Bluenami Decoder for an A/F Challenger

Tim, I am more than a little surprised that you have not received a reply to your question by this time. I have a Challenger myself, knowing it is powered by two motors I would believe that you would want the 4 amp model 4408. I am not sure if that is available with sound for an articulated locomotive or not. I believe you would need to use relays if you wanted to use the smoke unit and electric couplers, if you search the Blunami threads on OGR you will find more info on these applications. I know there is mention on the OGR that Blunami has no way of co-coordinating the chuff and smoke with the fan driven smoke unit.

Hope this may help you,

Ray

@Rayin"S" posted:

Tim, I am more than a little surprised that you have not received a reply to your question by this time. I have a Challenger myself, knowing it is powered by two motors I would believe that you would want the 4 amp model 4408. I am not sure if that is available with sound for an articulated locomotive or not.

Ray

Me too Ray.  I looked up the 4408 and articulated loco sounds are available.  I'm not sure, but after reading a bit about Blunami steam sounds, it appears you can synchronize the chuffs to the wheel rotation using CV 114.  Also the description of the 4408 states it is for S, 0, and large scale locomotives.  Prices sure have gone up since last I looked.

Tom Stoltz

in Maine

For safety sake, I always had 4 amp in my DCC applications.  So far none have gone bad.

With 14.5V on the track each of my Challengers draw 4.25A at stall. With 18V on the track that number would be higher. At steady speed up a 2.5% grade pulling 20 freight cars it is about 3.75A. These values include the smoke unit but not the electrocouplers. Putting those two items on separate relays as Ray says would lower the current below 4A.

Upgrade, you're at the edge of the 4408 card's rating.  Sourcing the smoke unit and electrocouplers from the rectified AC supply, before the Blunami card, takes them out of the load calculation (see my post on my electrocoupler interface circuit).  Yet you're still approaching the edge.  Soundtraxx advises that the card can take more current for short durations, but I really don't like violating the ½ max current nominal objective, to ensure adequate range for the cruise feature etc.  At the end of the day, it's a matter of the degree of failure risk that you're willing to take.  20 cars on the flat is likely not a problem.  10-12 cars uphill is likely OK.  But 20 uphill?  Probably not a good idea.  This problem would fade fast, were Soundtraxx to offer an 8A card.