Okay...I've just purchased a Digitrax system, and I'm ready to install my first decoder. I could use some general tips, but here's the BIG question. I'm installing a DH121 digitrax decoder into a Proto 2000 SW9/1200. I looked at the circut board on the loco, and I'm TOTALLY lost where to start. Can anyone offer advice for installing a decoder into this (or similar) loco? (It is HO scale, by the way..) Any advice would be GREATLY appreciated!
Firstly, did you receive instructions with the decoder. If so follow them. You could also try Loys Toys web site for advice or TTX for advice. Good Luck Loys Toys Tony Train Exchange
I have good instructions on installing decoders in general, and I pretty much understand them. However, the LL P2K SW9/12 loco...for one thing...I don't know if I should REMOVE the circut board that is in it? Or cut traces on it? (Which scares me...heh) Also, this loco has a rear light, but the rear light is mounted on the shell, and has two copper contacts that look like they touch the frame or circut board or something...so I'm not certain how to wire up that light without permanently connecting the shell to the chassis. TTX has a nice picture of their custom SW9/12 chip, but that's about it. And I haven't found anything on ANY site regarding this particular loco. (A few places had some commentary on working with a similar unit in N scale, but not HO.)
Hi C.K., I model in HO steam so this is somewhat foreign territory for me, but here goes. <UL TYPE=SQUARE>Does the DH121 have the standard 8 pin NMRA plug on the end? If it does just swap it for the circuit board. If it does not have the NMRA plug, call Loy's toys or TTX-DCC and order one, then carefully unplug the wires from the decoder and put in the plug and procede as above. Regarding the rear light: you may need to extend the blue common wire and either the white or yellow wire[ whichever you want the rear light to be]. I'm away from my layout and I think white is front and yellow is back. It should be noted in your decoder instructions. Anyway extend the wires, purchase from TTX-DCC a couple of micro minature plugs, install one end on the copper straps and the other on the wires and that way you can unplug the rear light to remove the shell. I do it all the time in the front of the smoke box on my steamers. [/list]Hope this helps. [ 09 May 2001: Message edited by: ChrisDante ]
First, I would like to recommend you join the Digitrax egroup at http://groups.yahoo.com There are over 1500 other Digitrax users on the group just waiting to assist you. I have done about 20 decoder installs and you really picked a tough locomotive to start installing. I am not sure that a DH-121 will fit inside this loco. I would recommend that you buy the TTX decoder. If you don't want to do that then try the following: See if the DH-121 will fit in the cab with the wiring harness attached. If it doesn't then you will have to get one that does. If it fits then just follow the instructions on the card that came with your decoder. I personally always remove the circuit boards and do a direct hardware to the lights and motor. Red/Black wires go to track pickup, Orange/Gray wires to motor, Blue/White to front light, and Blue/Yellow to rear light. Notice that the blue wire is shared by both lights. You will need resistors for the lights on the White and Yellow leads. You will need heat shrink tubing on all connections. I don't have the resistor value readily available for the LL bulbs. I know it is in the database at the Digitrax egroup. Check out Don Crano's primer on decoder installs at: http://pages.sssnet.com/donc/primer.html If you need more help just ask. David
Thanks for the advice gents. Wish I had picked an EASIER loco for my first install. Heck, I'm just getting started at all of this. Chris - Thanks for the tip about the micro plugs. I'll look into that. David - Many thanks for the tips. There is room for the DH121, *IF* I remove the weight on the front of the chasis. I'm not sure if I want to do that. (I'm not sure if there is room in/under the cab...have to look later...) Removing the weight is what the LL instructions suggest, but that is the limit of their DCC instructions for this loco. SIGH. I don't know that I want to remove the weight...anyone have thoughts on that? Other than that, the advice you guys have given is great. I'll have another look at the whole assembly when I get home from work...and probably pull out the SW9's built-in circut board... If anyone has more to add...please do. No such thing as too MUCH advice. [ 09 May 2001: Message edited by: Canadian Knight ]
Hello CK I may be a little late on this one but here goes. If it is not a plug and play circuit board I always take them out completely and hardwire the decoder in place. You will have to either replace the light bulbs or make sure you have at least a 1/4 watt 470 ohm resister between the blue wire and the bulb lead. The other lead goes to the white wire for front light and yellow wire for rear light. Hope this helps. Larry at PapasTrains.com
Hey, CK, Here's a thought; will the decoder fit in the fuel tank area of your engine??????? I don't do desiels but, there's some space down there.
