Trains.com

Subscriber & Member Login

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

jerky dcc performance (new to dcc)

6227 views
7 replies
1 rating 2 rating 3 rating 4 rating 5 rating
  • Member since
    February 2002
  • From: Mpls/St.Paul
  • 13,892 posts
Posted by wjstix on Tuesday, February 19, 2013 4:57 PM

Generally I've found sound decoders are a bit finicky, haven't really had trouble with regular decoders. Some older engines, like the original Mantua ones, only picked up power from the drivers on one side and the tender wheels on the other, so can have trouble with power pick-up. TCS makes a "keep alive" series of decoders that will keep an engine running from a couple of seconds up to 20 seconds without power. I had an 0-8-0 from Like-Like that I couldn't get to run on DC or DCC, but with the new TCS decoder, it runs great.

Stix
Moderator
  • Member since
    June 2003
  • From: Northeast OH
  • 17,249 posts
Posted by tstage on Tuesday, February 19, 2013 1:06 PM

You are correct, Greg.  DCC is more sensitive to dirty track than it's cousin DC.  Even certain decoders are more sensitive to it than others.

Tom

https://tstage9.wixsite.com/nyc-modeling

Time...It marches on...without ever turning around to see if anyone is even keeping in step.

  • Member since
    July 2009
  • From: lavale, md
  • 4,678 posts
Posted by gregc on Monday, February 18, 2013 7:18 PM

thanks for all the comments.   In this case, it was nothing more than dirty track.   I could visibly see that they were tarnished after cleaning each rail individually with a bright boy.   Still a bit surprised by how big  a difference it made.  Didn't think it was more than a week or so when i last ran an engine with DC.

Perhaps DCC is a bit more sensitive to dirt and needs clean track, but not unreasonable clean.   Don't use rail joiners and make sure every piece of track is fed power.

greg

greg - Philadelphia & Reading / Reading

Moderator
  • Member since
    June 2003
  • From: Northeast OH
  • 17,249 posts
Posted by tstage on Monday, February 18, 2013 2:54 PM

If you used rail joiners and sectional track, it's possible that your rail joiners have also become loose and you now have intermittent continuity of track power to the rails.  Dirty track and intermittent power can make locomotives run as you described.

Tom

https://tstage9.wixsite.com/nyc-modeling

Time...It marches on...without ever turning around to see if anyone is even keeping in step.

  • Member since
    March 2007
  • From: South Carolina
  • 1,719 posts
Posted by Train Modeler on Monday, February 18, 2013 2:42 PM

From the way this is worded it seems it's been a while since you've run trains.  So, I would clean the track.  I would not say that DCC requires a lot cleaner track than DC, particularly when running your DC locos at a very slow speed.

Richard

  • Member since
    February 2005
  • From: Vancouver Island, BC
  • 23,330 posts
Posted by selector on Sunday, February 17, 2013 12:25 PM

It might be track that is dirty, or perhaps not smooth enough for the wheels to make contact reliabliy from point to point during motion, or the wipers are dirty, or the contact points for the wipers are dirty or corroded or oxidized, or the wipers are oxidized, or you have a broken wire, or a solder/connection of wire inside the locomotive, or the contact to the decoder is iffy, or the decoder's BEMF is not on, or it needs dither set higher.....

Some of those older engines have what would be termed questionable or insufficient pickup.  Modern steamers have many pickups under the engine and under the tender, so they tend to do better in the long run, particularly over longer turnouts with dead frog zones to keep the DCC system from shutting down.

Crandell

  • Member since
    September 2003
  • 10,582 posts
Posted by mlehman on Sunday, February 17, 2013 12:22 PM

If you haven't cleaned track lately, I'd say that's a good place to start, along with the wheels on the locos.

Assuming that the locos all were good runners on DC, they should be just as good or better on DCC. With DCC, you get full power on the tracks all the time and -- hopefully -- to the decoder. But there can be fuzz or grunge at a contact point between the wheel and the decoder, so check you pickups.

Finally, intermittent ops after an install could indicate a loose wire somewhere. Check those connections.

Now, with the track, you don't mention feeders. Every rail should have a feeder. Don't rely on rail joiners for electrical connections, unless you solder them. However, this is an issue that should have occurred on DC, too, so may not explain what's happening now.

Mike Lehman

Urbana, IL

  • Member since
    July 2009
  • From: lavale, md
  • 4,678 posts
jerky dcc performance (new to dcc)
Posted by gregc on Sunday, February 17, 2013 10:37 AM

decided to avoid the need for a control panel and associated work,  and bought an nce power cab and tcs t-1 decoder.   I was able to quickly try it in a dcc ready mantua 0-6-0 and later my gem rdg B-8a.

I only recently wired up my track, and therefore it has not seen much use.  Both these engines tended to run OK with a simple PWM DC controller.   But with DCC, both would frequently stop and start only after getting a push.   Behavior was better on sections with longer lengths of rail.

i'm not familiar enough with the characteristics of DCC to understand what is going on.

is the behavior simply due to dirty track and wheels.

please share you experience, thanks

greg - Philadelphia & Reading / Reading

Subscriber & Member Login

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

Users Online

There are no community member online

Search the Community

ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT
Model Railroader Newsletter See all
Sign up for our FREE e-newsletter and get model railroad news in your inbox!