Hi all,

I've installed a Tsunami TSU-1000 decoder in an Athearn bluebox C44-9W recently.
While everything went fairly painless, I'm struggling with the speed control. It
has probably to do with the quality of the motor, but I just can't seem to get
the BEMF function set properly. Default this is '0'. Using this value the loco
'jumps' in small steps, a bit like what happens in programming mode, and the
sound goes on/off with it. changing this value to 20 meant the loco didn't move
at all, could hear the motor hum and the engine sound revving up/down.
Increasing the value to 80 gave me a rather rapid start and no slow speed
control. I've been playing with values in between but not much luck. Does anyone
have (had) similar issues and how have you solved it? Cheers!

Koos

Which CV are you adjusting? BEMF in the Tsunami is configured by CVs 209,210, 212, 213, and 214. They all work in oncert together to control the variables in the BEMF control equation in the decoder. Download the DIesel Users Guide and look on page 48, they have some tips on adjusting the BEMF settings. It's a trial and error process, so hopefulyl your DCC system supports Ops Mode programming so you don;t have to keep moving back and forth tot he program track every time you want to adjust a CV.

--Randy

Cheers Randy,

I'll have a look at that guide. I was using JMRI software, but I think I will try some direct CV programming to go into the BEMF in detail.

Cheers,

Koos

Hi Randy, that was indeed very helpful. I adjusted some of the CV's you mentioned individually, and the loco now runs quite well. Low speed (read crawling) is not that fantastic with the standard Athearn motor, but it's not bad. Besides, this is not a switcher anyway so I can live with it for a while, until I get the time and money to upgrade the motor for a Mashima can motor or similar.

Koos

You might want to take a look here: http://www.mcor-nmra.org/Publications/Ar...uneUp.html
and try some of these tuneup procedures.The AThearn motors are buitl with fairly loose tolerances so doing a bit of tweaking goes a long way - there's probably no need to remotor it if you spends a little time optimizing what's already there.

--Randy

Hi all,

I've spend hours and hours, but this one is just did not work well, with all the tuning and tweaking (including the mechanical kinds).
In the end, I've decided to replace it with a mashima. The motor swap took about 1 hour, and then the programming and fine tuning of the DCC decoder no more than 20 minutes, and it runs like a dream now. Still odd that it ran fine with the TCS decoder, but was untamable with the Tsunami. I guess the BEMF and other control settings of the TCS were better suited to the Athearn motor. Anyway, all is well now and I've got a good running GP38-2 (yes I mixed up two projects, my CW44-9 mentioned at the start of this thread has the same decoder and an Athearn motor, but it runs fairly reasonable, the GP was the one I struggled with) . On to the next project :-)