Hi
I'm trying a new kind of decoder, at least new to me, the NCE D13SRP. I installed 3 in 3 different locos and they all have a very high piched buzz coming from the decoder (not the motor). It's quite faint, hard to pick out when the loco is moving, but definately still there.
Is this normal? Does anyone know what is causing it and is there any way to stop it?
ThanksDan
That is not normal at all. What system are you using? Could it be possible that DC is leaking onto the rails from another power source? Or if they are plugged into the Athearn 8 pin socket did you remove the 9 pin jumper plug first? I have seen this burn up several decoders before.
Pete
I pray every day I break even, Cause I can really use the money!
I started with nothing and still have most of it left!
Thanks for the reply. The system I am using is the NCE powercab. I don't think there is an DC leaking, I have no DC power supplies hooked up. The locos are not Athearn, they are British Hornby with the 8 pin DCC ready socket. I've converted many before with Hornby decoders and one with an ESU loksound decoder, this is the first time I've noticed this sound. The decoders seem to be working fine, I'm able to change CVs etc.
Thanks again
Dan
Any type of buzzing noise at all is not coming from a non-sound decoder -- they contain no components that can generate a buzzing noise.
Read the documentation concerning CVs 116 and 117, torque compensation kick rate and strength. These should both be set at 0 for the factory default.
Try resetting the decoders to factory default and see if the buzzing goes away. I've installed close to 100 NCE decoders and have never heard a buzzing noise from any of them.
Thanks Cacole. Maybe a high pitch whistle would be a better description than a buzz, but it's definately coming from the decoder. The decoder is in the tender so it's easy to differentiate motor noise from this.
I did try resetting the decoders, 116 and 117 were both 0 and the noise was present, I adjusted both and the noise didn't change.
I put 3 different decoders (same type) in 3 different locos and they are all making this noise.
I cannot even begin to count the number of NCE decoders that I have in lcoos on my layout including the D13SRP, and none of them make any noise. It is not the decoder that is the problem even if it is producing the noise. The problem is caused somewhere else.
Rich
Alton Junction
False. I also have the NCE POwercab system, and I have the exact same sound on my Soundtraxx TSU-750 medium steam engine decoder. It's the decoder.
Cooped, I have not tried this yet, but it could be a clipping sound. Maybe try muting all sounds pressing the F8 function on your NCE POwerCab remote. If the sound persists, then you're going to have to send the decoder in for repair/replacement.
Interestingly enough, the sound goes away when the speaker is removed. One other thing you can try is to lower the volume to see if that does it.
Regardless of the cause of the problem the sound is coming from the decoder. Different decoder type, no sound.
And this is not a 'sound' decoder with a speaker.
Dan,
I agree with Chuck. It sounds like the torque-compensation of the decoder. NCE uses this instead of BEMF to achieve good low-speed response with their decoders. It can be adjusted or turned off via CVs.
For confirmation you can always call Larry Larsen @ NCE on Tuesday. Keep in mind that they might be shut down for that week so that their small staff can spend time with their families.
Dan, are all three decoders working well otherwise?
Tom
https://tstage9.wixsite.com/nyc-modeling
Time...It marches on...without ever turning around to see if anyone is even keeping in step.
Tom,
thanks. The noise however is present regardless of the settings for the torque compensation, but yes, otherwise the decoders seem to be performing ok. If I can't figure it out before Tuesday I'll give NCE a call as you suggest.
Dan.
Is the buzz all the time or only when the locos are moving? If it is only when moving does the locos have core less motors or some other type of motor besides a wire wrapped permanent magnet type? I am not sure what type of motor Hornby uses.
I have 5 NCE D13SRP decoders on my layout, and none make any noise whatsoever.
So, prior to the OP's call to Larry at NCE, what are we concluding? That all three of his decoders are faulty? Not likely.
I don't think anyone is challenging the fact that the noise is coming from the decoder. But, that doesn't necessarily mean that the decoder is faulty. It could be that something outside the decoder is causing the decoder to produce the noise. Yes? No?
Noise occurs when the train is stationary and moving, doesn't seem to change either way. Hornby use 5 pole skew wound motors, further than that I don't know.
It does not seem to be connected with the motor. As the decoder is in the tender I tried just placing the tender on the track without the engine and the noise it there, so it's happeneing even when not connected to the motor.
Thanks for everyone's thoughts.
Not sure if it makes any difference that the locos are steamers, not diesels.
How about this. Do you have a decoder tester? If you do, remove the decoder from the tender and wire it up to the decoder tester. Does the noise still occur?
It sounds to me like you are hearing something on the decoder proper being excited at 60 hertz. I don't think it should do that. So..............
Crandell
selector It sounds to me like you are hearing something on the decoder proper being excited at 60 hertz. I don't think it should do that. So.............. Crandell
So.................................what?
No, I don't have a decoder tester. I tried the decoder in a Proto 2000 loco, same noise.I then put the other decoder (hornby) type I've used in and now I'm listening for it I can hear it with that decoder too,but quieter hence I didn't notice it before.
The mystery deepens.............
Cooped The mystery deepens.............
It sure does. Keep us posted.
Cooped,
You may or may not be amused by this but, in NCE's literature for the D13SRP, they state:
"Directly replaces noisy Lenz LE103/LE103XF series decoders". Rich
"Directly replaces noisy Lenz LE103/LE103XF series decoders".
Ha ha, yes don't worry I'm not verging on crying yet. If it turns out i have to just put up with this noise so be it. I'm now thinking that as I can hear it faintly on the other decoders I've used (Hornby R8249 if anyone wants to look them up, they're pretty basic) then maybe it's something with my powercab.
Do you live in Europe? The Power Cab was designed to work off of 120 volts at 60 hertz. Most European countries are 220 volt at 50 hertz. This could be the issue here. I am sure there is some sort of authorized power supply for the Power Cab in your country.
One thing I would try is to take one of the offending decoder/ locomotive combinations to another DCC system and give them a try. This would either confirm or deny a power cab problem.
Hi Dan,
I'm in the U.K. using a Powercab. The supplied power pack is a 100 - 240V 60Hz unit that's obviously made for the U.S. market as it has two flat blade prongs. I use a shaver adaptor to plug into the BS standard three pin socket. The voltage is OK but as has been mentioned before, the frequency is wrong for Europe.
That said, I've just tried three locos, one Atlas, one P2K and a Kato, all with NCE D13SRP's and none of them exhibit the sound you can hear.
About four years ago, I did have a Digitrax decoder with their Sound Bug in a Kato loco. Even with the sound muted there was a high pitched faint noise I likened to an electrical whine. This occurred every time power was on, whether that loco was selected or not. I contacted Digitrax who acknowledged the problem but said there was nothing they could (or would) do.
I would be surprised if it was the Powercab, though that seems to be the only constant.
As a last resort have you considered hard-wiring the decoder?
Ian
Logical guess guys, but no I'm in New Jersey (a Brit transplant hence the hornby). I'm trying to think of the easiest way to try them out on a different DCC controller.
Maybe a local hobby store or is there a club layout near you?
Some of the U.K. forums have mentioned that some aspects of Hornby are (or at least in the past, were,) not fully NMRA DCC compliant. There were certainly issues with their Select DCC controllers and perhaps this is tied into your problems in some way?
richhotrain selector: It sounds to me like you are hearing something on the decoder proper being excited at 60 hertz. I don't think it should do that. So.............. Crandell So.................................what?
selector: It sounds to me like you are hearing something on the decoder proper being excited at 60 hertz. I don't think it should do that. So.............. Crandell
So the decoder is defective?
Ok, first things first, Merry Christmas everyone.
I haven't been able to test anything ona different DCC system yet, but would certainly like to if possible. I find it hard to imagine the decoders are defective, that would be 3 brand new NCE decoders all defective and around 30 Hornby R8249S all defective. Seems unlikely to me.
I did recieve an email notification of a post which I didn't see appear on the forum thread (maybe removed by the poster?). Anyway it seemed to make most sense to me. The poster implied that perhaps I could hear pulses from the pulse width modulation at 15-16khz. so well within the human audible range, although close to the top end so perhaps not audible to 'senior' member of the model railway community (and I saw this with the utmost respect!!).
What does everyone think of this idea?
Oh, and as far as I know it is only the Hornby select controller that is not NMRA compliant. Some old decoders were not, but all current ones are.
Cooped I did recieve an email notification of a post which I didn't see appear on the forum thread (maybe removed by the poster?). Anyway it seemed to make most sense to me. The poster implied that perhaps I could hear pulses from the pulse width modulation at 15-16khz. so well within the human audible range, although close to the top end so perhaps not audible to 'senior' member of the model railway community (and I saw this with the utmost respect!!).
Try changing the frequency of the PWM - many decoders have this capability - and see if the sound changes or goes away.
Also, the PWM can generate noise in the motor. The motor is actually a more likely source of the PWM sounds than the decoder. For sound to occur, something has to vibrate at an audible frequency. While a loose component is possible on the decoder, the motor is a much more likely source of vibrations.
Older low frequency PWM (and other pulse shapes) were known for inducing motor "growl", and producing heat in the motor. Which is why most decoders have a variable PWM frequency, often known as "Silent Drive" or similar. At the very least, a fixed pulse frequency is generally moved to 3KHz or higher. Usually, a variable pulse frequency within a range is available to tune the locomotive to the desired qualities.
The down side of higher pulse frequencies is that tie-crawling slow speeds are not quite as good as with a very low frequency pulse (all other factors being equal). But nobody in their right mind operates their locomotives or trains at 1 scale MPH for very long. At 1 scale MPH, it takes a 40ft box car about 30 full seconds to pass a switch stand (in any scale).
Fred W
Cooped ... I did recieve an email notification of a post which I didn't see appear on the forum thread (maybe removed by the poster?). Anyway it seemed to make most sense to me. The poster implied that perhaps I could hear pulses from the pulse width modulation at 15-16khz. so well within the human audible range, although close to the top end so perhaps not audible to 'senior' member of the model railway community (and I saw this with the utmost respect!!). What does everyone think of this idea? Dan
...
That post was by me. After posting that I read one of your posts that I missed earlier that seemed to counter what I had posted, so I deleted it (should have just edited it instead, but it was late and I was tired) because I did not what to confuse the situation. Here is the gist of what I posted:
Many of the "high frequency silent drive" decoders have a PWM (pulse width modulation) motor drive in the 15-16 khz range, which is within the range of hearing of many people (and the younger you are, the more likely you are to be able to hear them). I understand the Loksound decoders have a much higher PWM, above 20 khz, so much less likely to be audible.
The thing is, if the PWM drive is the culprit, then the noise should not come from the decoder itself, but from the motor. Reading that the decoders still made the noise even if not connected to the motor is what made me discount this theory
Are these plug and pray setups you have? If they are can you unplug the decoders and ohm the pins? I am thinking that there may be some jumpers or traces on the board that needs to be cut maybe? Just this past weekend a club member had a similar problem with an Athearn plug and pray with a Digitrax decoder. He had plugged it into the 8 pin socket and failed to remove the 9 pin jumper from the 9 pin plug that he should have used. Needless to say it buzzed very loud but only for a short time before the decoder popped.