# DCC problem



## rocheung (Apr 28, 2013)

Hello all,

I am a newbie to loco model. I just found one problem on my DC loco which I have convert to DCC. I found even I set CV5 to the largest value, the converted DCC locos' top speed is much slower than those which are DCC genuinely equipped. I have two DR110 (HO), one is genuine DCC and one is converted from DC. The DCC chip I used for conversion is a Roco 10881. strangely, the Largest number for setting the Cv5 is 63 according to the manual. So the slow speed I achieve in the converted loco, is due to the chip does not support the value which is greater than 63????? Or because the Main board on the DC loco limit the speed??? hope some body can advise me. thank u!


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## Southern (Nov 17, 2008)

What scale?
What brand of model locomotive?
What loco?


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## rocheung (Apr 28, 2013)

Southern said:


> What scale?
> What brand of model locomotive?
> What loco?


Roco Db140. (62409) -HO, sorry, the genuine dcc one I mention above should be a Roco DB110, I have checked that the motor parts numbers are the same.

Trix BR 285 CRB (12362) - N

Brawa BR216 (61201) -N

Thanks a lot!

Alex


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## NIMT (Jan 6, 2011)

Alex,
Top value is 64, That will give you max speed.
There is always some speed loss from DC to DCC.
Most of the time it's minor, if it's a major difference then there is probably a problem with either the decoder or install.


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## rocheung (Apr 28, 2013)

NIMT said:


> Alex,
> Top value is 64, That will give you max speed.
> There is always some speed loss from DC to DCC.
> Most of the time it's minor, if it's a major difference then there is probably a problem with either the decoder or install.


Hi. Thanks for your help first. Too bad that will be just 60-70% of top speed as compare with my genuine DCC.


You said top value is 64, but I see the manual said the range is 1-63. Do you mean I still can set out of range so that I will become more "reasonable" top speed during 64?? I haven't tried this. 

OR Should I Buy A Plus 22 decoder with max value of CV5 is 255?

thanks

Alex


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## rocheung (Apr 28, 2013)

Hello,

The shops preliminary told me that there may be the motor problem. I have reinstalled the analogue chips back to the loco and control by the analogue controller, the top speed is still no remarkable improvement as compare with Digital operation, so that it may not be the problem of the decoder.

Cheers
Alex


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## NIMT (Jan 6, 2011)

If you can try a different decoder.
But yes it could be the motor or even the drives giving you problems.
Non of my decoders do 64 they all do 255, It's the difference between speed steps is all.
I am not familiar with Roco Decoders, I sell and use Soundtraxx decoders, but have in the past used Digitrax, Lenz, MRC, NCE, ESU, and TCS.
I've had the greatest problems with MRC, Lenz, and ESU decoders, most have either failed or had poor performance.


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## rocheung (Apr 28, 2013)

NIMT said:


> If you can try a different decoder.
> But yes it could be the motor or even the drives giving you problems.
> Non of my decoders do 64 they all do 255, It's the difference between speed steps is all.
> I am not familiar with Roco Decoders, I sell and use Soundtraxx decoders, but have in the past used Digitrax, Lenz, MRC, NCE, ESU, and TCS.
> I've had the greatest problems with MRC, Lenz, and ESU decoders, most have either failed or had poor performance.


yes you are correct. Roco just answer me the drive gear have different ratio so that the speed is different. thank you very your advice again


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