Thank you all for the assist.  That was more information than I rec'd from the hobby shop! I'm on it.  Additionally my set up does contain very long passenger cars.  Perhaps I should remove the "S" turns or try shorter rolling stock.  That gives me an excuse to add to my new hobbie.  Thanks again.   

Hi,  Im new to the forum and model railroading.  I have a simple question that is way below the level of expertise I've been reading on this website.  My spectrum HO train set I purchased last year frequently uncouples.  I've added lots of track to the kit.  Instead of around the tree for the holiday I'm running around the living room.  The family loves it.  I've replaced all the couplings with new Bachmann couplings.  It helped some.  Should I have gone with Kadee?  Thanks and I am enjoying this website.