MRC/MP 4-4-0 decoder question

[brokemoto]

I did post this question on another forum, but got answers that were not definitive, so let me try here.  I am not a DCC user.  I noticed that MRC finally listened and added an all wheels live tender to the old MP 4-4-0.  There are supposed to be two versions of this:  sound and decoder equipped and "DCC-ready".  The only place that I have found one without a decoder is on the MP page of MRC's website.   Of course, it is available there only for full list price.  All of the e-Tailers that I have surveyed have only the sound and decoder equipped versions of this.  Several of said e-Tailers have these things for less than the full list price of the models with no decoder.

I would like to order one or two of these things, but MRC's website is not clear on whether or not the decoder is dual-mode.  Does anyone out there know if the decoder on these things is dual mode?  If anyone has one that he runs on DC, how does it run, especially at slow speeds?  If it will run on DC, does it keep going even though it coasts over a dead spot (as does the B-mann 2-8-8-4) or does it stall and re-set the decoder (as does the BLI Baldwin Centipede)?

Thank you in advance.

[CBQ Fan]

I just received a 2-6-0 with the DCC and sound decoder from Mbklien. While not the same exact model it came out at the same time as the DCC sound 4-4-0. I rn dc only.  It does run with sound on dc only. It runs well in dc and sound is good.  I personally could take or leave sound but this appears to be a fun little loco.  It pulled a Kato California Zephyr with no issues for me.  I liked the Mbklien sale price on the 2-6-0 better than the 4-4-0, but either loco would have worked fine for me.  Top end speed seems a little slow but then again the engine has small drivers, and if used with DCC this may be able to be adjusted faster.

[peteski]

I would like to order one or two of these things, but MRC's website is not clear on whether or not the decoder is dual-mode.  Does anyone out there know if the decoder on these things is dual mode?

Ever since I have been into DCC (around 20 years) I have yet to encounter a decoder which will not run on DC.  If there are some, I have never found them. The dual-mode is pretty much a standard (and it makes perfect sense for manufactures to follow it).  DC mode does not need any extra components on the decoder (just a firmware routine to handle that mode), so again, it makes sense for manufacturers to incorporate it in their design.

But how well a decoder-equipped model will run on DC is another story.  So is compatibility with various DC throttles (since most do not actually output pure DC voltage).  And also I would never expect any decoder in DC to provide the same fine level of speed control as a DC loco with no decoder.

Non-sound decoders in general work well with most DC throttles. Of course the starting voltage is a bit higher (since the decoder's microcontroller needs at least 3-4V to operate.After that the speed control should be pretty good, but again it may depend on the brand of the DC throttle used.

Sound decoders are another story. They need much higher starting voltage (around 7-8V), so that limits your speed control range. I also noticed that even at full throttle (12V) they usually don't run even close to the full speed.  So while they are dual-mode, their performance in DC is not the greatest.  These are generic observations from my dealings with decoders - I do not have any specific info on the MRC loco you are askign about.

[brokemoto]

Thank you for the replies.

I am assuming that the decoder in the MP mogul is the same as that in the eight wheeler.  I really do not need all that much speed from these things:  forty to fifty SMPH is the most at which I run them, anyhow.  I, too, have noticed on certain models, that the control at either end of the speeds is not the best.  I have a BLI Badlwin Centipede that requires half throttle to get the sound's going, three quarters to move at twenty-five SMPH and at just shy of full it will do about forty.  That is fine for me, as I use it to pull freight trains which I run at about twenty-five SMPH.  In addition, I like starting up the engine, bringing the idle up to speed, then moving.  Also, if it stops so that the switchers can remove cars from its train, you can set the throttle low enough and it will idle while it waits to resume its work.

I have seen wild variations in the B-manns.  The 2-8-8-4 has excellent slow speed control and requires far less starting voltage than do the others.  Rarely do I run it faster than thirty SMPH, although it will run at fifty.  The seventy tonners, and GP-7s, on the other hand, have horrid slow speed control and will stall when coasting over a dead spot because the decoder re-sets.  The 2-8-8-4 does not do that (the Centipede does).  I have fried more than  a few B-mann decoders, and this is on an MRC 2400 with the pulse OFF.  It has happened on the 2800, as well, which has a discreet pulse.

I have some of the old MP moguls and already have done the tender swap-out, so I do not need any more of those.  They came with the traction tyre.  I do have some of the old eight wheelers.  I did do the tender swap-out on those, but they need traction tyres.  This is why I am interested in one of the new ones.  I guess that the thing to do is order one.  If I like it, I can order another one.  If not, I can wait until one without the decoder appears at a good price.

Thank you.

[peteski]

Sounds like you have lots of experience running decoder-equipped models on DC.
Like I said, the results will vary dramatically depending on the throttle and the brand or even  model of a decoder. But they are all dual mode, so they will function on DC assuming that feature is enabled. Usually it is using the decoder's factory settings. But if you end up wit a 2nd hand model where the previous owner disabled the DC operation, the model will not work on DCC until the setting is changed.