Locomotive Decoder Choices

GSEC Apr 27, 2016

  1. GSEC

    GSEC TrainBoard Member

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    Sometime in the future I want to convert my old DC locomotives to DCC. Should choice of decoder for each engine be based primarily on a decoder designed for those specific engines (physical fit and/or electrical characteristics) or for the DCC system in use?
     
  2. woodone

    woodone TrainBoard Member

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    You did not say what scale you are working with. There are some locomotives that only one manufacture makes a decoder that will fit into it ( drop in type)
    has they are called. If you hard wire the decoder the list is pretty much endless.
    When you say old- you must watch out for too much current draw of the locomotive's motor. Decoders are rated for specific amp rating.
    With older motors you must make sure that the motor is isolated from the frame too.
    Most all DCC systems will control the decoders.
     
  3. jdcolombo

    jdcolombo TrainBoard Member

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    Here are some considerations I've found useful over the years.

    1. All dcc decoders work just fine with all dcc command stations. I use a Digitrax Chief command station and have done so since the mid-1990's, but I have all kinds of decoders on my layout: ESU Loksound, ESU LokPilot, Zimo, TCS, and CT Elektronik are all represented. All of them work fine with the Chief; all of them can be programmed using the Chief and a programming track (though something like JMRI's Decoder Pro running on a computer with an interface to the layout is far easier from a programming standpoint). So you DO NOT have to choose decoders based upon your DCC system. Choose the command system that you are most comfortable with and that best fits your needs (that's a whole different subject, and one that is likely to elicit VERY strong opinions from different users).

    2. It is a lot easier in the long run to use decoders from a single manufacturer. All manufacturers have slightly different implementations of advanced features, such as lighting effects, momentum, braking, function key remapping, BEMF (motor control) tuning and so forth. Even the speed table implementation, which you would think would be the same across all manufacturers, isn't exactly the same. If you "standardize" on one manufacturer, then it is easier figure out how to use these features and to do things like speed match different engines; adjust momentum; get the best motor performance, and so on.

    3. Having said that, not all manufacturers have "drop in" decoders for current diesel models. Digitrax and TCS are the leaders for drop-in decoders. If you are wedded to using drop-ins wherever possible, then you are going to end up using decoders from one of these two companies.

    4. I do not use drop-in decoders; instead I hard-wire everything. The drop-in concept sounds wonderfully simple, but in practice it often is not. For example, you still have to remove the shell and in N scale you must at least loosen the frame considerably to get the old PC board out and put the new decoder in. The trucks will fall out if you're not extremely careful, and you are within a hair's breadth of taking the frame apart just like you'd do with a hard-wire. Moreover, often drop-in decoders have electrical pickup issues: the pickup pads on the decoder are often not quite thick enough, and don't contact the "fingers" of the frame well enough to provide reliable electrical pickup. So . . . you end up having to put a thin coat of solder on the pads to thicken them, or use some .005 phosphor bronze or something else to provide reliable electrical pickup. In addition, sometimes there are issues with the motor brush tabs providing good electrical contact to the motor tabs on the underside of the drop-in. So while the drop-in concept is great in theory, in practice it often is as much trouble as hard-wiring a small motor decoder, and using pieces of the old PC board to provide the lighting and electrical pickup from the frame. Plus if you go the hard-wire route, you have a larger selection of manufacturers to choose from - not just Digitrax and TCS, but Lenz, ESU, Zimo, and CT Electronik to name a few (see next point).

    If you are in HO scale, the drop in process tends to be easier, but even in HO you probably will be limited to Digitrax or TCS for some models. And when I do a decoder install on one of my friends' HO units, I still solder the wires to the decoder. It's just more reliable.

    5. While I have not used the latest generation of Digitrax decoders, I've tried just about everything else - including TCS's current generation, Digitrax's prior generations, and decoder from ESU, Lenz, Zimo and CT Electronik. There is no question in my mind that the Europeans (ESU, Lenz, Zimo and CT) provide the best motor control in the industry, and that Zimo is the best of all (maybe by a hair over the other Europeans, but still best). I don't know why the US manufacturers seem to be a step behind the Europeans on this front, but I'm not the only one that believes this to be the case. On the other hand, you may or may not care. The European's superiority in motor control is much less noticeable in HO scale. In N scale, if you're not completely anal like I am about slow-speed performance (e.g., tie-to-tie creep ability; the ultimate smooth startup and slowdown, etc.), the slow-speed performance edge of the Europeans may not matter. And it's not that Digitrax or TCS are "bad" - they just aren't quite in the same league. It's like Manchester United vs. a really good pro US soccer team. The US team is good, but . . . just not quite that good.

    To sum up, all this has led me to standardize on ESU decoders (I model in N scale). I use the ESU LokSound Select Micro for sound installations, and now use the ESU LokPilot motor decoder for non-sound installations (the Lok Pilot is very small, and will fit in anything currently made, even an Atlas Shay). I hard-wire all the decoders, which is a bit more work than using a drop-in, but in the end I believe it provides a more reliable installation. Your mileage may vary, as they say.

    John C.
     
    Last edited: Apr 27, 2016
  4. GSEC

    GSEC TrainBoard Member

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    Appreciate the responses. (y)
     
  5. Carl Sowell

    Carl Sowell TrainBoard Supporter

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    John,

    That is an excellent review and should be a lot of help to many guys or gals wishing to get into decoder installs. I sure wish I had read the note about 5-6 years ago, maybe I would not have to bother you for help now. I know, you do not mind and that is my point, you are more than willing, and I think you actually enjoy, helping newbies before we get into trouble.

    I too have just about decided to go with ESU products 100% for sound as well as non-sound decoders. However I and another modeler on TRW have the same problem with an EMD 567 file that will not perform the random sounds. To his credit Matt has been looking into the problem. Perhaps he will tell us what we are doing wrong or that there may be a problem with the decoder.

    Thank you John for all the assistance you have given me,
    Carl
     
  6. GSEC

    GSEC TrainBoard Member

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    I really appreciate the information, John. Have you tried any of the dielectric/conductive greases on those drop-ins? Unless the plugs/receptacles are poorly manufactured and loose, a good dielectric grease keeps out the things that cause the connections to become problematic - moisture, dust, etc. - and doesn't hinder conductivity at all. Some articles I've read indicate these greases actually improve electrical properties of the connections. I know from experience that GE and Allen Bradley strongly recommend (in installation instructions as well as a tube of grease that come with each card) use of such substances on plugs and pins on most, if not all, of their low voltage (mostly 5, 15, and 28 volts) applications within AC and DC industrial drives.

    None of my engines, though, are DCC ready, so I'll have to hard-wire. Being a lazy as well as grumpy, whiny, old man, I'll probably just do it once and not worry about drop-ins at all. When I get a round tuit.
     
  7. jdcolombo

    jdcolombo TrainBoard Member

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    Hi Carl.

    Well, 5-6 years ago I didn't know what I know now :).

    I suspect the random sound problem is an issue with the file. I've never been able to get anything but the random pop-off valve noise working on the 567 file.

    I do enjoy helping folks with decoder installations. In my "real" life, I'm a professor at the University of Illinois. The greatest joy of teaching is watching a student "get it." I get this same joy from someone having tried and successfully installed their own decoder, when they were afraid to do so before. Decoder installations DO take some level of skill - you have to be decent at soldering, for example, and sometimes you need some mechanical ingenuity to fit everything inside an N-scale engine. But it's not nuclear physics; "normal" people can do this with a bit of patience and practice. If I can help someone get over the hump to success, well, that's what I do for a living and I enjoy it.

    John C.
     
    RBrodzinsky likes this.
  8. edbaar

    edbaar New Member

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    One thing I think I "got" from this thread is that "all DCC decoders work with all DCC command stations." That's reassuring, since I have a Kato diesel locomotive with an NEC decoder, but am planning to use a Digitrax command station and Digitrax decoders in future locomotives I will purchase. Presently, everything that I have are Kato products and Kato seems to recommend using Digitrax in their locomotives.
     

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