# Which decoders are you using in Dash-9's?



## Cougar Rock Rail (Jan 2, 2008)

Hi all,

A friend of mine has two Dash-9's that he keeps burning up the decoders (Digitrax) in. Since he is using the older MTSII, I know he can't be putting any more than 5-6 amps through, but he says he can trip the system out pulling long trains up his grades. So I'm curious what other decoders have proven to be successful in these locos, assuming they are being heavily loaded most of the time. I'm recommending that he use one of the new XXL Massoth decoders which are supposed to take 6amps constant, 10amp peak, because I know they could handle it. I've read that some of you guys are using the QSI decoders but I would like to know if they can handle full time heavy load conditions. 

Thanks
Keith


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## Greg Elmassian (Jan 3, 2008)

I would not use the QSI in this case, I think you are probably running 4-5 amps judging from what you have written. The transistors on the QSI are rated 5 amps, but there is no heat sink. If he's working these things hard, a small fan like a cpu fan on the heatsink would be good. 

Now, that said, the QSI units will shut themselves down on thermal overload (and announce the temperature as long as they are over temp!). It's possible that a cooling fan blowing over the QSI would be fine. 

Another QSI tip is bend the 2 caps and the coil up away from the board to allow cooling air to circulate. I did a number of tests of the board temp in a Mallet with an IR thermometer and found hot spots on the board that improved when I did this. 

He's got to be running some heavy loads to nuke the Digitrax, although they are not the most sturdy decoders by a long shot. 

If it was me, I would try the QSI just for the ease of installation and cost. 

Regards, Greg


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## George Schreyer (Jan 16, 2009)

NCE D408SR has worked fine in an SD45 for years


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## Cougar Rock Rail (Jan 2, 2008)

Thanks for the info, guys. 

Keith


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## Cougar Rock Rail (Jan 2, 2008)

As a follow up, my friend ended up burning up two more Digitrax decoders before switching to Massoth XXL's. Since the switch to Massoth he's had no more problems...he's a happy camper! 

Keith


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## willebrand (Jan 3, 2008)

Hi

I use Zimo MX69V. I have very heavy loads here and running two dash - 9 together


Jos


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