Hello out there. I am still new to DCC but I have quite a few units running. My question is simple but I cannot figure it out. I have an Atlas U23b that I have installed a NCE KRS-SR decoder. It works great at less than half throttle, however, as I approach 2/3rds throttle, the locomotive begins to slow. Advance the speed control and the locomotive races and at full throttle the locomotive stops. I have the Atlas MasterDCC system and I can place the Commander in 14, 28, or 128 speed steps and the response is the same. Does anyone think it could be too high of track voltage? Any other ideas
I am not familiar with this specific decoder so some of the CV numbers I use may not be correct. It sounds like you may have a speed table inabled. The speed tables allow you to specify a specific output to the motor at specific throttle settings. Check to make sure you have the speed table disabled. To do this you need to check what value you have in CV29. I usually have 22 Hex programmed into my decoders. This gives me 128 speed steps, analog conversion off, speed tables off and 4 digit addressing. You may want to temporarily join the NCE group at http://groups.yahoo.com. That way you can post your question to the people who really know NCE products. I hope this helps.
If I were you I would put the unit back on the programming track and start over, making sure you don't enable the speed table. Just let it use the defaut settings. Of course I have a NCE system and I am not sure of Atlas's way of doing things. Also on my Atlas units I use the DASR decoder. I have also read that the Atlas puts out a higher voltage, so you may want to put either resistors or a bridge diode rectifier between the power supply and the command station. Tony's Train Exchange website has some technical information on how to reduce the output on the Atlas System. It seems that the Atlas System has too much power for some decoders and some sound decoders were getting damaged.
