Atlas N-scale GP38-2 with factory installed decoder - problems

[nicksandru]

 I have bought a few monts ago an Atlas N-scale GP38-2 with factory installed decoder and I discovered that I couldn't program the decoder. I tried both at home (with a Zephyr control station) and at the club (the New Jersey Model Railroad club in Union) with Digitrax PR3 and a laptop running DecoderPro. In both cases the decoder could not be read or written, neither in programming or operations modes. Eventually I replaced the factory-installed decoder with a Digitrax DN163A0 and I had no problems programming it. What kind of decoders are mounted on Atlas locomotives and is it worth buying locos with factory-installed decoders (Atlas or other brands)?

 

Nick

 

[jeffrey-wimberly]

 I have several decoders that exhibit the behavior you described. I put a 1k resistor across the rails of the program track and that fixed the problem. BTW, my decoders are all non-sound.

[CSX Robert]

davidmbedard

The Atlas decoders do not support speed tables or bemf.  So, you will not be able to speed match them to any other loco.  

The Atlas decoders certainly do support speed tables. They do not support Vmid and Vmax, so you can not speed match them just by using Vstart, Vmid, and Vmax, but you can speed match them using the full 28 step speed table.

davidmbedard

To change the address with a voltage-limited programming track, you need to write CV17, CV18 THEN CV29...and you have to do it manually.

I have never had to maually program the three CV's on my Atlas engines with factory equipped decoders. I do have to use the resistor across the rails trick, but I just use the regular 4 digit address programming routine of my Zephyr.

[nicksandru]

 I solved the problem by replacing the factory-installed decoder with a Digitrax DN163A0. From now on I will stik to buying the locos and decoders separately...

 

Nick

[CSX Robert]

davidmbedard

Well....I assumed the OP didnt know of this trick.  Why dont you explain it to him?

I did not explain it because jeffrey-wimberly already had in the post before yours:

jeffrey-wimberly

...I put a 1k resistor across the rails of the program track and that fixed the problem...