I picked up an Atlas GP39-2 this past weekend. Looking through the included exploded diagram, I see that the DCC 'jumper' appear to have some 'logic' on it. When replacing it with a decoder, will I need any resistors for the lamps? What decoders have most folks been using in these engines? I think the 'plug/play' light board replacement decoders are for the older 'red box' Atlas engines.
Jim
Modeling BNSF and Milwaukee Road in SW Wisconsin
Pretty sure the bits on the dummy plug are just diodes to make the lights directional, the resistors are on the rest of the circuit board that stays. You cna plug in any decoder with an 8 pin plug. If there's enough clearance, the IP type with the 8 pins as part of the decoder board instead of at the end of a harness will work.
Some of the newer board replacement decoders also have resistors built in since the new locos use LEDs and if you strip out the board you lose the resistors. They need a trace cut to work in the older locos with incandescent bulbs.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Randy,
I put a Digitrax DN135P decoder in the GP39-2 - everything programmed fine and the lights all work correctly. Now - on to 'ditch lights'!