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Wierd decoder failure

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  • Member since
    January, 2005
  • 537 posts
Wierd decoder failure
Posted by hdtvnut on Thursday, March 20, 2008 5:37 AM

A Digitrax DH123 decoder developed a fault that had me scratching my head about what was happening. 

My B unit loco was set up to use a custom speed step table so as to match its speed with an A unit containing a sound decoder at the same address.  I've done this on several other sets with no problems, including A-B-A, as an alternative to consisting.

I noticed that sometimes when I called a function F1-F4, this pair would suddenly slow down or stop; the B unit was the cause.  It seemed to happen only between throttle steps 60 and 64 or so.  Changing to 28 step mode, I found it only occured on step 16.  Reprogramming step 16 does not help.  Cycling power brings back step 16 until a function is called.

I checked other DH123's I had installed, but no such problem.  No big deal except nailing down the nature of the fault.  Anyone else have one do this?

Hal

 

 

  • Member since
    October, 2004
  • From: St. Louis, MO
  • 941 posts
Posted by river_eagle on Thursday, March 20, 2008 10:29 PM

This shoudn't be the answer, but maybe there's some sort of ghost in the machine.

the switching speed option for the 163 on function six, but might be worth a try.

Switching speed is controlled by CV54. The factory setting is 000/x00 for

OFF. To turn on the switching speed feature, program CV54 to a value of

001/x01. When this feature is on, use F6 to activate and deactivate switching

speed. When switching speed is ON and F6 is ON, the switching speed feature

is on. With the feature on the throttle's target speed is effectively reduced by

about 50% and the effects of accel and decel programmed into the decoder are

reduced by 1/4. This is useful for yard switching operations.

When in doubt, rule #1 applies  Central Missouri Railroad Association cmrraclub.com
  • Member since
    January, 2005
  • 537 posts
Posted by hdtvnut on Sunday, March 23, 2008 3:50 PM

A cv 8 = 8 reset did not change the problem with the speed table/user selected speed curve option, but I was able to use the default mode so salvaged the decoder.

Hal

 

  • Member since
    June, 2004
  • From: Orig: Tyler Texas. Lived in seven countries, now live in Sundown, Louisiana
  • 25,640 posts
Posted by jeffrey-wimberly on Sunday, March 23, 2008 5:53 PM
 davidmbedard wrote:

We have had so many DH123s come back with issues out of the pack to where I work that we have dropped the Digitrax DH123 line.  We now have replaced them with NCE SRJ decoders.

David B

I don't know about the DH123 but I believe Digitrax discontinued the DZ123 because of problems.

Running Bear, Sundown, Louisiana
          Joined June, 2004

Dr. Frankendiesel aka Scott Running Bear
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  • Member since
    February, 2001
  • From: El Dorado Springs, MO
  • 1,519 posts
Posted by n2mopac on Thursday, March 27, 2008 9:06 AM
 jeffrey-wimberly wrote:
 davidmbedard wrote:

We have had so many DH123s come back with issues out of the pack to where I work that we have dropped the Digitrax DH123 line.  We now have replaced them with NCE SRJ decoders.

David B

I don't know about the DH123 but I believe Digitrax discontinued the DZ123 because of problems.

I wonder if they are coming out with a newer version of the DZ123. I burned out 3 of these things in an N scale switcher. Would love to try again if they have a new beefed up version.

Ron

Owner and superintendant of the N scale Texas Colorado & Western Railway, a protolanced representaion of the BNSF from Fort Worth, TX through Wichita Falls TX and into Colorado. 

Check out the TC&WRy on at https://www.facebook.com/TCWRy

Check out my MRR How-To YouTube channel at https://www.youtube.com/c/RonsTrainsNThings

 

  • Member since
    June, 2004
  • From: Orig: Tyler Texas. Lived in seven countries, now live in Sundown, Louisiana
  • 25,640 posts
Posted by jeffrey-wimberly on Thursday, March 27, 2008 9:13 AM
 n2mopac wrote:

I wonder if they are coming out with a newer version of the DZ123. I burned out 3 of these things in an N scale switcher. Would love to try again if they have a new beefed up version.

Ron

They already have. It's the DZ125. http://www.digitrax.com/prd_mobdec_dz125.php

I have a pair of the in an HO Athearn F7 A-B set and they're working very well. If thgey'll stand up to Athearn BB they'll stand up to just about anything.

 

Running Bear, Sundown, Louisiana
          Joined June, 2004

Dr. Frankendiesel aka Scott Running Bear
Space Mouse for president!
15 year veteran fire fighter
Collector of Apple //e's
Running Bear Enterprises
History Channel Club life member.
beatus homo qui invenit sapientiam


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