Let me preface my remarks by saying this is my first attempt at programming decoders. I have an older Atlas SD35 that runs like a racehorse! In an attempt to compensate for this, I've tried to write a smaller value into cv5 but to no avail. While I have been able to program some of the other variables I can't seem to have any affect on cv5 at all. Any suggestions?
Is it a factory equipped decoder? If so it's a Lenz and you will probably need to set each of the 28 speed steps individually dependant on your system.
Hmmm… was under impression that while mfg. may very, cv locations were constant. As I said, this is all new to me. Live and learn. Removed shell to try and identify mfg but no markings. These were factory installed if that helps. Wanted to avoid complexity of loading speed steps. I’m double heading all my loco’s and have used technique of just adjusting cv’s 2,4,6 to get a better speed match. This has worked….so far. Thanks for response.
Are there any instructions that came with the locomotive? Seems like there would be some type of information that would let you know who's decoder you have in the unit. Are we talking Ho scale or ?
PRRFAN: I also have an Atlas SD35 with a factory equipped decoder. This is a 4-function dual mode decoder. You can download the decoder manual from the Atlas website. Exactly what do you mean by "running like a racehorse"? Right from the factory, mine ran very, very slow when starting out. I've never even tried to see how fast it would run but just control the speed to run at normal freight train speeds. It's correct that there are no CV5 or CV6's on this decoder, but only the start-up voltage CV2. In CV29, Bit4, you can select either the factory pre-set speed curve or a user defined speed curve. I just used the factory set curve. The speed curve CVs are 67 to 94 and you need to set these before selecting the Bit in CV29. In speed matching this loco to others it's easiest if you have a computer interface and use Decoder Pro. Then adusting the speed curve is very easy. Otherwise, it might be best to use your SD35 as your base loco and match others to it. I have two Atlas locos with this decoder and they both run great. I hope that you can get yours to run well also but when you do speed matching it does get a little tricky. Jerry
Sorry- n scale. Yes, they do run well. But 1 is noticeably faster than other even when run at low speeds. Info I found on Digitrax web site stated you could set up a simple 3 point speed curve. Guess I'm missing something. Will download manual from Atlas site as suggested.
The three point speed curve is CV2 (min), 5 (max), and 6 (mid-point). The three factory equipped Atlas locos I have ran like you report. Two (new run RS11's with Lenz LE063FX decoders) I have set each speed step in and they now run acceptably, the third (older SD60 w/LE062FX) I gave up on for the moment. It runs like your SD35 and needs the speed table manually set. Check CV29 as Jerry suggests.
“ In for a penny in for a pound.” Since most of my locos are Atlas, I’ll have to use speed tables. I’m going to do this manually. After I set the speed table, I don’t understand the process of setting cv29. Could you please explain that to me? I suppose some of this may have been discussed here before, so thanks for your patience.
PRRFAN, almost all my locos have Digitrax decoders so I am no help to you on cv28. I reduce the top speeds on my locos also as there are a few kids that I allow on the throttles but they must be restrained. Is this the same for you? Be carefull how slow you make them when running indipendantly as with the Digitrax the current is reduced even more when consisted. I like the effect myself as it makes the train look super heavy.
CV locations are constant. But the use of some is optional. This page has a chart which show all the CVs, which are Mandatory, Recommended, and Optional. (Since it is a Recommended Practice, I'm not quite sure what that means, but that's a different kettle of fish!) RP 9.2.2 Configuration Variables Jeff
