Atlas RS3/RSD4/5 question

[lvrr325]

More GTE show strangeness.  I picked up an Atlas Classic RSD4/5, looking up on their archive says this should be from a 2005 run.  Engine seems to be either new or very lightly used, end handrails never installed.  

I took a look inside tonight because the sheets with it gave no indication of DCC capability.  Turns out the board inside it has no DCC socket.  It's also marked RS1, so who knows what's going on. 

I have a U23B chassis on the bench and the board looks like it would swap straight over, it does have an 8-pin plug.  

The only question I have is how well will a decoder fit in one of these?  Not much room under the hood. That's the only reason I can figure they would have made these without a DCC socket.  

[craigz]

Uee a board-style decoder like an NCE DA-SR or a TCS A4X. They fit fine.

[middledivision]

If you use the Atlas board from the U-Boat, you will need an eight pin with a harness. The Alco shells are too narrow for eight pin direct (soundtraxx) decoders.

[Gino Damen]

You could also use an ESU Direct board with the NEXT18 connector. Just add the NEXT18 decoder to your linking. A NEXT18 decoder is very small and that combination should fit under the hood.

[wjstix]

I believe the Atlas RS-1, RS-3, and some other of their Alco models have always shared a number of parts like motors, chassis, lightboards, etc. so having an RSD with a lightboard marked RS-1 isn't that surprising.

DCC was still somewhat new in the early years of this century, so a lightboard not having a DCC receptacle was not uncommon. It wouldn't have anything to do with the room available.

As has been mentioned, replacing the lightboard with a lightboard-replacement decoder would be a good alternative. You could also hardwire in a nine-pin harness. An advantage of the latter is you can easily change decoders down the road. Like put in a regular decoder now, and replace it with a sound decoder in the future.

[lvrr325]

I bought an NCE board for it, the DA-SR. Per the directions I need to clip some connections to use the LEDs with it. But they're about invisible to me to see to cut and the directions only show one end of the board. Is there maybe a youtube video or something I can look at so I can understand that part of the install? The rest seems pretty obvious, take the caps off, take the wires out, swap to the new board and put the caps back on, soldering appears optional.

[Gino Damen]

If you look at the board you see several small SMD resistor with above them a staple-like shaped trace on the PCB. That trace needs to be broken. When not broken it just bypasses the resistor.

Where each of the resistor is places is mentioned in the manual (online : ncedcc.zendesk.com/hc/en-us/article_attachments/200303669/DASRv35-d-_solder_pads.pdf)

Best way to brake the trace is using a small (tiny) ball cutter in a Dremel that way you are sure that the trace is broken.