humming from DCC locomotives

[Anonymous]

I just hooked up an MRC Prodigy Advance DCC on my 4x8 HO layout and when I went to run my Athearn Genesis Challenger 4-6-6-4 I noticed that there was humming coming from it which I didn't hear when it was running on DC. Is this normal or is it something that could hurt the train?

[DigitalGriffin]

QUOTE: Originally posted by aburke252

I just hooked up an MRC Prodigy Advance DCC on my 4x8 HO layout and when I went to run my Athearn Genesis Challenger 4-6-6-4 I noticed that there was humming coming from it which I didn't hear when it was running on DC. Is this normal or is it something that could hurt the train?

As I found out with my soundtraxx decoder, older decoders have a humming problem with them. They don't switch the pulse current to the motor fast enough, so you hear a humming. Newer decoders switch > 20KHz so you don't hear them. They are often termed, "silent, or quiet decoders" Lenz just came out with a few on their gold line that are really cheap.

[rrinker]

That's probably what it is, I doubt the MRC decoder Athearn uses is 'silent running'

MOST decoders these days are silent running, even some of the cheaper ones like the TCS T1 and NCE D13SR. Soundtraxx motor and sound decoders are not, this is why a lot of people put two decoders in a loco when adding sound with SOundtraxx - a silent running motor decoder and a Soundtraxx sound-only decoder, to get the best of both worlds.

--Randy