Tsunami's issue in Atlas Classics?

[CIOR]

OK, I've installed close to 30 of the Tsunami decoders, 15-20 are on my personal layout. I have 2 Atlas GP7 Classics, I put Tsunami's in both of them and didn't have an issue with the first one, however the second one was an issue.

I've removed the board, so its just the basic wiring, and verified everything was good. I got the replacement decoder for it and installed it and all was ok at first. Then I noticed a pulsing, much like most of the Atlas units get, more or less a surge while running. It was more pronounced going downhill, but noticed on level runs as well.
After about 20 minutes of running the sound began to cut in and out and then the unit would stop running and take off again, much like it would hit deadspots.
Brian aka Minicooper was using this engine on his local job and noticed it got worse.

After the session I waited a week and decided to test it, this time it ran for about 30 feet and then just STOPPED, dead. The engine made sound, but nothing more. I tested the motor output and found nothing there. There is good juice to the decoder.

This engine ran just fine and no issues with a Digitrax decoder in it (140 series).

I've had a few other guys comment to me that their Tsunami's performed poorly in Atlas Classic's.

I've never had a single issue with the Tsunami outside of this engine. My other Classic GP7 runs just fine!

I've spec'd over the entire engine and find NOTHING wrong, no shorts, no weak links electrically.

Any suggestions?

[Mark R.]

My guess is the decoder itself is defective. While Tsunami's aren't well noted for their motor control, I've had four of them go bad over the last year. Like you, I went over everything with a fine toothed comb and couldn't find any other problem .... replaced the decoder(s) and they've been fine ever since.


Mark.

[samoa switcher]

I agree with Mark. It sounds like a defective decoder. I had installed over 30 tsunamis in my friend's fleet of Athearn Genesis F7s. We had one that had the issues you are referring to and it turned out to be the decoder. When the bad decoder was removed and replaced with another decoder it ran just fine. While ours wasn't an Atlas Classic issue your problem sounds very similar. I have installed two Tsunamis in a pair of Atlas Classic Alcos and they run very well. Hope this helps.

Cyrus

[CIOR]

Thanks guys. I've installed enough decoders over the years and knew something was amiss. But anymore I figured it was a good idea to ask around and see. Its the only engine I have had any issues with.

Now we talk Digitrax decoders and its a whole crappy ballgame so to speak..LOL

[diesel]

I had installed a Tsunami in an Atlas GP7 (older with the metal walkway, I think 1985 release) and it runs very smooth.

I installed a Tsunami in an Atlas GP38-2 (trainman) and it ran with a constant jerking motion, very slight, just enough to annoy a model railroader. I took the decoder out and put it in an Athearn SD38-2 and it runs fine.

I've heard many complaints about Tsunami decoders not running well in Atlas locos. If you have a Kato, Athearn or P2k around, try putting it in one of those and see if the perfromance is the same.

Tsunami has the best sound for EMD units. I'd like to be able to use them in every brand of EMD I buy. -especially the Atlas

[Mark R.]

Possibly (I haven't looked into this yet) the BEMF on the Tsunami decoders could be the issue - especially the slight lurching. Try shutting the BEMF feature off if posssible and see if that makes any difference.

I've read many cases where the Tsunamis require extensive tweaking in the motor control department to get them to function properly (smoothly).


Mark.

[diesel]

ok, that's sounds like good info! We have decoder pro, so it should be an easy thing to do.

[liquidfantasy]

I confirm the BEMF theory as a possible reason for this problem.
In spent already DAYS fine tuning two B23-7, one C420 and three GP40-2 (All Atlas and Tsunami Equipped) and I run them all with BEMF disabled because I'm not able to get them running good with BEMF. Yes, I have decoder pro what might give you an idea what it means to work DAYS with it trying to get the engines running smooth.

I'm really close to add another few bucks to each loco and replace the tsunami motor control with a Zymo or Lenz decoder ... using the Tsunami only for the sound.

I don't get it how they can have such a great sound experience but a very poor motor control ...

@ Matt: Let us know if turning off BEMF is changing anything

[CIOR]

Denis,
That decoder won't do anything but make sound now! I've gotta believe the fuse or something else is up.
I'll attempt the BEMF change next time I take the laptop down there.!

[Mark R.]

If you want to add a decoder for just motor control, go with an ESU (loksound) basic decoder. Their decoders have always had superior motor control over anything else !


Mark.

[CIOR]

Dec 9, 2010 13:20:26 GMT -5 Mark R. said:

If you want to add a decoder for just motor control, go with an ESU (loksound) basic decoder. Their decoders have always had superior motor control over anything else !


Mark.

I prefer the TCS decoders for the basics. I've never had a issue with them. Granted, I've never used a ESU for that.

[Mark R.]

ESU is kind of the underdog on this side of the pond, but they are starting to make their precence known. They have been known for their superior motor control for years - especially in the european market.

I recently acquired a few of their basic decoders to try. It is slightly smaller than TCS's T1, has three functions and actually retails less than the T1. Having a fleet of over 50 TCS decoders myself, I was hesitant to try something different .... but I must say, they are a great little decoder !


Mark.

[CIOR]

Might have to try em out. I believe DCCTrain has them...that is who I deal with.

[steeltiger1]

New Loksound selects are awesome. They will drive either 8 ohm speakers or can handle 4 ohm speakers with incredible results.

[liquidfantasy]

Tom, I don't like the sound of the selects! Even if Tsunamis has a scrap motor control, the sound is yet on a notch no other sound decoder is reaching.