There are two types of dual mode locos. Those with, and those without sound. I can't imagine anyone is actually happy running sounds ones on DC, but it appears many are.
It is absolute unavoidable, unfixable, unsolvable, that a dual mode sound loco is going to require you turn turnt he power pack up pretty far before the loco moves. This is to get enough voltage to power the electronics, so the stationary sounds can play without the loco already creening around the layout. Leaving little control range between sitting there simmering and flying at full speed. Effectively impossible to run with any ordinary DC loco. And how you would run this with a DCC loco, I have noi idea - because if you put it on DCC track, it will run as a DCC loco, and be perfectly controllable like any other DCC loco.
And then there are ones with motor only decoders. They don't have as huge a voltage drop, because there's no sound circuits to start up. Still will be slower at the same throttle position than the same loco with no decoder. On DCC - again, it won;t be running in "dual mode", it will be runnign in DCC, and work like every other DCC loco.
Almost every DCC loco sold today, sound or not, is dual mode. It's mostly older ones that weren't - so to the point of ANY DC power pack causing circuit damage, hence internal jumper plugs to select DC or DCC withotu actually removing the decoder. Other than that, some people turn off DC mode in their decoders - I do in mine, I never run any of my locos on DC, and disablign DC in the decoder can help prevent the loco from taking off at full speed if there is some sort of interruption of the DCC signal to the rails. If you have DCC capability, there's no point running a decoder equipped loco on DC.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
jwells Thanks for all your replys. I thought I replied to this earlier and was waiting for it to be approved, but maybe I never actually hit post. If theres two of my posts in a row thats why. Anwyays heres for the new replys "Was it advertised as having DCC?" No, I bought it used untested without box "What type of DC power does your powerpack produce?" I'm not sure, its a MRC tech II loco-motion 1500. I know it's pretty old but my other engines until now have mostly been older and all DC. The only other even semi-modern power pack I have is a bachmann spectrum. Tried that and it would start up then stop constantly, never getting to any decent speed. "In the tender" I've seen other rivarossi locos that have tender electrical pickup but this particular one can actually run without the tender After seeing these replys I ended up taking it apart. I hadn't wanted to originally from previous experience with steam engines being complicated to put together, but this one only ended up only needing 2 screws removed to access the drive system, top just lifts off. Decoder (I assume) pictured below It'd be a shame to not run this for fear of damaging the decoder, so I may resolder the wires directly to the motor until I get a dcc system. Seems silly to remove DCC but it may be a while before I can get my hands on a DCC system.
Thanks for all your replys.
I thought I replied to this earlier and was waiting for it to be approved, but maybe I never actually hit post. If theres two of my posts in a row thats why. Anwyays heres for the new replys
"Was it advertised as having DCC?"
No, I bought it used untested without box
"What type of DC power does your powerpack produce?"
I'm not sure, its a MRC tech II loco-motion 1500. I know it's pretty old but my other engines until now have mostly been older and all DC.
The only other even semi-modern power pack I have is a bachmann spectrum. Tried that and it would start up then stop constantly, never getting to any decent speed.
"In the tender"
I've seen other rivarossi locos that have tender electrical pickup but this particular one can actually run without the tender
After seeing these replys I ended up taking it apart. I hadn't wanted to originally from previous experience with steam engines being complicated to put together, but this one only ended up only needing 2 screws removed to access the drive system, top just lifts off. Decoder (I assume) pictured below
It'd be a shame to not run this for fear of damaging the decoder, so I may resolder the wires directly to the motor until I get a dcc system. Seems silly to remove DCC but it may be a while before I can get my hands on a DCC system.
That appears to be a motor only decder, an older one at that. Brand unknown since it has no visible brand markings.
Some digging around makes me think it is an Arnold 81201 - pictures match, anyway.
It's supposed to be dual mode, although if originally sold in Germany after Dec 31, 2000, it's not automatically detecting, it has to be programmed to be one or the other.
Unfortunately the web site with this information does not mention HOW to do this, only that it is a feature. This would be something other than the usual CV29 setting to enable automatic detection of DC/DCC. And also supposedly does not apply to locomotives/decoders sold outside of Germany.
Seems like they have some other quirks, too. Might as well remove it for now, and when you get DCC, put in a better, more modern decoder.
Yes. That is very obvious.
Rich
If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.
If the OP wants to put a dual mode decoder into to it and run it on DC, he will have to turn the pack up to five volts for the decoder to wake up and about seven volts for the loco to move. Nature of the beast.
Better to wire for DC or switch to DCC.
Unfortunately I can't see the OP's pics on this computer, so I'm kinda shooting in the dark. Anyway, in recent years, all decoders have been "silent" decoders, early decoders often had a noticeable "buzz" sound when power was applied. I still have 3-4 of them on my layout, both sound (Digitrax "LC") and non-sound.
It being noisy doesn't mean there's a problem or that the decoder is being harmed, it's just noisy. You can either replace it with a modern dual-mode decoder (maybe $15-20 if you shop around) or if the engine uses an eight-pin DCC receptacle, you might be able to track down the correct "dummy" plug to convert it back to DC only.
For those in the know: does the 1500 pose comparable danger to decoders as the 1300? If so, our new poster ought to know, STAT.
Someone might also offer him the appropriate jumper or board to make his locomotive fully DC-compatible until he's set up to operate DCC correctly.
If it has a motor decoder, it shouldn;t make any noise untilt he voltage gets high enought o move it, any more than a DC loco would - it's possible for the motor to buzz slightly when it's just under the threshold of having enough power to start the loco moving.
If it's a sound decoder, at around 5 volts or so it should start making the basic boiler hiss sound, and then at slightly higher voltage, start moving and making the chuffs.
For a 1998 vintage, it's VERY likely that it could have a sound decoder that does not operate on DC. Many older decoders, and especially sound ones, were DCC only. That could account for the strange noises.
I don;t think Rivarossi offerend them with sound at that time, so if it has a decoder, it was added by the previous owner at some point. If added at the time the loco was new, it's very likely not dual mode and won't run on DC.
I have nothing to add to the conversation about #4011, but I do want to recognize a new participant in the Model Railroader forums.
-Kevin
Living the dream.
Sounds like it might have a decoder. The microprocessor needs about five volts just to wake up.
No idea what type of power pack you have so a lot of guess work here. Some power packs have pulse power. Older decoders might not be dual mode.
Open up the tender. When you buy a used loco, that is the first thing you should do.
If it has a decoder it will be in the tender. A decoder will have at least four wires between the tender and locomotive. A DC Rivarossi or non DCC locomotive will only have the drawbar for power from the tender to the locomotive.The older Rivarossi (pre 1995) motors do have a lot of motor noise and draw a lot of current.Could be a decoder was added and unless it has the capacity to drive the older motor the high current could have damaged the decoder causing erratic running. EDIT:
The Rivarossi articulateds make great runners so don't give up on it.
Mel My Model Railroad http://melvineperry.blogspot.com/ Bakersfield, California I'm beginning to realize that aging is not for wimps.
jwellsIs this what DCC does when on a DC layout?
to the forum. Your initial posts are delayed in moderation.
I cannot confirm it, but I found one source that says the 4011 was made in 1998. That doesn't mean it was or was not DCC or was or was not converted to DCC.
DCC now, not sure about 1998, can be dual mode, meaning they can be programmed to run on either. Internet wisdom is that allowing DC mode on a DCC system can cause run away behavior.
I always assumed that a DCC loco, programmed to only run on DCC, would do nothing on a DC layout. It never occured to me to test that hypothesis. Someone has I am sure.
I can't explain the failure to respond to reversed polarity.
Henry
COB Potomac & Northern
Shenandoah Valley
It came without a box, used, untested, so no advertising about dcc.
Looks like I'll have to open it up at some point to see exactly what it has, or get a dcc system. I've heard some decoders can get burnt out running dc too much, so I don't want to do that.
Thanks for the help
Yes it sounds like it has a DCC decoder installed. Was it advertised as having DCC?
Sheldon
I recently recieved a rivarossi big boy 4011. When I place it on track with a DC power source and turn the throttle up, the engine kind of buzzes or hums a bit before it actually gets started. It starts moving just below 4 volts, but only after humming for a bit. The much odder thing is that if I switch the polarity/direction of the DC current while it is running it just keeps on going in the same direction, still responding to throttle changes.
Is this what DCC does when on a DC layout? I don't have a dcc system to test with.
I can think of some reasons for the slow start every time, but not the ability to switch polarity while running.