Which Decoder?

Discussion in 'DCC & Electronics' started by ScottyB, Dec 19, 2004.

  1. ScottyB

    ScottyB Member

    Hey all. I am at the very beginning of starting a railroad with my grandfather's old HO scale trains. The locomotives I have confirmed working are all made by Life-Like and AHM, are all diesels, and were manufactured in the 70s.

    I am very interested in creating a layout run by DCC. The big question -- How do I know which decoder I need for each locomotive? Just for an example, I am looking at this list and I am not sure where to even begin.

    Until a few weeks ago I knew absolutely nothing about DCC, so your help is appreciated!


  2. MasonJar

    MasonJar It's not rocket surgery

    Hi Scott,

    I would check out the Digitrax Big Book of DCC. While it is slanted towards Digitrax, it can answer a lot of questions. If you want an on-line resource, try looking through Woodie's links at the top of the DCC forum.

    In general, your older locos will be more difficult (but not impossible) to convert. This may be due in part to older designs tending to use the metal frame itself to carry current to the motor. With DCC, the current must first go to the decoder, which then gives the motor as much power as is needed for a specific speed.

    All decoder manufacturers make basic decoders suitable for a wide range of applications. You need to go somewhere on-line that gives more info than the list you posted. Try Tony's Train Exchange, Litchfield Station, or the decoder manufacturers themselves. Again, you can find links in Woodie's useful links post.

  3. tweet469

    tweet469 New Member

    The older locos you mentioned can be converted, but I would question whether it was worth it. Do these locos pull with all wheels. I have some old AHMs that only pulled with one truck. This severely limited the # of cars they could pull. With new Lifelike Proto 2000 locos listed as low as $29.99 at MBKlein and Trainworld you may be better off buying new units. I made a couple of my old AHMs dummise with working lights.
  4. ScottyB

    ScottyB Member

    Thanks for your help guys. I opened up a few of the locos to see how they were wired, and each of them (so far) are the same. One wire feeds from the front truck and is soldered to the motor, and the other wire goes from the motor to the rear truck. A headlamp is wired in parallel. That's it. Four wires.

    I'm assuming installing a decoder would involve either snipping or un-soldering the wires from the motor? And routing them to/from the decoder. Or maybe not...

  5. 60103

    60103 Pooh Bah

    You've got it.
    Check the colour-coding for the DCC wires. You may be able to put a socket in the circuit and wire everything to that; this would make replacing the chip easier if you have to. You might also want to make the joint to the motor wires temporary until you get it running the right direction. I would try not to unsolder from the motor if there's enough wire or if you can unhook from the trucks.
    Measure the amps and get a decoder that's hefty enough. The older the loco, the higher the current (generally).
  6. ScottyB

    ScottyB Member

    Okay, at least I'm headed in the right direction. There seems to be plenty of wire to splice into, but I don't see any sort of computer chip at all. It's just hard wired to the motor, and the headlamp wires connect directly to the same place on the motor.

    I'm looking to buy a DCC system soon (still not sure which one) and I just wanted to be sure that there is SOME way to convert these. And it looks like there probably is.

    Thanks again,
  7. Russ Bellinis

    Russ Bellinis Active Member

    Run those locos on dc first to see if they pull well enough to suit you. You can order a t-1 decoder from Loys Toys ( see the sticky at the top of this forum) for under $20. It will control the motor and lights. It comes with a pigtail with a plug to fit the t-1 on one end and wires on the other end to wire into your loco and complete instructions for installation. Again before spending the money, run the locomotives on dc and make sure they run well enough to suit you. They are pretty light and the motors are not very good so they tend not to want to run slow and don't pull very well at all. If you are on a tight budget, you can probably pick up Athearn "blue box" locomotives cheaply either on ebay or from mail order and get locomotives that will pull a lot better.
  8. ScottyB

    ScottyB Member

    Thanks for the advice Russ. I'll test those out first.

    I've read a little about "blue box" locomotives, but I have no idea what they are. I'll search the forums for it, but can anyone elaborate?

    I gotta stop researching for a while and just start building! Thanks all!

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