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OPERATION - DC (SILENT)
If your GMD-1 locomotive is not equipped with a sound decoder, it should function like
most other HO scale locomotives. Put it on the track. Give it some juice. Watch it go.
If you are new to the hobby (or just like to occasionally “play trains”) and you have a
DC-powered train set, please contact us before operating your GMD-1 as it may not be
safe (for your engine and/or your wallet) for you to use your controller.
Some train set throttles put out a very high maximum voltage that is not suitable for scale
model trains. The maximum recommended voltage is 16 volts DC. Similarly, controllers
designed for large scale trains put out a much higher voltage than your GMD-1 can
handle.
If you use a train set throttle or a throttle designed for large scale trains, your locomo-
tive’s circuitry may end up looking like those “your brain on drugs” commercials. In
such situations, we’ll try our best to fix it for you. But we may have to charge you for the
replacement parts and/or the labour involved. That’s because you didn’t read this bit
of the manual. In DC, the number boards are always on and the headlights/ditch lights
are directional. The class lights are installed and wired, but they will not work in DC.
INSTALLING A SILENT DCC DECODER
The GMD-1 contains an ESU-designed motherboard which is connected to the track,
motor and lighting outputs. A blind plug is attached to the motherboard using a 21-pin
connector. To install a decoder, remove the blind plug and install a 21-pin decoder
(recommended) or a 21-pin adapter to attach an 8-pin or a 9-pin decoder. Your chosen
decoder should have six function outputs.
At the time of writing, we recommend the following 21-pin decoder:
•
ESU #54615 - LokPilot V4.0 DCC with 21MTC
We feel the 21-pin connectors are superior because there are enough pins to ensure that
all your lighting functions are connected. The necessary resistors are included on our
ESU-designed motherboard so you don’t have to futz around with resistors. Just plug in
the recommended decoder and you have DCC.
ESU has made a GMD-1 function mapping which can be downloaded into their non-
sound decoder (54615) so that the function buttons and motor control are exactly the
same as our factory-released sound versions. This is available for download on the
GMD-1 page in the Support section of our web site. You will need an ESU LokProgram-
mer to write the function mapping to the 54615 decoder. If you don’t have a LokPro-
grammer, you can adjust CVs in the usual way.
We will be selling rebuilt GMD-1 sound decoders separately; if they aren’t on our web
site by the time you read this, call Dan Garcia at the office and yell at him.
