N-TRACK
UNION-PACIFIC STEAM

Here you will find how I digitalized my railroad and engines,
decoders and cv-values.

..Digital or not... We will start by adressing the pro's and con's of going digital or why should I make the step from analog (direct current DC) to digital (direct current DCC) -Pro's- - You can run several engines with different speeds on the same track (block), so you don't have the need to divide your railroad into blocks. - You can run everything: engines, switches, signals and more with one controler. - You can also use several controlers on the same track. (block) - The wiring for your railroad underneath is even simpler, basicly two wires. - You have always full current on your tracks, so the lighting of your engines and coaches will always be on. - You can program decoders so that your engines run more prototypical. (acceleration, deceleration, topspeed, etc) - Consisting is made easy, up to .... engines (doubleheaders, pushers) - And you can hook up everything to your computer and run complete timetables without ever crashing a train. -Con's- - There are several protocols (brands) that don't communicate with each other like Motorola (märklin), Selectrix (fleishmann), DCC (is used by most brands, this is what you could call the standard protocol). - And offcourse there are higher costs involved. Well, how does this digital stuff work? On your tracks there will always be current present, this differs from 12 to 18 volts, depending on manufacterer and scale (gauge) Every button you push on your throttle is translated into a digital data signal. This signal contains an command for, and the adres of an engine ( acceleration or lights on, etc) The signal is then enhanced by the booster and send to the tracks. When this signal arrives at the tracks it is read by every engine on it, but only the engine with the adress that is send with the signal will act on the given command. This also goes for switches and signals which all have there own adress.
Here a few "links" to other sites with digital information.


back to top
Installing DCC mobile-decoder. Here you can follow the installing of one of the mobile-decoders into an engine of mine. The engine is an Atlas FM 15-44 and I am installing in it a Digitrax DN163A0 decoder. What you always need to do first is to check if it runs fine under regular DC, (analog) if the engine doesn't run well analog, it doesn't run well digital.
This is the engine still complete.
This is the Digitrax DN163A0 decoder. Gently lift off the shell and pull down the frame, remove the fuel tank cover.
The Atlas 2002 split-frame side view.
back to top
The Atlas 2002 split-frame top view. Carefully remove the plastic light shrouds.
Light shrouds removed. Remove the frame screws, but leave the frame together, problably the trucks will fall out, but that's no problem.(I can know) You need to get them out anyway, so pull the frame slightly apart untill they drop out. Remove the electrical pickup strips.
Trucks and pickup strips removed.
back to top
Location clips. On the marked locations there are plastic motor cradle tabs which hold the frame together, loosen these. Pull the frame apart and remove the circuitboard. At this point I must tell you that digitrax's manual tell's us to install the replacement board. But... experience tell's us that we need to hardwire the engine to the replacement board. This experience is not only my own, but from several fellow model railroaders. I did it the digitrax way but the motor tabs didn't make enough contact with the replacement board, so the engine wouldn't run, the lighting however did burn this is another contact on the board.
Remove the motor and drive-shafts.

back to top
Cut two wires app. 1.18 inch of length and strip both ends 0.2 inch. (there is a certain color to be used for motor wires, but I didn't have them on hand so I used random colors, I'm not bothered)
Solder the wires to the motor-tabs. I also used shrinking-tube to prevent the tabs touching the frame-halves You can also use isolation-tape, but either way bare-wiring must never touch the frame, this will short-circuit your decoder. This will be a certain death for the decoder.
Soldered wires on motor
back to top
Replace de motor with drive-shafts back into the frame. Install the decoder, square CPU to the top, one wire on each side, between the frame halves.
Now install the other frame-half and only tighten the screws a little. Solder the two wires to the motor tabs on top of the dcoder. Don't solder the tabs together this will short-circuit the decoder.
Replace the trucks and tighten the frame screws fully, replace the the electrical pickup strips. place the locomotive on the track, select address 03 on your throttle and apply power. If the motor does not respond but you can control the lights, check the installation for motor open circuits. If the engine responds correctly replace the light-shrouds and locomotive shell. Now your conversion is complete and your engine awaits commands. Have fun!