Did "Momentum" command kill my 2-8-0 decoder?

[Hunt]

If the Bachmann supplied documentation

http://www.bachmanntrains.com/home-usa/images/44913_Decoder_IS.pdf

is relevant for this decoder, then 0 value is not valid for CV 3 or CV 4. If this is the situation, a 0 value sent to the decoder would be ignored and CV 3 and CV 4 would be left with the value set when momentum level 5 was entered.

To test this is the reason I ask, "What is the value of CV 3 and CV 4 before and after you set the momentum level to 0 for locomotive 705?"



Also since there is no motor control, expect there is a loose wire/connection.

[Maletrain]

Hunt, you seem to have missed the mystery.  The decoder was responding to short address 3 when depowered before this morning's new testing exercise.  And, the resets for CV 8 = 8 did not work when tried on the Main for short address 3, long address 3 or long address 705.  Only page programming seemed to work A LITTLE for changing CV 8 to reset value 8.  And that only got me light control.  I did try programming CVs 3 and 4 to "1" in case setting the NCE value to "0" set those CVs to "0", but that had no  effect.  It is not clear that the NCE set them to "0" when ITS scale of 0 to 9 was selected as 0.  The whole problem seems to be that the NCE coding has compatibility issues with the Bachmann decoder coding.

Kewatin,  I used the value of 5 as a mid-level momentum test.  That should have had an observable effect without taking forever to get up to speed or stop, again.  It is basically irrelevant what I chose that was not zero.  And resetting it to zero did not make things work.  I have never programmed the Power Cab for anything but showing current instead of clock, so resetting it at this point seems to me to be grasping at straws at the expense of adding yet another potential issue.  As for currents seem when THIS unit was running, they ranged from 0.04 to 0.18 amp, running without cars on an oval with 15" radius track and 30" straightaways at throttle settings from creep to max.  However, once I tried the momentum button on the NCE Power Cab, the amps read 0.01 no matter what I do (which seems to only turn the light on and off).  For the OTHER loco, the readings ranged from about 0.14 to 0.41 amp and were highly variable at a fixed throttle setting when I just tried it.  The Bachmann tech said that is probably also a decoder issue, rather than a mechanical issue, but I am not convinced either way.  let's not work on the second loco's problems right now.

So far, I have talked to techs at NCE, Lenz and Bachmann, plus a tech that repairs Lenz decoders who was driving to a meeting at the time.  There is a lot of conflicting information about what the NCE Power Cab really does when the "momentum" function is use, what voltager is required by the Bachmann decoders to accept programming, and other issues that simply do not make sense when compared to what happened.  My next step is to take it to my club and get it on JMRI Decoder Pro and see if that gains me any insights.  So, more later.

I did join the Yahoo group for NCE DCC.  I am waiting to post this there until I get it a little more organized.

[kewatin]

hi steve, at least you are on the right track for solving your problems.i have a much better understanding now of your issues.the good news is you have access to your club.do  they use an NCE system? if so maybe a member will try your power cab programming an address on his loco to verify your cab is working properly.i see also that you did not touch cv3 or 4. your track current seems normal also.i am  still convinced you have a decoder issue,i looked back thru my records that i keep for each of my locos and the 2 that died on me were both decoders,notes were it could not read cv's etc and in the one case light was on ,but no other functions were available.also if 0 was pushed when momentum button was pressed it will be what is commonly called direct drive &the decoder will jump to the speed selected by the throttle.HUNT  is right about bachmann  lenz decoders having a cv3 &4 value that can be adjusted to suit each loco,if desired.again these are wonderful little locos and i would just update  the decoders. also i see a tread going on about wishing bachmann would do a rerun on these over at the train forum.please keep us posted as to how this all works out for you.
regards&later KEWATIN

[Maletrain]

I tried the JMRI Decoder Pro setup at the club this afternoon.  Same problem - can't read CVs, and writing CV 8 = 8 from that system had the same null result.  So, as far as I am concerned, that decoder is dead. I had hoped to find a way to recover it so that I could see if the problem was repeatable.  I would have been willing to do that with this one loco.  But, I am not about to do the same thing to another loco.  I would be interested in hearing if anybody else has used an NCE Power Cab "momentum" button successfully with a Bachmann N scale 2-8-0 with OEM decoder.  Or with any other Bachmann decoder.  The decoder in my 2-8-0 reads (or should I say used to read) manufacturer = 101 (Bachmann) and version = 046.

As for me, time to select a new decoder with quality sound and good back-EMF control features.  Already have one suggestion from the "another run" request thread on another forum.  Any other suggestions?

Steve

[kewatin]

hi steve,glad you were able to determine that it was the decoder.i had thought this from the start as i indicated in previous posts.i have 5 of these locos and last night i went in and using momentum  on all of them put a value of 5 into them,i had no issues,i then went in and changed out the cv 3&4 values to 5 and again no issues i also tried on my berkshire sound equip unit and again,no issues.what i did find is that i personally did not like the performance using the momentum settings and reset every thing back to 0.i also reset my motor start voltage on the 2-8-0's back to 5 instead of 0 where i had them. the only reason in my mind you would want to use momentum is for locos in consist so as to try &match them together..there are several videos on installing sound in these  and doesn't appear to difficult, john colombo over on train board& rail wire has some excellent ones. have a great day &good luck.
regards and later KEWATIN

[Mike C]

As for me, time to select a new decoder with quality sound and good back-EMF control features.  Already have one suggestion from the "another run" request thread on another forum.  Any other suggestions?

Steve

I just had an Econami installed in my 2-6-6-2 . The sound is very nice !  Comparing it to the TSU 750 that I installed in a 2-10-2 , I prefer the Econami over the TSU 750 .  I still have 2 more sound installs that I want done , one of them being my 2-8-0 . I will definitely be putting the Econami in both of them . Just cant beat the price , and the sound and motor control is excellent ! Also , be sure to use some kind of capacitor with the decoder to prevent short power dropouts .