Atlas GP9's and Digitrax

[shark_jj]

I am the only one who is having grief with Atlas GP9's and Digitrax DN163AO decoders.  I know about the solder tinning issue on the corners and have addressed that, the motor contacts at the decoder are a royal pain.  I'm making contact because I can program the decoder, however, they still run poorly.  Tested a GP9 with a factory installed Atlas decoder and it runs excellent.  Has anyone had any experiences they can share.

[wm3798]

Mine works just fine, as does the GP35 I have with the same decoder.  I do have a GP38 with a Digitrax decoder in it, it's fine until I m.u. it, then it runs at only half speed and fights the other units in the consist the whole way.  I've reassigned it as the mill switcher, where it works by itself... at least until I get around to replacing the chip.
Lee

[Ed Kapuscinski]

After I installed a TCS decoder in two of my latest purchases, I have decided to swear off of Digitrax's mobile decoders. I've just had and heard of too many issues from people. I have NO desire to be their QC department.

It's a shame, I really like how they've supported the hobby, and all they've done, but seriously, their mobile decoders are CRAP.

[SD452XR]

I am leaning more towards TCS as well. Better all around.

[NA Tower]

What is the decoder doing? (Or not doing really)

Will it not program?

Thanx

Rob

[MEC_FAN]

Lee, had the same problem last week, as soon as I M.U.ed two units together one ran about half speed. My buddy Pete was here at the time and remembered Digitrax decoders have a feature called switching speed which cuts speed by about 50%. Its controled by function six button. ( cv-54 ) must be turned on to use this function and on this loco it was on ( factory default is off I think). I think when we m.u.ed them we may have hit the F-6 button and turned it on causing that unit to run at half speed. We broke up the consist and hit the F-6 button to turn it off and redid the consist and they ran fine together. On a Digitrax throttle you can see on the top of the display in very small numbers if the function is on.
   Anyway we found four locos on the layout that cv-54 was on. If you have the booklet that came with the 163AO decoder look at the top of page 5 and it tells you all about this feature. We're going to go back and set cv-54 to zero to disable this so we don't get screwed up again. Hope this helps.

MEC

[shark_jj]

mec fan you could be right.  They are running very slowly.  I have had similar problems with digitrax decoders in the past having the "brake" function set on from the factory.  Ed is right about the quality control problem.

[wm3798]

I did a factory default reset, and checked to make sure it wasn't on switching mode...  I'll try it again, but I'm pretty sure I already checked that...
Lee

[Walkercolt]

It's not just Digitrax. Now that DCC's getting around, we're getting calls on every brand, doing or not doing things. 90% of the time, I haven't a clue. Lenz, MRC, a bunch I hadn't heard of, B-mann, Atlas, Athearn(HO and N). Could be a static thing...they're getting zappped when you touch them. Waaaay too common with IC's. Maybe...maybe not ???

[Rich Businger]

If you're using the DN163A0 decoder in the GP9, you're using the wrong one.  The correct one is the DN163A2 for that locomotive.  Part of the problem with all Atlas locomotives is the design of the motor cradle and contacts.  The cradle allows the motor to move from side to side and the contacts rely on tension to make contact with pads. 

In the past, I've had a locomotive that ran great before taking it apart and then ran like crap afterwards.  You have to make sure that everything is seated and replaced exactly as it was before disassembly.

Digitrax (along most other DCC manufacturers) have switched to ROHS lead free solder.  This is required of all electronics manufacturers.  The only exceptions are Military and Medical.  The components are heated at a higher temperature during assembly and solder joints are more fragile.  Unfortunately, over flexing the decoder during installation can break a solder joint.

I was told by AJ @ Digitrax that in the Japanese market, way less than 1% of decoders are returned for repair.  In the U.S. well over 10% are returned for repair.  The decoders are the same whether being shipped to Japan or the U.S..  What does that tell you?  You would be surprised at the number of decoders returned to Digitrax that have nothing wrong except for incorrect programming.

If you have a problem with a decoder send it back to them, they'll replace it.  Usually free of charge.  Use a padded envelope and send it first class, last time I sent one in it cost less than 75 cents.


Rich   
   

[shark_jj]

rich, the decoder is the one recommended by the hobby shop I deal with as there is no listing on the digitrax website for the new GP9's.  I also do not find a listing for a DN163A2.  Is this a new decoder?

[Rich Businger]

It is newer.  Probably been out about 6 months now.

Here is a link:

http://www.digitrax.com/prd_mobdec_dn163a2.php

It is shorter than the DN163A0.


Hope this helps,
Rich

[shark_jj]

That's interesting Rich, thanks.  How did you find it on the website, it isn't listed under either mobile decoders or under decoders for N scale locos?  Is this the one that Digitrax is recommending for GP9's? 

[Rich Businger]

Scroll down the home page, its located under What's New, Recent N and Z Scale Related.

I'll look later today at my GP9 make sure this is correct.  I'm 99.9% sure it is.


Rich

[shark_jj]

Thanks Rich, the number of times I have been on that website and I have never scrolled to the bottom (lesson learned), it says it is designed for the GP30, which is the same as the 9 so I think you are absolutely correct.  I am going to get one and give it a try.  I have 9 GP9's, none of which I would describe as good runners at the moment so if this works it will be great.  I may be having an intermittent contact problem.

Also worth noting, I gave a couple of them to a friend to play around with.  He says he thought the motor contacts were slightly oxidized (these are straight out of the box units).  He cleaned them up and says they are running much better.  I haven't seen them yet, so I am not sure what running better means.