Auto Reverse jerky transition : LUSENET : Wiring for DCC : One Thread

I have just wired and tested a new layout in DCC (first time!)with two simple reversing loops. I installed two separate Digitrax AR1 modules--one for each loop--as per the directions with double gaps in and out of the section. The first test went as per install instructions...the locomotive tripped the reverse section once and stopped. However, after fiddling with the TTC adjustment screw the locomotive did not move through the reverse section seamlessly. It momentarily paused as it went through the reversing section and only worked better as I ran it faster through the section and each truck pick-up crossed quickly over the insulated joint. Is this the only way to get a smooth action through the reverse? Should I move the insulated gaps further away from the turnout or is there a wiring trick I am not aware of? All else is working fine and I am otherwise very pleased with DCC! ANy help appreciated.

-- Thom Lehman (, March 01, 2005


Going in and out of a reversing track sction should be seamless. that's the expectation of all auto-reverser units. There should be no hesitation at any loco speed. It sounds like your booster may not be able to supply enough current to trip the A-R unit or the booster itself may be cutting out before the A-R unit trips. I'm not familiar with the digitrax AR1 unit. If there is a sensitivity adjustment (the TTC ?) keep making it more sensitive, just shy of continuously switching with a loco running inside the loop.

Be sure to read the DCC item about A-R units in the April '05 issue of MR magazine. Some combinations work better than others.


-- Don Vollrath (, March 02, 2005.

I look into what Don talked to you about....However, I have some other questions just In case we can figure out something else might be going on.

What is the make and model of the booster your using? Does the booster shutdown when the loco stalls? What type of wiring do you have between the booster to the AR1 and then to the loop itself? Length and Wire gauge(size)? Where is the AR1 located? Next to the booster or reverse loop? Do you have some kind of optional circuit breaker protecting the reverse loop and if so, it that tripping? Are you sure you have no other track feeders going to the reverse loop other than what comes from the AR1?

-- Mark Gurries (, March 02, 2005.

Don and Mark helped me fiqure out the problem...I had wires from the main bus wired into the reversing loops. Chalk this one up to a newbie mistake and anyone else who has this problem, remember...the reversing section should only be connected to the main power bus through the AR module; no other feeders or connections should cross over. My modules are working perfectly seamlessly now at slow speeds.

-- Thom Lehman (, March 04, 2005.

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