Short answer yes. Do I think it is a good idea? No. It defeats all the good things about DCC.
Lee
A couple of problems arise when you have a multi-unit DCC set:
The single decoder will have to be able to handle ALL the power for the several motors.
There will have to be at least two wires between each unit, and four is better. This means the units should be connected with drawbars, instead of couplers. It's not too difficult to do this with two, but any more will make you wish you were an octopus.
Non-sound decoders are cheap and eliminate the above problems. And you can re-arrange to your heart's content. Should your heart drift in that direction. Later.
Ed
Both very good answers. This can be done, but it is not at all advised, and for the reasons given: you want the sounds of several prime movers straining or idling when they should be heard that way (a lash-up of two or more locomotives), but more importantly, you don't want a lone decoder to contend with the demands and throughput of amperage that all those straining drives will need to do the work you want of them. Remember, heat is the great enemy of electronics. Running your electronics hot is what amperage is all about. More amperage is more heat.
Yes with FOUR provisions:1. You will never break up your MU consist
2. You don't need lighting functions on every loco3. You don't exceed 1 amp with all motors stalled
4. You don't care about BEMF.I would also use perm couplers. (couplers not designed to open so they hold together better)And oh yes, I forgot about sound. With Tsunami you can get the sound of 4 engines with one decoder by setting up the REVERB and using an EMD E Unit decoder (which has the sound of two engines already. The reverb effect just echo's the engines sounds to make it sound like 4)
Don - Specializing in layout DC->DCC conversions
Modeling C&O transition era and steel industries There's Nothing Like Big Steam!
Unique1028Is it possible to wire multiple locomotives for DCC using only one decoder? Example set up. F7 A-B-B-A.
How are you going to pick the whole thing up? Individual decoders will make things a whole lot simpler and will provide you with many more operational possibilities. Even splitting the consist into two locomotives each would make handling easier.
Dave
I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!
hon30critter Unique1028 Is it possible to wire multiple locomotives for DCC using only one decoder? Example set up. F7 A-B-B-A. How are you going to pick the whole thing up?
Unique1028 Is it possible to wire multiple locomotives for DCC using only one decoder? Example set up. F7 A-B-B-A.
How are you going to pick the whole thing up?
That was my first thought - how would you pick up four engines at once (well, maybe if it's N scale I guess).
hon30critter Even splitting the consist into two locomotives each would make handling easier.
Real railroads that bought A-B-B-A F-units meant to run together as a unit generally set them up as two A-B sets with drawbars between them, with couplers at the front of the A unit and rear of the B unit. Most late-steam turntables and roundhouse stalls could fit an A-B set of Fs, and it took a while for railroads to move from using roundhouses to 'squarehouse' diesel houses. That works for models too. I have several A-B sets of Fs with drawbars and it works well.
One other problem is there's no guarantee any two engines - even by the same manufacturer and same model - will run exactly the same. It's likely if you take an A and a B unit, one will run faster, and start or stop sooner, than the other. With one decoder for both, there's no way to adjust for the difference. If each engine has it's own decoder, you can speedmatch both units so they all start, run, and stop the same. For an A-B-B-A set you can speedmatch all four to run together, and speedmatch your other engines so they all can run together however you want them - like an F7A and a GP9 together.
hon30critter How are you going to pick the whole thing up?
DigitalGriffinhon30critter How are you going to pick the whole thing up?
DigitalGriffinI've seen multiple lashups similar for passenger cars. They would use all the pickups of all the trucks to feed all the cars so that dropout was non-existenent. (This was obviously well before LEDs which can hold a light for a second or two with a simple cap)
Hi Don:
It wasn't so much the electrical pick-up that I was concerned with. What I was asking was, assuming that you are going to use drawbars to couple all four locomotives together, how do you physically lift the A-B-B-A consist off of the track? I guess drawbars aren't mandatory.
I think Mark makes a very good point about the ability to speed match all of the locomotives if each has it's own decoder.
In the end essentially that's what I did. I installed decoders into each unit. And now to speed match.....