Problem adjusting speed settings on my N scale MRC sound decoder

[pereirad]

Hi guys,

I have a MRC N scale sound decoder installed in my Kato AC4400.  I'm having problems with my speed settings as  the locomotive won't move until the throttle is at more than %50 of the max setting.  I've tried adjusting CV2, CV5, and CV6's, but nothing seems to change the locomotive's slow response. I've consulted the manual but the lack of information on recommended speed CV values is not much help.  I've got many Digitrax decoders and I'm quite familar with adjusting their CV values.   I only have the one MRC decoder equipped engine.

Can anyone help or offer advice?

Thanks

Daryl

[peteski]

How does the loco run without a decoder? I know that this is supposed to be a very smooth running locomotive but I had to ask this question. You didn't mention doing this and yet taking the decoder out of the equation is always the first troubleshooting step.

[pereirad]

Peteski,

I didn't try running the loco without the sound decoder.  I'll try that first.  Do MRC decoders respond to the same CV values as a Digitrax decoder? 

Thanks for your reply

Daryl

[peteski]

Yes, try running the loco without the decoder.

I don't have much experience with MRC sound decoders (I've heard too many bad stories about them and I also saw them in action and wasn't impressed) but the basic CVs like 2, 5 ans 6 should work in a way similar to Digitrax decoders.  If you don't have a printed manual for that decider, you should be able to find one online. That should explain its functionality.  If the loco runs fine on DC then you might want to reinstall it and disable BEMF on the MRC  decoder (if it has it and if there is a way to disable it) to see if that changes its behavior.

[sizemore]

I might be mistaken but I thought MRC doesnt support BEMF? That's what has swayed me away when originally thinking about using sound decoders.

The S.

[pereirad]

It looks like my locomotive's gears were being hampered/restricted by cat fur that got caught up in there.  I guess my engine needed a major overhaul 
 

I've re-installed the sound decoder after getting the fur out and it is working better.  I also had to really cranked up the starting voltage (CV2) to make the loco more responsive to the throttle.

Thanks for all your suggestions and help. Who would have thought the answer was a simple one to fix.

Cheers,
Daryl

[mmyers]

If it's a 1642 decoder, there is no CV6 setting. It does have Cv2 and Cv5. There's a reason those MRC manuals are so short and simple to read.  They don't need a lot of instructions.

Martin Myers

[peteski]

That is good news Daryl!
Yes, it always pays to check for the simple problems. 

[pereirad]

Martin,  yes I think it is a  1642 decoder.  Thanks for letting me know about the no CV 6 setting. It is one less CV to calibrate with other locos.

Thanks again everyone for your help

Daryl

[trainforfun]

So Martin since CV6 is not there how do you adjust mid speed ?

[peteski]

So Martin since CV6 is not there how do you adjust mid speed ?

You don't.  The speed curve will be linear between Min and Max values. 

[SkipGear]

The 1900 series decoders now have speed tables and I am pretty sure BEMF. The 1900 steam decoders I have played with definitely have BEMF.

There is a new 1960 for the SD70 / AC4400 that has the features that you are looking for.

http://www.modelrectifier.com/search/product-view.asp?ID=12281

I have one of the 1642's in an Athearn SD70 and slow speed performance is lacking. I had to adjust the other loco's in the consist to match it.