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Digitrax Sound decoder problem.

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  • Member since
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  • From: Northern Minnesota
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Digitrax Sound decoder problem.
Posted by NP2626 on Thursday, April 9, 2015 8:20 AM

I have installed a Digitrax DH123D motor decoder along with a SFX064D sound decoder in an MDC Roundouse 10 wheeler,  The loco has an older can motor and the stall current draw was .71 amps on this motor.  Motor and light control is handled by the DH123D and sound is controlled by the SFX064S decoder.  

The sound starts and lights operate as I would like, the chuff starts long before the motor starts to turn and the moror only starts turning at about 75% of throttle. I understand that the chuff and motor can be synced; however, the motor starting at 75% is what I need help with.  Is there a problem with the motor?  Any suggestions will be greatly appreciated.  

This is my first sound decoder installation and I wanted to see what a Digitrax Sound decoder sounded like.  The DCC installation in this decoder is new. 

NP 2626 "Northern Pacific, really terrific"

Northern Pacific Railway Historical Association:  http://www.nprha.org/

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  • From: Sierra Vista, Arizona
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Posted by cacole on Thursday, April 9, 2015 10:37 AM

The problem seems to be not with the sound decoder, but with the motor decoder.  You need to tune it up by experimenting with the settings of CVs 2, 3, and 4; particularly CV2, start voltage to the motor.

I had a similar problem with an older IHC with a motor decoder in the boiler and sound decoder in the tender (not Digitrax).  The sound would start up long before the loco would start to move.  Since the decoders I used were a sound-only and motor/light-only from TCS and SoundTraxx, adjusting the CVs of the TCS decoder never affected the sound decoder.

 

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Posted by NP2626 on Thursday, April 9, 2015 4:38 PM

Digitrax instructed me to disconnect the sound decoder and re-set the DH123-D by programing CV8 to 8.  Now I have nothing, no motor, no lights!  

NP 2626 "Northern Pacific, really terrific"

Northern Pacific Railway Historical Association:  http://www.nprha.org/

  • Member since
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  • From: Sierra Vista, Arizona
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Posted by cacole on Thursday, April 9, 2015 6:11 PM

After the CV8=8 reset, the decoder will be on address 3.  Did you cycle the power after the reset; i.e., tip the loco and tender off the rail on one side, then set it back down.

 

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Posted by hon30critter on Thursday, April 9, 2015 8:50 PM

Hi NP2626

I don't think you will be able to tell if there is a problem with the motor until you disconnect the drive shaft and test the motor on its own. If it still takes 75% throttle to start the motor then I'd say the motor is toast.

However, I'm more inclined to suspect the drive train as being the cause of the reluctant start ups. Without wishing to sound like I don't give you any credit as a modeler, how well did it run on DC? Also, have you done basic maintenance i.e. cleaning and lubrication, and have you tested how free rolling the chassis is?

Just as an aside, I bought a selection of Nano-Oils not too long ago, and I was pleasantly suprised by how well they work. I have crudely tested them against Labelle #107 oil and #106 grease, and there was a noticeable increase in RPMs when the Nano-Oil was applied. Unfortunately the stuff isn't cheap but a little goes a long way:

http://nano-oil.com/Products.html

My latest use was on a BullAnt drive. I tested the drive with the lubrication installed at the factory, and then I added a tiny amount of Nano-Oil #10 to the motor bearings and a tiny amount of #85 to the gears. Within a few seconds the drive speed had increased significantly. I have no way of measuring RPMs but I'm going to guess at an increase of somewhere around 20%. That was before the manufacturer's recommended two hour break in period.

Dave

I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!

  • Member since
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  • From: Northern Minnesota
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Posted by NP2626 on Friday, April 10, 2015 5:39 AM

Davidmbedard, .71 Amps is the stall current test result, not normal amperage draw.  I would remotor in a heart beat, if that would fix this.  The chassis alone, is very free rolling.  It was checked just before installing the motor.

I think the locomotive operated O.K. in DC; however that was along time ago.  The loco was kit bashed and detailed into a Northern Pacific S-4 10 wheeler, many years ago and I am finally finishing it up.  

I will be working on this loco when I get a chance too this morning. 

NP 2626 "Northern Pacific, really terrific"

Northern Pacific Railway Historical Association:  http://www.nprha.org/

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Posted by De Luxe on Friday, April 10, 2015 7:46 PM

I also have a Digitrax problem. Sorry for asking about it in this thread, but I didn´t want to open a new thread about it after seeing this threads name.

I have a SDXN136PS SoundFX Decoder by Digitrax. It´s actually a N scale decoder but works totally fine for HO scale too. It´s installed in the tender of an IHC 2-10-2 steamer. Although not designed for it, I successfully installed a Seuthe Smoke unit into the 2-10-2 which works very well, BUT: I want the smoke to be activated by pressing f1 which works fine, but the problem is that the bell sound is also located on f1, so everytime i turn on the smoke, i turn on the bell sound automatically. Of course this shall not stay like this, so I´m asking myself now the following question: is it possible to relocate the bell sound from f1 to another number, for example f3? Because f3 is coupler crash, a sound I can totally live without and that I can skip for good. I myself am not familiar with decoder programing at all, and my friend who is familiar with decoder programing (but not familiar with Digitrax!) couldn´t do anything about it. So now I´m hoping to find some help here. It would be nice if somebody can tell me IF it is possible at all to change/relocate functions on this decoder and if yes, how to do it exactly. Would be great if it works out and if I could have the smoke function on f1 only, and the coupler crash sound replaced by moving the bell sound from f1 to f3. By the way another problem is the sound: as soon as the engine touches the rails (I run it on DCC), the steam locomotive sound starts. I don´t like that. I would like to turn on and off the sound whenever I want, because sometimes there are indeed moments where I want to run a sound equipped engine without sound. Still didn´t find out how to do that.

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Posted by NP2626 on Saturday, April 11, 2015 6:46 AM
I have completely torn the locomotive down, tested the motor's stall current out of the loco and found the stall current to be .111 amps.  My previous stall test had erroneous readings for some reason.   So, the Digitrax DH123-D has an amperage limit of 1.5 amps and my .111 Amp stall test shows the motor to be well within 1.5 amps.  So, I feel the motor is not the problem.
 
While reassembling the loco, I improved some of the solder joints and ran some continuity tests.   I improved something, as the locomotive now starts rolling at about ¼ throttle; but, there appears to be poor contact with track power at this point.  Frustrated, I set the loco aside and went on to another project and have spent some time considering what might be the problem!

When I started final assembly a while back, I thought it would be a good idea to use Micro-Mark’s Neolub #2 to increase the conductivity between the wheels, frame and trucks.  I’m wondering if this hasn’t actually caused problems with conductivity as opposed to helping.   So, my next project will be to clean off all parts in the circuit where I used the Neolub #2.

NP 2626 "Northern Pacific, really terrific"

Northern Pacific Railway Historical Association:  http://www.nprha.org/

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Posted by hon30critter on Saturday, April 11, 2015 7:22 PM

NP2626

Well, at least you have made some progress.

After all the work you have done you have eliminated a lot of the variables that could have been contributing to your throttle response problem. Improving pick up and re-lubing might help some more but if those don't solve the problem then logically that takes you back to the decoder settings. I would repeat cacole's suggestion to try adjusting the start voltage CVs.

Dave

I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!

  • Member since
    February 2008
  • 8,878 posts
Posted by maxman on Saturday, April 11, 2015 10:32 PM

De Luxe
I also have a Digitrax problem. Sorry for asking about it in this thread, but I didn´t want to open a new thread about it after seeing this threads name.

I think you will have a better result if you open a separate thread.  It appears that the only thing your question and the original question have in common is "Digitrax".

Brief answers to some of your questions:

Yes, you should be able to "move" things around.  They call this function remapping.

Yes, I believe that there is a way to have the sound not come on when the loco is first powered up.  There is probably a CV change that would accomplish this.

To get definitive answers, best to ask your question independently.

  • Member since
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  • From: Northern Minnesota
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Posted by NP2626 on Sunday, April 12, 2015 6:51 AM

hon30critter

NP2626

Well, at least you have made some progress.

After all the work you have done you have eliminated a lot of the variables that could have been contributing to your throttle response problem. Improving pick up and re-lubing might help some more but if those don't solve the problem then logically that takes you back to the decoder settings. I would repeat cacole's suggestion to try adjusting the start voltage CVs.

Dave

 

I agree and at some point I will need to adjust CVs.  My project right now is to make sure power get's through the loco as best I can.  Certainly the Steam Chuff needs to be better synced to the wheel rotation.

By the way, I like this decoders whistle and bell, better that my Soundtraxx equipped loco.  So far the Steam Chuff is not as good.

NP 2626 "Northern Pacific, really terrific"

Northern Pacific Railway Historical Association:  http://www.nprha.org/

  • Member since
    December 2011
  • From: Northern Minnesota
  • 2,774 posts
Posted by NP2626 on Monday, April 13, 2015 2:03 PM

I have removed the tender trucks from the tender, cleaned off the Neolub #2 from anywhere there needs to be good continuty, brightend up the metal where it makes contact and reassembeled everything.  Running some more tests, I found that the bolt holding on the lead truck on the tender was low enough to make contact with closure rails in my turnouts.  So, I screwed this in farther.  I need to do more testing now; but, this will have to wait until I can get back to it, maybe this evening. 

NP 2626 "Northern Pacific, really terrific"

Northern Pacific Railway Historical Association:  http://www.nprha.org/

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