Atlas GP7 Decoder

[Bangorboy]

I bought two Atlas GP7s oh so long ago.  At the time, I was deep into DCC, but family issues prevented me from converting them at the time.

The engines in question are Atlas GP-7 #48030, Santa Fe #2693. {Plan to renumber one of them}

I am now getting active with my layout and want to install decoders in them.  I am looking at the Digitrax web site for recommended decoders, but can't determine which one I need.  At best, I can swap in the  DN163A4.  Will it fit, or do I have to go with a wired decoder?Thanks for the help.
Bill B

[SP-Wolf]

Bill,

For your GP-7 - the Digitrax DN163A4 is correct.

Here is Digirax's decoder selection page: https://www.digitrax.com/products/engine-matrix/decoder/

Best regards,
Wolf

[central.vermont]

I bought two Atlas GP7s oh so long ago.  At the time, I was deep into DCC, but family issues prevented me from converting them at the time.

The engines in question are Atlas GP-7 #48030, Santa Fe #2693. {Plan to renumber one of them}

I am now getting active with my layout and want to install decoders in them.  I am looking at the Digitrax web site for recommended decoders, but can't determine which one I need.  At best, I can swap in the  DN163A4.  Will it fit, or do I have to go with a wired decoder?Thanks for the help.
Bill B

I don't believe the Digitrax DN163A4 will work for you. I don't think you have a decoder ready chassis in it. According to the Atlas archive the engines you have were released in 1995. That was before they came out with the decoder ready chassis. I suggest you remove the shell to see what you have inside. If it has the 2 light boards then you will need to go with a TCS CN-GP decoder but if it has one long board the m the Digitrax board mentioned will work.

Jon

[Sumner]

Putting a wired decoder in those earlier GP7/9's isn't really that hard.  Since one still has to do some wiring anyway with the TSC decoders for less money I'd prefer using a ESU non-sound LokPilot.  It also has more functions available and good motor control.  If you want sound that is possible also but does require a fair bit of milling for the speaker but very doable...

https://1fatgmc.com/RailRoad/Decoder-1/page-31.html

For those of you who are set up with a milling machine....



.... I have the frame holders shown above up on thingivrse.com.  More info on the frame holders and print links ( HERE )

Sumner

[Bangorboy]

Thanks, guys.  I was getting desperate trying to get the shell off these locos.  I finally did get one off this morning, and verified that a drop-in decoder won't work.  These have the two light boards as one of you mentioned.  I can't remember when I bought them, but it could easily have been in the 90s.
Sumner, thanks for the photos.  They make the project a lot clearer to me.


I want to thank you all for the answers and information you provided.  These are really nice models and I want to get them going.
Bill B