Some time ago someone posted instructions for eliminating the hum in a
> decoder by changing a CV. Now I have that problem too and don't recall
> which CV gets changed to what.
>
> Could that person, or some other knowledgable reader, help me with that
> information please?
>
> Thanks/Carter
CV9 controls the Pulse Width Modulation frequency of the motor drive. On NCE SR series decoders setting CV9 to zero (0) will engage the silent running feature. TCS decoders are set there as default. Other decoders may need the CV set somewhere between 0 and 255 to get the right effect. It seems to vary by loco, but a good starting point seems to be a value for CV9 around 180, adjust the value by 10 until you get close, then zero in on it from there. I recently installed a Soundtraxx LC in a brass loco and it was quietest set at 214. You may also might want to check your decoders manufacturers web site for more info or downloadable manuals.
Karlb visit the FCSME at
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