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Do DCC decoders emit ultrasonic sounds?

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Posted by riogrande5761 on Sunday, February 12, 2023 8:06 AM

betamax

If you are watching a video, is it using an old CRT television? They scan at about 15,750 Hz.

As a kid I could hear that sound from tube TVs.  I could tell if the TV was on with the volume turn all the way down, even down the hall in my bedroom.

Rio Grande.  The Action Road  - Focus 1977-1983

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Posted by wvgca on Friday, February 10, 2023 6:51 AM

a simple answer, yes, but at very low volumes ..

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Posted by maxman on Thursday, February 9, 2023 10:34 PM

restorator
Does anyone have any experiences with any pets or any info on this? 

We have a Senegal parrot and are baby sitting an Eclectus.  Whenever there is something going on that we don't want them to hear we put little birdy ear muffs on them.  We got them from Amazon.

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Posted by betamax on Thursday, February 9, 2023 4:47 PM

The better decoders use high frequency PWM to drive the motor, which we don't hear, up to 50kHz. Cheaper decoders may use frequencies much closer to the range animals hear, but just out of our range. Your pet might be picking up high frequency sounds from the motor, or the locomotive is resonating at a specific frequency. 

If you are watching a video, is it using an old CRT television? They scan at about 15,750 Hz. 

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Posted by Mark R. on Thursday, February 9, 2023 10:56 AM

The power is being pulsed roughly every 62.5 microseconds (the Pulse Cycle time), or at a frequency of around 16,000 Hz to a high of 43,000 Hz. That is normally above what we can pick up, but other animals (birds) may very well hear it.  Older decoders that utilized a lower frequency, 30 Hz to 200 Hz, had a very noticeable "buzz" that humans could hear.

Mark.

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Do DCC decoders emit ultrasonic sounds?
Posted by restorator on Thursday, February 9, 2023 10:37 AM

I have an African Grey Parrot and he often makes a repetative high-pitched squeaking sound when I am running trains or even watching a video. The it hit me that DCC could be causing an ultrasonic sound that I cannot hear that is dsiturbing him. Either that or he is just excited, because he definately does like to watch the trains run. But I certainly don't want to bring him into the train room if it hurts his ears!

Does anyone have any experiences with any pets or any info on this? 

Thanks in advance

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