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Problem With My Athearn?

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  • Member since
    January 2009
  • From: good ole WI
  • 1,326 posts
Problem With My Athearn?
Posted by BerkshireSteam on Sunday, March 3, 2013 5:53 PM

I have an Athearn R-T-R GP35 with plug-and-play DCC and a Digitrax DH123 decoder. When setting it up yesterday I had to set start voltage (CV2) to around 70 before it started to move at a fast walk (I couldn't get it to crawl properly in step 1). Nothing added to it electrically, only extra is factory LED headlights. Using Digitrax's formula of .5% per CV value, the loco is a little over 4 volts to start.

Does this seem kind of high?

Should I plug the DC module back in and measure amperage?

Is there any help or do I just have to live with it?

  • Member since
    July 2006
  • 3,312 posts
Posted by locoi1sa on Sunday, March 3, 2013 8:07 PM

I never really had any luck with the Digitrax decoders. Taking amp readings before adding a decoder is a good thing to do but the DH123 should be plenty for your HO loco. I would try a different brand of decoder such as TCS. I have over thirty of them and none has given me any issues.

      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!

  • Member since
    January 2008
  • From: Big Blackfoot River
  • 2,788 posts
Posted by Geared Steam on Sunday, March 3, 2013 8:30 PM

My Digitrax decoders crawl, no reason to try another decoder. Is the loco broken in?

"The true sign of intelligence is not knowledge but imagination."-Albert Einstein

http://gearedsteam.blogspot.com/

  • Member since
    February 2002
  • From: Reading, PA
  • 30,002 posts
Posted by rrinker on Sunday, March 3, 2013 9:03 PM

 Starting at 4 volts is indeed about right on. Look up some old reviews of the units and see what their start voltage was. 70 out of 255 sounds like a really big number for CV2, but, at least with Digitrax, it works out to about the 4 volts - so it really isn't much.

 You can tweak the kick start a little to maybe get it to run reliably at a lower voltage, but to get real solid low end you'll need a BEMF decoder like a DG165 or a TCS (TCS has MUCH better motor control). To REALLY get it to run better, google Athearn tune up and tweak the motor and gear train as shown, it will allow the loco to start on a lower voltage, and more importantly run smoother at the low voltage.

           --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
    January 2009
  • From: good ole WI
  • 1,326 posts
Posted by BerkshireSteam on Monday, March 4, 2013 1:47 AM

Thanks all, at least I know something isn't wrong. I wasn't sure because I also have an Athearn R-T-R F7 (with super weight frame!) with same decoder model and it is set at 15 I think.

Now that I know all is well though the decoder will eventually get upgraded. Want to add ditch lights and a roof-top strobe (or two), and possibly sound.

Currently have 3 Athearn engines (two mentioned plus F45 w/sound that has problems) two with Digitrax decoders, a P2K GP18 that is currently in pieces (stole the DG decoder for different loco), and Bachmann 44T that I converted to a TCS decoder.

The hobby shop sells mostly Digitrax for DCC, with some TCS thrown in there. I don't know what they carry for DCC sound.

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