EMD SD70ACe/SD70M (Revised)

Tips on successful DCC Installation


Picture (Click to Zoom)




Selecting a Decoder


The EMD SD70ACe and 2nd Generation SD70M share a circuit board with the Kato N SD40-2 Mid Production locomotive, and is compatible with decoders designed to fit the same circuit footprint. This guide is focused around the installation of the Digitrax DN163K1C or DN163K1D, but the Train Control Systems K1D4-NC will also fit the locomotive.


Important Note: The MRC SD40-2 Drop-in 0001806 decoder board will NOT fit in the SD70ACe due to height clearance on the board.


Tip 1: Removing the Stock Board

The mechanism for the SD70ACe/SD70M Revised has locking surfaces in two places to hold the circuit board in place, one at the back of the mechanism that holds it from the top, and one at the front that locks it in from the bottom. To remove the board from the mechanism you will need a tool such as an exacto knife to pry the board up and over the forward ridge as shown here. This will allow the board to slide back and out from under the overhanging metal ridge at the back.


Insertion of a circuit board will work the same way in reverse; make sure that the rear of the board will slide under the overhanging piece and use the natural flex of the board to carefully slide the front over the forward locking ridge.


   Tip 2: Placement of insulating tape


When installing the Digitrax DN163K1C or DN163K1D decoder, you will want to place the included insulating tape as shown in the picture to the right. Due to manufacturing tolerances, the board may need to be trimmed slightly to fit properly in place.


   Tip 3: Trimming radiator pegs to prevent decoder interference (SD70ACe Only)


If using a DCC board such as the DN163K1C decoder or DN163K1D with the SD70ACe, both of which are longer than the stock circuit board, you may need to trim the furthest forward locking pegs for the radiator detail pieces on the inside of the shell so that they do not press against the circuit board, as shown in the photo here (just trim them enough so that they do not extend into the cavity within the bodyshell and sit flush to the edge, instead).


This can be done with an exacto knife or razor saw and will not effect the appearance or solidity of the model.