I've Found A Good Solution For Adding DCC To Atlas Kato HO Locomotives

I became a dedicated collector of Atlas Kato yellowbox HO engines from their first release in 1985. The 1986 RS-1 and the 1990 GP7, with their heavy metal frames, were even better. I was a late adopter of DCC, starting only in 2012, so I'd accumulated a good number of Atlas Kato locos, all of which had been developed before DCC arrived in the mid 1990s. This meant that at some point, I'd have a project on my hands to convert all of them, and none would have anything like an 8-pin socket for an NMRA plug.

At various times I've tried the NCE DA-SR and the Digitrax DH165A0, which are nominally intended for Atlas locos. It's only been very recently that I'd even heard about the Digitrax DH165K0, which is nominally intended for Kato HO locos without 8-pin NMRA sockets. But other than the Atlas Kato yellowbox locos, I think the Kato HO GP35 is the only one that doesn't have an NMRA socket, although the old pre-Bowser Stewart Kato locos are also compatible with the DH165K0.

But I finally tried a Digitrax DH165K0 on an Atlas Kato HO GP7:

There are two big advantages to the DH165K0 over the DH165A0 for Atlas Kato locos. The first is that the contacts for the motor leads are designed specifically for the flat brass strips that reach up to the Kato plastic distribution plate on top of the motorr that carries the contact wires from the trucks and the single incandescent headlight bulb. The second is that the DH165K0 carries wire extensions from the track power nubs at the end of each end of the decoder that correspond to the former brass wires on the Kato plastic contact plate over the motor. Both make the conversion more of a drop-in with less need to strip the track power wires from the trucks or solder new wires to the flat brass motor contacts. Also, the interface between the flat brass strips and the decoder gives you a positive forward and reverse for the install without the need to test the motor polarity.

I've also found you can bend golden white LEDs as shown in the photo above and solder them directly to the headlight contacts on the decoder for bidirectional LED headlights.

With the bidirectional LEDs installed as shown, you need to shorten the light bars for the headlights. You can do this with wire cutters directly on the light bars still in position the body shell. There is no need to flatten or polish the cut ends for the light to pass through to the headlights on the shortened light bars.

In the 1990s I got four Altas Kato Illinois Central GP7s. I renumbered two of them with the old Herald King decals, which I think worked out well. I got four due to family connections with the IC, as my uncle worked variously for the Lackawanna, the Western Pacific, and the Illinois Central, winding up his career as the CEO of IC.