I have an upgraded bachmann DDA40X (item no. 62105) with a dz126 non-sound decoder that is spotty. I do have a SDXH166D but I wanted to know if there is a better alternative. I have not cracked open the locomotive but I can take a peek when I have the table space.
Is this an HO scale locomotive or N scale? A DZ decoder might simply be too weak to drive a road engine, particularly pulling a normal sized cut of cars.
As I recall, the Digitrax DH126 is a basic old DH123 motion decoder with front and rear headlights only, plus the ability to plug in a Digitrax Sound Bug.
it is HO scale
Well I Bought this from a club member at my model railroad club, and he said he does not have that big chip above the motors.
I could take a picture and put it on here once i have the table space to open it up.
Thanks for the clarifacation of my problem
Bachmann sells a sound board for this model:
https://estore.bachmanntrains.com/index.php?main_page=product_info&cPath=68_595&products_id=10496
You’d need to add a speaker to get sound. Should be awesome with two prime movers. Bachmann fitted a soundtraxx decoder to sound equipped versions. Bachmann calls these their Sound Value line.
https://estore.bachmanntrains.com/index.php?main_page=product_info&cPath=68_595&products_id=8462
Another possibility is to see if the existing motor only decoder is set for 128 speed steps. The original model equipped with Bachmann’s choice of decoder could handle 128 steps but came from Bachmann set for only 28 steps. You may get better motor control using 128 speed steps.
Here’s Bachmann factory installed decoder:
https://estore.bachmanntrains.com/index.php?main_page=product_info&cPath=68_595&products_id=5612
thanks for the tips! this will sure help me fix this thing
The DZ126 is rated 1 amp continuous/1.5 amps peak. With fairly modern motors, even a dual motored HO locomotive would be highly unlikely to stress a DZ126. If it does, I would suspect a problem with the locomotive itself.
What is “spotty” about the DZ126? One possibility is the noise suppression chokes and caps Bachmann includes in the motor circuit of many of their locomotives. These can interfere with bemf compensation. If that is the issue, the components can be removed or you can turn off bemf compensation in the decoder.
You can’t set a decoder for only 28 speed steps. The decoder configuration only destinguishes between 14 and 28 speed steps, 128 speed steps is determined entirely by the command staion. This is because the 14 speed step commands and 28 speed step commands look exactly the same but have different bit meanings (one bit in the 14 speed step command controls the headlight), so if you are using 14 or 28 speed steps, the decoder has to know which one. If you are using 128 speed steps, the commands look completely different from the 14 and 18 step commands so the decoder doesn’t have to be told to look for 128 step commands.
The review I read was a MRR review from 2009. The words used were: use 128 speed steps.
Most DCC users could care less whether the decoder or the command station is the device effecting 128 speed steps.
The point that CSX Robert was making is that if the decoder “came from Bachmann set for only 28 steps”, the decoder was also set for 128 steps because 28/128 steps are one and the same on the throttle, at least on NCE systems. You simply toggle a button to choose between 28 steps and 128 steps.
What the review stated was that the instructions indicated the decoder did not support 128 speed steps (which is clearly incorret), not that the decoder was set for only 28 steps: “Although the instructions state that the decoder has only 28 speed steps, it actually does support 128 speed steps for finer speed control.”
When changing speed steps it’s pretty important to know whether or not you have to change anything on the decoder, besides, even if “most DCC users could care less” that’s no reason to leave faulty information uncorrected.
I meant spotty as in a decoder that doesn’t respond some of the time i give it commands, like stopping takes 10 extra seconds. if anything i was talking about a sound replacement, but this brings a whole new “what?” to the question [Y]
Does it always take extra time to stop , or sometimes? Have you checked the value of CV4 (decceleration momemtum)?
sometimes its on point, and sometiems it takes a bit. i believe this loco does not have momentum. thats also the other reason i wanted to replace the decoder for a newer sound one