metal enclosure is well grounded to signal ground, and connect a 47pF ceramic capacitor between the signal and ground right on the input jack. Then either insert a 1K resistor in series with the input signal wire after the jack and before the wire goes to any other component, or slip a ferrite bead over the signal wire. Then use a 47pF cap to ground where the input signal goes onto the PCB.

With luck, one of those will drop the RF level quite a bit. It will still pick up radio, but it will be at so low a level you can't hear it, even after a big power amplifier.

Without luck, you're going to have go hunting RF demons down.