Wcu boy, on the SD 40-2 main problem I had was if you let the decoder lay it seems it should (toward the rear) center of the shell wants to pop off. I bent the decocder and wires toward the cab this last time and center now fits fine. I have found the DH 163 to be the better choices.
WSOR, I am 95% sure my Athearn SD 40-2 (Santa Fe long low hood) does not the tall section of the weight in front of the PC board.
Cuda Ken
I hate Rust
The Kato NW2 is a very difficult install, due to the metal frame casting using all available room inside the shell. Follow the link, or a decoder would fit inside the cab. Running the wires to it is still a pain, as well as soldering the wires to the motor tabs without shorting anything out. Definitely not a good candidate for your first decoder install.
Athearn SD40-2 is much easier. Newer ones have the Quick-Plug board, with a 9-pin plug, and headlights on both ends. Looks like this.
Older ones need a hardwire job. Not too hard. For headlights, a little more work is needed, as the stock bonfire in the cab is less than pleasing. I usually rip that out right away.
Mike WSOR engineer | HO scale since 1988 | Visit our club www.WCGandyDancers.com
As a brand newbie to model railroading, I am mindful of that great quote from Sergeant Schultz of Hogan's Heroes, "I know nothing!!" Truer words have never been spoken about me and my model rialroaidng knowledge, especially about DCC decoders.
I looking to purchase a Digitrax Zephyr to "jump in and learn to swim in deep water in the world of command control." What problems am I going to run into when placing a digitrax decoder (or any other recommended decoders from you experts) into a Kato NW-2 and an Athearn SD40-2. My understanding is that the Athearn model already has a NMRA plug, but the Kato does not. Please help me avoid any bad decoder purchases or installation mistakes in these two models!!