MTH 0-8-0 PS2 Steam Engine – Sound Dropout

Just for starters, with the engine on the track and running at 14+ volts in a different location on the layout, I'd check the voltage at the drop out location to see if it is consistent with the voltage measured at other spots around the layout.

FWIW, I have one of the MTH 0-8-0 locomotives with the two pickups on the tender, I added a pickup on the locomotive for better reliability, makes a huge difference.

MTH Switcher Reliability Upgrade

If you run the engine in reverse, does it dropout at the exact same location?

If you face the engine the other direction, does it dropout at the exact same location?

I realize at 14V the engine is moving along and may be hard to pin-point the problem location down to a track-tie...but above experiments might help isolate if the drop-out occurs when one or the other pickup roller passes some particular point...or maybe when the driver wheels with the traction tires passes some particular point...or may uncover some other unusual behavior.

My guess is some mechanical mis-alignment in the electrical pickups in that specific engine..in the rollers or the wheels or both.  And that specific track section has some slight anomaly that forms the perfect storm relative to just that engine.

I believe it's safe to assume the whistle keeps the sounds running because the transformer puts out a modified track voltage when the Whistle button is held down.

If you release the Z-4000 Whistle button just before you reach the problem area...and the whistle is playing its several-second "tail" sound as it fades off (assuming your engine's whistle has that) I'll bet the whistle sound cuts out.

@gunrunnerjohn posted:

FWIW, I have one of the MTH 0-8-0 locomotives with the two pickups on the tender, I added a pickup on the locomotive for better reliability, makes a huge difference.

MTH Switcher Reliability Upgrade

I thought of that but prefer to avoid that particular fix. But, I think you're correct.

MELGAR

Given the one location and the voltage variation affecting it, I'd look closely at the track and any joints near that location.

@gunrunnerjohn posted:

Given the one location and the voltage variation affecting it, I'd look closely at the track and any joints near that location.

I did that. Took up three sections of track, replaced one (rail separated from ties when removed) and replaced all rail joiners. I don't have a functional multi-tester right now. The problem location is two 10-inch track sections from a power feed and occurs at the same and some other locations when running opposite direction. No other locomotive has any such problems on the layout. I think it's the locomotive power pickup or paint on wheel treads. Thanks for responding.

MELGAR

Well, enough paint on the wheels could cause an issue, been there, done that!  If it's the power pickup, then my extra pickup roller is worth consideration.