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New to DCC and a speed ?

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  • Member since
    July 2006
  • From: Third rock from the sun.
  • 337 posts
Posted by D&HRR on Saturday, December 1, 2012 6:37 AM

Track bus is 12GA, feeder wires are 18GA. longest bus is 22', longest feeder is 12"

  • Member since
    July 2006
  • From: Third rock from the sun.
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Posted by D&HRR on Saturday, December 1, 2012 6:35 AM

It is a DH123PS, I didnt thing that 50 was too high. I talked to several others who were in that area for Athearn RTR units. All the gears are clean, no gum on any. Thanks for the info.

rrinker

 Consider also it's probably a DH123, with no BEMF.

Most of my locos start and run on step 1 or 2 without setting CV2, but I use only BEMF decoders from TCS. Even the Athearn one, although it is a newer RTR RS3, not an old Blue Box type.

                 --Randy

 

  • Member since
    February 2002
  • From: Reading, PA
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Posted by rrinker on Thursday, November 29, 2012 8:30 PM

 Consider also it's probably a DH123, with no BEMF.

Most of my locos start and run on step 1 or 2 without setting CV2, but I use only BEMF decoders from TCS. Even the Athearn one, although it is a newer RTR RS3, not an old Blue Box type.

                 --Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

  • Member since
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  • From: Pa.
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Posted by DigitalGriffin on Thursday, November 29, 2012 8:11 PM

Wow, remind me to remotor an SD40-2 if I ever get my hands on one.

Wait is this the Athearn motors that sound like they come out of a vacuum cleaner?  Didn't they stop using those like 10 years ago?  (I learned something new today)

Don - Specializing in layout DC->DCC conversions

Modeling C&O transition era and steel industries There's Nothing Like Big Steam!

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  • From: Trois-Rivieres Quebec Canada
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Posted by jalajoie on Thursday, November 29, 2012 5:04 PM

DigitalGriffin

I believe what you say David if you encountered this, but it's quite surprising.  I never encountered one over 30 myself. (40+ engines)

CV2 = 70 is ~4V give or take

Especially with modern decoders which usually implement start pwm and kick feature.

I agree with David, I have one Athearn RTR SD40-2 that needed CV2=70.

 

Jack W.

  • Member since
    December 2004
  • From: Pa.
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Posted by DigitalGriffin on Thursday, November 29, 2012 4:57 PM

I believe what you say David if you encountered this, but it's quite surprising.  I never encountered one over 30 myself. (40+ engines)

CV2 = 70 is ~4V give or take

Especially with modern decoders which usually implement start pwm and kick feature.

Don - Specializing in layout DC->DCC conversions

Modeling C&O transition era and steel industries There's Nothing Like Big Steam!

  • Member since
    December 2004
  • From: Pa.
  • 3,361 posts
Posted by DigitalGriffin on Thursday, November 29, 2012 1:51 PM

CV2 of 50 is way way way to high!  I never seen it go above 30 for an open frame motor.  Today's can motors can be as low as CV2 = 2 or 3!

Do you know what your track voltage is?

You can measure it using a standard volt meter.  If you are running way too thin a wire over a long distance, the voltage to your train will drop drastically causing a much higher CV2 value necessary.  14.25 VDCC is the standard track voltage for HO.

Don - Specializing in layout DC->DCC conversions

Modeling C&O transition era and steel industries There's Nothing Like Big Steam!

  • Member since
    July 2006
  • From: Third rock from the sun.
  • 337 posts
Posted by D&HRR on Thursday, November 29, 2012 10:12 AM

Changed CV2 to 50, works perfect, thank you.

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  • From: Pittsburgh, PA
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Posted by JoeinPA on Thursday, November 29, 2012 9:42 AM

David offers good advice. Many times a locomotive needs a good break in period to loosen it up and the performance improves. In some cases the gear grease has thickened an inhibits running. This can be a problem with a "new" loco that has been sitting on the hobby shop shelf for a long time. Check the values for CV2 (start voltage). This can be adjusted to that your loco will start at a lower throttle setting. Check CV5 (Top speed).  It can be adjusted to give you a higher top speed at the high throttle setting. CV6 (mid range) is the setting for the middle range speed. These values will differ for each loco.

Joe

  • Member since
    July 2006
  • From: Third rock from the sun.
  • 337 posts
New to DCC and a speed ?
Posted by D&HRR on Thursday, November 29, 2012 8:21 AM

I am running HO scale with a Digitrax Super Extra Chief and all my decoders are Digitrax. I noticed that some of my locomotives dont start until I reach around 60 on the control knob and when I reach 99 they are not moving that fast. There are a few Atlas and some Athearn RTR units that do this. I guess I am wondering why they are like this and how to change this so they start sooner on the speed knob. Thanks in advance.

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