Foil Tape Under Helix?

That’s one huge helix. Nice job. I would try running trains first. You may be surprised that there is no signal loss.

That helix is impressive. I would caution against putting aluminum foil tape under all that helix track. In the post immediately after mine, CJACK posted additional information that is relevant here. While my layout has three, and in some areas four levels of track, very little of that track is directly stacked one above the other. The levels are offset or they cross at an angle.

Below are two pictures. One shows the underside of one of the modules during delivery. The five foil curves are on the -6” level, they are part of the hidden staging yard. Looking in the extreme upper right there is straight foil under track at the 0” level. It is crossing the -6” tracks at a 90 deg angle. The second picture, taken during installation, shows track at the 0”, +6” and +12” levels. Note they are mostly offset from each other. There is no foil under the track on the long viaduct.

AmFlyer can you elaborate why not to cover everything? I'm not against doing it. I prefer to do something now before I lock everything in place. Because this is exposed on purpose I want to avoid adding a ground plane tied into a socket and having a wire strung all over. I'm not sure. Thanks for your insight.

As cjack explained, it adds a lot of capacitance which can reduce the Legacy signal. I did have some problems in a few areas of my layout. Some engines worked fine and others would loose the signal. I purchased one of Gunrunnerjohn's Buffers to increase the legacy signal. Setting that to about 75% solved all those issues. 100% also worked fine but the signal level was so high that my three Sensor Tracks quit working.

My layout has about 700' of track. It looks like yours will have more. In areas where I do have some stacked track the Legacy system is working fine. I suppose if you apply all the foil and there are problem areas the ground wire can be disconnected from that length of foil.

As others have suggested, too much capacitance between the earth ground and the track can actually defeat the purpose of the ground plane.

I'll have to move on than and deal with any issues as they come up. Thanks for everyone's input.