DCC decoder for an Atlas N scale GP-9

[BOK]

I am looking for a drop in DCC decoder for an Atlas GP-9. Can anyone point me toward a brand/store for purchase?

I recently, bought another GP-9 with DCC on line and it has a TCS GP-CP decoder but seems difficult to program. It only has a functioning rear head light not front and erratic speed control. Any suggestions?

I generally have only Soundtrax decoders in my HO locomotives and they are easier to program.

Thanks, in advance for any assistance.

Barry

[woodchip]

The only drop in is for the later version that has a 1 piece board. You might be able to order the parts from Atlas to do an upgrade but with their newer models being DCC/Sound the availability of parts for the older releases is not what it used to be. I'd check the install of the TCS CN GP decoder. I've done 3 of them and they all work properly and can be programmed which in my case is with Decoderpro and a Digitrax PR3. The instruction sheet is probably accessible from the TCS web page.
                                                                                Cheers Hugh

[BOK]

Thanks, Hugh.

I have been going through the TCS instructions but can't determine what CV/Value to use to operate the headlight both in forward and reverse direction. Any suggestions?

I also like the idea of swapping Atlas GP shells for a Bachmann chassis with DCC.

Thanks,

Barry

[mu26aeh]

Given you have no headlight and it runs erratically, I'd do a reset on the decoder.  CV8 = 8

or

CV30 = 2

[nickelplate759]

I've installed a bunch of the CN-GP (and plain-old CN) decoders.  It's not hard, but they do have one quirk - both boards must make good contact with the frame on both sides.  If not, either they don't work or (happened once - surprised the heck out of me) the engine takes off full-speed-in-reverse.

So before you do something more drastic, check to see if both boards are making good contact with the frame.  If either is loose find a way to tighten it up (a layer of solder on the contact pad is one way) and see if that fixes the problem.

[EL3632]

Do you know if your engine has the one piece board or the split board?
Also, the Bachmann decoders in their GP7s are, in my experience, unreliable and eventually (after around a year of use) fail. I have had that happen in two units and seen it happen in a third. Also seen this happen in RS3s, to a lesser extent.

[Southern1970]

If it’s the dcc ready version, I’ve used the TCS asd4 with no issues. 
I’ve also used a spare TCS amd4 in an atlas gp9 with no problem. 
Maybe check the condition of the brass contact strips in the loco (that contact the trucks).  A few days ago I bought a “new” atlas GP38 (was a model released about 18years ago) when I put it on track it was running a bit erratic and noticed a bit of corrosion on the brass contact strips.  Swapped the brass contact strips with a spare set I had and the locomotive now runs a lot smoother even at slow speeds.

[thomasjmdavis]

I've installed a bunch of the CN-GP (and plain-old CN) decoders.  It's not hard, but they do have one quirk - both boards must make good contact with the frame on both sides.  If not, either they don't work or (happened once - surprised the heck out of me) the engine takes off full-speed-in-reverse.

So before you do something more drastic, check to see if both boards are making good contact with the frame.  If either is loose find a way to tighten it up (a layer of solder on the contact pad is one way) and see if that fixes the problem.

+1
That has been my experience also.  In my own case, mine were 15 years old when I installed the decoders, and a good wheel and contact cleaning also helped.  No problems once I followed these recommendations. 

[woodchip]

Hi again   

I think your problems are from a install that didn't go well. The finished product should be identical to this image from TCS https://tcsdcc.com/installation/n-scale/1569   I've actually done 5 0f these not 3,I forgot the 2 C424s I did. Hopefully you have Decoderpro to do programing if not consider a digitrax PR3 or PR4. You'd be able to read what may have been done to the decoder and also program it to your requirements. If the decoder was installed properly both headlights should work depending on direction of travel. If one end is not working it's either a decoder fault,programing by the installer or most likely install problems. As  mentioned in another post this decoder requires both boards to make contact with the frame. There is the possibility that you'd have to put a small blob of solder on the contact pads that you'd then massage with a small (really small) file to create a snug fit for the board into the frame. If you haven't got it here's the link to the CN GP info from TCS https://tcsdcc.com/1286#edit-group-dec-documents.  I don't know if the Bachman chassis would work. Good luck with this as it seems to be the problem that will end with the the "no way man" solution.
                                          Cheers Hugh

[BOK]

Thanks to all who responded and yes right out the box it wouldn't move (wrong address 92 out of 9215) and only the rear head light would function. Once, using the correct address it took off like a rocket was hard to stop with out changing direction and then finally I was able to gain speed control but definitely on the high end.

To add to this challenge I had undergone surgery on my right hand the day before receiving the engine in the mail so currently have limited mobility to remove the body shell (is it a simple matter of slipping it on and off?) and look further. However, before doing that I'll try the re-set procedure and go from there.

BTW, the seller has told me he will make it right so if all else fails I'll mail it back to him to handle/repair.

Once again many thanks, for everyone's help.

Barry

[peteski]

Thanks to all who responded and yes right out the box it wouldn't move (wrong address 92 out of 9215) and only the rear head light would function. Once, using the correct address it took off like a rocket was hard to stop with out changing direction and then finally I was able to gain speed control but definitely on the high end.

To add to this challenge I had undergone surgery on my right hand the day before receiving the engine in the mail so currently have limited mobility to remove the body shell (is it a simple matter of slipping it on and off?) and look further. However, before doing that I'll try the re-set procedure and go from there.

BTW, the seller has told me he will make it right so if all else fails I'll mail it back to him to handle/repair.

Once again many thanks, for everyone's help.

Barry

The problems you are experiencing with that particular TCS decoder (or any other decoder for that matter) are not normal.  It is likely some sort of electrical connection issue, or a defective decoder. TCS decoders are usually as well behaved, as well-behaved as any other brand decoders.

[BOK]

mu26aeh is the Winner!

I reset the decoder to CV30=2 and address 3 and the unit runs like a charm. Good speed control and both head lights, lite and  function correctly.

I thank you all and my hand thanks you too.

Barry