# decoder selection question



## jfriedrich (Dec 28, 2013)

Hi All, 

As you may recall my recent thread about installing DCC into older athearn locomotives. Well I purchased a locomotive today, not a bluebox but a RTR series Athearn. This is the locomotive http://www.athearn.com/Products/Default.aspx?ProdID=ATH77151 . It appears that this critter is basically a bluebox updated to RTR standards but with the same motor. 

I found that the decoder used by everyone was the Digitrax DH163AT or the 123AT with the Athearn connectors on them, but it has since been discontinued, it has been replaced by the DH163D or 123D. Now here is my question, the Hobby shop sold me a DH126P, is this the right decoder or should i be taking it back? 

Thanks,
Jordan


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## Ray Haddad (Feb 19, 2014)

The color coding on the wires is standardized based on the NMRA Standards and Practices S-9.1.1 located here for download: http://nmra.org/standards/sandrp/pdf/S-9.1.1_2012_07.pdf

The pinout on your connector is also defined there. You can actually purchase a pigtail that plugs into that connector and make it more familiar for hand wiring or manual installation. After you plug it in, be sure to wrap the connector joint with insulation of some kind.

According to what I saw on both original decoders and the new decoder, it should work just fine.


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## jfriedrich (Dec 28, 2013)

Hi Ray, 

Thanks for the reply, and thanks for the link the NMRA standard on wiring. Can I just cut the pin out off in order to direct solder the wires instead of buying that pigtail? Or should I just go back to the hobby shop and get the decoder that's ready for hand wiring? 

Thanks again,
Jordan


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## golfermd (Apr 19, 2013)

The pigtail is a nice convenience. I use them. But there is nothing that prevents direct soldering of the wires. Just make sure you solder the correct wire to the correct place.


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## jfriedrich (Dec 28, 2013)

golfermd,

Thanks for the reply. Will keep that in mind when soldering. I know there is the videos on youtube of people doing dcc installs on these, but is there a picture out there showing the wires/locations, that i can use in conjunction with the NMRA standard? I find it easier to reference a picture than having to rewind a video many times just to get the job done.

Thanks Again,
Jordan


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## Ray Haddad (Feb 19, 2014)

jfriedrich said:


> Thanks for the reply, and thanks for the link the NMRA standard on wiring. Can I just cut the pin out off in order to direct solder the wires instead of buying that pigtail? Or should I just go back to the hobby shop and get the decoder that's ready for hand wiring?


Jordan,

You can use the wires alone. Using markers, color the wires on the standard after you print it. If that helps you only need to do it once. Before you cut the pins off, be sure your wires are long enough to reach the motor and that you can insulate the motor body from the frame. You may not need to do that but I always make it a habit do do that because some motors use the body of the motor as ground for a DC hookup.


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## Ray Haddad (Feb 19, 2014)

By the way, I use Kapton tape to insulate the motor from the frame. It's very thin.


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## jfriedrich (Dec 28, 2013)

thanks again Ray for the replies, and the help. Just trying to get everything sorted out before having a go at the install. 

Jordan


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