I think I read here that the same decoder that fits the Kato Dash-9 will fit these new units from Athearn. I pulled one from an existing unit just to test and found it does fit. I put it on the program track to make sure their were no shorts and got good reads etc... But when I put it on the main no action. Lights worked at first but no motion. So I adjusted the decoder and have found that they don't fit very tight where the metal tabs slip into the frame. Has anyone else experienced this and if so how did you slove the problem. I tested them in DC and was pretty happy with the way they ran so I wanted to give them a longer run and make sure the decoders fit before I ordered the new ones. Its too bad more manufacturers don't sell units with decoders installed as an option. It costs the same in the end either way just saves a step. Thanks, Bryan
Hi Bryan: I'd rather not disagree but it does cost more. To inventory double the part numbers requires more capital and it requires more space. Now some will say that N is small but if Atlas does 20part numbers of GP-38/40/40-2 in 2 road numbers each and also has them in DCC we have to double the space to display. Shelf space and inventory cost money. I would prefer if the manufacturers would make their products DCC ready PnP or Drop In and work with the DCC manufacturers to get the decoders on the market at the same time as the actual model.
Alright George I see your point but I still need to figure out how to get this loco running on my DCC layout? Any thoughts on that? Leave it to the dealer to call me out! LOL
Bryan: You can solve this problem by hard wiring the decoder pads to the motor contacts of the loco. Atlas diesels have the same problem when a Digitrax DN163AO decoder is installed on the frame. The copper motor contacts of the loco donot properly contact the decoder. You can also drop a ball of solder on each of the copper motor contacts of the loco. The hard wiring of the decoder pads to the motor contacts is a more permanent solution however. Hope this helps.. Stay cool and run steam....
Check to make sure you just dont have a short. I had the same problem when I put in the DN163K1B, it would light but wouldn't move. I put electrical tape behind the motor contacts to make sure they don't touch the frame, this took care of the problem. ignore the circled piece in the picture
William, I did that to accomplish the barrier needed but haven't messed around with it enough to find success. I am waiting to get the decoders in before I really dig in. I don't want to pull the other Kato unit out of service for good. I did email digitrax and got a reply this morning: "At this point, there has not been a new decoder developed for the Athearn SD-75, so some experimenation will be in order. If you don't plan on moving decoders around, you may want to consider soldering a wire to the contacts to assure good contact. Hope this helps." I plan on getting down to business with these when I receive the decoders I will use for these units. Then If I have to do any soldering it will be permanent. Thanks for the help! How is your unit running now that you have the decoder in it? Does it run well with others? How does it pull? Take care, Bryan
What are you talking about? The pads that make contact with the frame or the pads that make contact with the motor? From your description I thought it was the pads that make contact with the frame if so just add a small amout of solder to the pad to make it thicker so it will get good contact. If it is the motor the afformentioned wires from the pads to the motor will fix the problem. I do this to all my atlas engines, I had so many problems in the beginning with the atlas decoders that I finally hard wired them to the decoder and have not had a problem since.
Bryan, The unit runs pretty smooth. I needed to adjust the start CV value and the high CV value to match with a Kato AC4400 I run it with, but it didn't take too long to get them speed matched. My layout is flat, so it was able to pull the following train 5 Athearn autoracks, 6 atlas autoracks, 4 MTL TOFC cars, 1 Walthers 5 unit articulated well car, 4 MDC double stack cars, and 2 deluxe 5 unit articulated twin stacks, without any slippage.
I agree with Paul York, I think it's the pads to the chassis. They were a bit loose on my 75i, so I applied just a bit of solder to each pad to thicken. This is a very fiddly thing - too much and you could damage the board by forcing it in, too little and you'll have intermittant contact. Gotta be like Goldilocks - juuuust right! The copper tabs to the motor have plenty of spring to them, I doubt that is the issue. When I checked into the Dash 9 decoder, I was told they were on about a six week back order. (The same decoder also fits a couple other units...)
