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Decoder for Atlas RS-1

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  • Member since
    December 2011
  • From: Northern Minnesota
  • 2,774 posts
Posted by NP2626 on Thursday, March 26, 2015 6:34 AM

I was able to get a Digitrax DH123D into my Atlas RS-1.  The decoder is taped to the top of the motor, I think and I believe I used the light tunnels, as the body comes  off without wires.  I need to take it apart to remember how I did it, maybe I will do that today.

NP 2626 "Northern Pacific, really terrific"

Northern Pacific Railway Historical Association:  http://www.nprha.org/

  • Member since
    April 2004
  • From: Ontario Canada
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Posted by Mark R. on Wednesday, March 25, 2015 11:07 PM

It doesn't look like this ? ....

https://www.flickr.com/photos/frankzappai/16431918649/

Mark.

¡ uʍop ǝpısdn sı ǝɹnʇɐuƃıs ʎɯ 'dlǝɥ

  • Member since
    November 2005
  • From: Utica, OH
  • 4,000 posts
Posted by jecorbett on Wednesday, March 25, 2015 8:49 PM

richhotrain

I have two Atlas RS-1 locomotives, and the NCE DA-SR decoder fits quite nicely.

If you are willing to forego sound, the DA-SR will work just fine.

Rich

 

This sounds like the best bet. I'll look into it. As long as it has wires I can solder to the existing wiring of the loco, I'm guessing it will work.

  • Member since
    November 2005
  • From: Utica, OH
  • 4,000 posts
Posted by jecorbett on Wednesday, March 25, 2015 8:46 PM

Mark R.

Randy touched on what your problem is .... the two light bars. They just don't allow any room for anything else to fit into the shell. The simplest fix is to cut the light bars shorter - about a quarter inch inside of the ends, then shrink-tube an LED onto the end of the remaining stub.

 

The TCS A4X decoder is a drop-in replacement for the old plastic board, the the decoder doesn't require extra resistors to be added for the LEDs - they can be attached directly to the decoder as it already has resistors on it for the LEDs.

 

Mark.

 

There is no old plastic board to replace. I don't know how old this loco is but it is wired the way my Atlas locos from the 1980s were. Wires run directly from the powered trucks to the motor. I had to splice a basic decoder into those wires and solder them. It definitely can't use a drop in decoder the way more modern DC locos do.  

  • Member since
    April 2004
  • From: Ontario Canada
  • 3,571 posts
Posted by Mark R. on Wednesday, March 25, 2015 7:54 PM

Randy touched on what your problem is .... the two light bars. They just don't allow any room for anything else to fit into the shell. The simplest fix is to cut the light bars shorter - about a quarter inch inside of the ends, then shrink-tube an LED onto the end of the remaining stub.

 

The TCS A4X decoder is a drop-in replacement for the old plastic board, the the decoder doesn't require extra resistors to be added for the LEDs - they can be attached directly to the decoder as it already has resistors on it for the LEDs.

 

Mark.

¡ uʍop ǝpısdn sı ǝɹnʇɐuƃıs ʎɯ 'dlǝɥ

  • Member since
    February 2002
  • From: Reading, PA
  • 30,002 posts
Posted by rrinker on Wednesday, March 25, 2015 7:32 PM

 If this is HO, the Kato-made ones, it IS DCC ready. You just repalce the palstic 'board' with an Atlas /Kato board format decoder such as the TCS A4x. Plugs and sockets do not "dcc ready" make - the P2K S1 has an 8 pin socket yet is NOT DCC ready (despite the claim on the box!) since the motor is not properly isolate. Motor isolation is what makes DCC Ready.

 The only complicated part about the Atlas/Kato Alcos is mechanical - cutting down the light bars so you can put in two lights or LEDs and have independent lights front and rear instead of one bulb in the middle.

                      --Randy


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

  • Member since
    September 2004
  • From: Dearborn Station
  • 24,075 posts
Posted by richhotrain on Wednesday, March 25, 2015 7:32 PM

I have two Atlas RS-1 locomotives, and the NCE DA-SR decoder fits quite nicely.

If you are willing to forego sound, the DA-SR will work just fine.

Rich

Alton Junction

  • Member since
    July 2006
  • From: Southern Quebec, Canada
  • 868 posts
Posted by Guy Papillon on Wednesday, March 25, 2015 6:21 PM

I am not a decoder expert but I hardwired a TCS MC2 decoder in a Bachmann GE 44 Tonner recently and it is quite a small decoder with good slow speed control.

I don't know for sure if it will fit in your RS1 but you can go on TCS  web site and compare MC2 dimensions with your decoder.

 

Guy

Modeling CNR in the 50's

  • Member since
    November 2005
  • From: Utica, OH
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Decoder for Atlas RS-1
Posted by jecorbett on Wednesday, March 25, 2015 5:46 PM

A couple years ago I purchased an Atlas RS-1 on ebay. It's an old fashioned DC loco and nothing DCC friendly about it. I got the most basic Digitrax decoder because I saw no chance of fitting both a decoder and speaker in the narrow shell for sound. I had to splice into the power wires and solder the 4 basic decoder wires. After completing that, I had a heck of a time fitting everything back into the shell and clamp it back into place. Several times I broke one of the soldering joints and had to resolder it. Finally I squeezed everything in and was able to clamp the shell down so it clicked into place.

I assigned the decoder address and started a test run. It ran fine forward but when I reversed it, it derailed at the first turnout it passed over. I could easily see why. By stuffing the decoder and wiring back into the one small space inside the shell that would accomodate them, the assembly was pushing down on the front of one of the power trucks causing the rear wheels to raise up off the track. I took the shell back off and tried to rework everything and discovered I could no longer power the motor. The light was coming on so it was getting power but the motor was not moving. I suspect what might have happened is that in stuffing everything into that small space, the tape I was using to insulate the soldered joints might have come off and caused a short which damaged the decoder.

I really like this engine and want to make it part of my roster. I'm hoping there is a smaller sized decoder that would more readily fit in the narrow shell. Just a basic decoder to control the motor and work the headlight is all I need. Can anyone recommend a good HO decoder that would work in this loco.

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