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Speed Matching With Tsunami??

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  • Member since
    April 2001
  • From: US
  • 416 posts
Speed Matching With Tsunami??
Posted by blabride on Sunday, November 14, 2010 9:23 AM

I hope someone can help me here. I am fairly new to DCC and have been reluctant about it but i do see the virtues. I have an Intermountain FT set that runs very close together up to about 40% throttle. If I advance the throttle quickly the B unit wants to overrun the A unit. Above 40% throttle the B unit will also catch up to the A unit in about 12 feet. 

I have searched everywhere and even read the Soundtraxx manual until eyes bleed, but I'm just a History person and the Tsunami looks like trying to control a shuttle launch from the Space Station. 

I can't figure out where to even begin with the Tsunami to match the B unit with the A. Do they run close enough not to worry about it? Do I change settings in the A unit or B unit? Is there a common CV that can be adjusted? The lack of CV 5 and 6 makes this one confusing.  I am using an NCE Powercab. 

Thanks

SB

  • Member since
    May 2008
  • 4,612 posts
Posted by Hamltnblue on Sunday, November 14, 2010 9:38 AM

Do both loco's have a Tsunami in them?

When you say the B unit will catch the A unit in 12 feet, how far apart are they when you start?  If they're within a foot or so I'd say they're close enough.

As far as the one overrunning on quick throttle changes, make sure you turn off both acceleration and deceleration by changing CV3 and 4 to 0.

Also when consisting turn BEMF off.  Should be CV10 to 0

Springfield PA

  • Member since
    April 2001
  • From: US
  • 416 posts
Posted by blabride on Sunday, November 14, 2010 11:19 AM

I started them off about five inches apart. I will try the CV 3 and 4 to 0. Yes they both have the same Intermountain Tsunami decoder.

SB

  • Member since
    April 2001
  • From: US
  • 416 posts
Posted by blabride on Sunday, November 14, 2010 11:58 AM

Success! I changed CV 3 and 4 to 0 for both units and now they run MU in an advanced consist at all speeds without changing distance more than an inch over five minutes of running. 

Now I have a new problem but I'll start another thread since it involves an Atlas RS 1 and a Digitraxx decoder.

Thanks

  • Member since
    February 2002
  • From: Reading, PA
  • 30,002 posts
Posted by rrinker on Sunday, November 14, 2010 5:57 PM

 If you want the sounds to rev up before they move though, you will need a little momentum in CV3. If they are both set the same they SHOUDL accelerate at the same speed, given that they are both the same decoder. I can imagine differnt brands of decoders being somewhat different - there is a recommendation for how to calculate the momentum in CV3 and 4, but it's not strictly adhered to between brands. But allt he same - it should have the same delay per speed step as long as the values match.

                                  --Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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