I bought a magnetic uncoupler set (from JL enterprises) that consits of a small metal plate and four circular magnets I put into the plate’s corners. I plan on putting it at the yard’s throat and notice that the ONLY way to get the cars’ coupelrs to uncouple is by having the magents underneath the track w/o ties. I even put foil on top of the track, but don’t get enough connectivity. Perhaps the plastic ties serves as an insulator (physics lesson!). How can I have the magents work correctly? Can I ballastc the area near the magnets?
I doubt the plastic ties are having much effect on the magnetic field. It’s more likely the distance that’s weakening the field before the coupler pins can react to it. It’s more the spacer effect than the plastic disturbing the field. If you want the physics of it, the field weakens by the root-mean-square law as you move away from the magnet.
I’ve never used the JL Enerprises magnets, I’ve stayed with the Kadee ones and have the three main examples at various points on my layout, the above tie and below tie permanent magnets, and the below ties electomagnet. I’ve heard good things about the Bachmann magnets but have yet to try them.
I use the Kadee uncoupler bar magnets, that are placed in a slot in the ties, so that the “air hose” of the car coupler nearly touches the surface of the magnet. There will be no room for ballast above the magnet. I paint it the color of the ballast, and it works fine. I, too, have never used he JL Enterprise magnets, or the Bachmann magnets, so, cannot comment on them. Bob Hahn