Good evening, I’m looking for the correct Digitrax decoder for the Athearn RTR SD45T-2 with the tunnel motor (DM&IR). I tried two different Digitrax DH126D decoders. Lights work, decoder responds to programming, but no power to the motor. On a related note, I originally purchased the Digirax DH126D decoder for a Life-Like Proto 2000 GP20 based on the decoder selector at Digitrax. This is an older GP20 which doesn’t have a plug. I’m guessing the recommendation from Digitrax is for a newer GP20. I’m looking for decoder recommendations for the older GP20. Thank you, Jas
BTW, the Athearn RTR SD45T-2 works on DCC track at address 0 without the Digitrax DH126D decoder installed.
I had a similar occurrence with a set of Athearn Blue box PA-1s. I installed identical decoders in 2 identical locomitves. One ran like a champ the other would hum but not run on DCC. Switch back to DC and it ran okay. I replaced the motor and the problem went away. One motor may have lost some of its magnetism. To me the DC signal is higher impedance and than the DCC pulse signal. I had a couple of 25 year old Atlas/Kato RSD that did the same thing. I had to run them on DC for a while to seat the brushes and then they seem to work okay. I am not an expert but this was my experience.
