I have a 3 truck shay with factory sound which apparently is experiencing a problem running at 20 plus volts DCC under load. I measured 20.6 V at the same spot the locomotive begins to jerk with the headlight flashing 10 times in a row which indicates a voltage problem. It's supposed to be good up to 22 V from what I understand. Have any of you experienced an issue of not being able to run these locomotives with voltage this high? I called Soundtraxx and they suggested that I drop the voltage to 18V and hopefully this would resolve the issue. This is the only locomotive that I have with the factory Tsunami sound. All others have Digitrax and Phoenix decoders and run fine.
I measured it using a Ramp Meter which I think is accurate but it may be too close to the tolerance set by Soundtraxx. Thanks for your reply.
When the 3 truck sound enabled Shay was first lauunched on the market there was a lot of discussion about the fact that the Loco would not function correctly at a voltage in excees of 18V
There was a lot of info at the time on UK Forums, you may wish to look at G Scale Central
(www.gscalecentral.co.uk) check out the forum sign up for free membership and ask the question in the Digital section of the Forum.
Hope this helps