At a recent show, several of my engines exhibited a significant decrease in speed when under DCC control. CV values have not been changed. Also, at the same show, engines would stutter and the headlight would blink off and on as if there was a loss of contact. No 'keep alive' are employed unless they came with the decoders which I do not think they did. Track was cleaned thoroughly by at least three members. Some engines (most Katos and BLI) did not seem to be affected but my Kato E8's ran extremely slow at full throttle. DCC is an NCE running through JMRI using WiThrottle control with cell phones. I ran my engines at home on a straight NCE system and none of the stuttering problems occurred. I'm stumped by all this. Anybody have any ideas?
A blinking headlight may be a sign of mismatched speed steps between command station and decoder (i.e., decoder in 28/128 speed step mode; command station thinks 14). The other thing to check is whether any of your locos addresses might be a part of an NCE advanced consist in the command station.
Have you tried disabling DC compatibility mode on one or more of the locomotive decoders that are in question? Haven't experienced myself but heard that keeping DC compatibility on (which many loco manufacturer's set as default) can result in a comparable speed decrease?
I'm still learning about DCC ...... but ...... What voltage is going into your track at home and what voltage is going into the track at the show ?? I thiiiiiiiink this might cause a difference and I'm happy to learn if it doesn't.
Operating voltage for DCC varies from system to system. The current (amperage) is consumed by the locomotives, and varies a lot. If it exceeds the current capacity (ampacity) of the booster or circuit breaker, then the system would shut down and no trains would run, at least within that track power district. However, since it was noted that certain locomotives seemed fine, but others did not, that points to incompatible settings on decoders (like # of speed steps, etc.)
