Hi guys,I have been trying all day to get my Atlas GP38-2 to take new cv values for the speed table. CV-2, CV-6, CV-5. I have no clue how to make it work. can someone please help me. I read something about CV-29 having to do with accepting external speed tables? I need to get my Atlas to run like my FVM AC4400DC. At speed 20 on my NCE it runs great, but the Atlas won't run until like 70, or 80.Please HelpMj
Is this an HO engine? I thought that the Atlas GP38-2 was a Trainman series loco that came without a decoder. What decoder is in your unit?
Most decoder are set up with a "straight line" power curve. If you use CV2 (start) CV5 (max) and CV6 (mid), it will set a straight line between 2 and 6, and a straight line between 6 and 5. So if you leave CV2 at zero, make CV5 120 and CV6 60, the engine will speed up and slow down on a straight line, but only about half as fast as it did before, with about half the original maximum speed.
A speed curve or table is a little different. It can be a straight line, but it can be curve too so that the engine runs slower at lower power and speeds up more as it gets closer to the max. You can put in a separate number for each of the 20 or so CVs to make your own curve, but most decoders have built-in ones that you can select. Some decoders come with instructions how to do that, some you have to access the company website to get the full instructions.
Did you start with setting the 3 CV's at 0 for each. This will give you a slow speed increase as you turn the throttle from off to full. Full on being the fastest.
Now saying that, I have 2 Atlas engines that will not start until I get to about 14 on my throttle. This is no matter what I adjust. So to match each with an other engine I set the other one to also start at 17. One of these has a Digitrax decoder and the other has the Atlas factory decoder. All of my other Atlas engines take the CV's just fine.
Ken G Price My N-Scale Layout
Digitrax Super Empire Builder Radio System. South Valley Texas Railroad. SVTRR
N-Scale out west. 1996-1998 or so! UP, SP, Missouri Pacific, C&NW.
You do NOT need to change CV29 to use the basic CV2-6-5 settings for speed matching. Youonly need to change CV29 if you use the more complicated 28 step speed tables that use CV67-94.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Hi,
Thank you for the reply's. I have N Scale, sorry for not putting that down before. I will futz with the CV2,5,6. That is my problem though with the Atlas not starting until around 50 or 60. I need it to go good at 10 & 20.
Thanks
mj
Here's a link to Atlas' basic decoder for N scale. The CV's are basically the same in all of their products.
http://www.atlasrr.com/pdf/AN12A0.pdf
Springfield PA
Hi Guys,
I have the Digitrax Decoder in my Atlas. No matter what I seem to set it to it won't take any values for increasing the speed at lower throttle setting. I just don't know why it has to be this difficult. I guess I will have to wait for Decoder Pro
mjmueller Hi, Thank you for the reply's. I have N Scale, sorry for not putting that down before. I will futz with the CV2,5,6. That is my problem though with the Atlas not starting until around 50 or 60. I need it to go good at 10 & 20.
Try increasing CV2 (starting voltage) up to say 20 and see if it starts sooner. If not, increase it to 40 and try again. Keep doing that until it starts when you first crack the throttle open.