After two weeks of testing how and why my mobile phone caused interference when the Keeley Bassist was integrated, I owe you an answer.
A friend of mine, who is an active radio amateur, brought some sophisticated test equipment to tackle the problem.
Of course, the Keeley compressor ain’t part of the problem. The solid metal housing keeps it safe from outside signals.
We tested every connected component, instrument cable, pedal power supply, pedals and the bass itself.
To cut it short, the patch cable I used to connect the Keeley caused the trouble. The cable is no cheap junk, quality and shielding is fine. But it’s length makes it a perfect antenna for the frequencies used by my mobile. It’s length caused a standing wave with an amplitude that can’t get filtered out completely by the input low pass filter.
After this cable was replaced by a shorter patch cable the interference is gone even with the mobile in my pocket or resting on the amp some inches away from the pedals.
Hope this experience helps others to fix similar problems within seconds.
