Decoder sizes are stated exclusive of wires.  We recommend that you cut all wires as short as is practical in your installations.

    Plug ‘N Play decoders are available for most current production locomotives but you will need to be sure you choose the right decoder for the particular loco.  Your dealer will be able to help you with this.

    See the Decoder Selection Charts for plug ‘n play decoders.

    The space available in your loco for the installation may be a major factor in choosing which decoder to use. Look inside the loco to see how much room is available. In some cases, you may need to cut away metal to make room for the decoder.

    For HO installations where a DH series decoder won’t fit, you can use any Digitrax DN or DZ decoder since they are all rated at a full 1 amp.

    Digitrax decoder current ratings are stated as normal current and peak current. The peak current rating is good for short periods of time.

    All Digitrax decoders are rated for at least 1 Amp of current for long-term reliability and robust operation.

    The One Amp minimum rating on all Digitrax decoders means that you can use a “Z or N” sized decoder in an HO locomotive.

    Choose a decoder that can handle the current draw of your locomotive.

    The stated current rating includes the motor and all lights and functions handled by the decoder.  If you are planning to install several functions, remember to choose a decoder with a high enough current rating to accommodate this added draw.

 Determining the Stall Current of A Locomotive

    Most current production N & HO scale locos draw 1 amp or less so any Digitrax decoder can be used with these locos.

    Some HO locos have open frame motors and have current draws of up to 3 Amps.  If you think you have one of these locos, please perfom the stall current test detailed below to be sure before you choose a decoder for that locomotive.

    For S & O Scale locos we recommend running the stall current test to determine the current draw before you choose a decoder.  Digitrax 1.5 amp decoders will work in many of these locos.

    Most current production G scale locomotives with a single motor per truck draw 3 Amps or less.  Those with two motors per truck draw 5 Amps. Digitrax makes 3 & 5 Amp decoders for these applications.

Use the following steps to determine the stall current of your locomotive, especially if you have any doubts about its current draw:

1. Put the loco (without the shell on a track powered with regular DC at 12V for HO & N Scales (16V for G Scale).

2. Attach a DC current meter (ammeter) in series with one of the track feeds. If you have a power pack that has an ammeter, it will work for this purpose.

3. Apply DC power to the track.

4. Hold the fly wheel or drive shaft to keep it from rotating for a couple of seconds & measure the current drawn from the power pack while the motor is stalled.

5. Be sure that the power pack voltage remains at 12V for N and HO or 16V for G Scale during this test to be sure you get an accurate stall current measurement.

6. Choose the appropriate decoder from the list below

 Click Here To Choose the Right Digitrax Decoder for Your Installation.